Introducing a comparison tool for energy consumption of houses in Honduras

2012 Introducing a comparison tool for energy consumption of houses in Honduras

Robert Ruiter University of Twente - Techos Verdes 24-Aug-2012

Bachelor thesis 24-August-2012 Final version R.J. Ruiter University of Twente Civil Engineering & Management r.j.ruiter-1@student.utwente.nl Company: Techos Verdes, Plaza Comercial Bioclimรกtica San Pedro Sula, Honduras Supervisor Company: Architect A. Stassano Supervisor University of Twente: ir. A.G. Entrop 1

Preface This research has been conducted as part of my bachelor thesis of the study Civil Engineering at the University of Twente, The Netherlands.

The months May, June and July I lived in San Pedro Sula, Honduras. I have been working for ten weeks at the Plaza Commercial Bioclimática Techos Verdes. This is a company managed by the Architect Angela Stassano who does a good job in educating people about all kind of possible improvements in their lives. I am the fourth student from ‘Twente’ executing a research for Techos Verdes.

My research is a new kind of approach of the so called ‘bioclimatic building’ design. I did not know much about the European energy labels, and the people at the company even less. For me and for my supervisor the start of my research was a big search for the right approach and right results. I hope my work can be used for promoting more energy efficient building designs in San Pedro Sula, the whole country of Honduras and eventually in more countries with the same climate.

First of all I want to thank Angela Stassano for the opportunity she gave me to come to Honduras.

Special thanks go to Bram Entrop for giving me sharp but useful critics.

I also want to thank Renee, Janina and Saida from the office. It was always fun to work with you. I want to thank the gardeners, guards, workers and other guys for the fun times and playing ‘fútbol’ with me every day and of course I would like to thank the women from the cafeteria for cooking the best food every day.

Last but not least I want to thank my family and friends in The Netherlands, especially my parents.

Without you I would not be where I am right now!

Robert Ruiter August 2012

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Abstract Sustainability is rapidly increasing in importance. Buildings account for a large part of the annual energy consumption in modern societies.

Therefore the government in The Netherlands developed a labelling system for buildings, from A++ till G. When the building is really energy efficient, it will get an A++ label. When it uses a lot of energy it will get a G label. To sell or rent a building in The Netherlands, the owner is required to acquire a label that gives an indication of the amount of building related energy this specific house uses. The labels also stimulate the producers to design more and better energy efficient products.

In Europe the energy labelling system is already a common used tool to increase the awareness of house buyers and tenants about the energy consumption of buildings. The energy labelling system is not well-known in Honduras. Before the energy labels are ready to launch in the Honduran real estate market they first have to be made suitable for the tropical climate of Honduras. The energy label explained in NEN 7120 (Dutch Energy Norm) determines the ratio between the characteristic energy use and the maximum admissible energy use based on ground surface and building shell (thermal transmission surface). These three factors together are the input. The characteristic energy use is determined by the architectural specifications of the building, and the available building bound installations. The labelling model uses underlying assumptions about the specific conditions in The Netherlands to calculate an index and the final energy label.

The most important underlying assumption is related to climate conditions. The tropical climate in Honduras is totally different from the moderate sea climate in The Netherlands. The average temperature in Honduras is 26,2 ° and in The Netherlands 10 °C, the absolute humidity is on average 2,7 times higher in comparison to The Netherlands. There is more rainfall in Honduras and this is concentrated in 8 months of the year. For implementing the labelling system successful in Honduras, the assumptions used in the label calculation method has to be different too, because the climate is so much different. The big houses together with many offices in San Pedro Sula consume a large part of the country’s energy. Therefore these buildings are the scope of this research. The target group of buildings has a lot of design features in common. They are built with single walls of concrete blocks, have a metal roof structure with a metal sheet roof. Almost all the buildings use air conditioning for cooling.

For this thesis five buildings have been examined, three houses and two offices. The examined buildings can be classified into two categories of design. The first category is designed to use only shade and ventilation to keep the living area cool. This type of buildings is called bioclimatic buildings. The second category exists of the more common buildings, which use air conditioning for cooling. The first category is rare in Honduras.

After examining the buildings, the energy label was calculated. The characteristic energy use in the first calculation is the sum of the energy consumption by lighting, the energy used for cooling and the energy used for heating water. In the second calculation the characteristic energy use is the total energy used; this is the amount of energy consumption on the energy bill. The outcome was really positive; four out of five buildings got the best label. This is really unrealistic so the thermal transmission factor is removed. Reason for this is that the thermal resistance of a building has no influence on its energetic performance in the tropical climate of Honduras. After removing the thermal transmission factor, the calculations with the total energy use gave a realistic reproduction of the five Honduran buildings.

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Table of contents 1

2

3

4

5

Introduction ...............................................................................................................................6 1.1

Motivation...........................................................................................................................6

1.2

Problem and objective .........................................................................................................6

1.3

Research questions and method ..........................................................................................7

1.4

Reading guide ......................................................................................................................7

Modelling the energy performance of buildings ..........................................................................8 2.1

Introduction ........................................................................................................................8

2.2

Input ...................................................................................................................................8

2.3

Throughput .........................................................................................................................9

2.4

Output ............................................................................................................................... 11

2.5

Preliminary conclusion....................................................................................................... 11

Climatic differences................................................................................................................... 12 3.1

Introduction ...................................................................................................................... 12

3.2

General Climate of Honduras ............................................................................................. 12

3.3

General climate of The Netherlands................................................................................... 13

3.4

Climate in San Pedro Sula .................................................................................................. 14

3.5

Preliminary conclusion....................................................................................................... 16

Energy use in the Honduran context.......................................................................................... 17 4.1

Introduction ...................................................................................................................... 17

4.2

Energy consumption in San Pedro Sula .............................................................................. 17

4.3

General architectural specifications ................................................................................... 18

4.4

Energy consumption in Honduran buildings ....................................................................... 19

4.5

Preliminary conclusion....................................................................................................... 19

Applying the energy performance method on Honduran buildings ............................................ 20 5.1

Introduction ...................................................................................................................... 20

5.2

Examined houses ............................................................................................................... 20

5.3

Examined offices ............................................................................................................... 23

5.4

Data input in model ........................................................................................................... 25

5.5

Preliminary conclusion....................................................................................................... 26

6

Conclusions ............................................................................................................................... 27

7

Recommendations .................................................................................................................... 28

8

References ................................................................................................................................ 29 4

Appendix A: Checklist for examining a building ................................................................................. 31 Appendix B: Detailed architectural specifications case buildings ....................................................... 34 B.1 Las Casita 100 m2 .................................................................................................................... 34 B.2 Standard Honduran House ...................................................................................................... 35 B.3 Office Techos Verdes ............................................................................................................... 36 B.4 Office La Tara .......................................................................................................................... 37 Appendix C: energy consumption per building .................................................................................. 38 C.1 Las Casita 70 m2 ...................................................................................................................... 38 C.2 Las Casita 100 m2 .................................................................................................................... 40 C.3 Standard Honduran House ...................................................................................................... 40 C.4 Office Techos Verdes ............................................................................................................... 42 C.5 Office La Tara .......................................................................................................................... 43 Appendix D: Calculation Energy labels............................................................................................... 44

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1

Introduction

1.1 Motivation Sustainability is rapidly increasing in importance. At first, cars and machines had to be energy efficient. To do this, energy labels were introduced to increase the awareness of the crowd about the energy specifications of these machines. These labels also stimulate the producers to design more and better energy efficient products. In Europe, energy labels are also developed for houses.

Buildings account for a large part of the annual energy consumption in modern societies.

Within the European Union (EU) the energy use of the built environment is more than 40% of the total energy consumption (Entrop, 2009). The European Union implemented the Energy Performance of Buildings Directive (EPBD) with the explicit goal of promoting energy performance improvements in buildings. The Directive, which was recently recast, includes an explicit element on the disclosure of energy performance in buildings: ‘‘Member states shall ensure that, when buildings are constructed, sold or rented out, an energy performance certificate is made available to the owner or by the owner to the prospective buyer or tenant’’ (Brounen, 2011). When you want to sell or rent a house in The Netherlands, it is required to acquire a label that gives an indication of the amount of building related energy this specific house uses. This helps to increase the transparency of the real estate market. So these labels are being used as an extra tool for house buyers to take energy efficiency into account when making housing decisions.

42,5 % of Honduras total energy consumption is used by the current building stock (ENEE, 2010).

Most houses are made of single concrete walls with a roof of steel sheets. To cool the house, people use air conditioning or ventilation. The total amount of energy used by these houses can become lower by using sustainable building methods. Few Honduran inhabitants are familiar with the possibilities of sustainable building. Therefore this thesis is a good opportunity to encourage people to design and construct buildings which consume less energy. The way to do this is to increase awareness about the energy consumption of a specific house. This is possible by granting houses an energy label, which tells the owner how energy efficient the house is.

1.2 Problem and objective The energy labelling system explained in NEN 7120 is a method used in Europe to enforce the real estate market to become more energy efficient. In Europe this is already a common used tool to increase the awareness of house buyers and tenants. The energy label system is not well-known in Honduras. Before the energy labels are ready to launch in the Honduran real estate market they first have to be made suitable for the tropical climate of Honduras.

The Honduran houses are built to carry off heat as quickly as possible. There are two methods to do this. The first method is ventilating the house; the second method is installing air conditioning. Dutch houses are designed to keep heat inside. To this context arises the main goal: Adapting the Dutch energy labelling system, so it can be introduced in the Honduran real estate market.

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1.3 Research questions and method From the main goal four research questions arise. These will be explained below, along with the methods to find the right answers.

Question 1 (Chapter 2): How is the current Dutch way of modelling the energy consumption of buildings composed, and which parts have to be adapted to match with Honduran buildings?

