New garage..heating questions

[biggziff]

I got my building permit today so yay for me.

My question is more of a "what's your opinion"

The garage will be 34 X 26, 12' ceilings, 10 X 16 door on the front and 9 X 10 on the back. Right now I've spec'd 2X4 construction, but that could be changed to 2X6 for insulation, etc (or I can add foam under the siding) Several of my friends who are HVAC or commercial plumbing professionals are suggesting putting Pex in the slab as a "just in case" kind of thing. I do have a 150K BTU furnace (LP) in my existing garage and had planned to run some flex duct into the new (attached) space for the occasional use during NY winter. I was also planning to insulate the slab regardless just because it's cheap and it made sense to do it.

My wife reminded me that I'm close-ish to retiring from my IT job and that I may find other things to use this new space for that might include wintertime projects, so I'm trying to get some input. Do I just use the existing furnace or another Modine style hot air heater for the winter time stuff or plumb it up for radiant in case I decide to buy a wall mount boiler at some point and heat it all winter?

I think I know the answer, but it's all become real now that I've got the dirt work guys coming next week.

Thanks

 

[Adk Mike]

I'm not a big fan of in floor heating. But that's just me.
Simple go with a Modine Hot Dog HD60. Mounts on the ceiling and is out of the way. Square footage on a new building cost too much to tie up floor space with a heating unit of any type.
If you like something a different with those 12 foot ceilings you might consider a Detroit Radiant type heater hanging on the ceiling.

 

[biggziff]

I'm not a big fan of in floor heating. But that's just me.
Simple go with a Modine Hot Dog HD60. Mounts on the ceiling and is out of the way. Square footage on a new building cost too much to tie up floor space with a heating unit of any type.
If you like something a different with those 12 foot ceilings you might consider a Detroit Radiant type heater hanging on the ceiling.

Thanks, Mike. May I ask what you don't like about Radiant? I'm not in love with the idea of having to run it all winter as that's going to cost me $500 or more I'm sure.

 

[Randy in Maine]

I am a big fan of radiant in floor heating as it is not only cheap to run but super comfortable. My 40x28x12 garage is built out of SIPS. Probably R-40 or better everywhere.

My warm water for the slab just gets sent over to the garage from the house boiler. My insurance agent like the fact that there is no "fire" (or even a pilot light) in the garage.

 

[trashmanssd]

Go with 2X6 walls for better insulation, its my biggest regret from building mine last year. I was ignorant and had not been told why to go with 2X6 construction. Now this year I wanted to insulate and sheet rock and I had to do it on the down low because code is R19 or nothing (sounds stupid to me either you go this or you do nothing and really waste heat).

 

[engineer2]

I was in an outbuilding that had both. Radiant heat run off a residential water heater and a couple of overhead heaters.

 

[biggziff]

I am a big fan of radiant in floor heating as it is not only cheap to run but super comfortable. My 40x28x12 garage is built out of SIPS. Probably R-40 or better everywhere.

My warm water for the slab just gets sent over to the garage from the house boiler. My insurance agent like the fact that there is no "fire" (or even a pilot light) in the garage.

Thanks, while we do have a System 2000 oil fired boiler for the house, we use Coal for most of our heat in the winter...plus I'd have to run the zone 75' through some uninsulated space to get the water into the garage. I wish this were simpler...or maybe it is.

 

[biggziff]

Go with 2X6 walls for better insulation, its my biggest regret from building mine last year. I was ignorant and had not been told why to go with 2X6 construction. Now this year I wanted to insulate and sheet rock and I had to do it on the down low because code is R19 or nothing (sounds stupid to me either you go this or you do nothing and really waste heat).

I'd read that it's possible to use 2X6 at 24" spacing and have the same strength as 2X4 on 16" and it makes the cost difference nominal. True?

 

[6768rogues]

I do not have radiant floor heat in any of my buildings. I don't want to mess around with glycol and keeping the right amount of it in the system. Without it, you cannot turn it off if you want to and will have to be around to do something if the power goes off. We were in Florida for the winter and the power in our house in NY went off for 5 days. No radiant heat to worry about. After you retire, you might decide to be a snow bird.
Also, I don't want to pay the bill to keep it up to temp for working in the building. Radiant heat takes a lot of energy and time to increase temperature. My Reznor hanging furnaces will raise the temp from 45 to 65 in the time it takes me to go in the house and change into work clothes.
If you had a building that was used every day and had consistent temps year round, radiant would be an option.

 

[cidermill]

go radiant. pex is cheap , insulate the slab, if you dont have the time or money for the unit you can do it later. good luck

 

[like2wheel]

I was in an outbuilding that had both. Radiant heat run off a residential water heater and a couple of overhead heaters.

And???

 

[biggziff]

go radiant. pex is cheap , insulate the slab, if you dont have the time or money for the unit you can do it later. good luck

I'm leaning this way. Found 2.5" PolyIso sheeting (roof take offs) for $14 a sheet. Cheap enough to insulate it.

 

[Randy in Maine]

I buried my water supply lines about 4' deep (radiant heat supply and return lines as well as the hot & cold water supply lines) in a trench the 20' out to my shop from my house. Yes I have hot water that goes to one of my garden hose silcocks.

I used 3/4" pex for those lines inside 2 x 4" Sch. 40 PVC pipe (one for the domestic water and one for the heating system) and used scrap 2" rigid foam for insulation on 3 sides of that PVC trench. Since I had the trench open I ran electrical conduit and ran the electric cable (to feed the shop 100 amp panel) in there so it never in the way. Everything run under the foundation footers to an inside plumbing/electrical wall.

My system doesn't run very much due to really good insulation including under the slab and the 42 tons of thermal mass in the 21 cubic yards of concrete in the slab. It stays warm for a long time. I keep it about 55º (air temp at 4') which keep everything from freezing and me comfortable when I am out there.

I have my 2 manifolds for heating in and the return lines inside my "plumbing/electrical wall".

I don't run antifreeze in my heating pex system. I rarely lose power, have city water, and my set up could run on a camping battery or generator if I had to. My little baxi boiler uses little power and the 1 taco pump (for the radiant system) doesn't use much power either. Never been an issue. Maybe I will shut if off for a month this winter and track the temps to see just how long it could go.

Suggestion.... run a 2" separate electrical conduit for the thermostat and internet to the shop. Don't run the main power in the same conduit. My set up uses nothing tighter than a 45º angle for the PVC so that you can get the tubing in there as it doesn't like tight bends.

Whatever, I would get a pro to design the system and you can run the tubing and have them hook it up. My guy liked doing it that way so he did not have to do the grunt work.

 

[engineer2]

And???

I guess they could run one or the other or both. If you are laying on the ground, floor heat is nice. Place was for sale, so owner was not around to ask. Only downside is the next owner will have no idea where to safely drill the floor for a lift.

 

[trashmanssd]

I'd read that it's possible to use 2X6 at 24" spacing and have the same strength as 2X4 on 16" and it makes the cost difference nominal. True?

I am not sure, but it sounds plausible. Not sure if I would have been allowed to change spacing here (I am under mile from ocean which is a wind damage zone and requires different building codes) but I was told it would been around 1K to go 2X6 over the cost of 2X4. I would gladly have paid that for the extra insulation and to not worry about code problems.