# Advice on heating an uninsulated garage



## rwhite

I have a 20X24 uninsulated garage/shop. We don't use it for parking and it is detached. Open trusses, 10' block walls with one 8' garage door on one end and an entry door on the other. I have wrangled with idea of putting a wood stove in but haven't come to terms yet with the cost vs use. I would say I'm out there 4-5 hours a week piddling around. So considering that I probably will not insulate it because I use the upper storage space here are my options:

1. Wood stove. I like this idea the most just because I have the wood and I like the idea of having the coffe pot sitting on a trivet when I do work out there, Downfall is the cost. Here is one option I'm looking at but I would need to purchase the flue pipe:
http://boise.craigslist.org/for/4277455147.html

2. 40k propane heater. Right now I fire up my Mr. buddy about an hour before I work in there. For a 9000 BTU heater it does okay. It will bring the temps up to 45 or so which is workable but certainly not ideal. So maybe something like these:
http://www.northerntool.com/shop/tools/product_200612654_200612654

http://www.homedepot.com/p/Dyna-Glo...ank-Top-Gas-Portable-Heater-TT360DG/203534107

http://www.homedepot.com/p/Dyna-Glo...op-Gas-Portable-Heater-CSA-TT30CDGP/202895387


3. Kerosene heater. Never used one so I have no idea of the pros/cons of these but I was thinking something like this:  http://www.northerntool.com/shop/tools/product_200612643_200612643


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## Ashful

Having had and heated a few such buildings, I'd go minisplit.  In fact, I'm installing two more in my newest detached garage/shop. 

I see a woodstove as having several shortcomings, in this application:

1.  Required clearances... they eat up a LOT of your limited floor space.

2.  Fire hazard in a shop where sawdust is abundant and everywhere.

3.  It's never warm when you want it!  If you use this 4 hours per week, it'll just be getting up to temperature when you're finishing up for the day,then it goes back to cold for the rest of the week.

Conversely, a mini split can be programmed to run a schedule.  If you're only out there Saturdays, have it programmed to be at your desired temperature on Saturday.  They can be controlled remotely from the house, so you can turn it on an hour before you head out to the shop.  They hang on a wall, not eating up any floor space.  There's no ductwork or resistive heating element to cause fire or explosion hazards (I spray a lot of paint and finish).

I do have a direct vent propane heater in my attached garage, and use it when I'm working on a car or tractor.  It does the job of keeping the garage warmer in winter, but it's not programmable, and does nothing to keep me cool in summer.  I also suspect it's no cheaper to run than the mini split.


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## rwhite

Joful said:


> Having had and heated a few such buildings, I'd go minisplit.  In fact, I'm installing two more in my newest detached garage/shop.
> 
> I see a woodstove as having several shortcomings, in this application:
> 
> 1.  Required clearances... they eat up a LOT of your limited floor space.
> 
> 2.  Fire hazard in a shop where sawdust is abundant and everywhere.
> 
> 3.  It's never warm when you want it!  If you use this 4 hours per week, it'll just be getting up to temperature when you're finishing up for the day,then it goes back to cold for the rest of the week.
> 
> Conversely, a mini split can be programmed to run a schedule.  If you're only out there Saturdays, have it programmed to be at your desired temperature on Saturday.  They can be controlled remotely from the house, so you can turn it on an hour before you head out to the shop.  They hang on a wall, not eating up any floor space.  There's no ductwork or resistive heating element to cause fire or explosion hazards (I spray a lot of paint and finish).
> 
> I do have a direct vent propane heater in my attached garage, and use it when I'm working on a car or tractor.  It does the job of keeping the garage warmer in winter, but it's not programmable, and does nothing to keep me cool in summer.  I also suspect it's no cheaper to run than the mini split.


 
Do you have a link to the mini-split? I may have a worry about electrical capacity. Which is another item that needs to be upgraded out there. I get waht you say about clearances for a wood stove. With portable heaters I can put them where I want and put them away in the summer. I use a swamp cooler in the summer to cool the place.


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## Ashful

Just google Mitsubish mini split.  I installed an MSZ-GE12NA with MUZ-GE12NA in the room above my garage at Thanksgiving... it's working nicely.  This particular unit requires a 15A / 230V dedicated circuit.  These are professionally installed units, but there are competing units designed for DIY.


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## peakbagger

With block walls about all you can do is warm the air in the garage as the wall will suck whatever heat you put in the place . Covering the bottom of the trusses with plastic sheeting makes all the difference in the world. If they are open all the heat goes up and the floor never gets warm. Some folk stick a duct up near the ridge pole and suck the warm air back down but leaving an open attic will quadruple you r fuel usage.  I think you need something can throw out a lot of heat quickly and that would be propane or kerosene jet heaters. Gas fired radiant heat also works somewhat well. I rebuilt a car long ago and used K-1 reddy heater type unit with a line voltage thermostat. It heated a lot of air quick but was very dangerous if there were flammables around. I have a partially insulated garage now and have a wood stove designed for a hot air furnace so it has a blower on it. I fire off the wood stove and then run the ready heater for a few minutes.


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## Highbeam

I have a woostove in my shed. The walls are insulated but the ceiling is currently open and with a ridge vent is essentially ventilated as yours should be. You will never heat a ventilated building, the heat will rise and leave the space. You need to focus on radiant heaters and skip all forms of convective heaters which is why I think a minisplit is not the proper tool here.

Radiant tube heater mounted to the ceiling or radiant tanktop heaters on the floor. Heck, those palm tree patio heaters are actually excellent in this application.

I use the woodstove and have a thermometer in the shop. If I'm lucky I can raise the temperature 10 degrees in there after burning all day. Until you (we) can seal the heated space off, hot air will rise and leave the building through the roof vents.