First it is made clear out of which parts the Dutch model is compiled, this is found in NEN 7120. These subdivisions will be explicitly checked on relevance in the new, tropical, situation. Hereafter it is possible to see what specific parts have to be deleted or changed, and if new parts have to be added.

Question 2 (Chapter 3): What is the difference between the moderate climate in The Netherlands and the tropical climate of Honduras and how does this affects the labelling model?

To answer this question, weather indication data of the two countries is necessary. The main source for meteorological information in The Netherlands will be the KNMI (Royal Dutch Meteorological Institute). The number one source for the climate information in Honduras will be the SMNH (National Honduran Meteorological Service).

Question 3 (Chapter 4): In what way does a standard Honduran building consume its energy?

To answer this question, information is gathered from the national energy company and from local experts.

With their information it will be possible to sketch a picture of the average buildings and their energy patterns. (Figure 1.1) Figure 1.1 A house as a closed energy system

Question 4 (Chapter 5) In what way is it possible to use the determination method of the energy performance of Dutch buildings to calculate the energy performance of Honduran buildings?

To answer this question the adapted energy calculation method will be used. 3 Houses and 2 buildings are visited in the field. The buildings are examined on their architectural specifications, and checked for their installations and appliances. To calculate the energy use the residents are questioned for more specific information on the usage of the available equipment (see appendix A).

All this specific information is filled in into the Dutch method.

1.4 Reading guide In chapter two you will find the way of remodelling the Dutch energy labelling method to make it applicable in the tropical climate of Honduras. Chapter 3 describes the differences between the Dutch, and the Honduran climate, and how this affects the energy consumption. Chapter 4 is a description of the current Honduran buildings, their different parts and how this affects the energy consumption of a building. Chapter 5 is the final chapter in which the new energy labelling model is applied on 5 case buildings in Honduras.

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Modelling the energy performance of buildings2.1

2

Introduction The current Dutch way of modelling the energy performance of buildings is described in NEN 7120 (Dutch Energy Norm). The energy label explained in NEN 7120 determines the ratio between the characteristic energy use and the maximum admissible energy use based on ground surface and building shell (Equation 2.1) for Dutch buildings.

(EQUATION 2.1)

,

=

Ă—

Ă—

: Energy index calculated to comply with the EPBD (-) : Characteristic yearly energy use of a house based on NEN 7120(MJ) : Total ground surface (m2) : Total thermal transmission surface (m2) : Numerical correction factors 155 (MJ/m2), 106 (MJ/m2) and 9560 (MJ/m2)

,

The model can be subdivided into input, throughput and output (see Figure 2.1). The input of the model includes the variables in the denominator of Equation 2.1; the total ground surface and the total thermal transmission surface multiplied by the numerical correction factors. The other input is the data that gives together the yearly characteristic energy use; this is architectural information and data about the existing installations.

The calculation of the numerical correction factors from Equation 2.1 can be ranged in the throughput. These factors are based on assumptions about the climate and usage of the building and the installations in the building.

The output contains of two parts. The unprocessed output is the characteristic yearly energy use. The final output is the actual energy index which gives the energy label.

Figure 2.1 Schematic model for the calculation of an energy label

2.2

Input

The Dutch modelling system needs information about the building itself and the available installations. The desired information describes four parts: Floor surface is simply the number of m2 available for living. The thermal transmission surface is the part of the building which has contact with the inside and outside, and so has the possibility to exchange heat in or out of the building with the surrounding air, soil or water. This means the roof, outside walls, windows, floor and outside doors. The Rc-value or heat resistance is important for the thermal transmission surface. Infiltration of outside air into the building, this occurs especially at the joints between the walls, roof and floor. The heat capacity of the building is important to see how much heat is absorbed during daytime and what is repelled during the (cooler) night.

The NEN 7120 describes the whole labelling system and is a guideline to calculate the energy label for a house. There are ten categories of energy use which are included in this calculation (NEN 7120):

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1. Energy for heating. This is the gas or electricity used to heat the house.

2. Additional energy (for heating). When houses are heated with a central heating system which heaths water, this water has to be pumped around the premises and this costs energy.

3. Heating water. Water used for washing and cooking has to be heated to an acceptable temperature. Gas is used for heating and electricity is used to pump the hot water around the house.

4. Energy for fans. Fans need electricity.

5. Energy for lighting. Lighting needs electricity.

6. Summer comfort (installing shades).

This post is added to the list to because shading devices also have influence on the energy consumption of a building.

7. Energy used for cooling. Cooling by air-conditioning uses electricity.

8. Energy used for moisturizing (rare situations). Moisturizing equipment needs electricity to vaporise water.

9. Energy generation by photovoltaic systems. Solar panels use sunlight to generate electricity.

10. Energy generation by combined heat and power systems. Combined heat and power systems use gas to generate heat and electricity. These systems generate more energy (in heat and electricity) out of the same amount of gas.

2.3

Throughput

Inside the model, there is the so called ‘throughput’. Here are the underlying assumptions about the climate and the use of available appliances, in an examined building. There are a lot of differences in this throughput between the climates of The Netherlands and Honduras. The last computation is necessary for the comparison between other houses. The characteristic energy use has to be compared to the floor surface and the thermal transmission surface. This is done by means of Equation 2.1. To understand more of the underlying assumptions of the NEN 7120, it is useful to find out what the assumed values are. Not all of the values are specified. In Table 2.1 you can see that these assumptions are really different for both countries.

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Table 2.1 Elements of NEN 7120 with the Dutch and Honduran guidelines and assumptions.

Element Heating

Additional energy (for heating)

Heating water

The Netherlands - Desirable inside temperature: Min 20°C, Max 24°C - Average outside temperature 9,5°C (table 2) - Intensity incoming solar radiation is 300 W/m2/hour - Heating season lasts 212 days Energy used for pumps

Energy for fans

Heating water is usually done with a boiler, fuelled by gas.

Fans use electricity

Energy for lighting Summer comfort (installing shades)

Lighting uses electricity Some shades are electric and use energy

Energy used for cooling

Air-conditioning uses energy, they are only used a few weeks a year.

Moisturizing equipment is sometimes used in The Netherlands This energy generation is used relatively often in The Netherlands There is a big investment needed for such a system

Energy used for moisturizing (rare situations) Energy generation by photovoltaic systems Energy generation by combined heat and power systems

Honduras - houses do not have heating installations, no heating season - Average outside temperature is 26°C -the solar radiation is much stronger in Honduras because it is closer to the equator.

Heating houses is not necessary in Honduras so there are no pumps available.

Mostly only electric shower water heating.

This is more important in Honduras, most houses use fans for many hours a day.

Lighting uses electricity More important in Honduras, every house here needs shade.

Many houses do not have sufficient shading.

More important in Honduras, the air conditioning can be used the whole year round.

Moisturizing is not useful in the humid climate of Honduras.

Great potential for photovoltaic systems but until now not used.

Through the big investment and cheap energy prices not common in Honduras.

Table 2.1 makes visible that not all the ten Dutch elements can be used in Honduras. Only the water heating, energy for fans, lighting, summer comfort and cooling are useful. Photovoltaic systems and combined heat and power systems are unrealistic and will be left out further. In Table 2.2 are the average temperatures in The Netherlands and Honduras visible per month. As you can see in The Netherlands is a large variation in temperatures. In Honduras the temperature is the whole year round almost the same. Because the wide range of temperatures in The Netherlands, there are already elements for warm weather included so there is no need to introduce new elements.

Table 2.2 Average monthly temperatures (°C) (WKI, 1997)

Month The Netherlands Honduras

Jan 2,6

Feb 5,0

Mar 6,8

Apr 9,3

May 13,3

Jun 16,0

Jul 17,4

Aug 17,4

Sep 14,6

Oct 11,3

Nov 7,1

Dec 4,0

year 9,5

23,5

24,1 25,8

27,1

28,1

27,7

27,1

27,3

27,2

26,0

24,7

23,7

26,0 10

After the calculation of the characteristic energy use, this can be divided by the ground surface and the surface of the thermal transmission shell. By doing this, the model is suitable for comparing buildings of different sizes on their energy consumption.

2.4

Output

The output of the model will be the outcome of Equation 2.1. This is the energy index of the building, compared to other buildings. With Figure 2.2 it is possible to attach an energy label to a specific building and compare the building with other buildings.

2.5

Preliminary conclusion

The Dutch labeling system is partly applicable in Honduras. Because the wide range of temperatures in The Netherlands, there are already items which are also applicable in the tropical climate of Honduras. The elements for heating, moisturizing and special equipment can be left out of the calculations. The elements that are applicable to the Honduran context are heating water, energy for fans, lighting, summer comfort and cooling.

Figure 2.2 Dutch energy labels (Duurzaam thuis, 2010)

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3

Climatic differences

3.1

Introduction

The Dutch energy labelling system is attuned to the Dutch climate. The climate values are included in the correction factors used in Equation 2.1. This means the calculations which have to be done to obtain an energy label use Dutch temperatures and other Dutch climate values, namely the values from the TRY de Bilt, (Hensen, 2001). For introducing the energy labels in the tropical climate of Honduras and especially San Pedro Sula it is necessary to examine the prevalent climate. This has to be done to see what the differences are in the assumed values used in the throughput part of the calculations.

3.2

General Climate of Honduras

Honduras, with an area of 112,492 km², is located between the latitude 13 °N and 17 °N and between the longitude 83 °W and 89 °W. There are six different climate zones in the country (figure 3.1).

These are the Atlantic coastal zone, the northern interior, central zone, west zone, the eastern and the south part of Honduras. Each zone will be shortly described with their different climate specifications.

