Adaptive thermal comfort in offices of North-East India
Introduction
 India is a large country with vast climate, social cultural and economic diversity.
 India rapid growth is creating huge demand for infrastructure.
 The climate of North-East (NE) India as well as office buildings construction and operationis quite different compared to rest of India.
 Literature survey shows that no studies done on the assessment of thermal comfort in theoffices of North-East India.
 Studies showed that a more balanced approach is “Adaptive thermal comfort” which
integrate subject’s thermal preferences in deciding the thermal environment

Location of Study

Objective To assess thermal comfort, thermal preferences and behavioural adaptations in
the offices of NE India.
Figureshows
naturally
ventilated office setting, sitting
arrangement and furniture in
NE India. .

Griffiths comfort temperature is calculated byapplying following equation to every TSV.
Tc=Tglobe+(0-TSV)/GFigure shows the distribution of Griffiths comfort
temperature corresponding to constant 0.33. Comfort
temperature corresponding to Griffiths constant 0.33
is ≈ 27.3 °C.

Regression analysis of thermal sensation
votes w.r.t. globe temperature with 95%
confidence line shows slope of 0.33 andcomfort temperature at 27.2 °C. It meansthat approximately 3°C change in indoor
globe temperature will lead to shift in one
thermal sensation.

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Traditional dressing patterns of
women in the offices ofShillong. Clothing insulation
value of these ensembles are
not defined in ASHRAE
Standard 55.

加藤研究室・大岡研究室・菊本研究室
Kato Lab., Ooka Lab., and Kikumoto Lab.

Adaptive thermal comfort in offices of North-East India
Plot of clothing insulation value against thermal sensationshows that deviation in clothing insulation level is higher
towards cooler side of the thermal sensation scale. In
other words we can also say that subjects do moreadjustment or clothing related adaptation at cooler
temperatures compared to warmer temperatures.

Preferredtemperatureis
calculated by carrying out ordinal
regression and probit as linked
function after converting thermal
preferences votes to binary form.
thermalpreference
votes
converted to binary form. It can beseen that both lines intersect at24.5°C. Preferred temperature is2.8°Clower
than
comforttemperature.

Plot of clothing insulation
value against indoor globe
temperature
shows
that
cubic regression line bends
inwards at temperature atlow and high temperature
showing clothing adaptation.
This Figure shows the combined information
presented by above two figures (far left andright). Clothing value cannot go very low andvery high because of physical and socialcultural limitation.

Entire North-East India has high relative humidity and increasing air
velocity is the only remedy left with subjects in naturally ventilated offices
to restore comfort. Logistic regression analysis on proportion of fan use
shows that at 33°C almost all the fans in the offices are operating. It isinteresting to see that up to 22.5 °C almost no fan is in use.

Figure shows the percent
of opening windows w.r.t.
indoor temperature. We
see an adaptive behaviour
as windows start closing
atlowandhightemperature. From 22 31°C
percentageofwindows
opening
increases.

Analysed the comfort temperature proposed bystudies done in India and develop a regression
equation. Comfort temperature proposed for NV
buildings and plotted them against daily mean
outdoor temperature. Regression line shows theslope of 0.37, which is close to the slope proposedby in SCATS project. all comfort temperature falls
under 80% comfort band limit but not under Indian
National building code 2005.

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加藤研究室・大岡研究室・菊本研究室
Kato Lab., Ooka Lab., and Kikumoto Lab.