energy efficiency

1. CT3608 – Building Materials & Methods
for Energy Efficiency
MID TERM ASSIGNMENT
Submitted by: Pruthvirajsinh Vaghela
Guided by: Rashmin Damle
Spring 2023
Faculty of Technology, CEPT University

2. Location: Sargasan, Gandhinagar (Gujarat)
Type of residence: 4bhk Flat (7floors)
Latitude: 23°18’315”N
Longitude: 72°62’178”E
2

3. Location: Sargasan, Gandhinagar (Gujarat)
Type of residence: 4bhk Flat (7floors)
Farm Land
Trees
HOUSE MODELLED INIESSOFTWARE
Built-UpArea
Road
Water Body
Dwelling
N
Latitude: 23°18’315”N
Longitude: 72°62’178”E
SITECONTEXT PLAN
3

4. N
DWELLING LAYOUT
4

5. +2926.08 MM
SLAB BOTTOM LVL
+2438.4 MM
LINTEL LVL
+432.48 MM
SILL LVL
+00 MM
GROUND LVL
+1510.6 MM
SILL LVL
SECTION AA'
BEDROOM- 3 DUCT
TOILET BEDROOM- 1 Pooja HEN
KITC
STORE SERVANT ROOM
+00 MM
GROUND LVL
+2926.08 MM
SLAB BOTTOM LVL
+2438.4 MM
LINTEL LVL
SECTION BB'
DRAWING
LIVING ROOM
GROUND LVL
+00 MM
+2926.08 MM
SLAB BOTTOM LVL
+2438.4 MM
LINTEL LVL
SECTION CC'
KITCHEN DINING VESTIBULE DRAWING BALCONY
+1510.6 MM
SILL LVL
GROUND LVL
+2926.08 MM
SLAB BOTTOM LVL
+2438.4 MM
LINTEL LVL
+432.48 MM
SILL LVL
+00 MM
SECTION DD'
BEDROOM- 3
BEDROOM- 4
LIVING ROOM
N
SECTIONS
5

6. N
ELEVATIONS
GROUND LVL
+00 MM
+2926.08 MM
SLAB BOTTOM LVL
+2438.4 MM
LINTEL LVL
NORTH ELEVATION (WWR: 0)
+2926.08 MM
SLAB BOTTOM LVL
+2438.4 MM
LINTEL LVL
+432.48 MM
SILL LVL
+00 MM
GROUND LVL
EAST ELEVATION (WWR: 0.45 OR 45%)
+2926.08 MM
SLAB BOTTOM LVL
+2438.4 MM
LINTEL LVL
+432.48 MM
SILL LVL
+00 MM
GROUND LVL
SOUTH ELEVATION (WWR: 0.11 OR 11%)
GROUND LVL
+2926.08 MM
SLAB BOTTOM LVL
+2438.4 MM
LINTEL LVL
+432.48 MM
SILL LVL
+00 MM
+1510.6 MM
SILL LVL
WEST ELEVATION (WWR: 0.34 OR 34%)
6

7. 7
DOOR – WINDOW SCHEDULE
Window/Door Name No. of Openings Opening width (m) Opening height (m) Glass width (m) Glass height (m)
Door D1 5.00 0.90 2.40 - -
Door D2 8.00 0.80 2.40 - -
Other W1 2.00 1.25 2.40 1.00 2.24
Window-2 pane W2 2.00 1.00 1.80 0.84 1.64
Window-2 pane W3 2.00 1.17 1.80 1.01 1.64
Other W4 2.00 0.90 1.80 0.74 1.64
Window-2 pane W5 1.00 1.07 0.60 0.91 0.44
Door-Window Schedule

8. DOORS - WINDOWS SCHEDULE TYPICAL WALL SECTION
Tile Flooring
(10mm thick)
Internal Plaster
(12mm thick)
External Plaster
(20mm thick)
RCC Chajja
8

9. NORTH ELEVATION SOUTH ELEVATION
9

10. EAST ELEVATION WESTELEVATION
10

11. DWELLINGIMAGES
BEDROOM-1
BEDROOM-2 BEDROOM-3 BEDROOM-4
LIVINGROOM DINNINGAREA KITCHEN
DRAWING ROOM
POOJA VESTIBULE
WASH AREA SERVANT ROOM 11

12. 12
OPENABLE WINDOW-TO–FLOORAREARATIO(WFRop)
 Openable window-to-floor area ratio (WFRop) indicates the potential of using external air for ventilation.
Ensuring minimum WFRop helps in ventilation, improvement in thermal comfort, and reduction in cooling
energy.
 The openable window-to-floor area ratio (WFRop) is the ratio of openable area to the carpet area of dwelling
units.
 Total openable window area of all facades for my house is 45.96 m²
 Total carpet area of my house is 262.5 m²
 Therefore, WFR for my house = 0.1750 = 17.50 %
 Therefore, it does satisfy the minimum requirement of ECBC

