Good day, Can fan limit controls, like the Honeywell L4064B2236, be used as "firestats" to control attic fans? The product descrip says "on at 125 F, off at 100F, and high cutoff at 200F". The prod is designed to be mounted on forced-air heating plenums, with an 8" sensor wand protruding into the plenum. To be possibly used as an attic fan cutoff in case of un-natural heat rise in the attic space due to a fire, the unit would obviously have to be mounted with the sensor wand sticking out into the ambient air in the attic. Would the unit operate effectively in this manner? Questions about this type of device to my local Home Depot evoke blank looks and fruitless global inventory searches. They've never even heard of a "firestat" for auto cutoff of forced-air systems of any kind, and nothing listed uniquely as "firestat" comes up for me on any internet search engines - just fan limit controls. Thanks!
FAN LIMIT CONTROLS, USED AS FIRESTATS
Mar 29, 2008
3 Replies
In the past I've used thermo-disc switches, mounted to a 1900 blank cover with 1/2" knockout in it. Here's one from Grainger :
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I don't think that would meet code. At least the attic fan I bought specified that an interlock switch must be used and, as I recall, the code says you must follow manufacturer instructions.
Oops, I may have misinterpreted what you asked. You're saying in addition to the interlock with the furnace?
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