Figure 3.1 Climate zones Honduras, San Pedro Sula is in the orange box. (Google maps, 2012)

Atlantic coastal zone According to the Köppen climate classification, this area belongs to the climate of tropical rainforest.

Rains occur throughout the year, with an average of 2643 mm and 167 rainy days year. The rainy season begins in June with a gradual increase until September, showing the absolute maximum in October, November and December, with an average of 400 mm per month. The least wet months are April and May with an average precipitation of 80 mm per month. The average annual relative humidity is 82% and the average annual temperature is 27 °C. With an average maximum temperature of 30 °C and a minimum of 20.7 °C, the warmest months are May and June with an of 28.1 °C and 28.2 °C respectively. The freshest are December and January with averages of 24.3 °C and 23.9 °C respectively. (SMNH, 2011) Northern Interior This is the area where San Pedro Sula is situated, the place where I will gather my research data. The existing climate of tropical savannah is characterized by two seasons: the dry time in January through 12

April, with the months of March and April as driest with an average of 25 mm precipitation per month. The rainy season begins in June and ends in November or December. The average annual rainfall is 1128 mm. There is an average of 150 rainy days a year, with a maximum amount in September of 176 mm. The annual average relative humidity is 75%, with an average temperature of 26.2 °C, a maximum average of 30.0 °C and a minimum of 21.9 °C. (SMNH, 2011) Central zone This area is characterized by two seasons, one dry and one rainy. The first occurs between January and April, February being the driest month, with an average precipitation of 8.0 mm. The rainy season begins in mid-May and ends in October. Average annual rainfall is 1004 mm with 118 days of rain and average relative humidity of 70%. The average annual temperature is 24.9 °C with a maximum of 27.1 °C in April and a minimum of 22.7 °C in January for places as far as 500m above sea level. An average of 21.5 °C, with a maximum of 23.5 °C in April and an average minimum of 19.5 °C in January to places to 1.000 m above sea level. (SMNH, 2011) West zone For the terrain in this area are two types of weather, the first by Köppen is a "mesothermal" climate with a dry winter in places above the 1,400 m. This season starts in December en ends in March with a minimum precipitation of 0.5 mm in January. The rainy season starts in mid-April en last until November with a monthly maximum of 300 mm precipitation in June. The annual rainfall is 1290 mm which falls in 160 days, with a relative humidity of 76%. The average temperature is 18.3 °C, with an average maximum of 22.4 °C and a minimum of 12.5 °C. The second type of climate is tropical savannah to the sites below 1,400 m. With a dry season from December to April, and a rainy season which occurs from May to November with a maximum of 303 mm in September. The annual rainfall 1395 mm, this falls in 144 days and there is a relative humidity of 76%. The annual temperature is 24.5 °C, with a maximum of 28.9 °C and minimum 19.0 °C. (SMNH, 2011) Eastern This region includes a tropical savannah climate. The area is characterized by two seasons: a dry season between December and April, with February being the driest month with an average of 19.0 mm. The Rainy season occurs from May to November and has a maximum monthly average in September of 211 mm. The annual rainfall is 1200 mm which falls in 153 days, the relative humidity of 74%. The average annual temperature is 25.0 °C, with a maximum of 30.2 °C and a minimum of 18.6 °C. The hottest month is April with 27.0 °C average, and January as the coolest month with 23.0 °C. (SMNH, 2011) South According to Köppen the South region consists of a tropical savannah climate. The area has a dry season from December to April with a monthly average precipitation of 3,0 mm. The rainy season occurs from May to October, the absolute maximum occurs in September with 345 mm of rainfall per month. The annual average rainfall is 1,680 mm, which falls in 102 raining days. The average relative humidity is 66%. The average annual temperature is 29.1 °C, with an average maximum temperature of 34.5 °C and a minimum of 23.4 °C. The hottest month is April with an average of 30.7 °C with an average minimum of 27.5 °C in September. (SMNH, 2011)

3.3

General climate of The Netherlands

The Netherlands have a temperate maritime climate influenced by the North Sea and Atlantic Ocean, with cool summers and moderate winters. Daytime temperatures vary from 2 °C – 6 °C in the winter and 17 °C – 20 °C in the summer. Since the country is small there is little variation in climate from region to region, although the marine influences are less inland. Rainfall is distributed throughout the year with a dryer period from April to September. The average yearly rainfall is 766mm. Especially in fall and winter strong Atlantic low-pressure systems can bring gales and uncomfortable weather.

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Sometimes easterly winds can cause a more continental type of weather, warm and dry in the summer, but cold and clear in the winter with temperatures sometimes far below zero. The Netherlands is a flat country and has often breezy conditions, although more in the winter than in the summer, and more among the coastal areas than inland. The climate of The Netherlands can be classified as oceanic climate in the Köppen classification; a warm temperate humid climate with the warmest month lower than 22°C over average and four or more months above 10°C over average. (weatheronline, 2012)

3.4

Climate in San Pedro Sula

The research for this thesis will be done in San Pedro Sula, with her population of almost 900.000 the second largest city of Honduras. San Pedro Sula is situated in the Valle de Sula and belongs to the Northern Interior zone. It is known that San Pedro Sula is hot and humid all year long.

Temperature The temperature in San Pedro Sula is compared to The Netherlands really high; the monthly average temperature is always between the 24 and 28 °C. The maximum average temperature in The Netherlands is 17 °C, and in the winter lowers this to a minimum of only 2 °C (Figure 3.3).

Degree days The biggest difference in the temperature becomes visible when you look at the so called degreedays. A heating degree day is a day when the outside temperature is 1 °C below 18 °C. For example, when it is five °C below 18 °C, that single day counts for 5 degree days. A cooling degree day is a day when the outside temperature is 1 °C above 18 °C (KWA, 2012). In Table 3.1 becomes the difference visible, in San Pedro Sula occur a lot of cooling degree days and almost no heating degree days. In The Netherlands is opposite.

Table 3.1 Degree days The Netherlands and Honduras

The Netherlands, The Bilt (KWA,2012) Honduras, San Pedro Sula (degreedays, 2012)

Yearly cooling degree Yearly heating degree days days 79 3040 3086 2

Humidity The people in San Pedro Sula say it is really humid in their city. If you first look at the relative humidity you will see it is almost the same as in The Netherlands (Figure 3.2). When the absolute humidity is calculated, thus the actual amount of evaporated water per m3 of air, big differences become visible. In Figure 3.4 you can see the actual humidity in San Pedro Sula is on average 2,7 times higher as de Bilt (The Netherlands).

Figure 3.2 Relative humidity (%)

Figure 3.3 Average temperature (°C)

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3

Figure 3.4 Absolute humidity g water/m air (KNMI,1997)

Precipitation

Figure 3.5 Yearly precipitation San Pedro Sula (DIMA, 2006)

Figure 3.6 Average monthly precipitation San Pedro Sula (DIMA, 2006)

Information about the precipitation in San Pedro Sula is gathered by Van de Bent (2009). He got this information from the DIMA, the local water department of the municipality of San Pedro Sula. The measurement site is located 5 km from the centre. The average yearly precipitation in San Pedro Sula for the last ten years is 1301mm, with a minimum yearly precipitation of 905mm (1997) and a maximum of 1842mm (1995), see Figure 3.5. The average monthly precipitation shows the dry season which starts in February and ends in May. In June starts the rainy season, the rains becomes less until September but in October and November the rainy season is at his wettest point (Figure 3.6).

300

Dec

Nov

Oct

Sep

Aug

Jul

Jun

May

Apr

Mar

Feb

Jan

Sun hours As you can see in Figure 200 3.7 Honduras gets on San Pedro Sula average more than 200 100 De Bilt hours per month. The amount of daylight is 0 everywhere in the world the same. The difference between Figure 3.7 Sunhours per month light in the summer and winter are bigger in the Netherland as in Honduras (UNL, 2012). Here it is assumed that these differences elevate each other. Sunlight has on average the strength of 340 Watts per square meter.

In the Netherland this is less, in Honduras more because it is closer to the equator (NASA, 2012).

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Other weather phenomena The Caribbean has a hurricane season that also affects Honduras. Although there are not many hurricanes what effect the country (one every 4,12 years), there is always a possibility of a deadly hurricane like Mitch in 1998. (Hurricane city, 2012)

3.5

Preliminary conclusion

This chapter shows that the tropical climate in Honduras is totally different from the moderate sea climate in The Netherlands. The average yearly temperature is 26,2 째C in Honduras and 10 째C in The Netherlands, the absolute humidity is on average 2,7 times higher compared to The Netherlands.

The average yearly rainfall in San Pedro Sula is 1128 mm, the dry time is January to April. The yearly rainfall in The Netherlands is 766 mm. The rainfall occurs throughout the whole year.

This information shows that the changes in the Dutch model from Chapter 2 are correct. Heating is not necessary, cooling is yet vital importance, also by applying fans. The hours of usage for lighting will be similar to the Dutch situation. Summer comfort is really important through the strong sun and for moisturizing no energy is used because of the high humidity.

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4

Energy use in the Honduran context

4.1

Introduction

How a building consumes energy dependents on two things; architectural specifications and the installations present in a building. For this research 5 buildings are examined, three houses and two offices. They were looked at for their architectural specifications and for the installations and appliances. For a better understanding of the local buildings there were some interviews with local experts about the general design and use of local buildings. For the choice of the correct scope of this research information is obtained from the national energy company.

4.2

Energy consumption in San Pedro Sula

In Honduras officially lived around 8.200.000 people in 2010. Together they use 1.390.000 connections to the national power grid. This is the total amount of connections, the bulk of connections is for residential use (1.270.000). The Northwest part of the country has a contribution of 587.000 of the connections. Especially the region Cortes (1.570.000 inhabitants) and its main city San Pedro Sula (719.000 inhabitants) use a big part of the consumed energy (Table 4.1). (ENEE, 2012) Table 4.1 Energy consumption and connections to national grid in Honduras (ENEE, 2012).

