using house boiler to heat slightly detached garage???

[chainfeed]

My garage is only about 15 feet from my house.... House has a hot water system for heat, is it possible to use a heat exchanger and run insulated burried loop out to the garage for heat? I'd use a seperate loop with the exchanger so I can put antifreeze in that system. Thoughts???

 

[Rookie2]

I would go for good insulation and a ventless gas inwall heater.

 

[HoosierBuddy]

It might be possible. I'm not sure why you would need anti-freeze in the system, unless you're going to turn the garage off sometimes. If you are going to turn the garage off sometimes (like only heat it up when you are out there) then I would go with a different solution...like a gas fired unit heater.

I'm doing the opposite in my house. The wall boiler in my garage heats part of the house. That being said, it's attached...so the lines don't go outside. If they are heated and buried under the frost line though...it is possible. Not sure it's "the best"...but "possible".

Phil

 

[Amtrakjoe]

The heat exchanger with glycol is quite an expensive endeavor but required for what you describe. Without it you would need to bury your supply and return and insulate/heat trace. What is the reliability of your heating system as well as your power grid? How big is the garage, what temperature are you trying to heat it too and does your boiler have that much extra capacity ?

This being said, I would consider an independent system for the garage, probably all air. Good luck. Joe

 

[chainfeed]

its like 22 x 18 and I'd like to keep it around 55 deg. After reading up more I'm leaning towards radiant slab with a tankless ng hot water heater. My father also has a couple big solar hot water panels he offered.

 

[Sureshot]

It will work easier than you think. Bury extra lines for domestic water and spares in case you have underground trouble. Since it is heated you do not even need to be below frost but I would do it any way. Don't forget to run airline, ethernet and phone with your water lines and for that close I would double everything.

 

[Jackfre]

Yes, it is possible. I would check Uponor's site for pre-insulated direct burial piping. The outdoor wood boiler people use a lot of that. I think that by the time you do this you will be into it for at least the cost of a stand alone heater for the garage.

 

[Randy in Maine]

I have radiant floor heat in both the house and the garage.

My house boiler provides the heat for the garage. I ran mine out there in 4"' Sch 40 PVC buried 4' deep using 3/4" PEX.

I would suggest running an additonal 4" PVC set up for getting hot and cold running water out there as it gets a little tight dragging them all through 1 PVC run.

I don't run antifreeze.

 

[avc8130]

I have radiant floor heat in both the house and the garage.

My house boiler provides the heat for the garage. I ran mine out there in 4"' Sch 40 PVC buried 4' deep using 3/4" PEX.

I would suggest running an additonal 4" PVC set up for getting hot and cold running water out there as it gets a little tight dragging them all through 1 PVC run.

I don't run antifreeze.

Do you have any insulation?

ac

 

[Randy in Maine]

Do you have any insulation?

ac

I put 2" of foam over where the underground PVC is.

I have 2" of foam under the garage slab and along the stem walls and the whole garage is R-40 or better (I am using SIP panels). I ran the radiant floor heat to remove the sources of cumbustion out there, plus it was cheap to do (running PEX tubing in the slab), comfortable, and cheap to operate (I heat everything for about $1500 a year...600 gallons of propane at $2.50 a gallon).

My guess would be that if the power were to go out at -20º it would take about a week for anything to freeze. 21 cubic yards of concrete is about 42 tons of thermal mass.

 

[chainfeed]

I have radiant floor heat in both the house and the garage.

My house boiler provides the heat for the garage. I ran mine out there in 4"' Sch 40 PVC buried 4' deep using 3/4" PEX.

I would suggest running an additonal 4" PVC set up for getting hot and cold running water out there as it gets a little tight dragging them all through 1 PVC run.

I don't run antifreeze.

how far is the run to the garage?

 

[Randy in Maine]

It leaves ina trench from the under the frostwall of my crawlspace (about 4' feet below grade and continues on at 4' below grade about 15' to the garage stemwall. Once there it travels about 28' under the slab to the "plumbing and electrical wall".

I used some scrap 2" insulation taped together to form a 3 sided bottom open box about 12" x 24 "x 12" that went over the 4" PVC from the crawlspace to the garage stemwall. The electrical feed is in its own 2" Sch 80 conduit in the same trench.