Nature ventalation and double side ventilation for prototype office building by wchang72

Advanced ventilation studies

Chang Wen-Yi

Advance Ventilation - Prolog Building Condition:

P1: Hand Calculation Building Condition:

cm2/m length of edge(m)

south

north

ELA

west

east

south

north

east

west

1st floor

84.8

89.6

89.6 0.00848

0.0056

0.00896

2nd floor

84.8

89.6

89.6 0.00848

0.0056

0.00896

3rd floor

84.8

89.6

89.6 0.00848

0.0056

0.00896

4th floor

84.8

89.6

89.6 0.00848

0.0056

0.00896

5th floor

84.8

89.6

89.6 0.00848

0.0056

0.00896

6th floor

84.8

89.6

89.6 0.00848

0.0056

0.00896

7th floor

84.8

89.6

89.6 0.00848

0.0056

0.00896

8th floor

84.8

89.6

89.6 0.00848

0.0056

0.00896

9th floor

84.8

89.6

89.6 0.00848

0.0056

0.00896

10th floor

84.8

89.6

89.6 0.00848

0.0056

0.00896

Total

848

560

896

896 0.000848 0.00056

0.000896

1st floor ELA (m2)

2nd floor

south

0.00848

north

0.0056

east

0.00896

west

0.00896

3rd floor

4th floor 5th floor 0.00848 0.00848 0.00848

6th floor

7th floor

8th floor

9th floor

10th floor

Total

0.00848

0.0056

0.00896

0.00896 0.00896 0.00896

0.00896

0.00896 0.00896 0.000896

0.00896

0.00896 0.00896 0.00896

0.00896

0.00896 0.00896 0.000896

0.0056

0.00848 0.00848 0.000848 0.0056

0.0056 0.00056

Outline: For the first part about the ventilation or nature ventilation, we create a hand calculation model for the comparison with the later energy plus model or air flow net work model. To begin with that, I assume a simple model in Atlanta. The dimension of the model is 40m*160m*40m. The building type will be based on Ashare 90.1 2010 medium office. The Each faced has windows WWR_south= .7; WWR_north = .4m WWR_East = WWR_west = .5. To make the model less geometry problem in the model. I assumed the south face have bigger window but the east and west and north share the same window type. However, the north face window have less opening than east and west. The edge of each face is on the data above. The other number I assumed is the ELA x number which will be located between 0 to 1. In this case I assumed the x going to be the 1 just to make the calculation simple.

Site wind condition:

16 14 12 10 8

Environment:Site Wind Speed [m/s](Hourly)

8th Floor velocity [m/s]

4 2 1 93 185 277 369 461 553 645 737 829 921 1013 1105 1197 1289 1381 1473 1565 1657 1749 1841 1933 2025 2117

Wind Speed Grading : Based on the gravity and temperature vertical grading in the air, each height have different wind velocity. In this case if we would like to calculate the wind pressure in each face we have to make sure each floor wind velocity is correct on the floor outside face. In the energy plus document in the reference, the formula take the weather station condition and site terrain conditions. So in my site case I assumed the site condition is in the middle of the nowhere which donâ&#x20AC;&#x2122;t have any obstacle to block the wind. I use the energy plus site outdoor wind speed to convert my own site vertical wind speed grading. Energy plus use 10m as itsâ&#x20AC;&#x2122; reference height. In my case I have to set each floor a detect point to see each face wind speed which is 4 meter per floor. The result do show a clear different for different height and based on the terrain I assumed the result also have differences.

Surface Averaged Cp – SWAMI FORMULA

Facade Pressure Coefficient (General Assumption,30,60,90-360) 0.80 0.60 0.40 0.20 0.00

-0.20

120

150

180

210

240

270

300

330

360

-0.40 -0.60 -0.80 N

Facade Pressure Coefficient (Hourly data with local wind direction) 0.80 0.60 0.40 0.20 0.00 -0.20

000

-0.40 -0.60 -0.80 South Façade

North Façade

East Façade

West Façade

Wind coefficient and wind direction : Wind coefficient in for ventilation is one of the important factor that impacted the ventilation. To calculate the Cp, we have to used the SWAMI formula. The formula also used by energy plus. The formula include the wind angle and massing of the building. The G in the formula is to normalized the building massing to rectangular. In my case works fine. I create two different kind of the calculation. The first one is the general one which I assumed the wind will be coming from general direction 0 -30 – 60 - 90 ….etc. The result shows the Cp is complementary after 180 degree. This react from the A in the SWAMI formula, the A is incident angle of the wall. In this case A cannot be over 180 in order to make LN inside be positive. In that case the Cp is going to be a continuous number during whole 360 degree. However, hand calculation cannot act like energy plus to automatically count the domain of the wind directions. So based on that, I used the weather file’s wind direction to generate correct Cp for each floor.

Wind pressure and Mass flow

North PW 10.00

20.00

0.00

-10.00

-20.00

1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181

40.00

1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188

South PW

-20.00

1st Floor

2nd Floor

3rd Floor

1st Floor

2nd Floor

3rd Floor

4th Floor

5th Floor

6th Floor

4th Floor

5th Floor

6th Floor

7th Floor

8th Floor

9th Floor

7th Floor

8th Floor

9th Floor

10th Floor

West PW

East PW 20.00

0.00

10.00 0.00 -10.00

-40.00

1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188

-20.00

1 14 27 40 53 66 79 92 105 118 131 144 157 170 183

20.00

1st Floor

2nd Floor

3rd Floor

1st Floor

2nd Floor

3rd Floor

4th Floor

5th Floor

6th Floor

4th Floor

5th Floor

6th Floor

7th Floor

8th Floor

9th Floor

7th Floor

8th Floor

9th Floor

10th Floor

Quantity of wind (Without P0) 2 1

-1

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101 106 111 116 121 126 131 136 141 146 151 156 161 166 171 176 181 186 191

-2 STotal

NTotal

ETotal

WTotal

Total

After got the Cp in for each face and floor we can used the energy plus documentâ&#x20AC;&#x2122;s reference formula to calculate the wind pressure and the total wind flow that blow into the buildingâ&#x20AC;&#x2122;s infiltration.in this case the delta P in the formula I assumed is 0 which can not happened in the real case.. The result shows above which is not correct. The main reason is that the total mass flow is not zero. Based on mass conservation infiltration mass flow add exfiltration mass flow is going to be zero. However, the total result is not which means this is not correct. This also shows that there is going to be a P0 in the formula.

Calculate P0

P0 for each hour 4 2

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 181 187

0 -2 -4 -6 -8 1st Floor

2nd Floor

3rd Floor

4th Floor

5th Floor

6th Floor

7th Floor

8th Floor

9th Floor

10th Floor

Quanity of flow 2 1.5 1 0.5 0 -0.5 -1 -1.5 -2 Date/Time

07/01 24:00:00

07/02 24:00:00 South

07/03 24:00:00 North

07/04 24:00:00 East

07/05 24:00:00

07/06 24:00:00

West

07/07 24:00:00

07/08 24:00:00

Total

To calculate the actual P0 in the building, we have to use the mass conservation formula which to make each directionâ&#x20AC;&#x2122;s mass add up to be zero. Based on that the I count the P0 for each hour and each floor. The main goal is to make sure delta P in formula is going to be PW â&#x20AC;&#x201C; P0. After calculate the P0 in the formula, the mass flow through each hour is going to be very close to zero which make sense to the actual condition.

