make up air

[zevy]

hello

I manage a small deli (240 sqf...yep, that smALL) we have an 8' exhaust hood with no make up air. in the winter i ran an 6" round flex duct for make up air because it was sucking in too much cold air from underneath the door.
we have a 24,000 btu window unit which barely keeps up. I was thinking with the proper amount of make up air the exhaust will not suck out the conditioned air from the front half of the shop.
does this make any sense? and is a simple piece of 6" duct enough for the job or do i need a fan blowing air IN for this to work?

thank you

[TightDrunken]

how much is the hood exhausting cfm then u can size your make up air. do u have any propane or natural gas equipment installed u would need make up air for that as well.

[zevy]

Thanks td,

I have a grill, griddle and a fryer.

[rayr]

6" is NO way near enough MUA for a 8' hood. If it is not a pre-engineered hood then aprox. 2,500 cfm is required. That would be 80% of the required 3,200 cfm. Pre-engineered hoods require less exhaust and less cfm.

There should be a MUA unit on my web page. The MUA unit that is sitting on top of the ex duct is for a 9' hood in a small deli. Check out the commercial-exhaust hood design tab @ www.aaronrefrigeration.com