Tempered of Untempered Make Up Air?
Tempered of Untempered Make Up Air?
(OP)
I'm doing the hvac design for a commercial kitchen. I have used the formulas in the International Mechanical Code to find the required exhaust cfm. I'm trying to decide on how much make up air I need. The code says the make up air should be approximately equal the exhaust air. I know you want the kitchen to have a slightly negative pressure but what is the best way to determine the amount of make up air? Also, the code says that the temperature difference between the make up and the air in the conditioned room shall not exceed 10deg.F unless the air does not decrease the comfort level. How do you go about figuring the quality of the make up air?





RE: Tempered of Untempered Make Up Air?
RE: Tempered of Untempered Make Up Air?
You might also want to factor in the required ventilation requirements for the surrounding spaces when sizing your make-up air. Dining areas require a fair amount of OA and should be recognized in your air balance.
RE: Tempered of Untempered Make Up Air?
Coordinate also w/ hood manufacturer the control for the exhaust fans & makeup air fans. Under fire condition, should the exhaust fan continue to run while the makeup air fan & room supply air fan system shut down or should all shut down?
Don't forget exhaust & transfer air makeup for dishwasher
Typical CFM transfer air for pressurization would be about 200 CFM per door. Provide transfer air openings sized at maximum 300 FPM free area velocity. If not enough free are space available, use transfer air fan interlocked with hood exhaust.