Calculate Stack Flow

Environment:Site Outdoor Air Density [kg/m3](Hourly)

Environment:Site Outdoor Air Drybulb Temperature [C](Hourly)

1.18 1.16

1.14

1.12

1.08

1.1 1.06

1.04 1.02 1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181

1 14 27 40 53 66 79 92 105 118 131 144 157 170 183

Pstack 2.5 2 1.5 1 0.5 -0.5

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 181 187

0 -1 -1.5

Since my building total height is 40m even though is consider as low rise building, It still have stack effect through the whole building. To calculate stack effect, I used the Sherman formula in LBNL paper. Energy plus also shared the same formula with that. Based on the formula, I generate the result of the P stack. P stack is mostly affected by the temperature difference. According to the outdoor dry bulb temperature from the weather file in July the end of the month have highly temperature grading at the end time period of the month which caused the P stack high at the same time.

Stack Flow V calculation: Stack Flow 0.009 0.008 0.007 0.006 0.005 0.004 0.003 0.002 0.001 1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 181 187

0 DVs

Dve

DVn

DVw

Neutral Plan

After calculating the Pstack I can generate the mass flow that caused by the stack effect in my simulation. The result shows above. The result shows that the flow is going to be positive through the whole time period. The main reason is that the simulation ELA is going to based on the neutral planâ&#x20AC;&#x2122;s height. So this make me divide two on my ELA. This make the stack effect mass flow always positive in my case. I also assuming my stack flow do not include any HVAC fan system to make sure the neutral plan stays in the middle of the structure.

Stack flow and wind flow comparison Stack Flow and Wind Flow Comparison 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 181 187

0 Stack V Total

Wind V Total

Total Air Flow and stack effect 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 181 187

0 Stack V Total

Total V

After got the mass flow from wind and mass flow from stack, we can continuing count the total infiltration load. Before I do that it would be good to do some compare between the mass flow from wind and mass flow from stack to see which one is going to be the main issue to caused the mass flow. The result above shows that it looks like stack effect might have been the main part of the total flow. The stack flow have 40% of the flow in the total flow. That is the reason that the stack effect in the rise building is so important. In this case I assumed the stack coming in is equal to the stack that coming out which might have caused the flow raised up. However, in real cased the indoor might have some fan air coming from the HVAC. The profile will be different based on anther wind pressure sourced from indoor.

Load by infiltration Qload Total(KWH) 5 4 3 2 1

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 181 187

0 -1 -2

Environment:Site Outdoor Air Drybulb Temperature [C](Hourly)

Load Percentage Comparison 4 40 3

35 30

25 1 20

1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181

15 10

-1

QstackLoad

QwindLoad

0 1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181

-2

Based on the result I did in former page; I start to calculate the infiltration load. The result shows that in normal temperature difference which means the delta T is small, the main load is coming from the wind pressure but when the delta T is big like the weather profile at the end of the July (or in winter) The stack flow might be dominated in these condition. For the other situation the wind pressure still dominated for the infiltration. The other thing to talk about is the HVAC system running inside might caused the stack effect be more effective than normal situation. The main reason for that is the temperature difference between outside and inside.

ďźşone Infiltration and Air Flow network- Prolog General (Simplify) Simulation:

Original Simulation:

Second part I further the simulation into energy plus to test the result I got from the hand calculation. The method I will be using can separate into two. First one is the zone infiltration another is the air flow network. These two are the main way that energy plus used for ventilation. Both of these also sharing the same formula (Swami and Sherman). To separate these two method, I generate two model for simulation. The general one and complicated one. The general one only have one zone to 40m height. The main reason I did that is that air flow net work have to let me assign each surface for node connection. I also need to assign each window as detail opening to make the simulation process faster. For the complicated method, I tried to mimic the hand calculation model I did. Each floor are one zone. However, the difference is that in this case since the model is more lite I will assigned each floor to zone infiltration.

P2: Energy plus airflow net work and infiltration Comparison one: Energy plus zone infiltration and Hand calculation

Total V (Hand calculation)

Zone Infiltration Mass Flow Rate(e+) 0.7

0.5 0.45

0.6

0.4 0.5

0.35 0.3

0.4

0.25 0.3

0.2 0.15

0.2

0.1 0.1

0.05

1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181

Comparison 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 181 187

First one to compare is the comparison between zone infiltration and hand calculation. The main thing I would like to test during the simulation is the stack effect and wind pressure flowâ&#x20AC;&#x2122;s difference. According to the energy plus input and output reference in the zone infiltration part the air leakage infiltration will only let user to input total ELA number and fix number for stack coefficient and wind coefficient. From previous result this two number will be different from hour to hours. However, the energy plus only allow user to input Ashare hand book 2005 reference number which is way more smaller than my average hand calculation. These impact clearly reflect on the result. According to the result basically most of the table is the same as the have calculation but the zone infiltration flow is also smaller than the hand calculation based on the constant Cp Ps number.

Comparison one: Energy plus air flow net work and Hand calculation

AirFlowNetwork

Total V (Hand calculation) 0.5

0.45

0.4 6

0.35

0.3

0.25 0.2

0.15

0.1

0.05

1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181

0 1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181

Comparison 8 7 6 5 4 3 2 1 1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 181 187

For the other section to test is the air flow network infiltration mass flow and the hand calculation. According to the result the outline of these two is pretty much the same. The main reason is that the air flow network strategy is considering the Cp per hour and Cs for hours. These reason that caused the similar number trend for the mass flow. The only thing to noticed is that comparing the difference between the hand calculation and air flow network is the higher number that air flow network revise. The main reason is that the air flow network for count each surface the hand calculation count the whole floor and each dimensionâ&#x20AC;&#x2122;s ELA. The air flow networkâ&#x20AC;&#x2122;s ELA is clearly having larger numbers than hand calculation.

Comparison one: Energy plus zone infiltration and Air Flow network

AirFlowNetwork

Zone Infiltration Mass Flow Rate(e+)

0.7

0.6

0.5

0.4

4 0.3 3

0.1

0 1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181

1 13 25 37 49 61 73 85 97 109 121 133 145 157 169 181

0.2

圖表標題 4 3.5 3 2.5 2 1.5 1 0.5 1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 181 187

The final comparison is the Air flow network result and the zone infiltration result. According to the previous content, the stack flow and wind pressure is the main reason that caused the outline difference. In here it is clearer to see. During the end time period in the previous simulation the temperature difference is going to be large than other time. The result shows the same situation here too. The end of the time period the mass flow in zone infiltration is lower than AFN, that is because the Zone infiltration method use the constant smaller number in that time. The other difference is the number. It is clear that the high number that AFN is caused by the multi ELA surfaces.

P2.1: Energy plus airflow net work and infiltration Comparison one: Energy plus zone infiltration and Hand calculation infiltration load compare

Qload Total(KWH) INFILTRATION

Hand Calculation

2 1

-2 -4

0 1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188

1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188

-1

-6

-2

-8

-3

Comparison 10 8 6 4 2

-2

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101 106 111 116 121 126 131 136 141 146 151 156 161 166 171 176 181 186 191

-4 -6 -8

After previous delta V is counted we can use simple calculation to count the total infiltration zone in hand calculation. The result will also including the stack flow and wind pressure. In the first part of the load comparison is going to be zone infiltration and hand calculation. For the zone infiltration air leakage level, The outcome shows that since the Cp wind is going to be constant the whole year so during the outdoor temperature have small difference between inside temperature the load will start to dominate. The comparison shows the same thing. During first part of the simulation, the load difference between hand e+ is difference. The temperature difference at that time is very small. After the second part of the simulation the stack flow is not going to be the same situation just like the first part.