Connections

Connections Consumed Consumed energy (%) energy (kwh) (%) San Pedro Sula 140.129 10 90.334.515 21 North West Honduras 587.108 42 219.092.385 51 Total Honduras 1.392.034 100 430.687.680 100 San Pedro Sula consumes 21% of the nation’s energy. The residential and commercial part of the energy consumption in San Pedro Sula is 70% (respectively 38% and 32%) of the total energy consumption. The other share of energy is consumed by the industry (26%) and government agencies (4%). Moreover, when you look at the number of connections with the national grid you will see the residential and commercial electricity consumption per connection is a lot bigger compared to the whole region (70%) and it is more than double compared to the whole country, see Table 4.2. (ENEE, 2012).

Table 4.2 Power consumption in kWh per connection, per region, per month (ENEE, 2012).

Energy consuming sectors Residential Comercial Total

San Pedro Sula 248 1.575 645

Northwest region 139 1.094 373

Honduras 143 1.028 309

The city of San Pedro Sula is inhabited by less than ten percent of the nations citizens, nevertheless they use 21% of the total energy consumption in Honduras. Some neighbourhoods of San Pedro Sula are covered with big houses (more than 250 m2 ground surface) equipped with large, energy consuming air conditioning devices. There was no data available about the roll these houses play in the city’s residential energy use. Yet this research will focus on these houses because they play certainly a part in the elevated energy consumption of the city San Pedro Sula.

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4.3

General architectural specifications

The focus in this research is on houses in the higher part of the real estate market of the city San Pedro Sula. This is because these houses use the most energy, and so there are more opportunities to reduce their energy consumption. The houses in the examined category have a floor surface of between 200 and 500 m2 and are mostly only built on ground level. This type of houses cost between the 3 and 5 million Lempira’s (125.000-200.000 euro). Also included in this research are small offices, this is because there are a lot of these energy consuming buildings and it was easy to get access to two of these offices. The offices are used by 3 to 6 employees and their floor surface is about 30-40 m2. Through interviews with local experts the following general information about Figure 4.1 House composed of concrete blocks and a metal roof. buildings in the examined category were found.

The houses in the examined category have mostly a hipped roof, there are also some shed and gable roofs. The structure of the roof is totally made of steel, the upper part exists of metal sheets. This type of house has sometimes insulation under the metal sheets and at the bottom you can find sheetrock. The foundation of most buildings is made of a strip foundation, this is made of concrete blocks or reinforced concrete. The walls of the building are made of concrete blocks or sometimes bricks, there is always only a single wall without any insulation and the walls will be covered with plaster (Figure 4.1). The floor is made of concrete, covered mostly with tiles. The height of the ceilings is mostly 2,70 or 2,80 meters. Some offices are lower (2,40 m) because they are designed for using air conditioning. Old houses have cross ventilation in the roof, ventilation in top of the walls and in the point of the roof. The modern houses are designed for using air conditioning, they look like copies of buildings in the United States and do not have ventilation in the roofs. All the houses are freestanding. The windows of the houses are single glassed in aluminium frames. Many houses have big fixed windows, the smaller windows have a sliding system to open them. The parts which can be opened contain mosquito screens. Most of the windows are unprotected from the sun, the eaves are to small (60 cm) and there are no other possibilities to block the sun. Many times the only option for shade is curtains inside of the house. The thermal shell of the buildings has mostly a really low thermal resistance. The hot outside air can get in easily.

The average house is occupied by five or six persons; two parents, two or three children and a maid.

Houses have 3 or 4 bedrooms. Many houses in the examined range use air conditioning. This can be a central air conditioning device what cools the whole house or separate units in different rooms. Most house use also fans for cooling. When you buy a house, most of the time the only equipment installed is the air conditioning and a reserve water tank under the house. It is clearly visible that in most houses the designers do not think about the air conditioning (Figure 4.2), the placement is many times far from logical. In rare situations there are some installations for heating water and some build in piping with the connections for the use of gas equipment. Only the people with lower incomes use gas for cooking because it is cheaper but more work, because the input of gas is by portable gas canisters.

Figure 4.2 house with AC devices.

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4.4

Energy consumption in Honduran buildings

To calculate the characteristic energy consumption of a building it is necessary to examine what kind and how many installations are available in the specific building. In this research all the electrical appliances are included. The main categories in a house are: indoor climate control, kitchen equipment, water heating, lighting, the appliances for washing, and the other equipment such as televisions and computers. In offices the indoor climate control is important as well the lighting.

Electronic equipment, such as computers and printers, is also available in most offices.

The only appliances for influencing the indoor climate are fans and the air conditioning. Especially the air conditioning can be ranged under the biggest energy consumers in the building. Juusela (2003) shows cooling is much more energy consuming than heating. Air conditioning equipment is also useful to make the inside climate less humid. Most houses contain a big refrigerator and the necessary kitchen equipment such as an oven, stove and some houses had a water cooler. All of the houses in the examined category got some kind of water heater. Mostly, this is only for the shower, in this case it is an electrical heater, close to the shower. There are cases where water is heated with gas. The lighting of houses is almost the same as in The Netherlands. The use of washing equipment is also similar to The Netherlands, drying clothes is yet done more often outside. For the usage of other equipment (televisions, computers, iron, etc.) it is presumed this is similar to The Netherlands.

The three houses in the research (description in Chapter 5) use on average 500 kWh and a little bit of gas (only one house uses 17 m3 per month). Dutch houses use monthly 276 kWh and 125 m3 of gas per month. When you calculate the number of used MJ, houses in The Netherlands use almost three times as much energy the Honduran case houses.

Table 4.3 Dutch average energy consumption versus energy consumption of three Honduran case houses. (Nibud, 2012)

Honduras The Netherlands

4.5

Gas consumption (m3) 5,6 125

Electricity consumption (kWh) 500 276

MJ per m3 gas 38,4 38,4

MJ per kwh electricity 3,6 3,6

Gas Electricity in MJ in MJ

total MJ

218 4800

2018 5794

1800 994

Preliminary conclusion

In Honduras live 8,2 million people. 10% of them live in San Pedro Sula and they account for 21% of the total national energy consumption. Most of this energy is consumed by residential and commercial buildings. The big houses in San Pedro Sula account for a big part in the cities energy consumption. This is why the scope of this research is houses in the higher part of the real estate market and additional offices.

The target group of buildings has a lot of design features in common. They are all built with single walls of concrete blocks, have a metal roof structure with a sheet metal roof. Almost all the buildings use air conditioning for cooling. The inside of the house heats trough incoming hot air and especially sunshine. Houses are not well enclosed from the hot outside. The biggest difference in the energy use from Dutch and Honduran buildings is the heating over cooling.

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5 Applying the energy performance method on Honduran buildings 5.1

Introduction

The easiest strategy to find out if the Dutch labeling system is applicable to Honduran buildings is to try it out. By examining some buildings I found the input parameters for Equation 2.1. These are the characteristic energy use, the ground surface and the thermal transmission surface.

For my research I have investigated two types of houses and two types of offices in San Pedro Sula, Honduras (Figure 5.1). In total 5 buildings (one type is examined double). It is necessary to say these houses are not representative for all the houses in Honduras. Both of them belong to richer people compared to the average Honduran people. The supposed value increase of the building will also be larger for bigger houses (Popescu, 2012) as for average houses. The introduction of the energy labels will be more useful for these buildings as for average buildings in Honduras.

To know how much the different appliances use in a month there was a question list about the usage per appliance for the residents (Appendix A). After finding all the consumption values of the appliances it was possible to calculate the amount of energy consumed by the residents per month (namely: energy consumption in kWh = 1000 x Wattage x hours of use). To verify if this calculation is correct it will be compared with the real energy consumption, which can be found on the monthly energy bill. If there are big differences between these two it is clear the assumptions of the hours of usage are incorrect and have to be adapted. The length of the month is in the calculations 30,42 days (365/12). All the months are attuned to this value. A working week for the two offices is 5,5 days (Monday till Friday and Saturday morning)and 9 hours per day. Refrigerators and freezers are calculated for working 24 hours per day and 7 days a week.

Figure 5.1 location San Pedro Sula (red dot).

5.2

5.2 Case houses (1 and 2) and offices (3 and 4)

Examined houses

The first type of house (Las Casitas) is a house designed by my supervisor, Architect A. Stassano. It is a so-called bioclimatic house (number 1 in Figure 5.2). This type of house uses ventilation and shading for keeping the inside of the house cool, there is no air-conditioning installed. In the north of San Pedro Sula there is a private development inside the urban development located with 19 Bioclimatic houses. I have examined two of these houses, a small and a big one. The big house has a surface of 100 m2, the small house is about 70 m2.

The second house is uninsulated and uses air-conditioning for cooling for some rooms (number 2 in Figure 5.2). When I was in the house, it was really hot and humid, this was May 15th, at 3:00 PM. At 20

that moment the air conditioning was off, the residents said they only use it at night. The house is built of concrete blocks covered with plaster, and has a sheet metal roof. The information about the architectural specifications can be found in Appendix B. More information about the available appliances and how the residents use them can be found in Appendix C. 5.2.1 House one: Las Casitas (bioclimatic) The bioclimatic houses (Figure 5.3) are designed to keep the inside temperature at an acceptable level without the help of an air conditioning device. It has long eaves for shade; a high, ventilated roof to prevent hot air to accumulate under the roof. This building uses also a mix of different green surroundings to help to keep the building cool. Many people here do not believe it is possible to live in a house without air conditioning. The majority of new buildings is fully equipped with air conditioning, so people are used to use it in all the buildings. To avoid Figure 5.3 Las casitas (70 m2 version) people installing an air conditioning device on their own, the residents have to sign a contract to not use air conditioning. The living space of the big Casitas is 100 m2, the smaller ones are 70 m2. Furthermore the house is built on 2,4 m long stilts.

