building simulation
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Building environment and simulation analysisTRANSCRIPT
ARC 6780 Building Environment Simulation Analysis
ECO HOUSE
AASIYA TASNEEM ASLAM
MSc SUSTAINABLE ARCHITECTURAL STUDIES 110118909
1 ARC6780 Building Environment Simulation Analysis
TABLE OF CONTENTS
Introduction…………………………………………………………………………………………….2
Analyses tools adopted…………………………………………………………………………………2
Eco House, Cyprus……………………………………………………………………………………..3
Codes Compliance……………………………………………………………………………………...4
Eco house in New Delhi, India
Site and climate…………………………………………………………………………………………..5
Design Considerations……………………………………………………………………………………7
Performance Checks
Thermal………………………………………………………………………………………......11
Lighting…………………………………………………………………………………………..14
Resource consumption…………………………………………………………………………...18
Renewable Energy source………………………………………………………………………..20
Eco house in Montreal, Canada
Site and climate………………………………………………………………………………………….21
Design Considerations…………………………………………………………………………………..22
Performance Checks
Thermal……………………………………………………………………………………..……26
Lighting……………………………………………………………………………………….….29
Resource consumption……………………………………………………………………….…..33
Renewable Energy source…………………………………………………………….………….35
Comparisons……………………………………………………………………………………………36
Conclusions……………………………………………………………………………………………..38
References………………………………………………………………………………………………39
2 ARC6780 Building Environment Simulation Analysis
ECO HOUSE- Design Interventions and Analysis
Introduction:
Architectural designs, in today’s scenario, demand accuracy of energy consumption and
generation. It is seldom that designs do not take into account the impact they producing on the
environment or how efficient their construction and systems are. To confirm their environmental
performance, various design analysis tools are developed to constantly guide the designer through
various stages of design. These analysis tools are proven most effective, when utilised from the concept
stage of design, to create guidelines of design and energy checks of the building. The analysis tools
also tell the designer the performance of the building in the context it is located within and which
aspect of the building is causing discomfort to its occupants, which system is consuming most energy
or how the building is performing to the ideas stated by the designer.
Of the several developed softwares like Autodesk Revit, E-Quest, IES, etc., Autodesk Ecotect
and Design Builder will be used to carry out simulations of the Eco house project. The Eco House
project is analysed in two disparate climatic conditions namely that of India and Canada. With the
demand that climate will make on the design of the Eco house, suitable solutions will be proposed to
improve the performance of the building and the comforts of its occupants. Having proposed solutions,
these will be analysed to achieve best building performance in terms of heating/cooling loads,
illuminance level and near zero carbon standards.
Analysis tools adopted:
Autodesk Ecotect is utilised to carry out Thermal and lighting analysis. In order to get
familiarised with other analyses softwares, Design Builder is also used, to calculate the thermal
performance of the Eco house for an alternate location. Of the two, Autodesk Ecotect has a relatively
easier user interface and appears to be more resilient while constructing the 3d model. Despite its
advantages in constructing the model, Ecotect is often suspected of not producing accurate results. Since
Design Builder is associated with energy plus, it generates better results.
The calculations and analyses carried out for this project are- Thermal analysis, Day lighting
analysis and Resource consumption for each of the two locations that the Eco house is based in. Day
lighting calculations will be done solely in Radiance, because of the limitation of the older versions of
Design builder software.
3 ARC6780 Building Environment Simulation Analysis
ECO HOUSE DESIGN, CYPRUS
Image.1- Eco house design (Views) - Ecotect
Image.2- Floor plans- Eco house, Cyprus
4 ARC6780 Building Environment Simulation Analysis
CODES COMPLIANCE
The Indian Green Building Council has stipulated certain criteria for all new constructions in India to
achieve sustainability and make the buildings more energy efficient. The rules that apply to this design
are regarding the building construction elements and their U values. The U values target is as follows:
Element U values W/m2.K
Walls 0.3-0.6
Glazing 1.7 – 3.0
Roof 0.7-2.0
Floors 0.7-2.0
[IGBC, India (online)]
The Canadian Energy Code for the best practice in construction requires the following target values:
Element U values W/m2.K
Walls 0.35
Glazing 4.5
Pitched Roof 0.2
Floors 0.45
The requirements for mechanical ventilation as per ASHRAE are:
Equipment Type Size
Category Minimum
Efficiency
Air Cooled, with condenser electrically Operated < 150 ton 2.80 COP
2.80 IPL
≥150 ton
Air cooled without condenser, electrically Operated All capacities 3.10 COP
3.10 IPL
Water cooled, electrically operated, positive
displacement (reciprocating)
All capacities 4.20 COP
4.65 IPL
5 ARC6780 Building Environment Simulation Analysis
ECO HOUSE- New Delhi, India
Site Analysis and Location:
LOCATION DATA
Location New Delhi
Latitude 28.6⁰
Longitude 77.2⁰
Altitude 216.0m
Time Zone +5.5 hours
Climate Composite- hot humid summers
and cool dry winters
(US Department of Energy)
Image.5- Wind directions-Ecotect
New Delhi is the capital city of India and also one
of the four metropolitan cities of India, located in
the northern part of India (see.image.1). New Delhi
is located in the Indo-Gangetic Plains and is
surrounded by hills. New Delhi is a landlocked
city. New Delhi falls under the seismic zone-IV,
meaning it is susceptible to earthquakes. New
Delhi experiences a composite climate with high
variations between its summer and winters. The
hottest part of the year is late May to early June
and the August is when the monsoons set in
(Wikipedia, climatic data of Chennai, see image 4).
The coldest periods are from November to January.
Image.3- Location of New Delhi on
the world map (Google maps)
Image.4- Monthly Weather data
(Wikipedia)
6 ARC6780 Building Environment Simulation Analysis
Image.6- Degree hours-Heating, Cooling and Solar-Ecotect
Design Considerations:
Factors Analysis Solutions Image.
Building
orientation
Optimum building orientation
reduces direct solar gains and
overheated periods of the
building.
Building will be oriented in the
East-West axis so that only the
shorter side of the building receives
the harshest western sun(190⁰ from
North). The ancillary space such as
the garage and store will be facing
the western side and main living
space on the East.