Comparison two: Energy plus Air Flow network and Hand calculation infiltration load comparison

Air Flow Network

Hand Calculation

1 1 1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188

0 0 1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188

-1

-2 -3

-2

-4

-3

Comparison 5 4 3 2 1

-1

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 181 187

-2 -3 -4

For another comparison between energy plus AFN and hand calculations, I got use the simplify model strategy to solve the problem. The main issue for that is the stack flow is going to be neglected .The result shows that the total load without stack flow is going to be smaller than the normal one. The situation mostly happened in the time that temperature differences the most.

Comparison three: Energy plus zone infiltration and Air Flow network infiltration load comparison

Air Flow Network

Qload Total(KWH) INFILTRATION 10

0 1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188

1 12 23 34 45 56 67 78 89 100 111 122 133 144 155 166 177 188

-1

-2

-4

-3

-6

-4

-8

Comparison 10 8 6 4 2

-2

1 6 11 16 21 26 31 36 41 46 51 56 61 66 71 76 81 86 91 96 101 106 111 116 121 126 131 136 141 146 151 156 161 166 171 176 181 186 191

-4 -6 -8

The total comparing shows that each simulation method have some pros and cons for that. The most convenient way to do that I would say the hand calculation is handier and convincible. The zone infiltration do not have changeable Cp and stack efficient value the AFN have to assign each surface which is not very good to assign the whole building per floor. Eventually, the whole building infiltration load the form is still stay the same. This also mean the stack flow coefficient and wind coefficients is the main two reason to impact the ventilation model.

Simulation: Stack in Airflow network ? Temperature Difference 40 35 30 25 20 15 10 5

07/01 07/01 07/01 07/01 07/02 07/02 07/02 07/02 07/03 07/03 07/03 07/03 07/04 07/04 07/04 07/04 07/05 07/05 07/05 07/05 07/06 07/06 07/06 07/06 07/07 07/07 07/07 07/07 07/08 07/08 07/08 07/08

01:00:00 07:00:00 13:00:00 19:00:00 01:00:00 07:00:00 13:00:00 19:00:00 01:00:00 07:00:00 13:00:00 19:00:00 01:00:00 07:00:00 13:00:00 19:00:00 01:00:00 07:00:00 13:00:00 19:00:00 01:00:00 07:00:00 13:00:00 19:00:00 01:00:00 07:00:00 13:00:00 19:00:00 01:00:00 07:00:00 13:00:00 19:00:00

Environment:Site Outdoor Air Drybulb Temperature [C](Hourly) THERMAL ZONE 1:Zone Air Temperature [C](Hourly)

Air Flow Network (simplify zone and adding detail opening) 40 35 30 25 20 15 10 5

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 181 187

Since AFN in energy plus did not clearly say if there is an stack effect include in opening detail, I would like to test the result if it include in the final result. The way I did was taking the simplify model and assumed its detail opening in the model. The output of the simulation is going to be the out door temperature and indoor temperature after ventilation. The result shows that even though the outdoor temperature has difference the indoor temperature with ventilation help still stay very constant. The total compare can also shows that the big difference the AFN mass do have peak form.

Air Flow Network (simplify zone and adding detail opening) 40 35 30 25 20 15 10 5

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 181 187

Air Flow Network (Without detail opening) 5 4 3 2 1

-1

1 7 13 19 25 31 37 43 49 55 61 67 73 79 85 91 97 103 109 115 121 127 133 139 145 151 157 163 169 175 181 187

-2 -3 -4

Then continuing the load. The load compare shows the main reason that caused the load raised up is also stack effect. When the mass flow rate had clear peak form usually the temperature difference also raise up. In this condition I used the simplify method to simulate the model. The main reason also making the process easier. Since I simulate the simplify model the peak and bottom is going to be less dramatic than a fully built up model. Based on the previous temperature result it is clear that the stack effect do affect the model in the same time period this make the simulation outcome reasonable.

Advance window opening- Prolog General window open strategy in last semester

WINDOWVENTILATIONSCH:Sc hedule Value [](Hourly) 1.2 1 0.8 0.6 0.4 0.2

07/21 01/15 02/06 02/28 03/22 04/13 05/05 05/27 06/18 07/10 08/01 08/23 09/14 10/05 10/27 11/18 12/10

01:00:00 23:00:00 21:00:00 19:00:00 17:00:00 15:00:00 13:00:00 11:00:00 09:00:00 07:00:00 05:00:00 03:00:00 01:00:00 23:00:00 21:00:00 19:00:00 17:00:00

Original Simulation:

In the last semester we tried to discover the open ratio and its formula in the EMS. This semester with air flow networkâ&#x20AC;&#x2122;s help we can further the simulation to cross ventilation in the building. The previous assignment for open ratio we used one zone and one operable window to test the result. In this part of the project we start to use 3 zone model and each zone have one open window in the zone. This condition is closer than the one is only have one single opening and operable window. The cross ventilation might also include the crack of the wall opening of the window and last but not least the door gap between the wall. These elements have big impact in the building ventilation and have to take into consideration. The model I build up for the simulation each floor include 3 zone. West side and East side are considered two zone and have one opening in the zone. The last one zone is the corridor between two zone which allow air to go through the crack to another zone.

P3: Energy plus different side window opening Comparison one: Same floor different side ventilation and its open ratio

WINDOWVENTILATIONSCH_3F _E:Schedule Value [](Hourly)

WINDOWVENTILATIONSCH_3F_W: Schedule Value [](Hourly) 1.2

1.2

0.6

0.4

0.2

0 01:00:00 19:00:00 13:00:00 07:00:00 01:00:00 19:00:00 13:00:00 07:00:00 01:00:00 19:00:00 13:00:00 07:00:00 01:00:00 19:00:00 13:00:00 07:00:00

0.8

05/01 05/06 05/12 05/18 05/24 05/29 06/04 06/10 06/16 06/21 06/27 07/03 07/09 07/14 07/20 07/26

0.8

01:00:00 11:00:00 21:00:00 07:00:00 17:00:00 03:00:00 13:00:00 23:00:00 09:00:00 19:00:00 05:00:00 15:00:00 01:00:00 11:00:00 21:00:00 07:00:00 17:00:00

05/01 05/06 05/11 05/17 05/22 05/28 06/02 06/07 06/13 06/18 06/24 06/29 07/05 07/10 07/15 07/21 07/26

100% 90% 80% 70% 60% 50% 40% 30% 20% 10%

1 63 125 187 249 311 373 435 497 559 621 683 745 807 869 931 993 1055 1117 1179 1241 1303 1365 1427 1489 1551 1613 1675 1737 1799 1861 1923 1985 2047 2109 2171

The first to simulate is each side’s open ratio. The simulation in this section is the 3 floor open ratio. The result will also separate into two. One is the east’s thermal zone. The other is the west’s thermal zone. According to the result, the outcome shows that the each side’s open ratio is pretty much the same. To clarify these I will talk about these later. The main reason to open the window is to lower the cooling load in particular time period. In this stage I simulate from May 1st to July 31 these time period include hot month and cool month. The main reason to caused the east side and west side open ratio stay pretty much the same is the cooling load similar. Even though the temperature is the main impact in the open ratio formula, we still set a set point schedule in the zone which is going to be the main control of the building. I will talk more about these in later chapter.