In the Las Casitas (70m2) live 2 adults and 3 little children. The monthly total amount of energy they use is 425 kWh (Average of Dec and Jan 2011/2012). The house has only a few appliances (Figure 5.4), the only energy used for cooling the house is consumed by the fans and this is only 12% (49 kWh). The shower water heater is the biggest energy consumer and uses 29% (122 kWh) of the total amount of consumed energy. The dryer and washing machine consume 31% (131kWh) of the total energy. The total calculated amount of energy is 410 kWh. This means there is a rest consumption of 15 kWh per month.

Shower water heating Washer Fans Stove Air Conditioning Other

Dryer Refridgerator/Freezer lightning Microwave Oven

2

Figure 5.4 energy consumption Casitas (70 m )

In the Las Casitas (100 m2) live four adults and two children. One of the children is a baby and the parents say this baby counts for an adult with all the dirty clothes and heating bottles. Their monthly amount of energy consumed is 715 kWh (average Jan/May 2012). The residents claim they use in total only 348 kWh. This is not even the half of their real energy consumption (Figure 5.5).

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Shower water heating Fans Dryer, washer lightning iron Rest consumption

Refridgerator, freezer Stove Microwave Television Toaster,Coffee, Oven

2

Figure 5.5 Claimed energy consumption Casitas (100 m )

In the interview there are some doubts about a number of appliances; the use of the shower water heating, dryer and washer. The owner of the house did not have a good insight about the use of cooking equipment, lighting and fans because they live with a lot of people in the house, and the owner himself (the interviewee) has work elsewhere. If we will take more realistic values for the usage of appliances, we get a total different picture (Figure 5.6). There still is a big part of other consumption (26%), but this is realistic because they had a lot of small appliances like computers, electric games and small kitchen and bathroom equipment. The cooling of the house through fans consumes 8% (57kWh) of the total energy consumption. The shower water heating is the biggest consumer and is good for 21% (152 kWh) of the total consumption.

Shower water heating

Refridgerator, freezer

Fans

Stove

Dryer, washer

Microwave

lightning

Television

iron

Toaster,Coffee, Oven

Rest consumption 2

Figure 5.6 Recalculated energy consumption Las Casitas (100 m )

5.2.2 House two: Standard Honduran house (air-conditioned) Case house number two (figure 5.7) is a standard Honduran house. The house has a surface of 96m2. It is a house with a really simple design, the surface is square and the roof is a gable roof, applied with small eaves (40cm). On one side of the building the roof is extended to create a carport, this eliminates all the sun radiation on this side of the building.

Because of the supporting Figure 5.7 Case house two: normal Honduran house wall the ventilation decreases significant on this side of the building. Almost the whole house is fully exposed to the sun, there is at the front, and in the back of the house some coverage, which provide shade for some hours of the day. The big carport catches sun for almost the whole day. Furthermore the garden contains one bush that provides some shade.

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In the Standard Honduran House live 5 adults. Their monthly amount of electricity consumed is 362 kWh (May 2012). The residents claim they use between 560 and 738 kWh. This is the only building examined where gas is consumed. The residents say they use every month one 25 pound cylinder with gas to use their stove, oven and dryer (Figure 5.8). The stove, oven and dryer use almost the same amount of energy: 34% (213.000 kJ) , 33% (207.000 kJ) and 32% (201.000 kJ).

Stove Oven Dryer

Figure 5.8 Gas consumption Standard Honduran House

The people in this house maybe exaggerate their energy consumption. In the interview were some doubts, especially about the shower heating and the air conditioning use. To get to more realistic values these two energy consumers are once again looked at. If the value of daily usage of the air condition is changed from 3 to 1,5 hours, the air-conditioning energy consumption will drop from 224 kWh to 112 kWh. If the value of the average shower time will be lowered from 10 till 5 minutes, the shower energy consumption will drop from 176 to 88 kWh per month. The total energy consumption will be 347 kWh. This means there is still 15 kWh for rest consumption (Figure 5.9). The air conditioning is the biggest energy consumer; together with the fans, the total amount of energy used for cooling is 38% (136 kWh). Shower water heating uses 24% (88kWh).

Air Conditioning

Shower water heating

Refridgerator/Freezer

Fans

Water cooler

lightning

Washer

Microwave

rest consumption Figure 5.9 Energy consumption Standard Honduran House

5.3

Examined offices

The two offices are both small (40 and 30 m2) and contain both only the appliances which are necessary for a whole workday at an office. The first office (number 3 in Figure 5.2) is a bioclimatic office; it uses the same principals of design like the bioclimatic houses. There is no air conditioning, between the roof and the ceiling is free space to convey the hot air and there is plenty of ventilation and shade. The other office (number 4 in Figure 5.2) is a ‘normal’ office. The major part of cooling the building is using the air conditioning. The other cooling implement is the ventilated roof, between the roof and the ceiling of the office is some free space, this is ventilated through two openings. The second office is probably representative for most of the offices in San Pedro Sula. The information about the architectural specifications can be found in Appendix B. More information about the available appliances and how the residents use them can be found in Appendix C. 5.3.1 Office one: Techos Verdes office (bioclimatic) The Techos Verdes office (figure 5.10) is a so called bioclimatic design. This means the discharge of heat is done without the use of air conditioning. The front and back side of the building exists almost fully out of glass. The top and lower part of these windows consists of grid with mosquito screens, 23

these are always open. The office is situated between two other buildings, this decreases the opportunities for ventilation. The roof of the office has long eaves and there is a lot of free space underneath.

In the office of Techos Verdes there worked in the month May four people. The monthly total amount of energy this office used is 243 kWh (May 2012).

The office has only a few appliances; computers, 3 fans and a refrigerator (Figure 5.11). The only energy used for cooling the office is consumed by the fans and this is 20% (50 kWh). The computers Figure 5.10 Office Techos Verdes are together the biggest energy consumers and uses 40% (97 kWh) of the total amount of consumed energy. Furthermore goes 18% (44 kWh) of the energy to lighting, this is because every night, the whole night four lights are burning for security reasons. In the day time the lights are always off because there is plenty of light coming in to through the big windows. The total calculated amount of energy is 228 kWh. This means there is a rest consumption of 15 kWh per month.

Computers/laptops

Fans

lightning

Refridgerator/Freezer

Microwave

Coffee

Printer

rest consumption

Figure 5.11 Energy consumption Techos Verdes office

5.3.2 Office two: La Tara office (air-conditioned) The building is used as an office, there are on the left and right side of the building other buildings.

The front side is the only side with windows. The back of the office contains a wall used as a terrain separation. Between the ceiling of the office and the actual roof is some space which is ventilated at the front and backside of the building. (figure 5.12) In the office of La Tara there are four people working. The average monthly total amount of energy they use is 772 kWh (Dec 2011/April 2012).

The office has only a few appliances; computers, an air conditioning device, a fan which they never use, a refrigerator and some small appliances (Figure 5.13). The only energy used for cooling the office is consumed by one air conditioning device. This device uses 70% (537 kWh) of the total amount of consumed energy. The computers, lights and refrigerator use together 28% (222 kWh). The lights are turned on the whole day because there is only Figure 5.12 La Tara office one window. The rest consumption is calculated at 6 kWh.

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Air Conditioning Computer lightning Refridgerator/Freezer Microwave Radio Printer rest consumption Figure 5.13 Energy consumption La Tara office

5.4

Data input in model

For this research five buildings are examined, three houses and two offices. Two bioclimatic houses (Las Casitas) without air conditioning, a standard Honduran house with air conditioning, one bioclimatic office (Techos Verdes office) and a fully air conditioned office (La Tara office). The houses contained all the normal equipment such as a refrigerator, oven, stove, electric shower, lights and washing equipment. The bioclimatic houses use only fans to cool their rooms, the standard Honduran house uses fans and two air conditioning devices to cool the building. Both offices contain computers, a printer, a refrigerator and lights.

In the house with air conditioning the air conditioning was the biggest energy consumer. The next biggest energy consumer was the electric shower water heater. In small and big Las Casitas this shower was by far the biggest consumer with respectively 29% and 21% of total energy consumption.

The Ta Tara office (with air conditioning) uses 70% of his total energy consumption on cooling the room with the air conditioning device. Most of the other energy goes to the computers and the lights. The Techos Verdes office (without air conditioning) uses 20% of its energy on cooling. In real energy consumption, the office with air conditioning uses more than ten times as much energy on cooling than the Techos Verdes office. In Table 5.1 the numbers mentioned before in this chapter are shown.

Table 5.1 Significant numbers Paragraphes 5.1 -5.4, printed in bold are the buildings with air conditioning.

Building

Total monthly energy consumption

Residents/ personnel

Appliances used for cooling

Building bound energy consumption

Small Las Casitas Big Las Casitas

425 kWh

fans

197 kWh

fans

254 kWh

8

Standard Honduran House Techos Verdes office La Tara office

362 kWh 620.000 kJ (17 m3 gas) 243 kWh

2 adults 3 children 4 adults 1 child 1 baby 5 adults

Cooling energy percentage of total (%) 12

air conditioning and fans fans

246 kWh

38

94 kWh

20

air conditioning

602 kWh

70

715 kWh

772 kWh

4 fulltime jobs 4 fulltime jobs

To calculate the real energy index, and the energy label, the above mentioned information has to be filled in in Equation 1. The characteristic energy use is determined by the energy use of the building bound installations. This is all the equipment that is permanently fixed to the property. With these 25

buildings only the cooling equipment, the lights and the shower water heaters are permanently fixed.