8, 9
Construction wall
elements
Right choice of materials can
prevent the ingress of heat into
interior spaces.
Brick cavity wall with insulation
within the air cavity will be
provided.
10
Prevailing Breeze From the North west direction,
cooler evening breezes
Adding a portico (veranda) in the
front of the house with large
openings in the front.
13, 14
From image2, it is evident that
the hottest temperatures are attained
in May (around 39.6⁰C), although
45⁰C has also been recorded as the
highest and 7.3⁰C as the lowest. (The
Hindu, 2003, Retrieved 25 April
2007). Winters are cool and dry.
Humidity levels are high, around
49.2% annual average (Delhi
climate, Wikipedia). New Delhi also
experiences heavy rainfall during
August (258.7mm). Image 5 shows
the monthly diurnal average and the
comfort band to be achieved at 19-
26⁰C. The prevailing breeze
direction is North West in the
evenings (see image 5).
Image.7- Monthly Diurnal Temperatures, comfort levels-Ecotect
7 ARC6780 Building Environment Simulation Analysis
Fenestration
design
Design of windows and
openings should prevent
excess solar ingress into the
building.
Large windows with deep recess
shall be provided.
Double glazed windows with air
gap in between, having timber
frames.
-
Sun shading
devices
Due to high solar exposure,
windows need sun shading
devices, especially the ones in
the west.
Horizontal sun shading devices will
be provided on all windows.
Reduced size of openings on the
west side.
15
Ventilation In order to improve the scope
of naturally ventilated spaces
and reduce the dependence of
artificial ventilation and
reduce the humidity levels
indoors.
Cross ventilation will be provided
in the interior spaces by providing
large windows.
16
Lighting Maximise day lighting and
reduce glare conditions.
Windows opening in the north side
to get glare free north light will also
be provided.
14
Orientation:
Construction elements:
Constrtion Elements:
Optimum orientation for New Delhi is the East-west
Orientation as Southern faces have the potential for more
solar ingress during winters and lesser during summers
(see image 8). The living spaces are oriented to face the
east, so that it can enjoy the cool eastern sunshine in the
morning. The ancillary space like store and garage on
the west side will act as a buffer to the penetration of hot
midday sun into the living spaces (see image 9).
Providing a lawn in front of the southern façade which
will be accessed from the living space of the ground
floor will potentially minimise the reflected solar heat
onto the south façade.
Image.8- Best orientation-Ecotect
Image.9- Eco House orientation
8 ARC6780 Building Environment Simulation Analysis
• External Walls- Brick cavity wall with polyurethane insulation provided in the air gap. The
thickness of external walls is 0.28 m. with the break up 0.110 m masonry +0.050m air cavity+0.050m
polyurethane foam as insulation + 0.110m brick masonry+ internal plaster. The u-value attained is
0.53 W/m2K. Admittance is 4.96 W/m
2.K. Attaining a low U value will keep the summer heat outside
in the mornings and release coolth into the interiors.
• Internal walls- 115 mm brick wall with plaster. The U-values attained is 2.62 W/m2.K.
Admittance is 4.39 W/m2.K.
• Ground floor slab- starting from outermost consists of 10mm ceramic tiles+ concrete screed of
50 mm+ polystyrene insulation 50 mm+ plain cement concrete 100mm + compacted soil
1500mm. The U value attained is 0.36 W/m2.K. Admittance is 4.07 W/m
2.K.
Image.10- External Wall layers and Properties- Ecotect
Materials
Image.11- Internal Wall layers and Properties- Ecotect
Materials
9 ARC6780 Building Environment Simulation Analysis
• Roof slab (ground floor) – Suspended concrete ceiling consisting of a concrete slab of 150
mm+ air gap of 600mm+ gypsum of 12mm. U value of this assembly is 1.77 W/m2.K. Admittance is
2.09 W/m2.K.
• Floor slab (first floor) - From the outermost layers 10mm ceramic tiles+ concrete screed of 50
mm+ polystyrene insulation 50 mm+ concrete slab 150mm. U value of this assembly is 0.93
W/m2.K. Admittance is 4.07 W/m2.K.
• Roof slab- Starting from the outermost layers 20mm plaster board+ air gap of 500 mm+
concrete slab 150mm+ Concrete Screed 75 mm + Polystyrene as insulation 100mm+ Bitumen felt
20mm + light coloured ceramic tiles 10mm. U value of this assembly is 0.51 W/m2.K. Admittance is
3.56 W/m2.K.
• Glazing- Double glazed with aluminium frame consisting of 8 mm of glass on either side
sandwiching 20 mm of cellulosic insulation in the air gap. The U value of this assembly is 1.18
W/m2.K. Admittance is 1.17 W/m2.K.
Prevailing Breeze:
Since the prevailing breeze direction is
from the north-west in the evenings, the
entrance is projected out into a semi open
portico (veranda) which will draw in fresh
air into the living spaces through large
shaded windows in the front of the house.
This also shades the house in peak
summers.
Image.12- Floor Slab layers and Properties- Ecotect
Materials
Image.13- Prevailing breeze direction in plan- Ecotect
Materials
10 ARC6780 Building Environment Simulation Analysis
Thermal Analysis:
Fenestration and Sun shading devices:
The windows are recessed in the walls to
avoid the glare of the sun into the interiors. Double
glazed windows with aluminium frames are
selected as its performance proved to have the
highest impact on the entire thermal performance of
the building. Horizontal shading devices are
provided over the window to reduce the impact of
the sun in the hottest days of the year. These
shading devices project out by 0.60m from the
windows (see image 15). Internal venetian blinds
also prevent excess glare.
Ventilation:
In order to reduce the humidity levels in the
interiors all living spaces and bedrooms are
provided with cross ventilation (see image 16). For
the purpose of calculations a mixed modal system
with 95% efficiency is selected. The image below
shows the new location of the bedroom to enable
provision of windows on opposite walls promoting
cross ventilation.
Lighting:
The living spaces have increased window
sizes to capture glare free north lighting into the
interiors. The windows of the living room in the
south side are shaded by a semi open terrace. As
sky lights bring in excess heat also into the
building, it is advisable to rely on natural day
lighting through windows only. The Average
Daylight Factor achieved is 9.53% for the rooms in
the first floor.
