economical way to heat garage

hotwired

Hi All,

I have an attached WELL insulated 24x24 garage, which shares two walls with our home. When it's 0 degrees out, even for extended periods, it doesn't drop below freezing (like 36 lowest), most of winter hangs at 45. We have wood heat, central hwbb, and heat pumps. We don't need to heat the garage all the time but it's set up for entertaining so it would be nice to be able to from time to time. I had a bright idea to simply "rob" our central boiler. We have one zone for radiant floor in one room that we do NOT use. I was thinking of having our boiler person diver that to either a wall radiator or a good long length of baseboard. That way we have thermostat control. Alternately we could just "splice off" the nearest pipe that's cloest, and use valves to open and close it but that strikes me as 2d best when I have a spare zone already. Finally, we could just bite the bullet and have a toyostove put in with a pump (oil tank is in basement, and I do NOT like propane).

Thanks for any feedback and education!

hot_rod

Gosh if you already have a hydronic system and an easy piping route, look at panel radiator, or a small fan convector. Either a Modine or even a wall mounted kick space heater.

Any heater with a fan will heat quickly and dry snow cover cars quickly.

Fin tube would want to be at floor level, that may be a bad location in a garage.

Look at the pricing options to see what makes sense.

EBEBRATT-Ed

I would use something with a fan like a convector to help bring the temp up quicker and maybe some panel radiators. The convector will help bring the temp up but won't make it really comfortable. Using it as an on-off system you need more BTUs than normal to bring it up to temp.

As far as the water goes you could fill it when you want heat and drain it when you don't but that isn't great for the boiler. Leaving it with water in it risks freezing. You could use glycol with a heat exchanger but that adds components, HX, expansion tank, circ pump, glycol etc.

mattmia2

seems like if you're really confident it won't get below freezing you could put the emitters on the house wall where it is a bit warmer.

hot_rod

I have Infloor radiant in my shop and I run constant circulation as my freeze protection. Power grid is very stable here so I am not concerned about losing power. But I keep a LP construction heater as backup

I suppose panel rads or a unit heater could constant circulate also. As Ed mentioned, the heater on that common wall may not need much freeze protection with 36f being as cold as it gets.

I piped it with a. 3 way zone valve like this

HVACNUT

One 12K ductless head. Entertain in summer too.

GroundUp

Assuming you have an outdoor Central Boiler (based on context), it'd be pretty easy to add a fan coil unit of some sort in the garage. Your radiant floor zone is likely set up as low temp so simply diverting that to the garage unit heater wouldn't get you a whole lot of BTU but there are some variables that could potentially make it relatively simple to make it a high temp zone. A space so small with such a small heat load, frankly you could probably get away with a water to air heat exchanger with constant circulation and a regular old box fan behind it on a 120v thermostat.

Kaos

https://forum.heatinghelp.com/discussion/comment/1878380#Comment_1878380

This!

It is what I use for a garage to studio conversion. BOM cost would be less than a hydro handler plus plumbing bits, you don't have to worry about it freezing and gets you AC in the summer. There are units with pre-charged quick connect line sets so you can DIY install them. Make sure to get a unit with a base pan heater in snowy climate.