Comparison one: Same floor different side ventilation and its open ratio

WINDOWVENTILATIONSCH_8 F_E:Schedule Value [](Hourly)

WINDOWVENTILATIONSCH_ 8F_W:Schedule Value [](Hourly)

1.2 1.2

0.8

0.6

0.4

0.2

0 1 131 261 391 521 651 781 911 1041 1171 1301 1431 1561 1691 1821 1951 2081

0.2

1 139 277 415 553 691 829 967 1105 1243 1381 1519 1657 1795 1933 2071

0.4

100% 90% 80% 70% 60% 50% 40% 30% 20% 10%

1 65 129 193 257 321 385 449 513 577 641 705 769 833 897 961 1025 1089 1153 1217 1281 1345 1409 1473 1537 1601 1665 1729 1793 1857 1921 1985 2049 2113 2177

Comparison one: Same floor different side ventilation and its open ratio

3F West and 8F West comparison

3F East and 8F East comparison 1.2

1.2

0.8

0.6

0.4

0.2

1.2 1 0.8 0.6 0.4 0.2

05/01 05/03 05/05 05/07 05/10 05/12 05/14 05/16 05/19 05/21 05/23 05/25 05/28 05/30 06/01 06/03 06/06 06/08 06/10 06/12 06/15 06/17 06/19 06/21 06/24 06/26 06/28 06/30 07/03 07/05 07/07 07/09 07/12 07/14 07/16 07/18 07/21 07/23 07/25 07/27 07/30

To test the actual difference I tried to bird view to difference level. The comparison is going to be focus on same different floor but different side. The outcome shows that even the same floor only have small difference but the different floor still have some clear difference. The main reason is the one I assumed - the load difference caused the problems. The higher floor usually gets more solar gain. In this case the 8 floor usually gets more cooling need than other floor. So these reveal on the result in open ratio. During morning time the ambient temperature in the higher floor gets more solar than others. During that time the open ratio of the 8th floor is way higher than 3th floor. However, when the lower floor have in the night time the ambient temperature in lower floor is higher than upper floor. The ratio in that time will be higher than 8th floor.

Comparison one: Same floor different side ventilation and its open ratio

3F Cooling Load Comparison(without open ratio) 100% 90% 80% 70% 60% 50% 40% 30% 20% 10%

05/01 05/03 05/06 05/08 05/11 05/13 05/16 05/18 05/21 05/23 05/26 05/28 05/31 06/02 06/05 06/07 06/10 06/12 06/15 06/17 06/20 06/22 06/25 06/27 06/30 07/02 07/05 07/07 07/10 07/12 07/15 07/17 07/20 07/22 07/25 07/27 07/30

01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00 13:00:00 01:00:00

THERMAL ZONE 5 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly) THERMAL ZONE 14 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)

8F Cooling Load Comparison (without open ratio)

100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0%

THERMAL ZONE 19 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly) THERMAL ZONE 10 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)

After the former assumed , I output the thermal load for cooling from May to July to do a fully comparison . I simulate the same model but without any infiltration and window opening. I only would like to see how the load difference in different floor. Based on the result, the load calculation is more oblivious to see the difference between east side and west side. The final line between these two is going to be zagging line which means the load is difference during the sun goes up to sun goes down. In the morning the sun rise up the and make the east side load rise up and in the evening the sun goes down then make east side load goes down and at the time make west side load goes up.

Comparison one: Same floor different side ventilation and its open ratio

3F Cooling Load Comparison(with open ratio) 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 1 63 125 187 249 311 373 435 497 559 621 683 745 807 869 931 993 1055 1117 1179 1241 1303 1365 1427 1489 1551 1613 1675 1737 1799 1861 1923 1985 2047 2109 2171

THERMAL ZONE 14 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)O THERMAL ZONE 5 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)O

8F Cooling Load Comparison(with open ratio) 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 1 61 121 181 241 301 361 421 481 541 601 661 721 781 841 901 961 1021 1081 1141 1201 1261 1321 1381 1441 1501 1561 1621 1681 1741 1801 1861 1921 1981 2041 2101 2161

THERMAL ZONE 10 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)O THERMAL ZONE 19 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)O

Then the other simulation to add in is the after window openings its cooling load comparison. It is also clear that after window opening the indoor temperature stay less dramatic. The zagging line still exist but less dramatic. The main issue is that the simulating time step is too short. The simulation cannot show the actual difference during the whole 3 month. First, the time period for the May to July the temperature difference is too small to observe the difference from outdoor temperature to indoor. Second, since we have office-like schedule for cooling set point which is going to start 9:00 morning for 24c. The timestep is too small for the window to actual react from the opening window in the morning period to afternoon period .

Comparison one: Same floor different side ventilation and its open ratio 900000000 800000000 700000000 600000000 500000000 400000000 300000000 200000000 100000000

05/01 05/03 05/06 05/09 05/11 05/14 05/17 05/19 05/22 05/25 05/27 05/30 06/02 06/04 06/07 06/10 06/12 06/15 06/18 06/20 06/23 06/26 06/28 07/01 07/04 07/06 07/09 07/12 07/14 07/17 07/20 07/22 07/25 07/28 07/30

01:00:00 17:00:00 09:00:00 01:00:00 17:00:00 09:00:00 01:00:00 17:00:00 09:00:00 01:00:00 17:00:00 09:00:00 01:00:00 17:00:00 09:00:00 01:00:00 17:00:00 09:00:00 01:00:00 17:00:00 09:00:00 01:00:00 17:00:00 09:00:00 01:00:00 17:00:00 09:00:00 01:00:00 17:00:00 09:00:00 01:00:00 17:00:00 09:00:00 01:00:00 17:00:00

THERMAL ZONE 5 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly) THERMAL ZONE 5 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)O

After output the comparison between the cooling before window open and after window open, I discovered that not most of the time stack open will help to lower down the cooling load in the building. According to the result, the stack open only works for May to June. After that the load start to get larger than the one which did not get any window open. The main reason can be traced to the engineering document in Energy Plus. According to the documentation, the stack open load calculation is above. In this condition I would only like to talk about the infiltration load since the internal gain is the same. The previous result about the site wind speed is continuing to rise up during June to July. This make the Qs rise up during that time. I ignore the Qw since the wind pressure difference from May to June and from June to July is pretty much the same. This make me assumed another infiltration gain that caused the load rise than normal during June to July.

Simulation: Stack in Airflow network ? May 1st Cooling Load (Without Window open) 500000000

450000000 400000000

350000000 300000000 15 250000000 200000000 10 150000000 100000000

05/01 24:00:00

05/02 01:00:00

05/02 02:00:00

07/01 23:00:00

07/01 24:00:00

05/01 23:00:00

07/01 22:00:00

05/01 22:00:00

05/01 21:00:00

05/01 20:00:00

05/01 19:00:00

05/01 18:00:00

05/01 17:00:00

05/01 16:00:00

05/01 15:00:00

05/01 14:00:00

05/01 13:00:00

05/01 12:00:00

05/01 11:00:00

05/01 10:00:00

05/01 09:00:00

05/01 08:00:00

05/01 07:00:00

05/01 06:00:00

05/01 05:00:00

05/01 04:00:00

05/01 01:00:00

05/01 03:00:00

05/01 02:00:00

50000000

July 1st Cooling Load (Without Window open)

10 5

50000000

07/01 21:00:00

07/01 20:00:00

07/01 19:00:00

07/01 18:00:00

07/01 17:00:00

07/01 16:00:00

07/01 15:00:00

07/01 14:00:00

07/01 13:00:00

07/01 12:00:00

07/01 11:00:00

07/01 10:00:00

07/01 01:00:00

07/01 09:00:00

07/01 08:00:00

100000000

07/01 07:00:00

150000000

07/01 06:00:00

200000000

07/01 05:00:00

250000000

07/01 04:00:00

300000000

07/01 03:00:00

350000000

07/01 02:00:00

400000000

To look deeply about the result, I out the one-day timestep simulation. The first one is the May 1st 24 hour simulation and another one is July 1st . The difference between these two is the cooling load at 15:00 to 21:00. According to the result the July cooling load is way lower than the May. Since in this simulation we only consider about the cooling load during the simulation. I did not apply any heating schedule in the simulation .I would only be looking at the temperature difference during the simulation period. According to the site outdoor dry bulb temperature, May 1st have larger temperature difference than July 1st. The temperature difference I would is the difference between the set point temperature and the reality temperature difference. That is also the reason that caused the cooling load difference in 15:00 to 21:00. July one temperature difference maximum is 5 degree C but the May one maximum will up to 9 degree C.