Image.15 - Design Interventions- Ecotect Visualise Tab
Image.14- Design Interventions- Ecotect Visualise Tab
Image.16 - Design Interventions- Ecotect Visualise Tab
Image.17 - Design Interventions- Ecotect Visualise Tab
11 ARC6780 Building Environment Simulation Analysis
The thermal calculation was run and displayed the following result for the Average hottest day in
and average coldest day in New Delhi:
Image.19(a), (b)- Thermal Analysis for Hottest day Average,30th
June, in New Delhi
Total Conductance (AU): 1613 W/°K
Total Admittance (AY) : 11061 W/°K
It can be seen from the graph that upper band of Comfort zone is achieved between major parts of the
day (4:00-20:00) around 26⁰C. At night time in New Delhi, the temperature inside rises to maintain
warmth inside the house. The First floor experiences more heat at night because of the open terrace and
more exposed opaque surfaces. Hence light surface tiles are proposed for the external surfaces of the
first floor terrace to reflect off heat rays. However, both zones are comfortably lower than the outside
air temperature. A significant change in internal comfort is seen when the infiltration rate is changed to
cross ventilation with 200ach. This implies that providing cross ventilation in the living spaces can
reduce the cooling loads (see image 19b). Internal temperatures can further be regulated by operating
Thermal Analysis:
For calculation of the thermal performance of the eco house,
certain considerations were followed:
• The model was simplified in terms of zones namely the
Ground floor (zone1), first floor and roof top structure
(zone 2) and garage and store services as (zone 3).
• The thermal zones were given the following values-
Mixed Modal system (95% efficiency) was selected
which means the provision of both natural and artificial
system of ventilation, activity as sedentary-70W,
clothing as 0.6 clo, Air speed as 0.5 m/s, lighting level
as 300 lux with infiltration as 1 ach.
Image.18 – Alternate Materials
Settings- Ecotect
12 ARC6780 Building Environment Simulation Analysis
the venetian blinds. However, Ecotect does not account for such strategies. The average temperature of
the building in summer is 24.4 ⁰C.
Image.20- Thermal Analysis for Average Coldest day, 1st January, in New Delhi
The graph for the Average coldest day in New Delhi reveals that both zones have achieved comforts
around 18⁰C for most parts of the day. The temperature is low in the early part of the day and rises to
achieve comfort around mid-day finally reaching 18⁰C. The first floor achieves better conditions, again
because of its exposed roof slab. Average temperature of the building in winter is 13⁰C.The graph also
shows the peak solar radiation around mid-day.
During the average hottest day in New Delhi, the heat gains that occur by the fabric are 11 0404Wh
which is maximum at 16 hrs (because of the evening sun in the west), which is less as the fabric keeps
the heat from penetrating the building. However, the gains by the HVAC system are around 50
32507Wh. The maximum gain occurs by the penetration through opaque surfaces of wall and roof
around day (around 5:00 am to 5:00 pm). The maximum direct gains by the windows and openings
occur in April around 32 425 Wh from the west and east faces of the building at 11 am. The comfort of
occupants can be regulated by providing internal blinds.
Total Conductance (AU): 1613 W/°K
Total Admittance (AY) : 11061 W/°K
Image.21 – Hourly temperature gains- Hottest day Image.22 – Indirect Solar Gains- Hottest day
13 ARC6780 Building Environment Simulation Analysis
The graph for the average coldest day shows that the losses by the opaque surfaces of fabric are 8 7800 Wh,
where most fabric losses occur early morning at 6 am. Although the inter-zonal heat is nearly constant,
most conduction and HVAC loss occurs during the night time and early parts of the day. There is a small
internal temperature gain in the early morning. The most direct gain is 3 0235 Wh at 11 am during
February.
Max Heating: 2 8524 W at 05:00 on 23rd December
Max Cooling: 8 3179 W at 09:00 on 24th June
The distribution of temperature annually is between 16- 28⁰C. The most attained temperature level is
26⁰C. The building achieves comfort for 6570 Hrs (100.0%) in total for the entire year.
Image.23, 24 – Temperature Distribution and Sun Path on Hottest Day
Image.25 – Hourly temperature gains- Hottest day Image.26 – Direct Solar Gains gains
Image.27 – Temperature Comparison- Ecotect Image.28 – Sun path Diagram- Coldest day
14 ARC6780 Building Environment Simulation Analysis
While comfort has been achieved in most cases, a few limitations of the software prevent
accurate results displaying the performance of the building with the effect of natural cross ventilation.
While the capability of cavity walls to retain heat in the morning and dissipate it during the night is not
included as a source of improved thermal performance of the Eco house. In this case, Ecotect has just
assumed the effect of the orientation and building fabric, for calculating the thermal performance of the
building.
Lighting Analysis:
In order to understand the effect of natural lighting in this model, it was necessary to calculate
the Average Daylight factor and the Illuminance for each room and check if they have achieved the
standard prescribed by CIBSE.
A comparative tabulation of the lighting analysis was made:
The Daylight Factor measured in percentage and
is the ratio between the actual Illuminance at a
point inside a room and the illuminance possible
from an unobstructed hemisphere of the same sky
(McMullan, R., 2007). Design Sky values are
derived from a statistical analysis of dynamic
outdoor sky illuminance levels. They represent the
horizontal illuminance value that is exceeded 85%
of the time between the hours of 9am and 5pm
throughout the working year. Thus they also
represent a worst-case scenario that you can
design to and be sure your building will meet the
desired light levels at least 85% of the time
(Natural Frequency, 2012). Ecotect has the ability
to perform the calculations by itself to detect the
design sky component. This can be specified
either by the Tregenza Formula or by the Latitude
of the site. However, Tregenza calculator was
utilised for this instance which detect the sky
component to be 8875 Lux.
