exhaust fan sizing for cooling
exhaust fan sizing for cooling
(OP)
I have a 1,000 SF electrical room, with some transformers, panelboards, etc that is a free standing building. All four sides and the roof are exterior. I have close to 40,000 btuh of heat load due to internal equipment but my question is if I want to keep the room below 104F with an ambient of 94F do I take into account thermal loads through the envelope? I don't think I would because the indoor temp will be higher than the outdoor temp. Any help would be appreciated.





RE: exhaust fan sizing for cooling
If you supply lets say 4000 cfm with a inline fan and have a mixing box with return and outside air. This way you can modulate the mixing dampers via space or discharge air temp. If this is in a cold weather environment I would throw some electric heat in the room (duct coil or a unit heater). Then I would supply low and relief high. You can go simple and just have a barometric damper weighted. Or you can install a motorized damper to modulate open and close to maintain a certain space pressure.
hope this gives you some ideas, although maybe my ideas a dumb
RE: exhaust fan sizing for cooling
Some additional points to consider, that I forgot in one of my designs.
- How will you control the exhaust fan? Typically provide a Hand-OFf-Auto switch with a thermostat.
- When in Auto mode the thermostat will control the exhaust fan to maintain the set point temperature.
- When in Hand mode the exhaust fan will run continuously. (for use when personnel come into the room to work on the equipment)
Justin K, P.E.
http://www.engproguides.com
RE: exhaust fan sizing for cooling
RE: exhaust fan sizing for cooling
Justin K, P.E.
http://www.engproguides.com