500000000 450000000 400000000 350000000 300000000 250000000 200000000 150000000 100000000 50000000 0

THERMAL ZONE 10 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly) THERMAL ZONE 14 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly) THERMAL ZONE 19 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly) THERMAL ZONE 5 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly) THERMAL ZONE 10 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)O THERMAL ZONE 14 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)O THERMAL ZONE 19 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)O THERMAL ZONE 5 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)O THERMAL ZONE 10 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly) THERMAL ZONE 14 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly) THERMAL ZONE 19 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly) THERMAL ZONE 5 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly) THERMAL ZONE 10 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)O THERMAL ZONE 14 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)O THERMAL ZONE 19 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)O THERMAL ZONE 5 IDEAL LOADS AIR SYSTEM:Zone Ideal Loads Zone Total Cooling Energy [J](Hourly)O

The other one to test is the cooling load after windows opened. According to the result, after window opened, Julyâ&#x20AC;&#x2122;s cooling raise up obviously since the it allow hot temperature air in the outside to come to inside zone. Even though in the previous result, the temperature difference is the main result to caused the cooling in stack open, it still anther reason that can also effect the interior cooling load. It said that I did not assign any humidity to the formula of window opening. These can usually cause the cooling load to raise up especially in summertime.

Comparison one: Same floor different side ventilation and its open ratio

Open ratio from May 1st 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0

WINDOWVENTILATIONSCH_3F_E:Schedule Value [](Hourly) WINDOWVENTILATIONSCH_3F_W:Schedule Value [](Hourly) WINDOWVENTILATIONSCH_8F_E:Schedule Value [](Hourly) WINDOWVENTILATIONSCH_8F_W:Schedule Value [](Hourly)

Open ratio from July 1st 1.2 1 0.8 0.6 0.4 0.2 0

Then I investigate the open profile in the whole day both in May and July. It is clear to said that both the 3f got highest open ration through the whole simulation. The main reason is that during the simulation timestep the lower floor usually got higher temperature than higher floor during night time. These make the profile going to be larger than normal open profile. The only difference is that the same lower floor but not in the same side (east and west) The main reason for that is the solar gain. West side got bigger solar gain during the afternoon to evening time. These caused the profile between east and westâ&#x20AC;&#x2122; difference.

Decision making PV or Retrofit Window Open Ratio (C=5) 1.2 1 0.8 0.6 0.4 0.2

Date/Time 05/03 12:00:00 05/05 24:00:00 05/08 12:00:00 05/10 24:00:00 05/13 12:00:00 05/15 24:00:00 05/18 12:00:00 05/20 24:00:00 05/23 12:00:00 05/25 24:00:00 05/28 12:00:00 05/30 24:00:00 06/02 12:00:00 06/04 24:00:00 06/07 12:00:00 06/09 24:00:00 06/12 12:00:00 06/14 24:00:00 06/17 12:00:00 06/19 24:00:00 06/22 12:00:00 06/24 24:00:00 06/27 12:00:00 06/29 24:00:00 07/02 12:00:00 07/04 24:00:00 07/07 12:00:00 07/09 24:00:00 07/12 12:00:00 07/14 24:00:00 07/17 12:00:00 07/19 24:00:00 07/22 12:00:00 07/24 24:00:00 07/27 12:00:00 07/29 24:00:00

圖表標題 3.5E+09 3E+09 2.5E+09 2E+09 1.5E+09 1E+09 500000000 1 66 131 196 261 326 391 456 521 586 651 716 781 846 911 976 1041 1106 1171 1236 1301 1366 1431 1496 1561 1626 1691 1756 1821 1886 1951 2016 2081 2146

TotalLoadC2

TotalLoadC5

Changing C means changing the opening effective area. These usually make the whole cooling load bigger since the C in the formula is bigger. However, in this case the cooling load become smaller in July. The main reason for that is the formula of open ratio gets to 1 through the formula which mean the with larger C5 it will be easier to be more than 1 and it will stays to the 1 fully open. The SQRT in the Q load formula out can be 0.xxxx. The parameter multiply is going to be lesser than the previous calculation.

Decision making PV or Retrofit PV’s NPV – Retrofit’s NPV

圖表標題

0.02 0.018 0.016 0.014 0.012 0.01 0.008 0.006 0.004 0.002 0

THERMAL ZONE 10:Zone Mean Air Humidity Ratio [kgWater/kgDryAir](Hourly) THERMAL ZONE 14:Zone Mean Air Humidity Ratio [kgWater/kgDryAir](Hourly) THERMAL ZONE 19:Zone Mean Air Humidity Ratio [kgWater/kgDryAir](Hourly) THERMAL ZONE 5:Zone Mean Air Humidity Ratio [kgWater/kgDryAir](Hourly) 3.5E+09 3E+09 2.5E+09 2E+09 1.5E+09 1E+09 500000000

Total Load Original

Total Load With Humidity Logic

Final for the humidity add-in. In the window opening original formula it has humidity consideration to give EMS a logic to open the window. However, the humidity add-in does not have any difference than the previous open profile. The main reason is that the humidity constrain is larger than 60% which in this simulation time period do not have any timestep reach the condition. If we zoom out the time period it will apply to the logic of the open profile

01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00 01:00:00

-0.2

05/01 05/05 05/09 05/13 05/17 05/21 05/25 05/29 06/02 06/06 06/10 06/14 06/18 06/22 06/26 06/30 07/04 07/08 07/12 07/16 07/20 07/24 07/28

Air Flow Network with window opening 3f Window open Ratio Comparison in 3F east and 3F west

1.2

0.8

0.6 SUB SURFACE 89:AFN Surface Venting Window or Door Opening Factor [](Hourly)

0.4 SUB SURFACE 85:AFN Surface Venting Window or Door Opening Factor [](Hourly)

0.2

Window open Ratio Comparison in 3F east and 3F east (Zone Ventilation strategy)

1.2

0.8

0.6

0.4

SUB SURFACE 89:AFN Surface Venting Window or Door Opening Factor [](Hourly)

0.2

WINDOWVENTILATIONSCH_3F_E: Schedule Value [](Hourly)(zone ventilaiton strategy)

Window open Ratio Comparison in 3F east and 3F east (Zone Ventilation strategy) 1.2

0.8

0.6

SUB SURFACE 85:AFN Surface Venting Window or Door Opening Factor [](Hourly)

0.4

WINDOWVENTILATIONSCH_3F_W :Schedule Value [](Hourly)(zone ventilaiton strategy)

0.2

05/01 05/05 05/09 05/13 05/17 05/21 05/25 05/29 06/02 06/06 06/10 06/14 06/18 06/22 06/26 06/30 07/04 07/08 07/12 07/16 07/20 07/24 07/28

-0.2

Window open Ratio Comparison in 3F east and 3F east (Zone Ventilation strategy) 1E+09 900000000 800000000 700000000 600000000 500000000

Original Total

400000000

Open Total

300000000 200000000 100000000 1 86 171 256 341 426 511 596 681 766 851 936 1021 1106 1191 1276 1361 1446 1531 1616 1701 1786 1871 1956 2041 2126 2211 2296

After using basic airflow network to create the infiltration model, here is the creation of the window open model with open ratio. The difference between the open ratio with AFN and normal stack open is the cross ventilation. The stack open only consider one surfaceâ&#x20AC;&#x2122;s flow and stack flow but the AFN model set up and cross ventilation through the crack of the wall to another window. Based on the result I got from the simulation, the open factor in the AFN is smaller than the one I did in stack open control. The main reason is that the AFN include more flow than the stack open. This make the control less triggered than the stack one. The cooling load also reveal the open window in AFN simulation is good for lowering the cooling need .

