thermostats

[southernboys]

hey guys Ive got a customer who wants to put up an old roof fan but he wants to change the thermostat and he wants to make it remote. ie middle of the attic the guys a joke wish I had never helped him in first place. Is there a thermostat on the market that I can buy for this guy. where can I find this thermostat if there is one on the maket its going to be 110v line side as always thanks

 

[mdshunk]

Re: thermostats

Yes, there sure is, but you'll need to get it at an HVAC supply house. There are many line voltage controls, many of them even digital, that have remote sensors that you can run into the attic space. I use a Robertshaw digital model for remote line voltage temperature control that only costs about 50 bucks wholesale. I can dig through the books for the model if that's of interest to you. Most major cities in the US have a Grainger, Sid Harvey's, Johnstone Supply, or United Refrigeration that all have this control. Be advised that if the existing attic ventillator control incorporates a fire stat (many of them do), you'll have to tie the control in parallel with the existing fire stat.

[ May 27, 2005, 08:00 PM: Message edited by: mdshunk ]

 

[kiloamp7]

Re: thermostats

Would the firestat be connected in parallel with the t'stat or in series?

 

[mdshunk]

Re: thermostats

Originally posted by kiloamp7:
Would the firestat be connected in parallel with the t'stat or in series?

Well, now that you mention it, I'm not sure. I don't actually know if the firestat turns the fan on in the case of a fire to exhaust the smoke, or if it turns the fan off. If it turns it on, then parallel. If it turns it off, then series. I'm sure someone knows how these firestats operate in a resi attic fan.

 

[rattus]

Re: thermostats

Out of my area here, but it seems that a parallel connection would drive the fan all the time. Furthermore, you would want to kill the fan in case of fire. I vote for series.

 

[oliver100]

Re: thermostats

In NYC tunnels the computers are programmed to shut off the ventilation in case of fire. However, there is an override on the discretion of the commanding officer.

On the ships - it is the same procedure. Shut OFF in case of fire alarm.

 

[mdshunk]

Re: thermostats

The reason I was puzzled is because restaraunt hood fire systems turn off the make-up air (incoming) and turn on (or leave on) the exhaust air. I might have to look at a resi attic fan firestat to see if it turns the fan on or off on temperature rise. Maybe someone will post that knows for sure.

 

[tshephard]

Re: thermostats

I'm used to firestats that would 'burn out', open on heat, so series installation.

However, some fans for egress areas (stairwells) would be started in case of fire, irreguardless of temperature.

[ June 03, 2005, 10:01 PM: Message edited by: tshephard ]