Page 63 - GRIHA Manual Volume III - Introduction to National Rating System

56 GRIHA Manual: Volume 3

Comfort conditions for air conditioned spaces
In air-conditioned areas, the thermal comfort conditions as specified in the NBC-2005, BIS, Part 8
Building Services; Section 3, Air-conditioning, Heating, and Mechanical Ventilation; Section 4.4.3
Inside Design Conditions, should be met for all occupied hours.

Table 1 Comfort conditions for air conditioned spaces
Inside design conditions
Sl. No. Category
Summer Winter
(1) (2) (3) (4)
DB 23 ºC–26 ºC DB 21 ºC –23 ºC
1 Restaurants RH not less than
RH 55%–60% 40%

DB 23 ºC–26 ºC DB 21 ºC–23 ºC
2 Ofice buildings RH not less than
RH 50%–60% 40%

DB 23 ºC–26 ºC DB 21 ºC to 23 ºC
3 Radio and television RH 45%–55% RH not less than
studios
40%
DB 23 ºC–26 ºC DB 21 ºC–23 ºC
4 Departmental stores RH not less than
RH 50%–60% 40%
DB 23 ºC–26 ºC RH not less than
5 Hotel guest rooms
RH 50%–60% 40%
DB 23 ºC–26 ºC RH not less than
6 Class rooms
RH 50%–60% 40%
DB 23 ºC–26 ºC DB 23 ºC–24 ºC
7 Auditoriums
RH 50%–60% RH not less than 40%
DB 24 ºC– 26 ºC
8 Recovery rooms
RH 45%–55%
DB 24 ºC–26 ºC
9 Patient rooms
RH 45%–55%
DB 17 ºC–27 ºC
10 Operation theatres
RH 45%–55%
DB 20 ºC– 22 ºC
11 Museums and libraries
RH 40%–55%
12 Telephone terminal DB 22 ºC–26 ºC
rooms
RH 40%–50%
Source: Clause 4.4.3, NBC Part 8, Section 3: Inside design conditions

Comfort conditions for non-air-conditioned spaces
In non air-conditioned spaces in addition to air temperature and humidity, air movement also
plays a crucial role in achieving thermal comfort conditions at different temperatures and relative
humidities. Table 9 of NBC 2005, Part 8 Building services; Section 1, Lighting and ventilation, gives
minimum desirable wind speeds that are applicable to sedentary work in offices and other places
having no noticeable sources of heat gain. Table 10 of NBC 2005, Part 8 Building services; Section 1,