For a comparison, the label of the household with the total energy consumption is also calculated.

The floor surface and total thermal transmission surface are measured and calculated. The thermal transmission surface is composed of the floor surface, wall surface and the surface of the roof except from the eaves. With the calculated index, you can find the corresponding energy label with the index and corresponding energy labels as showed in Figure 2.2. It has to be said that the constant values (Equation 2.1) from the calculation are not changed during the calculations. The outcome of the calculations is shown in Table 5.2. The complete calculation can be found in Appendix D. Table 5.2 Calculated energy indexes and labels

Characteristic index Label Total index Label Las casitas 70 m 0,19 A++ 0,41 A++ Las casitas 100 m 0,19 A++ 0,54 A+ Norman Honduran house 0,18 A++ 0,28 A++ Techos Verdes office 0,13 A++ 0,33 A++ La Tara office 1,10 B 1,41 C As you can see, the investigated houses are really energy efficient, according to the current calculations method. This means the examined buildings are really efficient, or the calculations are wrong.

5.5

Preliminary conclusion

For this thesis five buildings are examined, three houses and two offices. The examined buildings can be classified into two categories of design. The first category is the bioclimatic building design which completely relies on shade and ventilation, the other type uses air conditioning for cooling.

The building bound energy consumption is composed out of the energy for cooling, the energy for water heating and the lights. With Equation 1 and the data about the architectural specifications the energy labels are calculated. All the buildings get the highest score except from the La Tara office.

When looked at the total energy consumption three buildings still score the highest score.

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6

Conclusions

With this research there is investigated if it is possible to introduce the Dutch energy labelling system in the tropical climate of Honduras. First the Dutch labelling system is unravelled. The input values of this system are the architectural specifications of a building, and the specifications of the available building bound installations. The installations can be divided into ten categories. Only five of these are applicable in Honduras; water heating, energy for fans, lighting, summer comfort and the biggest energy spender cooling. Divided by the architectural values (ground surface and total thermal transmission surface) and some constants, it is possible to calculate the energy index of the house.

The labelling calculation gives an index of the examined building compared to average buildings. This means it is possible to use it as a comparison tool.

The Dutch labelling model uses a lot of underlying values and assumptions; the climate is one of the most important underlying values. There are big differences between the climate of The Netherlands and Honduras. In Honduras, the temperature is much higher, 26째C compared to 10째C in The Netherlands, and the humidity is almost triple as high as in The Netherlands. Because of this it is not possible to use the same calculation method as in the Dutch model. The climate of Honduras is even warmer and more humid than the rest of the country. The scope of this research is concerning relative big houses and offices in San Pedro Sula, Honduras. These buildings have a lot of design features in common; they are built with single walls of concrete blocks, have a metal roof structure and a sheet metal roof. Because of this design, heat gets in really easy. To convey this heat, people use a lot of air conditioning devices.

In the last chapter three houses and two offices are examined. Three of these buildings were bioclimatic what means they only use shade and ventilation to cool the building. The other two buildings were more traditional and their residents used air conditioning for cooling. To get the input for the energy labelling model, the residents and employees from the office were asked for the usage of the building bound equipment. This and the total monthly energy consumption were used as characteristic energy use. After inserting the specifications into the model, the outcome of the calculations was really surprising. Four out of five buildings got an A++ label and one got a B label when only the building bound energy was used. The calculations with the total energy consumption gave almost the same unrealistic outcome, which can mean two things. The Honduran building use compared to Dutch buildings, significant less energy. Or the energy labelling system is not adapted correctly to the Honduran conditions.

The examined Honduran houses use only a third of the energy consumed by average Dutch households. Because the labeling model divides the energy use by the ground surface and thermal transmission shell surface, big, wide buildings score better with the same energy consumption. The Honduran buildings are like this and so they score automatically better. Furthermore this labeling model is a good step for more research to make a stable labeling system.

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7

Recommendations

The outcomes of the calculations with the adapted energy labeling system for buildings in Honduras were really high. As mentioned in the conclusion this can mean two things; the houses in San Pedro Sula use far less energy than Dutch Houses, or the calculations are wrong.

I think the calculations for Honduran buildings are distorted, through the TTS (thermal transmission surface) factor in the final calculations. This factor is less important in Honduras because of the hot climate. In table 7.1 you can see the same calculations as in Paragraph 5.4. Buildings who scored before a label A, stay in the same area. Only the La Tara office plunges to label D and with the total energy consumption even to E. The Standard Honduran house scores still good with an A+ label, this is strange because this house has two air conditioning devices. This is explicable because the used characteristic energy use in the calculations is based on the real energy use in the house. In this case, the energy bill was low compared to all the available equipment. This means the residents of this house use probably less energy compared to the average energy consumption of a Honduran family.

Table 7.1 Calculation energy labels without thermal transmission surface

Las casitas 70 m Las casitas 100 m Norman Honduran house Techos Verdes office La Tara office

Characteristic index 0,416972 0,437861 0,441549 0,257665 1,830148

Label A++ A++ A++ A++ D

Total index 0,89955904 1,232561852 0,675519362 0,666091371 2,346966925

A B A+ A+ E

The energy labeling model is working, the item what still has to change are the constant values in the equation, these are based on extensive long term research with hundred or thousand Dutch buildings. To fine-tune the model for Honduran building this will be also necessary with Honduran buildings.

For myself I have some doubts about the feasibility of the introduction of an energy labeling system in Honduras. Because many people are poor here, this research is aimed at the minority of rich people with larger houses. Still it will be hard to introduce the system. The electricity is cheap, so the people are not motivated to change their way of living. Honduras has no government agency to supervise a project such as introducing a labeling system and the government has other priorities before thinking about saving energy. Nevertheless, in de coming years, energy saving will become more important than ever. So when the country is ready, the first steps to an energy efficient real estate market are done.

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8

References

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KNMI, WKI_PROF. World Climate Information, Long term averages, (1997).

UNL Astronomy, Class action, Coordinates and motions, Animations (2012) Websites Archiexpo, SMEG, the virtual architecture exhibition, achieexpo.com (2012) Degreedays, Custom degree day data, the site with all the degree day information for the whole world, degreedays.net (2012).

Energysavers, website with information about the energy consumption of appliances Energysavers.gov (2012) Google earth (2012) Google maps (2012) Hurricanecity, hurricanecity.com (2012) KWA bedrijfsadviseurs, kwa.nl (2012). michaelbluejay.com NASA, Earth observatory, EOS Project Science Office, NASA Goddard Space Flight Center. (2012) Nibud, Nationaal instituut voor budget voorlichting, gas elektriciteit en water. (2012) Servicio Metheorologico Nacional de Honduras, general classification of the Honduran climate, website of the Honduran national weather service, www.smn.gob.hn, (2001).

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Warnerstellian, Energy guide, based on standard U.S. government tests warnersstellian.com/files/CTB1821ARW-eg.pdf (2001) Weatheronline.co.uk, Climate of the world, Holland/The Netherlands Interviews Architect Angela Stassano, architect in San Pedro Sula Employees of the architectural bureau of Canales Architectos, situated in San Pedro Sula.

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Appendix A: Checklist for examining a building These are the tables filled in together with the residents. Table 1 goes about the architectural specifications, this part took measuring, asking and observing. Table 2 was simply asking for the energy bill. Table 3 mend looking at all the equipment in the buildings, and asking how many hours the residents used them daily or weekly.

Questions for the occupants: - What materials are used for the roof/walls/floor? What parts are insulated?

- How is the roof ventilated? (ventilation in eaves and/or top part of the roof?)

- Which windows collect sunlight and how long do they collect sunlight?

Table A.1

Residents: Part building Roof

of What to How to measure measure Total surface Sum of length x width Material

Eaves of the roof

Ventilation Height of the roof

Height level

Length overhang

Floor

Windows*

above

Bad/Acceptable/Good

ground m

of Length of overhang m perpendicular to the wall Asking owners

Ratio*

Surface

Length x width

m2

Material

Asking, observing

Position

Number of hours the walls are collecting sun

Sunhours x m2

Surface

Length x width

m2

Material

Asking, observing

Bad/Acceptable/Good

in

Height for a Height house on poles Surface Length x width Amount

Value

m2

Determine what type of insulation and other materials are used Asking owners Ratio*

Ventilation installed eaves Walls

Quantity

m m2

Number of windows

31

Position

Number of hours the Sunhours windows are collecting x m2 sun

Mosquito screens

-

Yes/No

Surroundings Open space Verdure

-

Can I see your energy bill? What amount of electricity do you use?

What do you use for cooking? Gas, electricity or something else?

Table A.2

Table 2 Amount per (-) Electricity use per month (kWh) Gas use per month (m3)* Other energy sources *The gas will probably be carried into the house in canisters so I can just ask how many of those the occupants use.

-

How many hours do you use your specific devices daily? (fill in table 1 column ‘Usage per day’)

Table A.3

Device

Number

Capacity (Watt)

Table 3 Usage Electrical Year per day consumption (hours) (kWh)

Model

Airconditioning Fans Lighting

Refrigerator

24

Freezer

24

Stove Oven

32

Microwave Water heating Washer Dryer

Electrical consumption (kWh) = Capacity x Usage / 1000

33

Appendix B: Detailed architectural specifications case buildings B.1 Las Casita 100 m2 Part building Roof

Specifications Las Casitas (100 m2 version) to How to measure Quantity

of What measure Total surface

Material

Sum of length x width

m2

Determine what type of insulation and other materials are used

Ventilation Asking owners Ratio Height of the Height above ground m roof level Eaves of the roof

Walls

Floor

Length overhang

of Length of overhang m perpendicular to the wall Ventilation Asking owners Ratio installed in eaves

Value

172 m2 = pyramid hip roof consisting f 4 x a triangle of 13 m wide and 6,6 m long. The top of the roof is raised, this is to create an outlet for hot air accumulating under the roof.