13. 13
VISSIBLELIGHTTRANMITTANCEVALUE
 Table given above has all the values in m²
 WWR for my house including all facades =
25% = 0.24
 VLT considered for the glass used in
windows of my house = 40% = 0.4
 According to ECBC, VLT should be
minimum of 0.27, therefore it is satisfying
the limit.
GROSS WALL AREA WINDOW AREA WWR
NORTH
43.20
9.84 22.77%
SOUTH
52.50
7.08 13.48%
EAST
45.00
16.15 35.88%
WEST
48.90
13.16 26.91%
U value (W/m2-K) 1.3
SHGC 0.17
VLT 71
Material
U value (W/m2-K) 5.4
Material
U value (W/m2-K) 2.09
Material details
Brick
Aluminum
Glass
Frame
Wall

14. UVALUEOFROOF
 Thermal transmittance (U roof) characterizes the thermal performance of the roof of a building. Limiting the thermal
transmittance of roof helps in reducing heat gains or losses from the roof, thereby improving the thermal comfort
and reducing the energy required for cooling or heating.
 The U value of the roof is coming 2.97 W/m2.K
 According to ECBC maximum U-Value of the roof should be 1.2 W/m2.K but as the U-Value of the roof is coming
higher than the required value, it doesn’t comply with ECBC.
Components Layers T
hickness KValue RValue ∑ R
Surface Film T
hermal
Resistance (Rsi & Rso)
Rt = ∑R+ Rsi + Rso U Value
- - mm W/ m.k m2
.K/ W m2
.K/ W m2
.K/ W m2
.K/ W W/ m2.K
Granite T
iles 10 2.790 0.004
M ortar Bedding 20 0.719 0.028
RCC S
lab 125 1.580 0.079
Ceiling Plaster 12 0.721 0.017
U VALUECALCULAT
ION
According to - Eco-NiwasSamhita 2018 - (Energy Conservation Building Code for Residential Buildings)
Roof 0.1272 Rsi=0.17, Rso =0.04 0.3372 2.97

15. ENERGY ANALYSIS RESULTS
Table showing total energy consumed throughout the year
15
 Total carpet area of my house = 262.5 m²
 Therefore, annual energy consumption per unit area = 91..75 KWh/m²/yr
DATE RS KWh
January & February 252 1797
March & April 861 6148
May & June 1097 7856
July & August 606 4628
September & October 373 2728
November &
December
135 929
Summed Total 3324 24086

16. U VALUE AND SHGC VALUE
16
U Value
 Thermal transmittance (U value) is the heat transmission in unit time through unit area of a material or
construction and the boundary air films, induced by unit temperature difference between the environments on
either side. Unit of U value is W/m2.K. The U value for a wall/roof/glazing indicates its ability to transfer heat
through conduction.
 Orientation Factor (ω) : The orientation factor (ω) is a measure of the amount of direct and diffused solar
radiation that is received on the vertical surface in a specific orientation. This factor accounts for and gives
weightage to the fact that the solar radiation falling on different orientations of walls is not same.
SHGC Value
 Solar Heat Gain Coefficient (SHGC): SHGC is the fraction of incident solar radiation admitted through non-
opaque components, both directly transmitted, and absorbed and subsequently released inward through
conduction, convection, and radiation
 SHGC Equivalent is the SHGC for a non-opaque component with a permanent external shading projection. It is
calculated by multiplying the External Shading Factor (ESF) with the SHGC of unshaded non-opaque component.

17. RETV (Residential Envelope Heat Transmittance)
17
 Residential envelope heat transmittance (RETV) is the net heat gain rate (over the cooling period) through the
building envelope (excluding roof) of the dwelling units divided by the area of the building envelope (excluding
roof) of the dwelling units. Its unit is W/m2.
 The RETV for the building envelope (except roof) for four climate zones, namely, composite climate, Hot-Dry
climate, Warm-Humid climate, and Temperate climate, shall comply with the maximum RETV of 15 W/m2.
Summary of steps :
1) Openable window-to-floor area ratio (WFRop)
1.1. Calculation of total openable area (openable)
1.2. Calculation of total carpet area (carpet)
1.3. Calculate the openable window-to-floor area ratio (WFRop)
2) Visible Light Transmittance (VLT)
2.1. Calculation of window-to-wall ratio (WWR)
3) Thermal transmittance of roof (Uroof)
3.1. Calculation of thermal transmittance of roof (Uroof)
4) RETV of the building envelope (except roof)
4.1. Calculation of envelope area, in every orientation
4.2. Calculation of eqivalent SHGC of non opaque opening in each
orientation
4.3. Calculation of RETV

