06 energy and matter part 3 slides

CliC Climate Construction in Architecture Lecture 6.

Energy and Matter Sustainable Design Principles in Architecture Part 3.

Solar gain &Thermal mass

Time-leg effect

Thermal mass is crucial when it comes to temperature of the surrounding surfaces. In case temperature is hot outside, the heat starts to flow in the building (from hot to cold). This however takes time, especially when the surface has a large heat mass.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Time-leg effect

Thermal mass can protect the building from heating up if the Heat Storage Capacity is higher insolation of 1 day.

The question is how much do we need to cover the total solar energy gain of 1 day?

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Time-leg effect world_solar_radiation_large.gif 715Ă—395 pixels

7/19/11 6:30 AM

This map divides the world into five solar performance regions based on yearly averages of daily hours of sunlight and ambient temperature. Each specific site will, of course, be different Also, local weather conditions and seasonal changes can significantly affect the amount of sunlight available. Look on the map to find your location and select Zone 2 or Zone 4

Insolation depends on the day of the year and on the location of the building.
 Daily insolation in Taiwan is relatively high, between Z4 = 4.0-4.9, 5.0-5.9, Hours of Daily Solar Radiation.

2.55-6.66 kWh/m2/day for6.0-6.9 a horizontal surface.

Z2 = 1.0-1.9, 2.0-2.9, 3.0-3.9 Hours of Daily Solar Radiation.

OkSolar.com CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Time-leg effect

If the structure is not horizontal (like vertical walls), insolation is less, since the energy gain is highest when the solar rays are perpendicular to the surface. From June to August solar angle is between 82-90 degrees at noon.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Time-leg effect

In addition to the angle, the total energy gain also depends on the absorption of the surface and material. Dark surfaces have the highest absorption and white ones have the lowest.

Reflecting surfaces have almost no absorption at all.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Time-leg effect

In addition to the angle, the total energy gain also depends on the absorption of the surface and material. Dark surfaces have the highest absorption and white ones have the lowest.

Reflecting surfaces have almost no absorption at all.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Time-leg effect

In addition to the angle, the total energy gain also depends on the absorption of the surface and material. Dark surfaces have the highest absorption and white ones have the lowest.

Reflecting surfaces have almost no absorption at all.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Time-leg effect

In addition to the angle, the total energy gain also depends on the absorption of the surface and material. Dark surfaces have the highest absorption and white ones have the lowest.

Reflecting surfaces have almost no absorption at all.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Time-leg effect

Based on this, solar gain can be calculated as following: EnergySolar = sin(90-Angle) x Absorption x Insolation In case of a concrete vertical wall in Taichung in April:

EnergySolar= sin(90-74)x0.5x4.18kWh/m2/day = 0,57 kWh/m2/day CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Time-leg effect

Thermal mass of a structure depends on the utilized material and on it’s volume. Heavy building materials have high heat storage capacity: ThermalMass= VolumetricCapacity x MaterialVolume TM=Cv x Vm = Cv x (Area x Thickness)= Cv x (A x d) CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Time-leg effect

The solar load for the wall facing south in April is:

0,57 kWh/m2/day, which is 2052 KJ/day (1kWh/m2/day=3600 kJ/day)

The necessary heat mass equals the daily energy: TM= EnergySolar= 2052 kJ=Cv x (A x d) =2060 x (1m2 x d) Where thickness (d) is: 2052 kJ/2060=0,99 m CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Time-leg effect

Naturally, this is too thick, but if we change the absorption and add a shiny aluminum layer for example
 (which changes the absorption to 0.15): EnergySolar= sin(90-74) x 0.15 x 4.18 kWh/m2/day = 0.17 kWh/m2/day

Converted to KJ: EnergySolar=0.17x3600kJ/day=622.18 KJ/day CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Time-leg effect

EnergySolar=0.17x3600kJ/day=622.18 KJ/day The necessary heat mass equals the daily energy: TM= EnergySolar= 622.18 kJ=Cv x (A x d) =2060 x (1m2 x d) Where thickness (d) is: 622.18 kJ/2060=0,30 m Which is a more realistic thickness for the structure (30cm).

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Time-leg effect

If the aluminum layer is not used, the energy gain is much higher than thermal mass. If that is the case the wall only slows down the heating process (which is called time-leg effect), but temperature will increase.

Temperature Increase= Energy Gain/Thermal Mass ΔT=Egain / TM CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Time-leg effect

Temperature Increase= Energy Gain/Thermal Mass

In case of a concrete vertical wall in Taichung in April: EnergySolar= sin(90-74)x0.5x4.18kWh/m2/day = 0,57 kWh/m2/day Converted to KJ: EnergySolar= 0.57x3600 KJ/day= 2052 KJ/day

Our structure is 30 cm thick concrete, its thermal mass is:


TM=Cv x (A x d)= 2060 kJ/m3/K x (1 m2 x 0,3 m) = 618 KJ > 2052 KJ Thermal mass is not enough, temperature will increase.

Temperature increase is: ΔT=Egain / TM = 2050 / 618 = 3,32 K (Kelvin) CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Thermal conductivity Thermal mass is only one element that slows the heat flow between outside and inside. Thermal conductivity shows the amount of energy that can flow through a material in a given time. The higher the value, the more energy can pass through at the same time.

Thermal conductivity is different for each material (intensive property), some have higher resistance than others. Wood for example is very good insulator, while steel is a very good conductor.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Thermal conductivity Thermal mass is only one element that slows the heat flow between outside and inside. Thermal conductivity shows the amount of energy that can flow through a material in a given time. The higher the value, the more energy can pass through at the same time.