Multi layer metal roof:so called ‘cindu’ roof. There is an insulation layer underneath.

Under the roof is a lot of ventilation space for hot air to get out. In the highest part of the roof is a heat outlet.

Bad/Acceptable/Good Lowest point: 5,5 m Highest point: 7,2 m With heat outlet: 7,97 m 1,5 m on all the 4 sides

Not in the eaves but Above every window are big ventilation openings installed Bad/Acceptable/Good 2 Surface Length x width m Walls including windows and door: 4 walls x 10m x 2,4m = 96m2 Excluded windows and doors: 80,8 m2 Material Asking, observing The walls are all made of concrete blocks, the lower 40 cm is uncovered, the rest of the wall is covered with white plaster on the inside and outside.

Position Number of hours the Sunhours The walls catch a negligible walls are collecting sun x m2 amount of sunlight.

2 Surface Length x width m 100 m2 Material Asking, observing Metal sheets covered with concrete. The top layer consists of tiles Height for a Height m The columns are 2,4 m. The house on floor on ground level is 0,20 poles m.

34

Windows

Surface Amount

Position

Mosquito screens Surroundings Open space Verdure

Length x width

m2

Total surface of the windows is 15,2 m2 Number of windows There are 16 windows and two doors with light and air openings.

Number of hours the Sunhours Negligible because of the big windows are collecting x m2 eaves, some windows catch sun sun in the afternoon Yes/No Yes, every window and front door and in all the ventilation openings.

A lot of open space, the terrain is surrounded by a fence so the wind can go easily trough it.

Some trees and bushes around the house, none of them is really providing shade to the house.

B.2 Standard Honduran House Specifications Standard Honduran house Part building Roof

of What to How to measure Quantity measure Total surface Sum of length x width m2 Material Determine what type of insulation and other materials are used Ventilation Asking owners Ratio* Height of the Height above ground m roof level

Eaves of the roof

Walls

Length overhang

of Length of overhang m perpendicular to the wall Ventilation Asking owners Ratio installed in eaves Surface Length x width m2 Material

Position

Floor

Surface

Value 3,70m x 13m x 2 = 96,2m2 Steel Roof, no insulation.

Under the steel roof are panelit or sheetrock panels.

Bad/Acceptable/Good Roof type: Gable roof, with two slopes of 3,70m x 13m.

Angle of the roof: 14째 Lowest point: 3,2 m Highest point: 4,1m 0,4 m on 3 sides. South side of the building has a carport, there is never sun on this wall.

No ventilation under eaves Bad/Acceptable/Good

Front/back: 24,7 m2 Side: 41,6 m2 Asking, observing Concrete blocks, covered with plaster and painted green (inside white plaster) Number of hours the Sunhours long wall: half of the wall walls are collecting sun x m2 catches sun for 6 hours.

41,6 x 0,5 x 6 = 124,8 sunhours x meter. short wall: half of the wall catches sun for 8 hours.

24,7 x 0,5 x 6 = 74,1 sunhours x meter.

Length x width m2 93,6 m2 35

Material Asking, observing Height for a Height house on poles Surface Length x width

Windows

Amount Position

Mosquito screens Surroundings Open space Verdure

m

m2

Concrete, covered with tiles House on ground level

There are 9 windows faced to the sun; five are 1,4m x 1,4m, one is 1,4m x 1,8m and three are 0,50m x 0,50m. The windows under the carport never catch sunlight. The average time of incoming sun per window is estimated on 6.

Every window do has shadings on the inside.

Number of windows Number of hours the Sunhours The total windows collect 6 windows are collecting x m2 hours x 13,07m = 78 sunhours sun x m2 ~ 80 sunhours x m2 Yes/No Yes, every window and front door The house is at three sides surrounded by a wall; this obstructs the wind from reach the house.

Some trees and bushes around the house, one tree is providing shade to the

B.3 Office Techos Verdes Specifications Techos Verdes office Part building Roof

of What to How to measure Quantity measure Total surface Sum of length x width m2 Material Determine what type of insulation and other materials are used Ventilation Height of the roof

Eaves of the roof

Walls

Length overhang

Asking owners Ratio Height above ground m level

of Length of overhang m perpendicular to the wall Ventilation Asking owners Ratio installed in eaves Surface Length x width m2 Material Asking, observing

Value 7,1m x 10m = 71 m2 Roof is made of corrugated metal sheets, between the roof and the ceiling is a lot of fully ventilated free space. No insulation Bad/Acceptable/Good The lowest part of the roof is 4,3 m above ground level, the highest part is 5,7 m above ground level.

The roof is a shed roof type.

Bad/Acceptable/Good 1,2 meter Front and back ventilation Two walls completely closed: 8m x 3,5m = 28 m2. Two walls fully glazed.

The walls are made of 36

Position

Number of hours the Sunhours concrete blocks covered with walls are collecting sun x m2 plaster, outside no plaster The walls do not collect sun.

8m x 5m = 40m2 Concrete 2 Floor Surface Length x width m Material Asking, observing 2 walls fully covered with Height for a Height m windows: 2 x 5m x 3,5m = 35 house on m2 poles There are shades installed in Windows Surface Length x width m2 front of the windows, Amount Number of windows Position Number of hours the Sunhours nevertheless there gets some sun into the office. This is windows are collecting x m2 estimated on 20 sunhours x sun m2 per day Mosquito Yes/No screens Surroundings Open space Because the office is build between two other buildings and there is a lot of vegetation, there is almost no wind reaching the building.

Verdure Many bushes, trees and grass.

B.4 Office La Tara Specifications La Tara office Part building Roof

of What to How to measure Quantity Value measure Total surface Sum of length x width m2 2,75m x 6m x 2 = 32,9 m2 (with eaves = 45,5 m2 Material Determine what type The roof is a compound of a of insulation and other metal sheet, whit shingle materials are used underneath.

Bad/Acceptable/Good The Ventilation Asking owners Ratio roof has two ventilation holes Height of the Height above ground m in the front. roof level The ceiling is 2,40 m high. The (gable) roof is on average 3m high.

Eaves of the roof

Walls

Length overhang

of Length of overhang m perpendicular to the wall Ventilation Asking owners Ratio installed in eaves Surface Length x width m2 Material Asking, observing Position Number of hours the Sun walls are collecting sun hours x

0,50m

Bad/Acceptable/Good No ventilation installed in eaves front: 8,7 m2 (excluding windows) back: 14 m2 (no windows) Only the front and the back 37

m2

Floor

Windows*

Surroundings

Surface Length x width Material Asking, observing Height for a Height house on poles Surface Length x width Amount Number of windows Position Number of hours the windows are collecting sun Mosquito screens

Open space Verdure

m2 m

wall of the building are exposed to the elements, at both sides of the building are other buildings. So the sun on the walls will be really little.

The front of the building, with the door and the big windows, points east-south-east. This means is will catch sun for a long time (7 hours) = 61 sunhours/m2.

5m x 6m = 30m2 Concrete covered with tiles -

m2 13 Sun hours x m2 Yes/No

The outside door is always open, next to the door are 4 windows. Inside the building is another (closed) door what keeps the heat out. Behind the outside door is some sort of counter, with only small windows for more safety. This is more than a meter inside and there will never shine sun trough these windows. Total: 1,6 m x 1,75 m x 7 hours = 20 sun hours x m2 The big window cannot open; the small ones do have screens.

The office is situated on a complex with a number of other offices, there is some space between these buildings.

Between the offices are some little green beds, still most of the surroundings are paved.

Appendix C: energy consumption per building C.1 Las Casita 70 m2 Electricity use per month (kWh) Gas use per month (m3)* Other energy sources

Amount per (-) 441 kWh for 32 days/408 kWh for 29 days average for 30,4 days = 419/428 = 424,5 kWh -

Residents: two adults and tree little children Device Number Capacity Usage Electrical Model (Watt) per day consumption (hours) (kWh) Air0 38

conditioning Fans

Lighting

Refrigerator

Got 6 100Watt use only 4 2 20 Watt

4h

Monthly: 48,6 kWh

4h

Kitchen lights

8 1 Combi with freezer at top

2h 2h 24

Monthly: 4,8 kWh 19 kWh 1,8 kWh 600 kWh/year = 50 kWh per month 25,8 kWh / month

Whirlpool, super capacity 465 (archiexpo, 2012)

Freezer Stove

Oven Microwave

40 Watt 30 Watt

850W/h

Small one

800W

Water heating

4000W

Clothes washer

3x week

Clothes dryer

No info,

24 Half capacity 2 hours a day 0h 15 min

2 lights per fan bathroom Whirlpool Model: ET4WSKXKQ00 05-02

0 Below stove, never in use Monthly: 6 kWh 2 Adults 121,6 kWh Whirlpool, 220-230 V. 5500W, 2x, 3 per month 30A, 4 mm2 kids 1x, Total 1h 400W/h 7,8 kWh Whirlpool heavy duty, Twin Twin 1,5 h per turn

3x week, 2000W, 2,5 times/ 1995-2000 small less when 0,5h per week = 76 sunny turn kWh

Electrical consumption (kWh) = Capacity x Usage / 1000

39

C.2 Las Casita 100 m2 Electricity use per month (kWh) Gas use per month (m3)* Other energy sources

