furnace blower to recirculate

[87bob]

I have a 40x48x16H barn. With so tall of a ceiling i would like to use a old furnace blower to recirculate the hot air from off the ceiling to down across the floor when the furnace runs. The blower is 120V rated. How can I use the low voltage signal from the thermostat to turn on the the 120V for the blower fan? I believe what I need is a relay, but I’m not sure where to go and what to ask for.

 

[510ebl]

Why not use a 120V rated t-stat?

https://www.grainger.com/search?searchQuery=attic fan thermostats&suggestConfigId=6&searchBar=true

 

[87bob]

I want the fan to cycle with the furnace. Thank you for your response.

 

[Chris705]

Look for a pressure switch made by Tjernlund products. White bear lake, mn. I don’t recall where I found it but I used it to control a remote in-line duct fan. Would come and off when the furnace blower motor ran.

 

[510ebl]

I want the fan to cycle with the furnace. Thank you for your response.

I missed that detail

In that case, check out these relays, which I think fit with what you proposed:

https://www.grainger.com/category/e...safety/relays-and-accessories/prewired-relays

 

[lilredex]

I use a White Rodgers Fan Relay #90-293Q SPDT to switch the furnace fan and the central vacuum motor here. They need 24V for the relay operating coil, which was already available at both locations.

https://www.google.com/search?q=Whi...rome..69i57.2697j0j8&sourceid=chrome&ie=UTF-8

 

[arsco]

RIB 2401b relay.

 

[danski0224]

It's likely to be electrically cheaper to install and run a ceiling fan or two.

The furnace blowers draw quite a few amps, and have a tendency to over-amp when run outside of a cabinet. At a minimum, you should double check the running amp draw if you insist on using a furnace blower.

 

[nadogail]

When faced with a similar problem, I bought my relays and enclosures from Automation Direct. IIRC they were once known as PLC Direct.