Modelling and Passive Strategies - TMCCOSKER

Thomas McCosker
Modelling and Passive Strategies: Passive Building Model Study
BackgroundandShadingStrategies
1
Shading was modelled in Design Builder where it was found only minimal shading occurred when 8m between like modular homes were provided and a 20m
space was left for roadways.
Window shading devices were set at a 15 degree angle to minimize summer solar gain while still allowing winter sun to passively cool the space.
December 15, 9:00 December 15, Noon December 15, 14:30
July 15, NoonJuly 15, 6:00
July 15, 19:00 Figure 2: Site Shading
July 15, 14:00 December 15, 14:00
Figure 5: Final Shading Plan
To increase the natural lighting in the building, North facing roof lights were
considered to minimize solar gain while providing light.
Block 2 (Figure 4) varies in only a few ways from block number one in
terms of its optimization.
The primary difference is that Block 2 doesn't need roof lights to
achieve sufficient interior lighting.Figure 4: Modelled Block 2Figure 3: Modelled Block 1
Figure 1: Building locations within the housing block
Two buildings were modeled for this simulation. The first housing block is
the same as the second, but the second has an additional story, giving
the homeowners an additional bedroom/lounge or storage area, along
with access to their roof which can be designed to support a garden.

2
SolarPanelsandElectricLoads
Thomas McCosker
The addition of solar panels to the
South side of the roof lights
Electric Loads Satisfied
Electricity [kWh] Percent Electricity [%]
Fuel-Fired Power Generation 1944.44 94.82
High Temperature Geothermal* 0 0
Photovoltaic Power 2195.94 107.09
Wind Power 0 0
Net Decrease in On-Site Storage 2777.78 135.46
Total On-Site Electric Sources 4140.38 201.91
Electricity Coming From Utility 1517.56 74.01
Surplus Electricity Going To Utility 3607.34 175.92
Net Electricity From Utility -2089.8 -101.9
Total On-Site and Utility Electric Sources 2050.6 100
Total Electricity End Uses 2050.6 100
Not only is the energy demand met, but surplus is generated.
Table 4: Solar Panel Energy Breakdown
Figure 9:July 15, 18:00Figure 8:July 15, 12:00Figure 7: July 15, 6:00
Total Site Energy Energy per Conditioned Area (kWh/m2)
Base Case 17976.42 106.55
Optimized 4287.34 22.24
Optimized
Block 1 3812.87 23.46
Lighting
(kWh/m2)
Cooling
(kWh/m2)
Heating
(kWh/m2)
Other
(kWh/m2)
Total
(kWh/m2)
Base Case 15.62 24.97 52.42 13.54 106.55
Optimized 8.36 0 10.66 3.19 22.21
Optimized Block 1 7.8 0 10.37 4.89 23.06
Table 1: Block 2 Energy Consumption
Electric Loads Satisfied Electricity [kWh] Percent Electricity [%]
Fuel-Fired Power Generation 0 0
High Temperature Geothermal 0 0
Photovoltaic Power 2159.48 96.74
Wind Power 0 0
Net Decrease in On-Site Storage 0 0
Total On-Site Electric Sources 2159.48 96.74
Electricity Coming From Utility 1831.11 82.03
Surplus Electricity Going To Utility 1758.34 78.77
Net Electricity From Utility 72.77 3.26
Total On-Site and Utility Electric Sources 2232.25 100
Total Electricity End Uses 2232.25 100
An analysis was done as to the benefit of solar panels in Block 2’s garden
area and it was deemed un-feasible due to shading (Figures 7,8 &9).
Table 3: Solar panel energy breakdown
Table 2: Block 2 energy comparison by end user
Figure 6: Solar Panel Locations on Blocks 1 and 2

