Make Up Air Units - The Basics

[@abazism]

Thank you so much for your clear explanation.

[@rayertman]

Very clear and to the point. Thanks. I will be looking through more. I have a couple problems i need to solve re negative pressure cleanrooms that all compounding pharmacies must be USP 800 compliant due to newly implemented regulations. Current system not enough to account for 12 ACPH which is the requirement for Level C non sterile room. I believe I'm going to require supplemental source of air and trying to get a grasp on the process. Seems like the HVAC 'cabal' has this info very well guarded lol.

[@nimbo9492]

I think in the winter mode, it would be good to have a humidifier as well not just only a heating coil.

[@potentialhvac6074]

I work in San Francisco doing Commercial HVAC service. I noticed most the make up air units that I come across don't have any means of dehumidification ( at least not at the RTU), one doesn't even have a heat source and is only used if these large exhaust fans kick in due to heat on the 4th floor. My thought is that the ones I work on where done cheaply to save cost but some times I feel like it's just poor design. In some of these cases it seems like these building spaces would be a lot more comfortable if things had been done with the MAUs done correctly

[@quangquantv6789]

good. thank you very much

[@TAHIRHUSSAINMEPINDUSTRY]

how to add pre-treated cool fresh air in HAP program

[@vsolcar3696]

I figured that on a hot day you'd want to keep that 50° blowing into the inside. 72° sounds way too hot.

[@kevonslims7269]

Down here in south florida 72degrees on a 95 degree day will trigger no cool calls no matter how dehumidified that 72 degree air is..

[@donavonkeith8411]

Your correct. Send it to the downstream units and let the conditioned OA mix with return air and lighten the down stream coiling cools

[@riccardobertolino1386]

Hi! is there any pro/cons between outdoor make up air units and indoor one? gas plumber are very expensive and bring the natural gaz line up to the roof top maybe an issue... also many told me that electric heated make uo air are very expensive on bills, espcially in Canada where temperature go down to minus 20 easily in winter. someone can answer me?