01:00:00 15:00:00 05:00:00 19:00:00 09:00:00 23:00:00 13:00:00 03:00:00 17:00:00 07:00:00 21:00:00 11:00:00 01:00:00 15:00:00 05:00:00 19:00:00 09:00:00 23:00:00 13:00:00 03:00:00 17:00:00 07:00:00 21:00:00 11:00:00 01:00:00 15:00:00 05:00:00 19:00:00 09:00:00 23:00:00 13:00:00 03:00:00 17:00:00 07:00:00 21:00:00 11:00:00

-0.2

05/01 05/03 05/06 05/08 05/11 05/13 05/16 05/19 05/21 05/24 05/26 05/29 06/01 06/03 06/06 06/08 06/11 06/13 06/16 06/19 06/21 06/24 06/26 06/29 07/02 07/04 07/07 07/09 07/12 07/14 07/17 07/20 07/22 07/25 07/27 07/30

Air Flow Network with window opening 8f Window open Ratio Comparison in 3F east and 3F west 1.2

0.8

0.6

0.4

0.2

SUB SURFACE 152:AFN Surface Venting Window or Door Opening Factor [](Hourly)

SUB SURFACE 173:AFN Surface Venting Window or Door Opening Factor [](Hourly)

Window open Ratio Comparison in 3F east and 3F east (Zone Ventilation strategy)

1.2

0.8

0.6

0.4

0.2

SUB SURFACE 152:AFN Surface Venting Window or Door Opening Factor [](Hourly)

WINDOWVENTILATIONSCH_8F_E:Schedule Value [](Hourly)

Window open Ratio Comparison in 3F east and 3F east (Zone Ventilation strategy) 1.2 1 0.8 0.6 0.4 0.2

-0.2

SUB SURFACE 173:AFN Surface Venting Window or Door Opening Factor [](Hourly) WINDOWVENTILATIONSCH_8F_W:Schedule Value [](Hourly)

Window open Ratio Comparison in 3F east and 8F east (Load Optimize Comparison) 160000000 140000000 120000000 100000000 80000000 60000000 40000000 20000000 -20000000

1 73 145 217 289 361 433 505 577 649 721 793 865 937 1009 1081 1153 1225 1297 1369 1441 1513 1585 1657 1729 1801 1873 1945 2017 2089 2161 2233 2305

0 -40000000 8f

8th

I also test the floor open ratio and its cooling load AFN. The result shows that the 8th floor open ratio si bigger than 3th floor the main reason is that the ratio factor in the 8th affected by the indoor temperature and outdoor temperature difference. The indoor temperature in 8th floor which infiltration load is bigger than 3th floor. The caused the less temperature difference make the open ratio become bigger than 3th floor. For load comparison the 3th floor load cost down is also lower than the 8th floor. The main reason is the cross flow through window. Even in the same building the cross flow wind speed on 8th flor is higher than the 3th floor. These might have come out another issue for the flow control and the open ratio which I will talk about it in the next chapter.

Advance window opening- Flow Control Logic Method 1 â&#x20AC;&#x201C; Setting Flow by Ashare outdoor ventilation standard(Reference in Ashrae Standard 62-2001) https://www.ashrae.org/File%20Library/Technical%20Resources/Standards%20and%20Guidelines/Standard s%20Addenda/62-2001/62-2001_Addendum-n.pdf

Method 2 â&#x20AC;&#x201C; Combine Floor Windows Ventilation Flow (Reference in Wikipedia) https://en.wikipedia.org/wiki/Air_changes_per_hour#cite_note-ASHRAE_170-5

Last part, I going to add a new logic into the window open ratio logic. The main things is to control the flow and make the cooling load lower at the same time. The previous simulation shows that the ratio will be adjusted by the temperature and the humidity. However, there may be some situation the outside flow is so big that system only have to give window a small opening that the cooling load can cost down to particular goal. To do this, I reference two ways to control indoor flow and outdoor flow. The references are come from Ashare and other ACH references. The other thing to talk about is the different open area condition. In this stage, I chose different open area for different cases. There are two main reason. First, I assumed small area will not have a big impact in the final result this would be good to test. Second, different operable window area can be a good thing to test each method correct or not.

M1: Flow control and cooling optimization logic for AFN (8f)

ACH Formula:

IF fresh air (make up air) flow through the room (m3/s) >0.003 Set OpenRatio to 1 ,Else Stay with Formula Before 1.2

0.8

0.6

0.4

0.2

0 1 139 277 415 553 691 829 967 1105 1243 1381 1519 1657 1795 1933 2071

1.2

1 150 299 448 597 746 895 1044 1193 1342 1491 1640 1789 1938 2087 2236

After

The first method is setting the lower limit. The limit is based on ASHRAE62-2001. The table option the minimum ventilation rate in typical office building. The flow limit is 0.3 L/S*M2 which is going to be 0.0003 m3/s. Here is the logic I set, if the open ratio which did in first place flow rate lower than 0.0003m3/s the EMS have reset all ratio and turn it to fully open. If not, just stay the same ratio. The logic is to make sure all window flow rate has to reach minimum air change rate. The result shows that most of the ratio stay the same but it is also clear that some days the open ratio is going to reach to 1 which is fully opened. The interesting thing to think about is the infiltration volume flow rate. Is fully opened window can really benefit the indoor flow rate? I will tried to test the result later but it is clear to see it will still benefit the cooling load since the original formula is based on load calculation to managing the temperature difference.

Air Infiltration Compare 1.4 1.2 1 0.8 0.6 0.4 0.2

1 66 131 196 261 326 391 456 521 586 651 716 781 846 911 976 1041 1106 1171 1236 1301 1366 1431 1496 1561 1626 1691 1756 1821 1886 1951 2016 2081 2146 2211 2276 2341

SUB SURFACE 152:AFN Linkage Node 2 to Node 1 Volume Flow Rate [m3/s](Hourly) SUB SURFACE 152:AFN Linkage Node 2 to Node 1 Volume Flow Rate [m3/s](Hourly)

Load Comparison 900000000 800000000 700000000 600000000 500000000

Total Load:Flow + Opengin

400000000

Total Flow Origin

300000000

TotaL Load Opening

200000000 100000000 1 105 209 313 417 521 625 729 833 937 1041 1145 1249 1353 1457 1561 1665 1769 1873 1977 2081 2185 2289

In previous page I talked about the flow rate difference and cooling load difference. In this page I will try to use the result to test the logic and the assumption I made. First, the flow rate. It is very clear that the flow rate do not have any changes or just a slightly changes. The main reason is that the window I assumed to control in this condition is too small so the ventilation that caused by the wind and stack do not have that kind of difference. The formula of the infiltration is based on wind speed and open area. In this case the main thing to change is open area but the area here is very small these make the outcome still driven by the out door wind speed and it still the same. On the other hand the load part. Load do have some difference since the open ratio is changed. It is clear to see that the logic of flow control do make some difference here even though it cost down very slightly which is caused by small opening.

