Air Exchange Rule of Thumb
Air Exchange Rule of Thumb
(OP)
Is there a "Rule of Thumb" for the number of air exchanges for a light manufacturing industry? There are no chemicals in the indoor environment.
I have gone through Industrial Ventilation: A Manual of Recommended Practice by ACGIH without finding any guidelines that apply to my situation. TIA
Rich
I have gone through Industrial Ventilation: A Manual of Recommended Practice by ACGIH without finding any guidelines that apply to my situation. TIA
Rich





RE: Air Exchange Rule of Thumb
Do NOT use the following as absolute limits to follow, but for an idea I have seen the following criteria used with the actual value selected based on type of room:
5 to 50 cfm fresh air per person occupancy
0.05 to 4.0 ft3/min per ft2 of floor area
Air Changes (I have seen 1 to 50 air changes/hr; but I do not mean to limit you to that range)
I would pick the maximum recommended considering all the above and the room type.
There is also the issue of whether you need a clean or steril room which requires a minimum differencial pressure between clean and ordinary room environments. See a previous thread on this on Room Static Pressure Measurement.
The more you learn, the less you are certain of.
RE: Air Exchange Rule of Thumb
RE: Air Exchange Rule of Thumb
Thanks
The more you learn, the less you are certain of.
RE: Air Exchange Rule of Thumb
RE: Air Exchange Rule of Thumb
RE: Air Exchange Rule of Thumb
The air exchange method is not an energy efficient method and is recommended for hazardous areas for dilution of indoor contaminants. People tend to use 1 or 1.5 air changes for non-hazard applications and 6 to 12 air changes for hazardous application when it is defined by some codes.
RE: Air Exchange Rule of Thumb
20% fresh air is a good number. Some vaccine manufacturing facilities and cytotoxic formulation facilities, however, use once through systems (due to dearth of validatable data).
Fresh air requirement per person is generally 16 cfm based on dilution of CO2(by respiration) to safe levels. A good deal of information and calculations are provided in Air Conditioning book by Shan K Wang. Right now I don't have the book with me, but I will try to get the calculation.
Regards,
RE: Air Exchange Rule of Thumb
RE: Air Exchange Rule of Thumb