I remember seeing a special on odd inventions in Europe, one fella had a coverall suit made from heating blankets. Since he normally had an extension cord run for lights into his garage, he just plugged his suit into it and was nice and toasty while he worked. He also used it in the house, he would turn his house heater to bare minimum as to no freeze the pipes and plug the suit in whichever room he was in.  Hmmmmm, now where were those extra heat blankets????

It's a newer home and I'm pretty sure it's insulated as it's usually 10 degrees warmer in the garage then outside when it's cold out. The big problem is it's a 3 bay garage with one bay as my work shop so actually heating the entire garage isn't an option, so looking more for an area heat source most likely like the heater on the propane tank like you mentioned JOG.  I've worked in warehouses that use the kerosene heaters and although they heat a lot of space I remember always getting headaches from the fumes, while propane and natural gas have never seemed to bother me  

Hang a divider between your bay & the other 2. I got the heater at Academy, Harbor freight sells a 2 head unit for 5 bux less,, whoopee,, Ill take academy..for 65
If you have a gas grill,, swipe the bottle, If not, look for one that size or be ready to spend some $$. Collecting a junk grill for a low price & getting a propane bottle you can have refilled works. Mine has a built in Overfill Protection Device
look for OPD on the valve handle,

Propane runs stoves in homes, heaters in homes, UN vented,,Im pretty sensitive to petro crap & my heaters dont bug me, Even the kerosene.
If youve got the $$$, go big time,, But it isnt JUst the cost of the unit, you gotta pay for it to do its job, read up on that stuff,,

Good info.... i'll look around

I do have one of these, but its not good enough to heat the garage and it requires venting

http://www.lowes.com/pd_93043-88644-RMC-95C6B_4294765336__?productId=3471481&...

Funny that the site says no venting required but the manual suggests it....

I have had several differenet garage situations and heaters.

When I was in college I had a 2 car brick garage that had a small kereosene heater that was vented.  The heater used no electricity and had a gallon tank on the back.  I think you can still find heaters like this in junk shops and on Craigslist....but I believe they are not EPA compliant and probably not in production anymore.  I could go out and light it about an hour before I wanted to work, and it would have the place heated up pretty well.

My dad's 4 car garage had an old pot belly stove and we would buy lump coal and use it in the stove.  It made a lot of heat, and when night came you could load it up and turn the damper down and keep heat all night.  Later when that wore out and the local coal mine closed we installed a barrel stove made out of a 55 gallon barrel.  It still works very well and puts out a lot of heat.  You can put a lot of wood in one and keep a fire going most of the night.  They put out heat in all directions - so you need some decent clearance around them - and the shell is thin and won't last forever.

A friend of mine got an old electric furnace where the AC coil had gone bad and the resistance heat was still good.  He did not run any ducting  and just put in in the corner of his shop, and it worked good.  It was electric heat which is a bit expensive when compared to wood - but it is neat and clean and requires no flue or duct work.....and you can get old electric salvage furnaces pretty cheap.  All you need is the cabinet with restance coil and blower, and a thermostat.        

The most expensive heat is electric.
Hanging plastic is a great idea. Hanging 2 sheets a few inches apart is better.The dead air between will really help keep the heat in. You can make both "walls" one piece & lay a 2X2 in the bottom & staple it in a few places & use ropes to roll it up & raise it like blinds using a coupla pulleys per section.






This is as close to what I have as I can find. It wall mounts. Remember to build a trap in the propane line to catch any water that may condense. If you dont know , ask a plumber or PM me & Ill give you my number. I ran all the lines for mine. Still alive, Baybee!

Heres the LOWEsdown

Mr. Heater Vent Free 20,000 BTU Convection Utility Liquid Propane Space Heater VF 20K BLUE LP

Mr. Heater VF 20K BLUE LP Enjoy the comfort and warmth of safe, clean-burning heat with Mr. Heater Vent Free Wall Mount Heaters. You can use them in recreation rooms, room additions, workshops, enclosed porches, cabins, ice houses or lodges. Features: -Liquid Propane Blue Vent Free Wall Mount Heater. -20000 BTU. -Blue flame burner for even, convection heat. -Oxygen depletion sensor for safety indoors. -Legs included. -Quiet integrated blower for gentle circulation of heated air (Not on 10,000 BTU Unit). -Can be mounted or stand on the floor. -This item does not ship to California per state law as well as Canada. -Restricted from use in California and Canada. -This item is not CSA cert