Image.29 – Design Sky Values( Natural frequency)
Image.30 – Design Sky Values by Latitude
Image.31 – Stereographic diagram-Vertical sky component
15 ARC6780 Building Environment Simulation Analysis
Space Required (CIBSE) Achieved Accepted Refer
image. Daylight
Factor (%)
Illuminence
(Lux)
Daylight
Factor (%)
Illuminence
(Lux)
Living rooms and
Dining rooms
1.5 5-200 32.19 1200 Yes 34
Bedrooms 1 100 GFa- 3.7
FFa – 4.6
FFb- 2.8
FFc- 2.3
GFa- 500
FFa-750
FFb-350
FFc-350
Yes 35
Kitchen 2 300 13.68 450 Yes 36
Bathroom - 100 GFa-1.06
FFa- 1.1
FFb-1.2
GFa-200
FFa-250
FFb-275
Yes 37
Office 2-4 300 3.77 400 Yes 38
The following images show the light analyses for the ground and first floor respectively. Most of the
spaces are adequately lit. The day lighting analysis for individual spaces will be discussed in detail.
Image.32 – Daylight Analysis- ground floor Image.33 – Daylight Analysis- first floor
16 ARC6780 Building Environment Simulation Analysis
The following analyses were made by exporting the data to radiance the settings selected were-
Intermediate sky (mid season) settings, Using Ecotect’s sun angles and design sky which generates the
following images according to the camera settings.
Living room- Lighting Analysis shows abundant lighting levels achieved. The ‘False colour’ settings
enable to give a more uniform result of the space. More than 475 Lux is achieved uniformly. The ADF is
32.19 %.
Bedroom 1- Lighting Analysis of the ground floor bedroom shows that more than 500 Lux is achieved
uniformly. The ADF is 3.7 %.
Image.34 – Daylight Analysis- Living room
Image.35 – Daylight Analysis-Bedroom (ground floor)
Image.36 – Daylight Analysis-Kitchen
17 ARC6780 Building Environment Simulation Analysis
Kitchen- After analysing the lighting in the kitchen, it was found that it was below the required 300 lux
and 2% ADF. Hence another linear window was added on the wall facing the main entrance. Since it is
facing the main entrance it had to be at a higher level for the sake of privacy of the interiors. The ADF
now is 13.68%
Study- Lighting Analysis of the study shows that more than 500 Lux is achieved uniformly. The ADF is
3.77 %.
Lounge (F.F.)- Lighting Analysis of the ground floor bedroom shows that more than 600 Lux is
achieved uniformly. The ADF is 3.5 %.
Image.37 – Interventions to the Kitchen with analysis
Image.38 – Daylight Analysis-Study
Image.39 – Daylight Analysis-Lounge First Floor
18 ARC6780 Building Environment Simulation Analysis
Image 40-Bathroom- 200 lux and ADF is
1.06%
Having generated the analyses for the worst case scenario, it is evident that better natural lighting is
possible for sunny skies. The radiance tool is more accurate in displaying results related to lighting. The
other spaces were also tested to achieve satisfactory results.
Resource Consumption:
The resource consumption calculation is essential in understanding how much energy is consumed by
the building in order to maintain comfort and achieve everyday activity. Resources include electricity,
water, gas, petrol, diesel and oils. At the moment, only solar collection and water are considered as
production resources (Ecotect Help).
To supplement the load of the HVAC system and the electric loads, photovoltaic panels are added. The
system chosen is a mixed mode system with 95% efficiency. The maximum cooling is required in June
and maximum heating in January. The monthly heating and cooling loads indicate that 3 55 7304 Wh
is needed for heating, 17 14 0620Wh is required for cooling and 15 01 8696 Wh for electricity
(appliances, light fixtures). To reduce the impact on the environment, Compact fluorescent lamps are
suggested, which are energy efficient as compared to ordinary lamps. A 38 Watt lamp (specified for
lamps in the project) generates same illuminence as a 150 Watts ordinary lamp. Hence, more energy can
be conserved.
The images below illustrate the monthly heating and cooling loads consumed by the building. The first
graph( image 41) shows that during summers cooling of 41 52 8328 Wh is required and during winters 7
68 3341Wh of heating is required. However, when the infiltration values of air change rate are changed
to 50ach (cross ventilation), the second graph is generated (image 42). Now the cooling loads is reduced
to 22 36 3184 Wh which indicates that cross ventilation of the living and bed spaces can substantially
reduce the cooling loads. However it also increases the heating loads during winters as too much wind is
undesirable during winters. This can be manually controlled by shutting the windows during winters.
Image.41 – Resource Consumption Image.42 – Resource Consumption (@ 50 ach)
19 ARC6780 Building Environment Simulation Analysis
To relieve the building of excess load consumption for cooling during summers, PV cells are introduced
on the roof. The panels occupy a total of 70.7 m2. Ideally, the optimum orientation for solar panels
mounting is derived by the formula Optimum angle (in degrees) = (your latitude x 0.9) + 29. Hence for New Delhi,
the ideal orientation is a 54⁰ tilt towards the southern direction. The efficiency of the solar collectors was
set 95% for efficiency and 90% for space heating efficacy. During the summers, when there is maximum
sunshine, the solar panels can collect 19 84 1492 Wh of energy which is roughly a quarter of the energy
consumption of the building. When part of the resources is derived from renewable sources, the Eco
house is closer to attaining a low energy standard. The graphs below describe the solar energy
generation (19 84 1492Wh) and the hourly electricity usage (15 01 8696 Wh).
A chart describing the peak sun hours suitable for solar collection is shown below
Image.43 – Monthly Loads Image.44 – Monthly loads (@ 50 ach)
Image.45 – Hourly Electric Usage Image.46 – Total Solar Energy collected
Image.48 – Solar panels on roof Image.47 – Daily Load Matching
20 ARC6780 Building Environment Simulation Analysis
Potential Renewable Energy Sources:
Renewable energy is about using natural sources to create energy so that the dependence on electricity is
lesser. These natural sources usually include the sun, water, wind, and geothermal sources. A net zero-
energy building (ZEB) is a building which depends less on energy through efficiency gains such that the
balance of energy needs can be supplied with renewable technologies [Torcellini et al. 2006].
Apart from Solar panels on the roof, other techniques are ensuring passive ventilation by stack method
and cross ventilation. This will increase the cooling in the interior spaces and reduce the energy
consumption for cooling. All interior paints should be low VOC to improve the standards of the
interiors. The materials chosen for the house are also locally available such as brick and insulation
materials. This reduces the carbon footprint of the materials.