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## Warm_in_NH

I have a similar set up.  
Personally I like my propane powered dyna glow heater when I'm out there working.
I use a kerosene torpedo heater to get it up to temp but they always give off fumes when they start up and shut down so I run it hard and kill it. Then the dyna glow gets lit and maintains the temp quietly while I work. 

You can move the heater to where you're working (heat you not the whole space) and I already had the propane tanks so the cost was low. 

Spent a winter working in a she'd with a stove, it was usually getting comfortable right about when I was ready to leave for the day. Plus the space etc...unless you're out there all day I don't see it working out. 

My vote, dyna glow propane, cheap and efficient.  Keep an eye on Craigs list for a torpedo heater or even a propane top hat for the rapid start.


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## Highbeam

Warm_in_NH said:


> My vote, dyna glow propane, cheap and efficient.  Keep an eye on Craigs list for a torpedo heater or even a propane top hat for the rapid start.


 
What are you talking about? Dyna-glow is a brand that makes lots of stuff.

http://www.amazon.com/Dyna-Glo-RA18LPDGD-Propane-Cabinet/dp/B0041OEB7E

http://www.homedepot.com/p/t/202223...alogId=10053&N=5yc1vZ1xg1Z1z13935&R=202223041


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## Warm_in_NH

The dual head radiant one that r white (creator of this thread) linked to at HD in his original post....


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## Highbeam

Warm_in_NH said:


> The dual head radiant one that r white (creator of this thread) linked to at HD in his original post....


 
Got it, I have the single head version and can tell you that it is not "radiant" enough. You've got to back right up to it or stand in front of it and lift your shirt up over the top so that the heat rises up under your shirt and flows out your neck hole. 
It's kinda like standing next to a stove top burner. Maybe just roll your BBQ into the shop.


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## bassJAM

I grew up on a farm, where at best we had an old non-insulated garage to work in, but were often stuck in a bay of the barn working on a tractor or car.  Hands down the best heat was a kerosene jet heater.  They are loud, but they get the area up to a decent temperature quickly.  I heat my attached garage with one of those round barrel shaped kerosene heaters, and even then I wish I had dad's jet heater to get it up to temp quickly and then let one or two "regular" kerosene heaters take over.


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## Ashful

I have and use a Reddy kerosene jet heater.  It does the job, and gets any space (even working outdoors in my driveway) up to temp fast.  However, there are some drawbacks worth mentioning.

1.  Many folks have trouble with these giving them bad headaches or nausea, as they're exhausting directly into your shop.  I have one old friend who's a mechanic, who has a lot of trouble with this.

2.  There's a LOT of water vapor in the exhaust they put into your shop.  Do not be surprised if equipment stored in the space where this heater is used begins to rust, as that water vapor will condense late in the evening after you've shut off the heater and closed up shop.

3.  Dangerous!  These are downright frightening to use around a dusty woodworking shop or any spilled gasoline (eg. working on carburetors), which always seems to be the two places I need heat in winter.


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## Warm_in_NH

> Got it, I have the single head version and can tell you that it is not "radiant" enough.




That said, I re-read the original post and see where 45 degrees isn't "ideal". I would go with something larger, as 45 is like a tropical heat wave for me as my alternative is often to go work outside somewhere.  Although with the kerosene torpedo heater I can easily achieve 80 plus temps in there on a short burn and then the propane radiant keeps me warm while slowing down the cool down period but it isn't enough to really maintain a warm 50 plus temp for more than an hour or so.. Not in my shop anyway. 

I agree with Joful and the Reddy heater draw backs as well. While I find the fumes tolerable my helper can't work in the shop if I'm running it (thus the propane heater). Noisy, yes, smelly, yes, efficient, yes, lots of water vapor, yes, but I get it from the propane as well, especially when we used to run the top hat heaters. I think it's a fault on any un-vented system. My buddy used to heat his house with an unvented gas stove (vermont castings I believe) all winter, it was a log home with the standard air leaks in the corners, on the outside of the house there would be basketball size chunks of ice where the overly moist air from inside was escaping and condensing, crazy, was enough to change my mind about heating with the same set up and about buying a log home. LOL.


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## rwhite

Well I went for the dual head radiant heater and so far it's been to warm to really try it out. I did fire it up but it was already 45 outside so I'll report back how it does when it gets real cold again. I read to many bad reviews on the dyna-glo so I got the Century model. I also did the calculations to estimate propane use and attempting to heat with anything more than 30k BTUs seemed like it would have gotten expensive in a hurry. I think this will get me by for the short term and I may look into piping the NG from the house out there since it's only 20' away. That way I could get a real garage heater.


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## bsruther

I have 2 single tank top heaters. The detached garage is 24'X24' and while they won't heat the entire garage, they do a fine job of heating the general area where I'm working.
It isn't room temperature comfortable, but it's warm enough that I don't feel cold. I think it all depends on how much time you'll be spending out there.
In the winter, I only go out there to change the oil on the car or maybe cut and sand wood for a house project.
I attached sheet metal hoods to my heaters to keep the heat from rising too quickly and it works pretty well.
We regularly sit on the covered patio in 35F+ temps in front of one of these heaters and it's very comfortable.


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## gorooster

re. your concrete block garage, here's a decent fix: get rigid, poly iso sheets that are mylar backed and use construction adhesive to glue them to the block. Tape the seams w/ aluminum tape if you want to get a
 vapor barrier, though your garage door and high ceiling might preclude that. If you use plastic above or some kind of temporary ceiling you'll see a big change (and you can insulate the garage door as well).I didn't re-read the above posts but don't remember if the costs of a minisplit were addressed (!). Very expensive units when I was researching them. For that kind of money you can remodel your garage (or build a new one, if you're a framer).


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