Thermal conductivity is different for each material (intensive property), some have higher resistance than others. Wood for example is very good insulator, while steel is a very good conductor.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Thermal conductivity, resistance

The actual heat flow of a structure depends not only on conductivity but also on the thickness of the material. For example, the heat flow in a 1” wood is the same as in a 12” block of concrete, although the conductivity of the second is much higher (worse).

The actual heat flow in any structure therefore is calculated with thermal resistance, that depends on thickness and conductivity of the material.

R=d/λ (lambda) Or Resistance=thickness/conductivity

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

Energy flow

Finally, the total energy loss depends not only on the thermal resistance, but also on the total surface and the temperature difference. The higher the building surface or temperature difference, the more energy moves between inside and outside every second.

E=R*A*ΔT=d/Ν*A*ΔT Or

Heat =Resistance*Surface*Temp diff.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

PTW Architects: Water Cube, Beijing, China

Water Cube is a good example of using a thin air layer for both insulation and ventilation. Since the building contains a large pool, humidity is relatively high indoors. The water volume however also provides a large thermal mass.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

PTW Architects: Water Cube, Beijing, China

Water Cube is a good example of using a thin air layer for both insulation and ventilation. Since the building contains a large pool, humidity is relatively high indoors. The water volume however also provides a large thermal mass.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

PTW Architects: Water Cube, Beijing, China

Water Cube is a good example of using a thin air layer for both insulation and ventilation. Since the building contains a large pool, humidity is relatively high indoors. The water volume however also provides a large thermal mass.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

PTW Architects: Water Cube, Beijing, China

Water Cube is a good example of using a thin air layer for both insulation and ventilation. Since the building contains a large pool, humidity is relatively high indoors. The water volume however also provides a large thermal mass.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

PTW Architects: Water Cube, Beijing, China

Water Cube is a good example of using a thin air layer for both insulation and ventilation. Since the building contains a large pool, humidity is relatively high indoors. The water volume however also provides a large thermal mass.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

PTW Architects: Water Cube, Beijing, China

Water Cube is a good example of using a thin air layer for both insulation and ventilation. Since the building contains a large pool, humidity is relatively high indoors. The water volume however also provides a large thermal mass.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

PTW Architects: Water Cube, Beijing, China

Water Cube is a good example of using a thin air layer for both insulation and ventilation. Since the building contains a large pool, humidity is relatively high indoors. The water volume however also provides a large thermal mass.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

DWL Architects: Burton Barr Library, Phoenix, Arizona

The building is a well scaled optimization of solar gain in a hot-dry (arid) climate. 4 sides of the building are designed in a completely different manner: east-west faรงade contain services (stairs, elevators) with minimal openings to absorb solar gain. North-south opens the space for illumination.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

DWL Architects: Burton Barr Library, Phoenix, Arizona

The building is a well scaled optimization of solar gain in a hot-dry (arid) climate. 4 sides of the building are designed in a completely different manner: east-west faรงade contain services (stairs, elevators) with minimal openings to absorb solar gain. North-south opens the space for illumination.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

DWL Architects: Burton Barr Library, Phoenix, Arizona

Sun is strongest at noon (south), but it’s angle is the highest therefore absorption is higher for east and west walls.

East-West side façade is therefore designed with aluminum louvers to minimize absorption, and south side has a cantilevered roof to protect indoors from solar gain.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

DWL Architects: Burton Barr Library, Phoenix, Arizona

Sun is strongest at noon (south), but it’s angle is the highest therefore absorption is higher for east and west walls.

East-West side façade is therefore designed with aluminum louvers to minimize absorption, and south side has a cantilevered roof to protect indoors from solar gain.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

DWL Architects: Burton Barr Library, Phoenix, Arizona

Sun is strongest at noon (south), but it’s angle is the highest therefore absorption is higher for east and west walls.

East-West side façade is therefore designed with aluminum louvers to minimize absorption, and south side has a cantilevered roof to protect indoors from solar gain.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

DWL Architects: Burton Barr Library, Phoenix, Arizona

Sun is strongest at noon (south), but it’s angle is the highest therefore absorption is higher for east and west walls.

East-West side façade is therefore designed with aluminum louvers to minimize absorption, and south side has a cantilevered roof to protect indoors from solar gain.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

SANAA: Zollverein School of Design and Management, Germany

This building was designed without any insulation layer which is quite an achievement considering that it was built in Germany with strict thermal regulations. The structure utilizes waste heat of a mine nearby and controls temperature of thermal mass as an active insulation.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

SANAA: Zollverein School of Design and Management, Germany

This building was designed without any insulation layer which is quite an achievement considering that it was built in Germany with strict thermal regulations. The structure utilizes waste heat of a mine nearby and controls temperature of thermal mass as an active insulation.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

SANAA: Zollverein School of Design and Management, Germany

This building was designed without any insulation layer which is quite an achievement considering that it was built in Germany with strict thermal regulations. The structure utilizes waste heat of a mine nearby and controls temperature of thermal mass as an active insulation.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

SANAA: Zollverein School of Design and Management, Germany

This building was designed without any insulation layer which is quite an achievement considering that it was built in Germany with strict thermal regulations. The structure utilizes waste heat of a mine nearby and controls temperature of thermal mass as an active insulation.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

SANAA: Zollverein School of Design and Management, Germany

This building was designed without any insulation layer which is quite an achievement considering that it was built in Germany with strict thermal regulations. The structure utilizes waste heat of a mine nearby and controls temperature of thermal mass as an active insulation.

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD

HOMEWORK 2.

Calculate the temperature for a south facing wall in Taichung city in March, if the structure is: A)  30 cm concrete, dark-grey surface B)  30 cm concrete, shiny aluminum surface

CliC: Climate Construction Lecture Series by Asst. Prof. Matyas Gutai PhD