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Idea Transcript
Study of Thermal Sensation of Occupants in Office Buildings located in Hot and Dry Climatic Zone, Ahmedabad, India
Guide: Rajan Rawal Chinta Shree Sowmya Masters In Interior Architecture And Design CEPT University IA 1510 This work by ‘Chinta Shree Sowmya’ is Part Fulfillment of the requirement for Masters’ Degree in Interior Design Program at CEPT University. Intellectual property of these remains with CEPT University and any content of this should not be copied in total or in part without prior written permission.
Objectives
•
To analyse the suitability of thermal comfort standards set by ASHRAE 55 for naturally ventilated buildings with respect to Hot and Dry climatic zone of India.
•
To understand the relationship between thermal comfort and building envelope design in case of naturally ventilated office buildings.
Scopes and limitations •
This study is a part of a larger study that would validate the suitability of thermal comfort standards set by ASHRAE 55 for naturally ventilated buildings for whole of India.
•
The study is restricted to commercial buildings (Office buildings) of Ahmedabad and does not cover other cities which lie in Hot and dry climatic zone.
This work by ‘Chinta Shree Sowmya’ is Part Fulfillment of the requirement for Masters’ Degree in Interior Design Program at CEPT University. Intellectual property of these remains with CEPT University and any content of this should not be copied in total or in part without prior written permission.
Literature Review
Energy Balance equation
Factors affecting thermal comfort Air temperature, Relative humidity, Mean radiant temperature, air speed, Metabolic rate ,Clothing
Types of adaptation Behavioral adaptation Physiological adaptation Psychological adaptation
Thermal comfort models PMV Model Adaptive thermal comfort model Comparison of PMV model and the adaptive model.
Comfort zones (N.V, A.C buildings) Overview of Thermal comfort Studies in India This work by ‘Chinta Shree Sowmya’ is Part Fulfillment of the requirement for Masters’ Degree in Interior Design Program at CEPT University. Intellectual property of these remains with CEPT University and any content of this should not be copied in total or in part without prior written permission.
Methodology
Methodology
Licensed Survey form/Design of survey form
Pilot study
Field study
N.V building
Selection of Building Type
Identification of Physical parameters
Instruments used
Data collection
Calculation of various indices
This work by ‘Chinta Shree Sowmya’ is Part Fulfillment of the requirement for Masters’ Degree in Interior Design Program at CEPT University. Intellectual property of these remains with CEPT University and any content of this should not be copied in total or in part without prior written permission.
Conclusion
Pilot Study CEPT University
Inferences and Conclusions •
When TSVS were plotted against the zone specified by ASHRAE 55 Standards for naturally ventilated building, they were lying inside the zone
•
This clearly indicates that the ASHRAE 55 Standards
for
air
conditioned
buildings
underestimates the comfortable temperature ranges and these ranges are not suitable for naturally ventilated buildings in hot/dry
Adaptive comfort zone , ASHRAE 55, (N.V buildings) based on Mean monthly outdoor temperature and on 2nd Dec Based on Mean monthly outdoor temperature Based on outdoor temperature at 3:30pm on 2nd Dec
climate. •
ASHRAE 55 Standards for naturally ventilated are suitable for winter season in hot and dry climate zone. This work by ‘Chinta Shree Sowmya’ is Part Fulfillment of the requirement for Masters’ Degree in Interior Design Program at CEPT University. Showing occupants against comfort zone of N.V building Intellectual property of these remains with CEPT University and any content of this should notFigure be copied in totalTSVS or in of part without prior written permission.
Winter Survey
•
No of Buildings:2
•
Total No. of subjects surveyed: 326
•
Building Type: Air conditioned, naturally ventilated Building
•
Case Study 1- Torrent Power Corporate, Ashram Road
•
Case Study 2- Ahmedabad Urban Development Authority, Ashram Road
•
Dates of Survey- 16thJanuary – 20th January
•
Mean running air temperatureφ of preceding week=20.5°C
• φ
Mean monthly dry bulb
temperatureφ=
21°C
Proposed range of operative temperature for N.V building as per ASHRAE 55 in winter at mean outdoor temperature of 21°C
Data was obtained from the weather station located at CARBSE, CEPT University. This work by ‘Chinta Shree Sowmya’ is Part Fulfillment of the requirement for Masters’ Degree in Interior Design Program at CEPT University. Intellectual property of these remains with CEPT University and any content of this should not be copied in total or in part without prior written permission.
Case study 1 Torrent Power Corporate
Date: 16th Jan, 2012 Building Type: Air conditioned buildings No of Subjects: 169 Observations Operative temperature ranges: 23.0°C -28.7 °C Air velocities: Less than 2m/s Humidity levels: 56.4 % - 37.8% Outdoor environmental temperature: 23.525.5°C Clothing insulation : 1 clo Metabolic rates- About1.2 MET TSV: 151 subjects: -1.5 < 0 < 1.5 votes 19 Subjects: out of range
This work by ‘Chinta Shree Sowmya’ is Part Fulfillment of the requirement for Masters’ Degree in Interior Design Program at CEPT University. Intellectual property of these remains with CEPT University and any content of this should not be copied in total or in part without prior written permission.
Case study 1 Torrent Power Corporate
Ashrae comfort zone based PSYCHROMETRIC CHART
on the PMV model (A.C buildings)
30 34
100
33 30
95
25
29
DR Y
F
-°
C
O
27
TE MP ER AT UR E-
65
N
TE M
20
25
SA TU RA TIO
60
20
50
15
40
80
%
(TSV= -1.5 ≤ x ≤ 1.5) as well as dissatisfied (1.5 <
TSV ≤ 3 or -3 ≤ TSV ≤ -1.5) were not lying in winter
25 10
10
25 25
23 22 21 20 19 18 20 17 16 15 14 13
40
105
100
95
90
85
12 11
10
10
110
24
80
10
20
15
115
26
°C
25
PE RA TU RE
KG
PE R -K J
The occupants who have voted to be comfortable
%
9
75
8 7
5
30%
5
5
70
6
10 0
DEW POINT - °C
comfort zone.
WE TB UL B
75
70
120
28
AIR
80
EN TH AL PY
•
30
HUMIDITY RATIO - GRAMS OF MOISTURE PER KILOGRAM OF DRY AIR
Comfort Zone
125
30
85
1.
130
32 31
90
20% IDIT ATIVE HUM 10% REL
Y
5 0 4
65
3 -10
2
-20
1
60
-40 0
5
10
15
20
25
2.
Percentage of Dissatisfied:
•
Position of dissatisfied occupants were plotted and
Ashrae comfort zone based on the PMV model (A.C buildings)
found to be almost equally distributed in all the
PMV- Summer zone PMV- winter zone
wings. •
PPD was found to be 11%
•
Reasons for dissatisfaction was feeling of stuffiness
0
5
30
35
40
45
50
55
DRY BULB TEMPERATURE - °C
Linric Company Psychrometric Chart, www.linric.com
10
15
20
25
30
35
1.5 < TSV ≤ 3 or -3 ≤ TSV ≤ -1.5
due to lack of air movement, seating of occupants near to A.C outlets.
This work by ‘Chinta Shree Sowmya’ is Part Fulfillment of the requirement for Masters’ Degree in Interior Design Program at CEPT University. Intellectual property of these remains with CEPT University and any content of this should not be copied in total or in part without prior written permission.