Changes Made
Total Energy
(kWh)
Energy/Total Conditioned
Building Area (kWh/m2)
Electricity
(kWh)
District Cooling
(kWh/m2)
District Heating
(kWh/m2)
Lighting
(kWh/m2)
Base Case 14208.38 87.44 28.6 4.99 53.84 14.89
Walls, Roof and Floor Insulated 11985.54 73.76 28.6 15.8 29.35 14.89
Windows Upgraded 11032.83 67.89 28.6 11.51 27.78 14.89
Shading Added 10699.1 65.84 28.6 8.81 28.42 14.98
Roof Lights Added 11356.79 63.75 26.09 11.09 26.57 13.58
Natural Ventilation ON, Cooling and Mech.
Vent. OFF 8781.39 49.29 26.09 0 23.2 13.58
Natural Ventilation to 6 ac/h 8796.97 49.38 26.09 0 23.29 13.58
Catering and Computers ON, Office
Equipment OFF 7769.61 43.61 17.71 0 25.91 13.58
Detailed HVAC On (radiant ground floor
with first floor radiators) 4760.97 29.3 19.54 0 9.76 14.94
Inset Entryway 3557.03 29.15 19.01 0 10.14 14.77
Solar Panels Added to Non-Entry House 4700.53 28.93 19.54 0 9.04 14.39
Lighting Controls ON 3975.33 24.46 12.49 0 11.97 7.88
Improved Shading 3812.87 23.46 12.69 0 10.37 7.8
ZeroCarbonTargetsandReachingFEES
3
The FEES target of 39kWh/m2/year was
almost reached with only insulation, air
tightness and windows upgraded.
However, it was not actually reached until
the shading was added.
The changes made to the shading showed
differences in the energy used but the
maximum temperature experienced inside
rose slightly due to the increased louver
spacing. The increase in the maximum
temperature was seen as acceptable as the
overall overheating went down and extra
ventilation can be used to cool the building.
Thomas McCosker
Table 5: Changes made to achieve Zero Carbon
Fabric Energy Efficiency Standard (FEES)
(maximum space heating and cooling required)
39
kWh/m2/year
Carbon Compliance Target
(maximum CO2 for heating, cooling, hot water
use, fixed lighting and ventilation)
11 kg
CO2/m2/year
After these two targets have been met, on site generation can
be used to reduce final figures further
Zero Carbon Targets
for a Terraced House
Table 1: Zero Carbon Targets for a Terraced House
Figure 10: Comparison of energy usages to achieve Zero Carbon
0
10
20
30
40
50
60
70
80
90
100
Base Case Walls, Roof and
Floor Insulated
Windows
Upgraded
Shading Added Roof Lights
Added
Natural
Ventilation ON,
Cooling and
Mech. Vent. OFF
Natural
Ventilation to 6
ac/h
Catering and
Computers ON,
Office Equipment
OFF
Detailed HVAC
On (radiant
ground floor with
first floor
radiators)
Inset Entryway Solar Panels
Added to Non-
Entry House
Lighting Controls
ON
Improved
Shading
kWh/m2
Energy/Total Conditioned Building Area (kWh/m2)
Electricity (kWh)
District Cooling (kWh/m2)
District Heating (kWh/m2)
Lighting (kWh/m2)
By adopting zero carbon policy for the development at
the Northern Gateway, the houses will be compliant
with 2020 European building energy policy in line with
the Energy Performance of Buildings Directive.

