Basic Documentation

Table Of Contents
Chapter 8–Laboratory Temperature and Humidity Control Systems
Laboratory Room Humidity Control
According to the American Society of Heating, Refrigeration, and Air Conditioning
Engineers (ASHRAE), human comfort requires the relative humidity to be within the
range of 30% to 70%. Experienced HVAC designers tend to limit the upper end of the
range to between 50% and 60%, since higher levels of humidity promote the growth
of fungi and bacteria. Prevention of static electricity discharges, which is very
important in laboratory rooms where volatile chemicals and vapors are present,
requires maintaining a relative humidity of at least 45%.
Apart from temperature control, animal facilities typically require specific humidity
limits for the research data to be valid and the laboratory to maintain accreditation.
Following are laboratory animal temperature and humidity ranges established by the
U.S. Dept. of Health & Human Services, Public Health Service, National Institutes of
Health, NIH Publication No. 86-23, Revised 1996, Guide for the Care and Use of
Laboratory Animals:
Mouse, Rat, Hamster, Guinea pig
64.4 to 78.8°F
40 to 70% rh
Rabbit
60.8 to 69.8°F
40 to 60% rh
Cat, Dog, Nonhuman Primate
64.4 to 84.2°F
30 to 70% rh
Chicken (6 weeks and older)
60.9 to 80.6°F
45 to 70% rh
Unless a specific laboratory must be maintained at a different humidity due to unique
requirements, the best relative humidity level for all around purposes is 50%. In cold
weather, the humidity level can be lowered somewhat for non-critical applications to
prevent excessive condensation on exterior windows or wherever condensation may
occur.
78 Siemens Building Technologies, Inc.