How to cool a room open to outside temperatures?

[illuzionb18c1]

If I have a Oven Room (110 sqft) with one louver for exhausting air with a propellar fan and one louver for pulling in outside air.

What method do I use to size the fan (CFM-wise) in order to maintain my oven room to equal outdoor temperatures?

Lets just assume I'm generating 20000 btu/h from the ovens into the space and say outdoor temps are 85 degrees.

 

[IRstuff]

> You will never achieve "oven room to equal outdoor temperatures" since that's thermodynamically impossible, but you could get close. Realistically you might get to say 5° above external temp, but you'd probably need close to gale force winds in your room if you don't actively cool the inlet air.

But, you can do the math: area*heat_transfer_coefficient*delta_temperature = heating rate

The HTC will be a slow function of the airflow across the oven.

Without some

TTFN

FAQ731-376

 

[MintJulep]

Basic sensible heat equation for ventilation removal of heat load is

q = 1.1 x cfm x (To - Ti)

q is heat load in btu/hr
cfm is airflow cfm
Ti is the entering air temperature that you are bringing in.
To is the exhaust air tempreature.

 

[MintJulep]

To and Ti in degrees F.

 

[ChrisConley]

The net result is that the closer you want to maintain the 'oven' temp to outdoor temp the more cfm it requires.

If there is a need for cooling, adiabatic cooling might be a solution (not knowing what your process is).

 

[BronYrAur]

to tie it all together, a 5 deg temp difference would be 3,636 CFM. That is 33 CFM/Sqft. Sounds like gale force to me. You might want to add some cooling or try to vent the oven outside.