TECHNICAL NOTE
1
Indoor Air Quality Guideline Value for Japan (Law of Maintenance of Sanitation in Building) and South Korea
(Public Sanitary Law)
2
American Society of Heating, Refrigerating and Air Conditioning Engineers. (2010). Standard 55 – Thermal
environmental conditions for human occupancy. ASHRAE Standard 55-2010.
Internationally recommended ranges of temperature and
relative humidity in air-conditioned shop spaces
Comfort in an indoor environment is, in fact, complex and involves the interaction of different environmental
and personal factors. Hence, consideration of all these factors together is important to design operative
criteria that best suits the unique operation and climatic condition of an indoor space in a shopping mall.
There are some local and international standards stating the recommended design criteria with
consideration of the complex interactions between different factors. Careful design of the operative criteria
will enhance energy-saving without sacrificing occupants’ desire for a comfortable and healthy indoor
environment. Below are some recommended operative relative humidity and temperature ranges that are
considered acceptable by the majority of people for a given set of conditions.
International standard recommendation on relative humidity
1
:
Condition
Relative humidity (RH)
General
40% – 70%
Figure 29 Recommended ranges of relative humidity
ASHRAE standard recommendation on temperature/relative humidity ranges:
Temperature/relative humidity ranges (with still air)
2
Condition
Relative humidity
Acceptable operating temperatures (°C)
Summer (light clothing)
If 40%, then
22.5 – 25.5
If 70%, then
22.0 – 25.0
Winter (warm clothing)
If 40%, then
15.5 – 20.0
If 70%, then
15.0 – 20.0
Figure 30 International recommended ranges of temperature and relative humidity in air-conditioned shop
spaces
Read more at:
1. ASHRAE Standard 55-2010
The American Society of Heating, Refrigerating, and Air Conditioning Engineers. (2010). American
Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) Standard 55. Thermal
environment conditions for human occupancy.
2. Guidance notes for the management of indoor air quality in offices and public places
The Government of Hong Kong Special Administrative Region. Environmental Protection Department.
(2003). Indoor Air Quality Information Centre. Guidance notes for the management of indoor air quality in
offices and public places. Retrieved 5 April 2013, from
2.4
Comfort level
2
The basics
62 Hong Kong Green Shop Guide