M2: Flow control and cooling optimization logic for AFN (3f) Stack ACH:

Wind ACH:

ACH Formula:

ACH Reference:

ACH Formula:

IF fresh air (make up air) flow through the room (m3/s) >9.8 Set OpenRatio to 0 Else Stay with Formula

1.2

0.8

0.6

0.4

0.2

0 1 131 261 391 521 651 781 911 1041 1171 1301 1431 1561 1691 1821 1951 2081

1.2

1 139 277 415 553 691 829 967 1105 1243 1381 1519 1657 1795 1933 2071

Open Ratio After Flow Control

Open Ratio Before Flow Control

According to previous discovered I founded that air flow and its control is also connect to the cooling optimization. In sometimes the window may not need that much opening to reach the cooling goal, since the outdoor windspeed is potential helping cooling interior with small opening. To do this I have to add an flow control and tied it up with my open ratio control. I use the ACH formula to generate my logic. The normal ACH reference for public office is around 4. I assumed this is my reference point. To reach that I need about 9.8 air volume flow rate per second. I assumed this is my volume goal for the flow. When the flow indoor over 9.8 means it already enough for the indoor air change then I donâ&#x20AC;&#x2122;t need to open my window to full height . Based on these logic, the results shows the open ratio do make some difference. The obvious month is May. The main reason is connected to previous weather data which the wind speed in May is higher than other month. The ratio during that time is mostly to 0.

Volume flow rate Difference 16 14 12 10 8 6 4 2

-2

1 63 125 187 249 311 373 435 497 559 621 683 745 807 869 931 993 1055 1117 1179 1241 1303 1365 1427 1489 1551 1613 1675 1737 1799 1861 1923 1985 2047 2109 2171

Cooling Load Difference 1E+09 900000000 800000000 700000000 600000000 Original Total

500000000

Flow Control Total

400000000

Open Total

300000000 200000000 100000000 1 93 185 277 369 461 553 645 737 829 921 1013 1105 1197 1289 1381 1473 1565 1657 1749 1841 1933 2025 2117 2209 2301

To check the logic work correctly I output the volume flow rate to see if its reach the goal I set. The result is clear to see that the volume flow rate do under control do not over 9.8m3/s. At the same time the cooling load also goes down pretty good. These control is working correctly. It is also said that the control is doing after the window opening is finished so some time when it do reach 9.8the window control also work in the same time. That is why the whole cooling load go down. To take the logic further, it can be added in the lower limit for those window do not have enough wind in the particular time. However, the lower limit in this logic is tricky since when the low wind speed is occur open the window might get the result more cooling load. So the low limit strategy might need HVAC system to come in and solve the problem.

Constant Wind (All time 5m/s) Testing 3f Open Ratio Compare

5M/S Changing Ratio_3e

Open Ratio Before Flow Control_3e

0.8

0.6

0.4

0.2

0 1 127 253 379 505 631 757 883 1009 1135 1261 1387 1513 1639 1765 1891 2017 2143 2269

1.2

1 131 261 391 521 651 781 911 1041 1171 1301 1431 1561 1691 1821 1951 2081

1.2

5m/s With Flow Control Open Ratio

Open Ratio After Flow Control 1.2

1.2

0.6

0.4

0.2

0 1 149 297 445 593 741 889 1037 1185 1333 1481 1629 1777 1925 2073

0.6

1 141 281 421 561 701 841 981 1121 1261 1401 1541 1681 1821 1961 2101 2241

0.8

In this stage I would try to test the constant wind flow and its effect to the infiltration. The ratio in the previous window control is basic triggered by temperature difference and the stack infiltration also triggered by the same thing. However, changing the wind also changed the load coming inside. These can make into clear reason for the result that first the open ratio will have some changes. Second, the previous flow control will also be impacted. The main reason for that is the wind speed also make flow number changed.

Constant Wind (All time 5m/s) Testing3f Infiltration Volume 2500

2000

1500

1000

500

1 63 125 187 249 311 373 435 497 559 621 683 745 807 869 931 993 1055 1117 1179 1241 1303 1365 1427 1489 1551 1613 1675 1737 1799 1861 1923 1985 2047 2109 2171

Total(original)

total (5m)

Load Comparison 900000000 800000000 700000000 600000000 500000000 400000000 300000000 200000000 100000000 0

500

1000 Total

1500

2000

2500

Total 5m

The flow and load also will be affected since the open ratio changed. First, the volume flow rate. In the previous formula it is clear that the wind infiltration is caused by the wind speed and Cp. The stack is caused by temperature difference. In this case, the 3rd floor do not have big temperature difference since the height is not high enough. So in this case the dominate volume flow impact is the wind volume difference. After changing the weather file to constant wind speed the flow do make a clear difference. Second, the load. Load in here is going to be lower since the window fully open more times than before.

Constant Wind (All time 5m/s) Testing 8f Open Ratio Compare

SUB SURFACE 152:AFN Surface Venting Window or Door Opening Factor [](Hourly)

SUB SURFACE 152:AFN Surface Venting Window or Door Opening Factor [](5m) 1.2

1.2

0.8

0.6

0.4

0.2

0 1 139 277 415 553 691 829 967 1105 1243 1381 1519 1657 1795 1933 2071

1 139 277 415 553 691 829 967 1105 1243 1381 1519 1657 1795 1933 2071

SUB SURFACE 173:AFN Surface Venting Window or Door Opening Factor [](Hourly)

SUB SURFACE 173:AFN Surface Venting Window or Door Opening Factor [](5m) 1.2

1.2 1

0.8

0.6

0.4

0.2

0 1 139 277 415 553 691 829 967 1105 1243 1381 1519 1657 1795 1933 2071

1 139 277 415 553 691 829 967 1105 1243 1381 1519 1657 1795 1933 2071

For the eight floor, most of the ratio stay the same. The main reason is the flow rate is already not a big impact in 8th floor. Since the temperature difference is bigger than 3rd floor. I will talk about the flow in the next page. Since the flow control did not apply to 8th floor the normal open ratio will not be affected by flow. The temperature difference in this stage is going to be the dominate reason to control the window.

Constant Wind (All time 5m/s) Testing8f Volume Comparison 120000

100000

80000

60000

40000

20000

1 63 125 187 249 311 373 435 497 559 621 683 745 807 869 931 993 1055 1117 1179 1241 1303 1365 1427 1489 1551 1613 1675 1737 1799 1861 1923 1985 2047 2109 2171

TOTAL 5M

Total Original

Load Comparison 900000000 800000000 700000000 600000000 500000000 400000000 300000000 200000000 100000000 1 66 131 196 261 326 391 456 521 586 651 716 781 846 911 976 1041 1106 1171 1236 1301 1366 1431 1496 1561 1626 1691 1756 1821 1886 1951 2016 2081 2146

Total load (5m/s)

Total load (original)

Just like previous page said, the flow difference between constant wind speed and normal wind speed do not have any difference. The main reason is that the flow rate is going to be stack flow dominated. The temperature difference is gong to be a bigger impact than others. The wind flow difference only have a little impact in this stage. That explain why the flow rate difference is not very clear. Since the window and flow rate do not have very big changes, the load also do not have clear changes. The floor difference also explain not all floor ventilation strategy is going to be the same. Every floor have its own condition that make each floor caused by different environment impact.