Alternately, the solar energy can also be utilised to heat hot water in insulated solar thermal tanks (see
image 52). As Delhi receives adequate rain water, rain water collection is required to conserve and reuse
water. New Delhi also has the potential of being benefitted by the hydroelectric power generated by the
dams on the Chambal River. Off-site renewable Energy Sources can also benefit the accumulation of
energy.
Image.49 – Solar panels Energy Calculations
Image.50 – Solar panels Yearly Power Calculations
Image.51 – Solar panels laid on the roof
Available at http://www.millennialliving.com/content/up-your-
solar-panel-roof
Image.52 – Solar thermal heaters-operation
Available at http://mapawatt.com/tag/solar-thermal-schematic/
21 ARC6780 Building Environment Simulation Analysis
ECO HOUSE- Montreal, Canada
Site Analysis and Location:
LOCATION DATA
Location Montreal
Latitude 45.47⁰
Longitude -73.75⁰
Altitude 9.1m
Time Zone -5.0 hours
Climate Humid continental
(US Department of Energy)
Montreal is one of the largest cities in
Canada. Montreal is located in between the
St. Lawrence River on its south, and by the
Rivière des Prairies on its north. The climate
is classified as humid continental or
hemiboreal. Summers are warm with average
temperature being around 26°C. Winters in
Montreal are often very cold, snowy and
windy at times. Typical winter daytime
temperatures brings between -2 to -6°C and
overnight temperatures between -10 to -15°C.
Montreal receives plenty of snow throughout
the winter season. Average yearly snowfall is
218 cm (86 inches). Despite plenty of snow
during winter, Montreal still sees plenty of
days with sunshine. The maximum
temperature recorded is during July
(36.1°C).The hottest months are June, July
and August. The lowest temperature recorded
is -33°C in January. Annual precipitation is
218 cm of snowfall. The wind direction is
from the south west.
Image.53 – Montreal Location, Google maps
Image.54 – Montreal Wind direction-Ecotect
Image.55– Degree Hours-Montreal, Canada
Image.56– Climatic data, Montreal (Wikipedia)
22 ARC6780 Building Environment Simulation Analysis
Design Considerations:
Factors Analysis Solutions Image.
Building
orientation
Optimum building orientation
will increase direct solar
ingress into the house
Building will be oriented in the
East-West axis so that only the
so that the front faces the south.
(165⁰ from North).
59,60
Construction wall
elements
Right choice of materials can
retain heat in the interior
spaces.
Timber clad masonry is selected
with insulation in walls.
62
Prevailing Breeze From the West direction,
cooler evening breezes
The living space is on the west,
which will enjoy the breeze in
summers, but ample planting
will be provided to deflect the
harsh breeze in winter.
66
Fenestration
design
Design of windows and openings increase solar ingress
into the building.
Double glazed windows with
timber frames.
More windows facing South and
smaller windows on the north
side to reduce heat losses.
67
Precipitation Excess snowfall Sloped and pitched roofs
provided.
67
Image.57– Monthly Diurnal Temperatures and
comfort levels- Ecotect
Image.58– Psychrometric Chart- showing comfort
level
23 ARC6780 Building Environment Simulation Analysis
Orientation:
Ideal orientation for Montreal is the East-west Orientation where larger part of the building
faces south. The southern facade has the potential for more solar ingress during winters and lesser
during summers. Also, the living spaces oriented in the west and is shaded by an extended terrace. The
roof is a pitched is made sloping to prevent accumulation of snow on rooftops. A greenhouse is also
added on the southern façade to increase the heat in the evening times.
From the images above it is seen that that the northern faces receive very little sunshine. Hence it
is better to locate bedrooms in the north. These rooms will rely on artificial lighting.
Construction elements:
• External walls - Timber clad masonry with insulation provided in the air gap. The
external walls consist of the following layers: 25mm white wood fir +75mm air
gap+80mm polystyrene foam as insulation + 110mm brick masonry+ 75mm air gap
+110mm brick masonry +10mm internal plaster. The u-value attained is 0.28 W/m2K.
Admittance is 4.97 W/m2.K.
Image.59– Optimum Orientation-Ecotect Image.60– Building facing South
Image.61 (a), (b), (c)- Sunshine hours calculation on each facade
24 ARC6780 Building Environment Simulation Analysis
• Internal walls – The internal walls are brick plaster whose U value is 2.64 W/m2.K and
admittance is 4.38 W/m2.K.
• Floor Slab on Ground- Timber floor on Concrete Slab consisting of 50mm white wood
oak flooring + 75 mm Urea Formaldehyde cellulose+ 200mm Plain cement concrete+ 25
mm Vapour barrier+ Compacted soil 1500mm. U value achieved is 0.37 W/m2.K and
admittance is 3.48 W/m2.K.
• Floor Slab of first floor- Suspended Timber floor consisting of 15mm carpet + 5 mm
carpet underlay+10mm plywood+ 50mm Polystyrene as insulation+ 200 mm air gap+
Plaster board 10mm. U value achieved is 0.70 W/m2.K and admittance is 1.44 W/m
2.K.
Image.62– External Walls Layers and properties-Ecotect Materials tab
Image.63-Floor Slab Layers and properties-Ecotect Materials tab
Image.64-Floor Slab (F.F) Layers and properties-Ecotect Materials tab
25 ARC6780 Building Environment Simulation Analysis
• Roof Slab – Clay tiled roof that consists 30mm Clay tiles+ 0.6mm aluminium
foil+50mm fibre quilt+150mm Reinforced concrete slab+75mm air gap+ 10mm plaster.
U value achieved is 0.59 W/m2.K and admittance is 0.98 W/m
2.K.
• Glazing – Double glazed with timber frame with cellulosic insulation. U value is 1.65
W/m2.K and admittance is 0.87 W/m
2.K.
Prevailing Breeze:
Since the prevailing breeze direction is from the south west, this can be used as an advantage in
summers. Hence, the living room is on the western side. However, planting on the west side can deflect
the harsh winds in the winter.