4
IndoorTemperatures
Thomas McCosker
Insulated
Walls, Roof
and Floor Windows Shaded Roof Lights
Nat Vent On,
Cooling Off,
Mech Vent Off ACH to 6
Shading
increased to .1m
separation
Computers and
Catering ON,
Equipment Off
Detailed HVAC w/
Radiant Floor and
1st Floor Radiators
Inset
Entryway
Entry
Way
Solar
Panels
Lighting
Control On
PV With
Storage
New
Shading
Max Temp 27.88 27.28 26.93 27.12 34.95 33.68 33.41 28.9 28.23 29.24 27.2 27.14 26.55 30.05 31.6
Min Temp 16.58 16.88 16.81 16.84 15.48 15.43 15.39 16.56 18.53 18.36 13.71 18.92 18.72 17.75 17.78
Average
Temperature 21.8 21.5 21.2 21.4 22.0 21.7 21.6 21.0 22.2 22.3 19.2 22.5 22.0 21.9 22.1
Number of Hours
over 26 Degrees C. 77 47 31 46 1437 1019 933 26 32 51 3 2 1 1417 918
Number of Hours
over 26 Degrees C. 0.009 0.005 0.004 0.005 0.164 0.116 0.107 0.003 0.004 0.006 0.000 0.000 0.000 0.162 0.105
Because cooling was turned off
to reduce energy consumption
and cooling is primarily done
through natural ventilation,
overheating was monitored
closely. There are some instances
where maximum temperatures
do get quite high, but the overall
number of hours where this
happens is low and the average
remains comfortable.
Insulated
Walls, Roof
and Floor
Windows Shaded Roof Lights Nat Vent
On, Cooling
Off, Mech
Vent Off
ACH to 6 Shading
increased to
.1m
separation
Computers
and Catering
ON,
Equipment
Off
Detailed
HVAC w/
Radiant
Floor and
1st Floor
Radiators
Inset
Entryway
Entry Way Solar Panels Lighting
Control On
PV With
Storage
New
Shading
0
5
10
15
20
25
30
35
40
DegreesC
Max Temp Min Temp Average Temperature
Figure 11: Indoor Temperatures for
each change made
Table 3: Tracked temperature breakdowns
0
5
10
15
20
25
30
35
1/1/020:00
1/8/020:00
1/15/020:00
1/22/020:00
1/29/020:00
2/5/020:00
2/12/020:00
2/19/020:00
2/26/020:00
3/5/020:00
3/12/020:00
3/19/020:00
3/26/020:00
4/2/020:00
4/9/020:00
4/16/020:00
4/23/020:00
4/30/020:00
5/7/020:00
5/14/020:00
5/21/020:00
5/28/020:00
6/4/020:00
6/11/020:00
6/18/020:00
6/25/020:00
7/2/020:00
7/9/020:00
7/16/020:00
7/23/020:00
7/30/020:00
8/6/020:00
8/13/020:00
8/20/020:00
8/27/020:00
9/3/020:00
9/10/020:00
9/17/020:00
9/24/020:00
10/1/020:00
10/8/020:00
10/15/020:00
10/22/020:00
10/29/020:00
11/5/020:00
11/12/020:00
11/19/020:00
11/26/020:00
12/3/020:00
12/10/020:00
12/17/020:00
12/24/020:00
12/31/020:00
DegreesC
Date
Average Indoor Temperatures
Figure 12: Average indoor temperatures

5
Conclusion
Thomas McCosker
Fuel Type
Amount
Used
(kWh/m2)
Conversion
Factor kg CO2
Total kg
CO2
Electricity 12.69 0.46 5.87 7.78
Natural Gas 10.37 0.18 1.91
Fuel Type
Amount
Used
(kWh/m2)
Conversion
Factor kg CO2
Total kg
CO2/m2
Electricity 11.55 0.46 5.34 7.30
Natural Gas 10.66 0.18 1.97
Block 1
Block 2
Table 8: Carbon compliance for Block 1
Table 9: Carbon compliance for Block 2
In both Block 1 and Block 2, carbon compliance for attached homes at 11 kg
CO2(eq)/m2/year was met with room to spare. To calculate carbon compliance,
operational energy used must be converted into kg CO2 by multiplying each fuel
source by its conversion factor.
Furthermore with the addition of the solar panels, electric use was completely
offset for Block 1 and only missed the mark by 1.5 (kWh/m2) for Block 2. With
the addition of another solar panel or even increasing the size of the ones
already in place, both buildings will be well below Zero Carbon with the addition
of renewables.
While the work that was put in to the design aspect of these two building blocks
in terms of reducing offcuts, waste and site work to reduce carbon were not
realized in the Design Builder software, even without these saving measures it is
certainly still possible to accomplish a zero carbon building as seen in Tables 8
and 9.
Conclusion
Through significant increases in the provided wall, roof and floor
details as well as decreasing air infiltration and adding
significant shading, the amount of energy needed to heat these
buildings and the amount of energy escaping was decreased
significantly.
Further optimizations have been considered for these two
buildings. A CFD analysis was attempted to test the
effectiveness of the roof lights as aids to natural ventilation but
unknown errors and persistent crashes did not allow for those
calculations to be run. Further investigations will also be carried
out in regard to the roof lights and their lack of light projection
into secondary rooms and hallways.
Finally, solar hot water will also be considered for these
buildings but further persistent errors and crashes prevented
their addition to detailed HVAC.
Figure 13: Block 1 and Block 2

Modelling and Passive Strategies - TMCCOSKER

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