Constant Wind Direction and Speed 3f Load Compare 3f (CONSTANT WEST WIND) 1E+10 9E+09 8E+09 7E+09 6E+09 5E+09 4E+09 3E+09 2E+09 1E+09 1 63 125 187 249 311 373 435 497 559 621 683 745 807 869 931 993 1055 1117 1179 1241 1303 1365 1427 1489 1551 1613 1675 1737 1799 1861 1923 1985 2047 2109 2171

Original total

West Constant

Load Compare 3f (CONSTANT EAST WIND) 1E+10 9E+09 8E+09 7E+09 6E+09 5E+09 4E+09 3E+09 2E+09 1E+09

1 63 125 187 249 311 373 435 497 559 621 683 745 807 869 931 993 1055 1117 1179 1241 1303 1365 1427 1489 1551 1613 1675 1737 1799 1861 1923 1985 2047 2109 2171

Original total

East Constant

Constant Wind Direction and Speed 8f Load Compare 8f (CONSTANT WEST WIND) 1E+10 9E+09 8E+09 7E+09 6E+09 5E+09

Wind Constant Original Weather

4E+09 3E+09 2E+09 1E+09

1 89 177 265 353 441 529 617 705 793 881 969 1057 1145 1233 1321 1409 1497 1585 1673 1761 1849 1937 2025 2113 2201 2289

Load Compare 8(CONSTANT EAST WIND) 1E+10 9E+09 8E+09 7E+09 6E+09 5E+09

Constant East Wind

4E+09

Original Wind

3E+09 2E+09 1E+09

1 86 171 256 341 426 511 596 681 766 851 936 1021 1106 1191 1276 1361 1446 1531 1616 1701 1786 1871 1956 2041 2126

The previous page I talked about constant wind speed but not constant wind direction. In this case I will talk about the simulation model with constant wind speed and constant wind direction which constant in east side and west side. For 8th floor the constant wind direction the load do not have a very big impact for constant the wind just like I said in previous page. However, there are still some time the load have little obvious different. The main reason is that in previous simulation the wind direction do not constant in one direction. In this case the constant wind can caused one of the zone continuing lower its cooling need.

Infiltration Compare 3F

Infiltration Heat Loss Compare 18000000 16000000 14000000 12000000 10000000 8000000 6000000 4000000 2000000 1 66 131 196 261 326 391 456 521 586 651 716 781 846 911 976 1041 1106 1171 1236 1301 1366 1431 1496 1561 1626 1691 1756 1821 1886 1951 2016 2081 2146

Original Total Infiltration Heat Loss

West Constant Infiltration Heat Loss

East Constant Infiltration Heat Loss

Infiltration Heat Loss Compare 700000000 600000000 500000000 400000000 300000000 200000000 100000000

1 66 131 196 261 326 391 456 521 586 651 716 781 846 911 976 1041 1106 1171 1236 1301 1366 1431 1496 1561 1626 1691 1756 1821 1886 1951 2016 2081 2146

Total East Infiltration

Original Total Infiltration

Total West Infiltration

Based on the previous result, the infiltration is also good to compare. The infiltration in the 3rd floor is oblivious have some different. The load after changing the direction and speed can clearly see that load become lower than the original one. The other thing to noticed is that the east and west side wind infiltration difference. It is clear that no matter whether the wind is coming from east or west it still remain the same the load even in 3rd floor. For the 8th floor the constant wind speed and direction do have some impact on the heat loss but still not the dominated one in the simulation.

Flow Control and Humidity Control Open Ratio After Flow Control (East)

Open Ratio Humidity + Flow Control (East)

0.8

0.6

0.4

0.2

Open Ratio After Flow Control (East)

Open Ratio Humidity + Flow Control (West) 1.2

0.8

0.6

0.4

0.2

0 1 141 281 421 561 701 841 981 1121 1261 1401 1541 1681 1821 1961 2101 2241

1.2

1 141 281 421 561 701 841 981 1121 1261 1401 1541 1681 1821 1961 2101 2241

1.2

1 131 261 391 521 651 781 911 1041 1171 1301 1431 1561 1691 1821 1951 2081

1.2

3F EAST Flow Comparison in one of window surface 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 1 61 121 181 241 301 361 421 481 541 601 661 721 781 841 901 961 1021 1081 1141 1201 1261 1321 1381 1441 1501 1561 1621 1681 1741 1801 1861 1921 1981 2041 2101 2161

SUB SURFACE 89:AFN Linkage Node 2 to Node 1 Volume Flow Rate [m3/s](Humidity Control and Flow Control) SUB SURFACE 89:AFN Linkage Node 2 to Node 1 Volume Flow Rate [m3/s](Flow Control)

3F WEST Flow Comparison in one of window surface 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 1 63 125 187 249 311 373 435 497 559 621 683 745 807 869 931 993 1055 1117 1179 1241 1303 1365 1427 1489 1551 1613 1675 1737 1799 1861 1923 1985 2047 2109 2171

SUB SURFACE 85:AFN Linkage Node 2 to Node 1 Volume Flow Rate [m3/s](Humidity and Flow Control) SUB SURFACE 85:AFN Linkage Node 2 to Node 1 Volume Flow Rate [m3/s](Flow Control)

In another comparison I add in another constrain for the final EMS logic which is humidity. The humidity add in will be an constrain for window open or not in the first place and then goes to flow control to decide the window will close or not. Base on the result I got, the flow rate for heat loss is bigger than the original one. The original one which do not have any humidity constrain this make the heat loss lesser than the constrain one. The constrain one which have promising humidity heat loss which open the window can cooling down indoor temperature and at the same time do not gain any humidity.

Cooling Load Comparison 900000000 800000000 700000000 600000000 500000000 Original Total

400000000

Flow Control Total

300000000 200000000 100000000

1 89 177 265 353 441 529 617 705 793 881 969 1057 1145 1233 1321 1409 1497 1585 1673 1761 1849 1937 2025 2113 2201 2289

Cooling Load Comparison 1E+10 9E+09 8E+09 7E+09 6E+09 5E+09 4E+09 3E+09 2E+09 1E+09 1 67 133 199 265 331 397 463 529 595 661 727 793 859 925 991 1057 1123 1189 1255 1321 1387 1453 1519 1585 1651 1717 1783 1849 1915 1981 2047 2113 2179 2245 2311

Total Load(Flow Control)

Total Load (Flow Control + Humidity Control)

Then comparing the load. It is very clear that adding the humidity constrain help a lot on the cost down cooling load. The main reason is that in the previous constrain which remain the indoor air change rate than there still sometime the indoor cooling load is caused by the humidity problem. However, in previous control it still that the window open this make the indoor temperature rise up after the opening. The constrain of the humidity do help the first open logic to pick the best time to open the window and after that the flow control logic will continuing control the flow then make the final load optimization.

Topic problem and question Venting Schedule Ventilation Volume 3.5 3 2.5 2 1.5 1 0.5 0

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Open Factor

Schedule

Venting Schedule and open factorâ&#x20AC;&#x2122;s open ratio 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0

10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

SUB SURFACE 152:AFN Surface Venting Window or Door Opening Factor [](Hourly) WINDOWVENTILATIONSCH_8F_E:Schedule Value [](Hourly)

After all simulation, there are still question I encounter. During the simulation in AFN and how it connect with the EMS, the ventilation schedule and the open factor these twoâ&#x20AC;&#x2122;s definition is not very clear. According to the Mohannad section the control should be ventilation schedule, but I am a little not sure about that. I personally assumed the ventilation schedule is letting the system know when will it allow ventilation and the open factor is just for how much window area will it be opened by the system. I kind of simulate the result and test its difference. The strange thing is that the ventilation flow do not actual reveal the open ratio which ventilation schedule count. The small open ratio the high-volume flow rate. For normal window which is open and in normal wind speed this cannot be happened. These situation is still very bother me.