Amount per (-) 2000L per month average = 715 kWh (Enee,2009) -

Residents: 4 adults, 2 children (1baby who uses a lot) Device Number Capacity Usage Electrical Year (Watt) per day consumption (hours) (kWh) Airconditioning Fans 7 in the 4 fans 60 W / 56,6 kWh house, 2 used for 9 fan = 27 under hours a hours the day house Lighting 4 20W 8h 19,4 kWh Bedroo 22 W 3h 24 kWh m 12 24 lights 0h total Outside 0h 2 kWh light Refrigerator 24 50 kW/ May month 2002 Freezer In top of 24 fridge Stove 1 850 Watt 3 hours 77,6 kW a day Oven Only once a month used 4 kW Microwave 1 900W 1h a day 27,4 kW Water 1 5000W 1h a day 152 kW heating Washer 8 loads 8x week 400W/h 20,8 kWh a week 1,5 h per turn Dryer 8 loads 8x week, 2000W/ 34,7 kWh a week h, 0,5h per turn Toaster 5 kWh Coffee 5 kWh Television 2 100 W 6 h/ day 36,4 kWh ironing 1000 kWh 4h/ 17 kWh week

Model

Used occasionally Model ET4WSKXK000

Sunbeam, microwave

Whirlpool heavy Twin Twin

duty,

1995-2000 small

C.3 Standard Honduran House Amount per (-) 40

Electricity use per month (kWh) Gas use

Other energy sources

Residents: 5 adults Device Number

Airconditioning

Fans

Lighting

357 kWh for 30 days in May. Full month: 362 kWh 1 x 25 pound cylinder gas per month, the dryer, oven and the stove use gas. 602.500 BTU = 635.300 kJ -

Capacity (Watt)

Main AC indoor device: 36 W, outdoor max 3600, average 1240 W Window 1,18 kW AC Max = 3,55 kW 6 but 100W use only 4

Usage per day (hours) 1,5

Electrical consumption (kWh) 58 kWh

Model

1,5

54 kWh

Panasonic V 220, Hz 60

2h

4 x 2 x 100 = 1,2 kW per day.

Monthly 24,3 kWh 0,6 daily, Monthly 18 kWh 0,12 daily, monthly 3,65 kWh 480 kWh/year = 40 kWh/ month

10

20 W

3h

3

20 W

2h

Refrigerator

24 h

Freezer

24 h

Stove

Oven

Microwave

Water heating

2

Is included in the refrigerator 1h 7000 kJ or 6700 BTU per hour (uses gas) Monthly 212.800 kJ 0,5 h 13600 kJ or 13000 BTU per hour (uses gas) Monthly 206.720 kJ 0,25 h 1,5 kW, Monthly consumption: 11,4 kWh 5 persons 5 min/ 88 kWh x 2 shower showers a = 50

Lamps inside, mostly under fans Lamps outside, near the car

Model CTB1821AR Magic chef 115 v, 60hz (Warnerstellian, 2001)

41

Washer Dryer

Water cooler

2kWh per load 22.000 BTU/h = 23.196 kJ 1

day 2 loads a week 2 loads a week

min/day

550 W

2h

1h

17,4 kWh month 201.474 kJ (uses gas)

per Whirlpool LXR7244JT1 9,8 A; 120 V; 60 Hz Maytag, intellidry regular, permanent press Neptune, 22.000 BTU/h (6,4 kW).

Model MDG3000AWW

33 kWh

C.4 Office Techos Verdes

Electricity use per month (kWh) Gas use per month (m3)* Other energy sources

Amount per (-) 30 days, 240 kWh ďƒ 243 kWh per month -

Employees: 4 fulltime jobs Device Number Capacity (Watt)

Airconditioning Fans Lighting

Refrigerator

Usage Electrical Year per day consumption (hours) (kWh), 5,5 days of working

Model

3 70 Watt 1 T8 60 Watt light 4 20 Watt outside

Toilet Combi with freezer

Freezer Stove Oven Microwave

1

Water heating Washer Dryer

-

20 Watt Yearly energy use 310 kWh

10 h 10 hours a month At night 14 h + Sundays 10 h 1h 24 h

50,3 kWh 6 kWh per month 37,5 kWh

0,5 kWh Monthly 25,8 kWh

Model nr: RM4589SS-2 Avantiproducts.com

24

800 Watt

15 min a 4,8 kWh day

42

Computers

2

laptops Printer Coffee

2 1

200 Watt 9 h (PC + screen) 40 Watt 6h 100 Watt 15 min

85,6 kWh

11,5 kWh 0,6 kWh 5 kWh

C.5 Office La Tara

Electricity use per month (kWh) Gas use per month (m3)* Other energy sources

Amount per (-) Dec: 31 days, 890 kWh; April: 28 days, 618 kWh. Average per month: 671 and 873 = 772 kWh -

Employees: 4 fulltime jobs Device Number Capacity (Watt)

Airconditioning

1

Fans Lighting

0 5 x T8 60 Watt light kitchen 20 Watt light 1 83 Watt input 0 0 0 1 small 600W device 0

Refrigerator Freezer Stove Oven Microwave Water heating Washer Dryer Computer

Radio Printer

0 0 5

1 1

Rated cooling input 2,5 kW

Usage Electrical Year per day consumption (hours) (kWh) (5,5 days working) 9h 537 kWh per month

9h 2h 24

15 min

200 Watt 4/5 x 5 h (PC + screen) 10 W 9h 100 W 15 min

64 kWh per month 1 kWh per month 61 kWh per 02month 2012

Model

Max input power 3,8 kW

86 litre

3,6 kWh per month

96 kWh per month 2,1 kWh 0,6 kWh

43

Appendix D: Calculation Energy labels To calculate the final energy label Equation 2.1 is used. This equation 2.1 has four different parts: The characteristic energy use, total ground surface x a constant factor, the total thermal transmission surface x a constant and an other constant value.

=

(EQUATION 2.1)

,

,

Ă—

Ă—

: Energy index calculated to comply with the EPBD : Characteristic yearly energy use of a house based on NEN 7120(MJ) : Total ground surface (m2) : Total thermal transmission surface (m2) : Numerical correction factors 155 (MJ/m2), 106 (MJ/m2) and 9560 (MJ/m2)

First (step 1) I calculated the ground surface and the thermal transmission surface which is the sum of the ground surface, walls surface (including windows and doors) and the roof surface (without eaves). The monthly consumption of gas and electricity had to be converted to MJ per year.

The next step (step 2) was to fill in these values in Equation 1. I calculated each house twice, first with the building bound energy use as Qtotal, this gave the building bound energy index. The second calculation was with the total energy consumption, this gave the total energy index. See table D.1 for all the numbers of Las Casitas 70 m2. In Table D2 are all the numbers displayed of the calculations with the Thermal Transmission Surface (TTS) included. In Table D.3 you can find the final indexes whit their corresponding label. In Table D.4 are the same calculations done, without the TTS. In Table D.5 are the indexes and their corresponding energy labels of the calculation without the TTS shown.

Table D.1 Calculation Las Casitas 70 m2

Step 1 2

Ground surface (m ) Roof surface (m2) Length walls (m) Height walls (m) Walls surface, incl windows (m2) Thermal Transmission surface (m2) Monthly building bound energy use Monthly total energy use MJ per kWh Yearly building bound energy use(MJ) Yearly total energy use (MJ) Building bound energy index Total energy index

Step 2 70

With TTS

Without TTS

0,191232 0,412557

0,416972 0,899559

76,97272 8,3666 2,4 80,31936 227,2921 197 425 3,6 8510,4 18360

44

Table D.2 Energy index calculation with Thermal Transmission Surface

With TTS

Las Casitas 70 m 70

Las Casitas 100 m 100

Norman Honduran house

Thermal Transmission surface (m2) Monthly building bound energy use Monthly total energy use

227,292 1 197

Yearly building bound energy use(MJ) Yearly total energy use (MJ) Building bound energy index Total energy index

Ground surface (m2)

La Tara office

93,6

Techos Verdes office 40

306

322,4

150

89,24

254

246

94

602

425

715

243

772

8510,4

10972,8

362 kWh + 620 MJ gas 10627,2

4060,8

26006,4

18360 0,19 0,41

30888 0,19 0,54

16258,4 0,18 0,28

10497,6 0,13 0,33

33350,4 1,10 1,41

30

Table D.3 Energy indexes and their corresponding labels for the calculation with TTS

Las Casitas 70 m Las Casitas 100 m Norman Honduran house Techos Verdes office La Tara office

Characteristic index 0,19 0,19 0,18 0,13 1,10

Label A++ A++ A++ A++ B

Total index 0,41 0,54 0,28 0,33 1,41

A++ A+ A++ A++ C

Table D.4 Energy index calculation without Thermal Transmission Surface

Without TTS

Ground surface (m2) Thermal Transmission surface (m2) Monthly building bound energy use Monthly total energy use Yearly building bound energy use(MJ) Yearly total energy use (MJ) Building bound energy index Total energy index

Las Casitas 70 m 70 -

Las Casitas 100 m 100 -

Norman Honduran house

La Tara office

93,6 -

Techos Verdes office 40 -

197

254

246

94

602

425

715

243

772

8510,4

10972,8

362 kWh + 620 MJ gas 10627,2

4060,8

26006,4

18360 0,42 0,90

30888 0,44 1,23

16258,4 0,44 0,68

10497,6 0,26 0,67

33350,4 1,83 2,35

30 -

45

Table D.5 Energy indexes and their corresponding labels for the calculation without TTS

Las Casitas 70 m Las Casitas 100 m Norman Honduran house Techos Verdes office La Tara office

Characteristic index 0,42 0,44 0,44 0,26 1,83

Label A++ A++ A++ A++ D

Total index 0,90 1,23 0,68 0,67 2,35

A B A+ A+ E

46