Image.65-Roof Slab (F.F) Layers and properties-Ecotect Materials tab
Image.66-Prevailing wind direction and Design interventions
26 ARC6780 Building Environment Simulation Analysis
Other Interventions:
Thermal Analysis:
For calculation of the thermal performance of the eco house, certain considerations made are:
• The model was simplified in terms of zones namely the Ground floor (zone 1), first floor (zone
2), garage and store as services (zone3) and greenhouse (zone 4).
• The ground, first floor and services were assigned as- ‘Heating only’ system which is the same
as the air conditioning system with only heating being calculated(help file).
• The green house, although being a zone, is not given any conditioning being an external space.
• All the thermal zones were given the following values- activity as sedentary-70W, clothing as
2.0 clo, Air speed as 0.3 m/s, Humidity as 60%, lighting level as 300 lux, Occupancy 6 persons.
• The comfort band was set between18-22⁰C.
Image 67(a), (b), (c)-Design
Interventions
Image.68-Zone settings in Zone Management
27 ARC6780 Building Environment Simulation Analysis
The thermal calculation was run and displayed the following result for the Average coldest day in
and average hottest day in Montreal, Canada.
Image.69- Thermal Analysis for Coldest day Average, 17th
January, in Montreal, Canada
It can be seen from the graph that the ground and first floor and service rooms have achieved the lower
bands of comfort at 18⁰C for most part except at night, according to the operation of the heating system.
A passive strategy of having a greenhouse that dissipates heat into the house at night is proposed but
due to the limitation of the software to detect it, it cannot be displayed in the graph. Zone 4(greenhouse)
is not given any system of operation as it an external element. The average temperature is 18.7⁰C.
Image.70- Thermal Analysis for Hottest day Average, June 27th
, in Montreal, Canada
It can be seen from the graph that the ground, first floor and services (zone 1, 2 and 3) are within the
higher level of the comfort range at 20-22⁰C. Night time temperatures drop in small increments, but are
still within the comfort level. All the zones are below the external temperatures. The green house
however accumulates the heat in the mornings and will release it in the evenings. The average
temperature of all zones is 20.6⁰C.
During the average coldest day in Montreal (see image 71), 1 56 5614Wh of losses occur by the fabric.
The maximum solar gain is 16 2575Wh. The maximum gain occurs by the penetration through opaque
Total Conductance (AU): 2051 W/°K
Total Admittance (AY) : 11 534 W/°K
Total Conductance (AU): 2051 W/°K
Total Admittance (AY) : 11 534 W/°K
28 ARC6780 Building Environment Simulation Analysis
surfaces of wall and roof in the mornings (around 7:00 am to 12:00 pm). The maximum direct gains by
the windows and openings occur in July around 19 033 Wh at 12 pm, from the south faces of the
building.
The graph for the average hottest day average (see image 74) shows that although the inter-zonal heat is
nearly constant, the gains by HVAC are highest at mid day to maintain comfort. Minimum conduction
takes place during the day and increases during midday. The maximum gain through the opaque surface
of the fabrics is 17 2716Wh and gains by the HVAC system is 56 3080Wh. The maximum direct gain
through the windows is 4 8730Wh at 11 am in July.
Max Heating: 10 9171 Wh at 03:00 on 18th January
The distribution of temperature annually is between 16- 20⁰C. The most attained temperature level is
18⁰C (see image 76). The building is in comfort for 6729 Hrs totally, throughout the year.
Image.71-Hourly Gains- Coldest day
Image.72-Sun path-Coldest day
Image.73-Direct Solar Gains
Image.74-Hourly Gains- Hottest day Average Image.75-Sun path-Hottest Day Average
29 ARC6780 Building Environment Simulation Analysis
While comfort has been achieved in most cases, a few limitations of the software prevent accurate
results displaying the performance of the building with the effect of the greenhouse in dissipating heat
into the interiors. In this case, Ecotect has just assumed the effect of the orientation and building fabric,
for calculating the thermal performance of the building.
Lighting Analysis:
A comparative tabulation of the lighting analysis was made:
Space Required (CIBSE) Achieved Accepted Refer
image. Daylight
Factor
(%)
Illuminence
(Lux)
Daylight
Factor (%)
Illuminence
(Lux)
Living rooms
and Dining
rooms
1.5 5-200 33.27 1135 Yes 82,83
Bedrooms 1 100 GFa-1.28
FFa-39.82
FFb-1.17
FFc-4.65
GFa-150
FFa-950
FFb-250
FFc-450
Yes 84
Kitchen 2 300 16.57 400 Yes 85
Bathroom - 100 GFa-0.7
FFa- 1
GFa-100
FFa- 95
Yes 88
Zone Comfort(hrs) Comfort (%)
Ground 5315 90.2
First 5362 91
Services 5522 93.7
Greenhouse 2274 41.8
Image.76-Temperature Distribution Graph
Image.77-Comfort Chart- Each zone
The percentage value of the design sky using the latitude
is 7200 lux (see image 78). But for this analysis Tregenza
Formula is used which states the design sky value to be
7215 Lux. All calculations are taken at 85cm from the
ground. Image.78-Design Sky calculations- Latitude
30 ARC6780 Building Environment Simulation Analysis
FFb- 0.8 FFb- 115
Office 2-4 300 4.23 400 Yes 88
The following images show the light analyses for the ground and first floor respectively. The spaces on
the south are better lit than the rooms on the north. The day lighting analysis for individual spaces will
be discussed in detail. The bedroom on the north east corner is benefited with an extra window to
improve the Illuminence levels. Enabling the ‘Show Average Value’ displays the average daylight
factor which is 27.43% for the first floor and 22.56% for the ground floor. The Analysis grid was set at
850 mm from floor level in all cases.
All artificial lamps are 40 watts of Compact fluorescent lamps and the parameters of the lamp
fixtures are specified in the materials as shown in the image 79.
The following analyses were made by exporting the data to ‘Radiance’. The settings selected were-
Overcast sky settings, Using Ecotect’s sun angles and design sky which generates images according to
the camera settings in the following spaces:
Image.78-Daylight Analysis- Ground floor
Image.80-Daylight Analysis- First floor
Image.79-Artificial lamps- Materials Tab
Image.81-Daylight Analysis- First floor after Intervention
31 ARC6780 Building Environment Simulation Analysis
Living room- Lighting Analysis shows that when the overcast sky conditions are set, the living room
does not have enough illuminence (fig1). Hence, artificial lighting in the form of low energy compact
fluorescent lamps (CFLs) is recommended. The ‘False colour’ settings enable to give a more uniform
result of the space. More than 950 Lux of illuminence is achieved uniformly. The Average daylight
factor achieved is 33.27%.
