Copper hot water coil with blower.

[Cpeters]

I have a smaller garage apartment with 480 sf garage and 480 sf apt above. I was looking into putting a coiler with blower in it to hang someplace in the garage to keep pipes from freezing. I am not familiar any of the manufacturers I have seen while googling.

 

[Tom Sawyer]

Modine and reznor

 

[Sponsor]

 

[Cpeters]

Thanks Tom, I like the Modine HC model. It can be controlled by a thermostat. My next question would be that I can set the boiler up with a
separate zone for the the Modine with either a zone value or pump and this would. And a relay would trigger the boiler to turn on when the zone
is calling for heat?

 

[Dana]

The zone controller or zone relay taking the thermostat input would turn on the pump (&/or open the zone valve), not the burner. The hydronic coil would be set up with an aquastat to turn on the blower whenever the coil was hot enough. A cast iron boiler's internal controls would fire the burner once the temperature dropped to the boiler's low-limit setting.

 

[Cpeters]

The zone controller or zone relay taking the thermostat input would turn on the pump (&/or open the zone valve), not the burner. The hydronic coil would be set up with an aquastat to turn on the blower whenever the coil was hot enough. A cast iron boiler's internal controls would fire the burner once the temperature dropped to the boiler's low-limit setting.

I thought an aquastat was used for a tankless heater. So the aquastat could be on the blower coil, so when blower turns on with the thermostat the
aquastat would tell the boiler to turn on to make hot water if it's not hot enough? I just don't want the aquastat to act like it's on a tankless heater and keep turning on if the thermostat isn't calling for heat. I need 1 zone for the upstairs apt. with its' separate zone and a separate zone for the blower in the garage. Thanks.

 

[Dana]

I don't know if the Modine's come equipped with an internal aquastat or whether you'd have to add an external strap-on for the near-coil plumbing, but it's only function is to turn the blower on/off, not the pump. If the pump isn't pumping hot water to the coil, the plumbing will be cool, and the blower won't run. After the pump stops pumping the blower will run until the coil is cool enough that the aquastat turns it off. There are dozens (hundreds?) of aquastats of different adjustment ranges, contact ratings, etc. If the Modine doesn't come pre-configured with one, it's not hard to install a strap-0n type on the incoming water plumbing to the coil unit.

The thermostats only tell the zone relays or zone controller when there's a call for heat- the rest is up to you. A common configuration is to have the zone relay turn on the pump, to deliver hot water from the boiler to the zone radiation or coil. You can do this with one pump or two, with separate zone-relays or a two-zone zone controller.

 

[Tom Sawyer]

I usually control them with two things. I want a low limit aquastat ( an older honeywell 4006 or 6006 ) and a relay if I have it on its own circulator. Thermostat jumps the relay (honeywell Ra89 or 845) relay starts the fan only when water temperature is above 160 so so that it doesn't blow cold air. Now if you don't care if it blows a little cold in the beginning, ditch the aquastat.