Grassroots garage heating

I have a garage that is (mostly) insulated but not heated. I aim to finish off the interior and get some heat going, but insurance WILL NOT allow for a wood stove inside and I'm limited to electric heat otherwise, which is expensive.

My thoughts are to build a barrel stove outside, which I will use to heat water that will then be plumbed into base board radiators inside the garage. Nice quiet heat without fumes in the garage and (what should be) low running costs.

I have what could be described as a ton of fire wood on hand, as well as 9 acres of woods - all hard wood.

Thoughts? I know it's not a quick source of heat, but I'm OK with that. My workshop is closed off from the rest of the garage, so I don't necessarily need to heat the whole thing all the time and I can run a small space heater to be comfortable.

What about a waste oil heater? You can use the oil from your oil changes, and if thats not eough just have your buddies give you their oil.

LP heater with a 20 lb tank. Get one that's vented so you don't have to leave a window or a door cracked. I bet 10,000 btu/hr would be enough to keep it 60°F in most drafty two car garages.

Or a used outdoor wood boiler.

I would have concerns about making your own hot water boiler. Make sure you have a temperature and pressure relief valve. You'd be better off to just buy a water heater and a hot water circulation pump for the couple of baseboards.

Buy (more like haul away) an old oil furnace, convert to waste oil (easy).

How much sun in the winter? What does your south-facing wall look like. How about building something like THIS?

Really, it puts out more heat than I expected and it was built with a major concession to looks that robs be ot a lot of BTUs.

I've considered some solar arrangements.

Been doing a lot of reading on here: http://www.n3fjp.com/solar/comparisonhotair/comparisonhotair.htm

Problem being they don't generate squat when the sun goes down, which is when I'll be home and ready to work. It could work well to keep things warmer throughout the day though and I have very good sun exposure.

As for waste oil, I'm an island basically. Closest motorhead friend is an hour away and he's by far the closest.

I can start looking for discarded boilers, but that's not typically the type of thing you see in my neighborhood (mostly quite affluent).

The hot water system would not be pressurized, but likely a tank that would be plumbed to the radiators. The more I think about this the more convoluted it seems...

1. Buy a used but INTACT radiator from a pull a part/find it in your scrap pile
2. Build a box (4 walls and a base) of the same area as the radiator - use steel studs and cement "hardie" board, and insulate well with hi R value fiberglass insulation
3. Arrange the radiator on top of the box as a as a lid
4. Arrange a water line headed from the box to the baseboard radiators, and a line back to the box. Insulate the lines from the box to the garage
5. Insert a decent sized ($20) aquarium water pump outside near the box on the post garage leg of the water line
6. fill rad/lines with water
7. insert 6 sterno catering heaters into the brick box under the rad and light em.
8. turn on pump

The heaters should be able to transfer a significant amount of heat into the water via the rad/insulated box. The water will flow into the baseboard radiators via the insulated lines, and release the heat into the garage. The cooled water will head back to the box, through the pump, and back into the rad to be reheated.

Some work may be necessary to get the surface area of the baseboard heaters/length of exterior water line large enough to release enough heat to get the water to a temperature the pump can handle. Addition of antifreeze may be necessary to keep the water/rad/pump from freezing. I had a buddy who was able to keep his garage up around 60° during some pretty cold Februaries in the past. He used 50/50 GM long life coolant, and a submersible water pump inside a sealed sump well bucket. YMMV.

I have a small propane heater (vented). my garage is not insulated what so ever, and that little thing helps get things a little more pleasant in the winter. it would probably work pretty awesome if I had some insulation. courtesy of the PO, I am still running on the 100lb propane tank that was there when we bought the house.

for now I just stick a fan in front of it to help circulate the heat in the colder months, or put down the tools for a minute and warm up the hands.

DaveEstey wrote: I've considered some solar arrangements. Been doing a lot of reading on here: http://www.n3fjp.com/solar/comparisonhotair/comparisonhotair.htm Problem being they don't generate squat when the sun goes down, which is when I'll be home and ready to work. It could work well to keep things warmer throughout the day though and I have very good sun exposure. As for waste oil, I'm an island basically. Closest motorhead friend is an hour away and he's by far the closest. I can start looking for discarded boilers, but that's not typically the type of thing you see in my neighborhood (mostly quite affluent). The hot water system would not be pressurized, but likely a tank that would be plumbed to the radiators. The more I think about this the more convoluted it seems...

If it's insulated you'll be warm for a while after the sun goes down. And you can put thermal mass to store heat for a while after the sun goes down. Heck, if you keep the garage warm all day long imagine how much easier it'll be to warm after work. Think about all the metal in your garage, cars, tools, boxes, the pile of scrap metal. If that stuff is cold you're heater will have to work that much harder. You'd be taking a HUGE load off the heater that you'll be paying to use.

Agreed.