Bedroom 1 (GF) - Average Daylight Factor is between 1.28% which is sufficient for bedrooms.
Master bedroom (FF) - Average Daylight Factor is 39.82% which is sufficient for bedrooms, mainly
because of its southern orientation (see image 85).
Image.82-Lighting analysis Living room-Before and after adding artificial lighting
Image.83-Lighting analysis for Living room
Image.84-Lighting analysis for Bedroom (GF)
Image.85-Lighting analysis for Master Bedroom (FF)
32 ARC6780 Building Environment Simulation Analysis
Pantry (GF) – Two artificial lamps are provided to improve the ADF of
the pantry which is 2.05% with artificial lighting (see image 86).
Lounge - Average Daylight Factor first floor lounge is 4%.
Kitchen (G.F.) - Average Daylight Factor is 16.57% which is more than the required 2%.The
illuminence varies between 350-550 lux.
Bathroom (G.F.) - Average Daylight Factor is 0.7% for bathrooms in the ground floor.
Image.86-Pantry (GF)
Image.87-Lighting analysis for Lounge (FF)
Image.88-Lighting analysis for Kitchen (GF)
Image.89-Lighting analysis
for Bathroom (GF)
33 ARC6780 Building Environment Simulation Analysis
Other spaces:
Ground floor lobby-between 90-570 lux First floor bathroom-1% ADF Office/Study-4.23%
The analyses conducted in the eco house helps to understand the illuminence within the house of
various spaces for different sky conditions. As the Eco house is assumed to exist in an open site with no
surrounding obstructions, the overshadowing of surrounding structures has not been taken into
consideration. However, as choosing an overcast sky condition means analysing the lighting levels in a
much restricted scenario, and after achieving the required standards, it can be deduced that the spaces
are adequately lit. The overall consumption of the electric loads due to artificial lamps will be discussed
under resource consumption.
Resource Consumption:
The resource consumption calculation is essential in understanding how much energy is consumed by
the building in order to maintain comfort and achieve everyday activity. Resources include electricity,
water, gas, petrol, diesel and oils. At the moment, only solar collection and water are considered as
production resources (Ecotect Help).
To supplement the load of the HVAC system and the electric loads, photovoltaic panels are added. The
system chosen is a mixed mode system with 100% efficiency. The maximum heating is required in
January. The monthly heating loads (see image 88) indicate that 29 38 0136 Wh is required for heating
and 12 57 9360Wh load is consumed by electricity (appliances, light fixtures). To reduce the impact on
Image.90 -Lighting analysis for Bathroom (GF)
Image.91 (a), (b), (c) -Lighting analysis for other spaces
34 ARC6780 Building Environment Simulation Analysis
the environment, Compact fluorescent lamps are suggested, which are energy efficient as compared to
ordinary lamps. A 40 Watt lamp (specified for lamps in the project) generates same illuminence as a 150
Watts ordinary lamp. Hence, more energy can be conserved.
The image below illustrates the monthly heating loads consumed by the building. During winters 29 38
0136Wh of heating is required by the building. The maximum head loads consumed is 12 0976 W at
19:00 on 4th February.
Photovoltaic cells are used to generate energy and supplement the loads of the building. The panels
occupy a total area of 80.4 m2. According to the formula Optimum angle (in degrees) = (your latitude x 0.9) + 29, the
optimum orientation for solar panels mounting is 70⁰ tilt towards the southern direction. The solar panels
will be placed on the sloped roof. The efficiency of the solar collectors was set 100% for efficiency and
100% for space heating efficacy. During the summers, when there is maximum sunshine, the solar panels
can collect 16 14 7293 Wh of energy which is roughly a third of the energy consumption of the building.
When part of the resources is derived from renewable sources, the Eco house is closer to attaining a low
energy standard. The graphs below describe the solar energy generation (16 14 7293 Wh) and the loads
generated within this building is (29 38 0136 Wh). The size of each panel is 0.9x0.95 m.
Image.92 –Resource
Consumption- Daily Energy Use
Image.93 –Monthly Heating loads
Image.95 –Total Energy Collected Image.94 –Resource usage- Hourly Electrical Usage
35 ARC6780 Building Environment Simulation Analysis
Potential Renewable Energy Sources:
.
As Montreal receives very less sunshine during
peak winters and the hazard of snow accumulation
on rooftops cannot be ignored, the Eco house will
have to depend on an alternate source of
renewable energy as well. Apart from the solar
panels which can cater to the electric loads of the
building, the Eco house will rely on the potential
of the wind to generate electricity by providing
wind turbines. From the charts below the
character of the winds can be determined. The
direction of the prevailing breeze is south west.
The highest temperature that the wind achieves is
around 20⁰C. A building mounted wind turbine is
around 1-2kW in size, much smaller than pole
mounted wind turbines. A 6kW turbine is capable
of generating around 10,000kWh per year. For the
Eco house in Montreal, around 300 kW will be
generated with a 2kW size of Turbine placed on
the roof (Energy Savings Trust, 2012). This will
supplement the power requirements of the Eco
house.
Image.96 –Daily Load Matching Image.97 –Solar panels placed on roof
Image.98 –Annual Wind Analysis
Image.99 –Wind Turbine Operation
www.windenergy7.com (online).
36 ARC6780 Building Environment Simulation Analysis
DETAILED COMPARISON
FACTORS Eco house- India Eco house- Canada
Climate Composite- warm humid summers, cold
winters
Humid Continental- cold most of the
time
Climatic discomfort Overheating in summers, excess solar
ingress, cool winters
Too cold
Building orientation East west- to avoid harsh summer sun East-west- to gain solar ingress from
south face.
