Electric heater for garage.

I need a heater for my 3 car garage. Standard size. I use the 3rd car as a shop. The garage is insulated except for the garage door.

I am in the garage occasionally after work and then one day on the weekend. I live in Denver, so it does get cold, but not COLD.

I already have a 50amp 240v plug near where I want to have the heater. Does anyone have any recommendations for a heater?

Most I see are hardwired. Will there be any issues just installing a plug on the wires? I found on the  https://truckpowerup.com/ good 120v heaters I liked them, maybe you can advise some?

Thanks.

The max wattage you can run through a 50A circuit is 9600w, so your options are somewhat limited.  

Can you hang some sort of temporary wall to partition off the "shop" area from the rest of the garage? Heating less space will help whatever heater you choose get your work area up to a tolerable temperature faster.

Yes, installing a 50A plug on the heater cord shouldn't be a problem.

50a at 220v gives you a 10kw heater, like this.

https://www.homedepot.com/p/DEWALT-10-000-Watt-240-Volt-Forced-Air-Electric-Heater-DXH1000TS/305094120

That would be like 35,000 btu to put in reference to your home furnace.  I'm in michigan and have a 50k btu big maxx natural gas heater actually output is 45k btu.  It can keep my poorly insulated and rather drafty 2 car garage at 70 when it's in the 30's outside.  A thing I noticed is if your not running it constantly to keep the slab warm you'll notice it takes a long while to heat and warm the slab.  

As your going electric you can either do a forced air heater like the dewalt I shared or a infrared heater.  Forced air heats the air, infrared heats surfaces.  The latter might be nice to warm tools or a particular project you may be working on.  

I don't have a lot of experience with electric heaters to tell you if one rocks compared to others, just offering some general points to think about.

On a side note, if your getting a heater for your garage, insulate the door.  Menards has foam kits that will do a single door for $35 each that take less than an hour to pop up and will help with heat loss.  As it is foam probably ensure sparks wont be directed towards it.  Also take some time to check for air leaks, around the edges of the garage door are typically not well sealed and if you can keep the air in the garage you will have less to heat.

Seems like people disagree with me on this, but I'll say it again.

Heating the air in a shop is pointless.  With all the air intrusion, you're just spilling a significant amount of heat energy to the outside.  Don't heat the air, heat solids.  Radiant heat is your friend.  Heat yourself and your surrounding solid objects.

Electric radiant heat was the sole heat in our drafty loft when we lived in L.A. and it was great.  My shop at work is only radiant heat (gas) and it stays toasty.

Watt for watt, radiant will keep you warmer.  Air is a terrible conductor of heat, and when you're losing so much of it through air leaks, it isn't the most efficient way to keep things warm in a garage.

I have one of those $200 220V Milkhouse heaters in a small insulated garage and moved it from one garage to another when I moved...

• They suck power like its going out of style, even turned down to 45F it will drink a lot of juice.
• Clean and quiet power with no venting hazard is nice.  
• Installation is very easy, just run some adequately sized wires
• Make sure you have enough amps in your garage panel to cover the additional headroom.  I cant run my pizza oven and furnace at the same time.
• 5000 watts was enough to keep a 2 car garage at 70 in 0 degree weather.  But it was fully insulated, 1 common wall and a common roof with the house, and had a 2" thick insulated door with a cold-break in it.
• Best advice to using a forced air heater is use a ceiling fan if you have room for it.  Moves the air off the top of the garage and into the area you are working.  

All-in, its OK.  I wouldnt want one as primary source of heat in a 3 car garage unless I wasnt paying the power bill.  

For occasional use an electric heater is fine.  They're generally expensive to run (depending on what you pay per kilowatt-hour), but if you're only using it for a few hours now and then it's not that big a deal.  As mentioned in post #3 there are a number of 10kw portable contractor heaters you can plug in.  

Having said that, you really need to do a heat loss calculation to determine what size heater is required; there are a number of them online, you plug in the size of the space, how much insulation, number of windows and doors, your local climate conditions, etc. and it will give you a size estimate.

I have a wall mounted heater that I removed from a hotel.  Never use it.  Found out that one of those portable round barrel style propane heaters connected to a gas grill propane tank does the trick better than anything else.  I can sit it where I'm working and set a coffee on top of it.  Fire it up on high for a couple of minutes to take the chill out and then turn it down low and just let it simmer away while I work.  Too much metal in the garage to ever get everything up to a consistent 60 degrees, but where I'm working, its cozy.  A bonus is if I'm doing new construction in the winter, I can throw the whole thing in the truck and heat the house I'm working in.  Lost power and heat several times and it keeps the house plenty warm so that I don't have to worry about frozen pipes.  One grill tank will last a whole weekend when its really cold putting in long days in the garage.