How would your insurance feel about a wood stove in a small building separate from the garage but attached with a pair of insulated non-combustible ducts buried between the two?

Electric heat is usually more expensive on a per unit basis when compared to gas or oil, but if you're using it intermittently it isn't necessarily that bad - turn it on when you're out there working,and turn it off when you leave, so you're only using it maybe a few hours a week. Also, electric heaters are relatively inexpensive and easy to install so the upfront costs are reasonable.

How big is the workshop area? If it's not very big and it's well insulated you may be surprised at how little electric heat is required to keep it comfortable.

Since you mentioned that you live in an affluent area, are there HOAs or odd ordinances to deal with?

No HOA's or other shenanigans thank god. This is generally a population of horse/farm owners who wanted to have space to themselves and be left alone.

The workshop can be taken care of with a small space heater, but when I'm in the garage (little longer than an average 2-car) I'll need a greater heat source - especially since I'll be doing a lot of fiberglass work this winter for the RX7's box flares.

Perhaps some solar hot air units and a large(ish) electric heater will be enough to take care of it.

DaveEstey wrote: No HOA's or other shenanigans thank god. This is generally a population of horse/farm owners who wanted to have space to themselves and be left alone. The workshop can be taken care of with a small space heater, but when I'm in the garage (little longer than an average 2-car) I'll need a greater heat source - especially since I'll be doing a lot of fiberglass work this winter for the RX7's box flares. Perhaps some solar hot air units and a large(ish) electric heater will be enough to take care of it.

Sounds like paradise to me man!

I'm a big fan so far.

How about a gasifier , in other words running a gas generator on wood smoke. You could set it up outside and maybe scavenge some heat with a water system in addition

I installed an electric heater in my well insulated 2 car garage last winter, and it was enough to heat it up to ball-sweatingly-hot in about an hour.

I just bought a new place with a a 3.5 car detached and 1.5 car attached garage and will probably use the small electric heater in the attached garage once its insulated and put one or 2 of the bigger variants of the same heater in the big garage.

If you have room, get a ceiling fan. They work wonders for maximizing available heat in the garage in winter and keep the bugs away on those gorgeous summer nights.

If you need a take out boiler, I can help you out, but that seems like way more work than it's worth. Even being a plumber, I wouldn't go to that extreme. I use one of those round stove looking propane heaters hooked up to a propane tank. It can run all weekend and have my garage hot on less than one 20lb tank. It gets warm so quick, that I have to turn it down real low. I also have one of those heaters you see mounted to the wall in hotel rooms mounted to the back wall of the garage, but I never even use it. The portable unit is nicer. It sits where I'm working with a nice warm cup of coffee on top of it. Problem with heating the garage, is the thermal mass of all the cars, engines, tools, lift and other large pieces of metal in there. It will take all day for them to come up to 60 degrees, but the air comes up to temp fast.

I answer this based upon winters here that get to -40... i know there are many people on this forum to whom heating means bringing the temp from 50 to 70*f, so forgive me if I'm out of range.

Theres quite a few people up here that have remote wood burning boilers. Insulated tubes run underground to the heating coils, or rads, or floor heat. It strikes me as a very expensive way to create a great deal of work, but if there is no natural gas available, and you don't want a 500 gallon propane tank outside, it might work for you.

I think natural gas is the finest thing in the universe, and would pay quite a bit of money to not chop, cut, stack, season and burn wood.

Last winter I needed to undertake making a complete fiberglass body for my race car. My garage is a 26x32 uninsulated stick framed detached building.

After much deliberation I settled on a propane radiant-tube heater - 45k btu. I bought a "Mr. Heater" brand unit from Amazon w/ free prime shipping, as well as a 100# tank, regulator and venting kit and thermostat.

Installation was easy. I had to run 2 runs of 3" round duct - one for exhaust, one for fresh air to the burner box. While laying up a fiberglass nose or tail in the mold the air in the garage would likely approach combustible levels. I sealed all the ducting on the intake side w/ aluminum tape, and hi-temp silicone on the exhaust.

Getting 100# propane tanks filled locally is a bit of a pain. The cheapest 2 places will only fill if you have a vehicle capable of transporting the tank upright. As I have cap on my truck, I end up going to the more expensive place with the big parking lot. I roll up to the fill shed w/ my tank on a hand truck and they don't ask 'nothin'.

The nice thing about radiant is it doesn't heat the air - it heats the stuff. So I'd turn it on in the morning and after breakfast the room would be tolerably warm. In a couple hours the thermostat would be cycling, and it's a pretty long cycle.

As I was working on an 8x8 table in the middle of the radiated area, when doing layup I'd let the mold, table, and materials all heat soak to say, 80 degrees then turn the thermostat down so the heater would stay off 'til I was done laminating w/ resin. I laminated once while it was cycling and the resin cure time became unpredictable.

I recommend these highly.