Building parameters
Total Building area 724.168 m2 531.345 m
2
Total opaque exposed surface area 869.880 m2 450.349 m
2
Total glazing area 42.590 m2 92.818 m
2
Materials
Walls External- Brick Cavity Wall
Internal-Brick plaster
External- Timber clad hollow masonry
Internal-Brick plaster
Floors Concrete slab with tiles, insulation
provided
Suspended Timber carpeted floor
Roofs Suspended concrete Ceiling with
insulation provided
Clay tiled sloped roof with insulation
Glazing Double Low E glass with aluminium
frame.
Double Glazed with timber frame
Thermal Analysis-Hottest day Average
Average temperature achieved 24.4⁰C 20.6⁰C
Heat Flow(Fabric) 11 0404Wh 17 2716Wh
Heat flow(Glazing) 3 2425 Wh 4 8730Wh
By HVAC 50 3250Wh 0
37 ARC6780 Building Environment Simulation Analysis
Thermal Analysis-Coldest day Average
Average temperature achieved 13⁰C 18⁰C
Heat Flow(Fabric) -8 7800 Wh -1 56 5614Wh
Heat flow(Glazing) 3 0235 Wh 19 033 Wh
By HVAC 11 1472 Wh 56 3080 Wh
Building Design
Passive Techniques Thermal mass of walls, Stack effect Greenhouse
Ventilation Cross ventilation in living spaces Well sealed envelope.
System adopted Mixed Modal system-95% Heating only-100%
Shading External Sun shades an internal blinds -
Energy
Needed by HVAC 3 55 7304 Wh - heating
17 14 0620Wh – cooling
29 38 0136 Wh
Electricity 15 01 8696 Wh 12 57 9360Wh
Solar collected 19 84 1492 Wh 16 14 7293 Wh
Collection point and area Roof- 70.7 m2 On sloped roof- 80.4 m
2
Potential renewable Energy Source
To Supplement the loads of the
building
Solar panels
Hydroelectric power
Solar Panels
Wind Turbine
38 ARC6780 Building Environment Simulation Analysis
Conclusion:
The performance of the Eco house was analysed in two different climatic conditions. By
understanding the climate of each location, the behaviour of the entire building in response to the
climate was known. Then appropriate solutions were suggested to achieve the standards of thermal and
lighting. In order to make the building more energy efficient and consume lesser energy for operation,
alternate energy sources were recommended from renewable sources like the sun and the wind.
By understanding the demands that climate makes on the building, appropriate solutions were
made. For example, the Eco house in New Delhi, was sensitive to the maximum solar ingress from the
west direction and hence the building was oriented to curb excess soar ingress. Also considering the
impact of increased humidity in the home, cross ventilation was suggested. The heavy thermal mass of
the walls with its cavity and insulation prevents the ingress of heat in summers and at the same time
brings in the heat during the winters by slowly dissipating it into the interiors. The southern surfaces also
help to keep the building warm during winters but tend to accumulate heat during summers and hence a
lawn is proposed in front of the living room on the South, to disintegrate the solar rays.
In Montreal, the northern side receives lesser sunshine and hence the spaces are rearranged in
such a way that only the bedrooms are on the north side. As more heat losses occur from the northern
side, the size of the openings is reduced in the north side. Also to avoid the impact of the harsh breeze
from the south west direction, suitable planting of conifers and deciduous trees in the western side will
significantly help maintain comfortable interior conditions. The materials on the building envelope also
help considerably in achieving thermal comfort.
To achieve the best practice of construction, the U value standards were consulted and then
appropriate choice of materials that attain those target values were selected. By understanding the
properties of these materials and how low U values can prevent heat transfer into interiors and at the
same time even prevent heat losses, it was possible to maintain optimum comfort in the interiors.
Further, the choice of material is also governed by the context and easy availability in a particular
region. For example the abundance in oak wood in Canada, was related to specifying it as a façade
material.
Lighting analysis for India proved that all spaces were adequately lit naturally during daytime. In
Montreal, the rooms in the north required certain alterations to meet adequate standards. Further,
artificial low energy CFLs were suggested to achieve adequate illuminence. Since winters in Montreal
receive lesser sunshine especially the facades, it is wiser to provide skylights on the roof to cater to
natural lighting. Since, New Delhi suffers from excess glare of sun in the evenings in summers and the
high solar incidence, it is better to provide illumination by shaded windows on the wall surfaces instead
of skylight.
It is always better for a building to derive benefits from the passive environmental system for
heating and cooling systems. By doing this the building will depend less on mechanical methods of
achieving comfort. Having done the analysis for both thermal and lighting, and proposing relevant
solutions, the performance of the building and its loads will help realise how energy efficient the Eco
house is.
39 ARC6780 Building Environment Simulation Analysis
References:
• CIBSE concise handbook / [Chartered Institution of Building Services Engineers,(2001), London
• Energy Savings Trust.(2012). Available at http://www.energysavingtrust.org.uk/Generate-your-
own-energy/Wind-turbines. (Accessed on 22/12/2012).
• Green Building Guide.(2012) Available at http://www.greenbuildingadvisor.com/green-
basics/structure-exterior-walls. (Accessed on 22/01/2012).
• Indian Green Building Council.(2012) Available at http://www.igbc.in/site/igbc . (Accessed on
22/01/2012).
• McMullan, R. (2002) Environmental Science in Building. 6th Edition. United States, Palgrave.
• Natural Frequency. Ecotect Community (1994 - 2011) Design Sky, available at
http://wiki.naturalfrequency.com/wiki/Design_Sky. (Accessed on 22/01/2012)
• Torcellini,P., Pless, S. et al. (2006) Zero Energy Buildings:A Critical Look at the Definition.
Conference Paper at National renewable Energy Laboratory, Pacific Grove. California.
• Solar panel orientation.(20120. Available at http://24volt.co.uk/info/SolarPanels/Mounting
SolarPanels. (Accessed on 22/01/2012).
• US Department of Energy (2012) available at http://apps1.eere.energy.gov/buildings/energyplus
/cfm/weather_data.cfm
• WIKIPEDIA (2012) New Delhi, India climate available at http://en.wikipedia.org/wiki/Acapulco
(Accessed on 22/01/2012)
• WIKIPEDIA (2012) Montreal, Canada climate at http://en.wikipedia.org/wiki/Rome (Accessed
on 22/01/2012)