How to do the Air Turnover Calculat
How to do the Air Turnover Calculat
(OP)
How to do the Air Turnover Calculations for a space (our machine shop here) which is 200, 000 cubic feet and there are two ceiling exhaust fans which are 6000 cfm each. Like for how much time should both the fans be kept on in an hour to ensure at least one air turnover per hour? There is no air makeup unit inside the plant. The air leakage into the plant is primarily through the numerous doors and windows. If the outside temperature is cold, then keeping the fans on for a longer period of time lowers the temperature inside the plant and workers complain. At present the fans are kep on for one minute in an hour and this serves to increase the pollution in the plant. In summer (25°C) it is ok to keep all the doors and windows open and run the fans for longer periods.
Is there any formula which might help me calculate the air turnover time requirement?
Is there any formula which might help me calculate the air turnover time requirement?





RE: How to do the Air Turnover Calculat
RE: How to do the Air Turnover Calculat
Chris is correct. Use the formula cfm = volume(in cu.ft)*air changes per hour(ACPH what you call as turnover)/60.
To check whether the leakage through doors and windows is sufficiently maintaining the required air change of 1 per hour check the actual cfm of each fan by a velometer (not on nameplate) and then back calculate.
Regards,
Truth: Even the hardest of the problems will have atleast one simple solution. Mine may not be one.
RE: How to do the Air Turnover Calculat
I have gone through both the answers above but frankly I think insteaed using bigger fans like you have in your factory try using four small size fans (one on each side facing each other) at some where MIDDLE of the room height .
By doing this you may help in changing room air (polluted and staled air ) with out letting insiders to know anything .
good luck jhon.
alley.
RE: How to do the Air Turnover Calculat