18. 18
RETV (Residential Envelope Heat Transmittance)
Opening Details Non-Opaque (Glass) Area Opaque Area 1 (Frame)
Orientation
Window/Door/
Ventilator
Name
No. of
Openings
Opening
width (m)
Opening
height (m)
H
overhang
V
overhang
H
right
V
right
H
left
V
left
Opening
area
(m2)
Total
Opening
area (m2)
Glass
width
(m)
Glass
height
(m)
Glass
area in
opening
(m2)
Total Glass
area in
opening
(m2)
Opaque area
(m2)
Total Opaque
area (m2)
North D1 1.00 0.90 2.40 2.16 2.16 - -
North D2 1.00 0.80 2.40 1.92 1.92 - -
East W1 2.00 1.25 2.40 2.50 3.00 2.50 3.00 2.50 3.00 3.00 6.00 1.00 2.24 2.24 4.48 0.76 1.52
East W2 1.00 1.00 1.80 0.60 2.00 0.60 2.00 0.60 2.00 1.80 1.80 0.84 1.64 1.38 1.38 0.42 0.42
West D1 1.00 0.90 2.40 2.16 2.16 - -
South D2 1.00 0.80 2.40 1.92 1.92 - -
East W3 1.00 1.17 1.80 0.60 2.00 0.60 2.00 0.60 2.00 2.11 2.11 1.01 1.64 1.66 1.66 0.45 0.45
West D1 1.00 0.90 2.40 2.16 2.16 - -
North D2 1.00 0.80 2.40 1.92 1.92 - -
South W4 2.00 0.90 1.80 1.68 2.00 1.68 2.00 1.68 2.00 1.62 3.24 0.74 1.64 1.21 2.43 0.41 0.81
West W3 2.00 1.17 1.80 0.60 2.00 0.60 2.00 0.60 2.00 2.11 4.21 1.01 1.64 1.66 3.31 0.45 0.90
East D1 1.00 0.90 2.40 2.16 2.16 - -
North D2 1.00 0.80 2.40 1.92 1.92 - -
West W2 1.00 1.00 1.80 0.60 2.00 0.60 2.00 0.60 2.00 1.80 1.80 0.84 1.64 1.38 1.38 0.42 0.42
East D1 1.00 0.90 2.40 2.16 2.16 - -
South D2 1.00 0.80 2.40 1.92 1.92 - -
West W5 1.00 1.07 0.60 0.60 0.90 0.60 0.90 0.60 0.90 0.64 0.64 0.91 0.44 0.40 0.40 0.24 0.24
North D2 1.00 0.80 2.40 1.92 1.92 - -
West D2 1.00 0.80 2.40 1.92 1.92 - -
East D2 1.00 0.80 2.40 1.92 1.92 - -
U value (W/m2-K) 1.3
SHGC 0.17
VLT 71
Material
U value (W/m2-K) 5.4
Material
U value (W/m2-K) 2.09
Material details
Brick
Aluminum
Glass
Frame
Wall
[(a x Total A) + (b x Total B) + (c x Total C)]
A ev
a 6.06
b 1.85
c 68.99
RETV Obtained 12.42 W/m2
Max RETV 15 W/m2
Calculation of RETV
RETV

19. 19
South
East
West
North-East
North-West
South-West South-East
22.5
67.5
112.5
202.5 157.5
247.5
292.5
337.5
RETV CALCULATIONS
Orientation 1 (Original North)
North
South
East
West
North-East
North-West
South-West South-East
22.5
67.5
112.5
202.5 157.5
247.5
292.5
337.5
Orientation 2 (North-East)
North
South
East
West
North-East
North-West
South-West South-East
22.5
67.5
112.5
202.5 157.5
247.5
292.5
337.5
Orientation 3 (East)
North
RETV- 12.33
Orientation 7 (West)
North
South
East
West
North-East
North-West
South-West South-East
22.5
67.5
112.5
157.5
247.5
292.5
337.5
202.5
RETV- 12.28
Orientation 4 (South-East)
South
East
West
North-East
North-West
South-West South-East
22.5
67.5
112.5
157.5
202.5
247.5
292.5
337.5
RETV- 12.42
Orientation 5 (South)
North
RETV- 12.23
South
East
West
North-East
North-West
South-West South-East
22.5
67.5
112.5
157.5
202.5
247.5
292.5
337.5
RETV- 12.37
Orientation 6 (South-West)
North
RETV- 12.31
North
South
East
West
North-East
North-West
South-West South-East
22.5
67.5
112.5
157.5
202.5
247.5
292.5
337.5
RETV- 12.40
North
South
East
West
North-East
North-West
South-West South-East
22.5
67.5
112.5
157.5
202.5
247.5
292.5
337.5
Orientation 8 (North-West)
RETV- 12.41
12.37
12.33
12.28
12.23
12.31
12.4 12.41
12.2
12.15
12.1
12.25
12.3
12.35
12.42
12.4
12.45
N NE E SE S SW W NW
Direction vs RETV Value
Conclusion:
 RETV value of original (North) of dwelling is 12.42 which is highest from
the other orientations. If the orientation changes to South, RETV value
improves to 12.23 which can be the best orientation of dwelling.
 RETV value should be under 15, all the orientations’ value are under 15.

20. RETV CALCULATIONS
20

21. 21
ASSUMPTIONS
 For detailed formulas and calculations, please do refer the attatched excel sheet where you can find all the
necessary steps and answers.

22. 22
Thank you