Heater for garage

regarding 120v/240v

Every house gets two phases piped to the house (out of the available three, your neightbour most likely only shares one of your phases for load distribution)....they are both 120V but the frequency is offset slightly so the peaks are not at the same time. Connect two phases together on the Live side and voila, you have your 240V.

And remember kids, wires dont give a rats *** about the voltage thats going through it, only the amperage. Thats the whole reason high draw appliances step up to 240V, so the lines dont have to go nuts in size.

Watts = Amps X Voltage. So if a heater draws 1500w it could either draw 12.5Amps at 120V or it could draw 6.25 Amps at 240V. Frequency comes into play as well but since all house AC is 60Hz it doent matter for this topic but FYI aircraft A/C generation systems are 400Hz!! This allows for smaller components outputting huge amounts of power and the ability to run lots of power through smaller lines.

With that being said, i currently just use two spot lights for heat. I turn them on anyways for better light when working on something and they get the garage pretty warm, we'll see how they do when it really gets cold as my garage is high ceiling and unfinished.

Until you surpass the voltage rating of the insulation.
 
I use a combination of heat for my 1.5 car garage. I insulated it a couple years ago but do not have an insulated door.

Mostly I use a small 1500w 110v and a 18,000btu Mr Buddy propane heater. I also have one of the electric radiant heaters like the one in Rodney's video. For the super cold days I also have a 55kbtu forced air propane heater but it's a bit overkill.

http://www.mrheater.com/product.aspx?catid=41&id=116

That's my main source of heat. It's rated for use indoors as it has an oxygen sensor. I have run this in my garage for 10+ hours and never had my CO detector even chirp. My drafty door and ample soffit vents must be sufficient.

If you can make your working area smaller, you will need much less heat to be warm. In the winter I use plastic sheet to close off most of the rafters and keep the heat down where I am. At the front of the garage where my work bench is has a storage loft above it. I run a sheet of plastic down from the loft to the floor and create a little warm room to work in. My little electric heater on the 750w setting will keep this area more then warm, actually after a while I will turn it off as it is too warm.

If I need to work in the main area (like on a car or somthing that will not fit in my warm room) I just use the propane heater and electric on high. Just takes longer to warm up, but the combo has no problem keeping up to 20c in the dead winter so long as you leave the door closed. Im hoping this winter with the radiant heater mounted above I can do away with the electric heat in the main area.

Something to remember with using heaters in your work area, keep flammable stuff away from it. Take care where you place your heater when using volatile spray chemicals or dealing with gasoline.
 
regarding 120v/240v

Every house gets two phases piped to the house (out of the available three, your neightbour most likely only shares one of your phases for load distribution)....they are both 120V but the frequency is offset slightly so the peaks are not at the same time. Connect two phases together on the Live side and voila, you have your 240V.


And remember kids, wires dont give a rats *** about the voltage thats going through it, only the amperage. Thats the whole reason high draw appliances step up to 240V, so the lines dont have to go nuts in size.

Watts = Amps X Voltage. So if a heater draws 1500w it could either draw 12.5Amps at 120V or it could draw 6.25 Amps at 240V. Frequency comes into play as well but since all house AC is 60Hz it doent matter for this topic but FYI aircraft A/C generation systems are 400Hz!! This allows for smaller components outputting huge amounts of power and the ability to run lots of power through smaller lines.

With that being said, i currently just use two spot lights for heat. I turn them on anyways for better light when working on something and they get the garage pretty warm, we'll see how they do when it really gets cold as my garage is high ceiling and unfinished.

Sorry wrong you only have one phase (240) with a grounded center tap in residential power. Apts and condos use 3 phase like you described but not houses. The rest is correct and it doesn't really matter whether you have 1 or 3 phase type power system.

Single phase residential

Fig. 1


Drawing for 3 phase
fig1-4.gif



 
Last edited:
That's my main source of heat. It's rated for use indoors as it has an oxygen sensor. I have run this in my garage for 10+ hours and never had my CO detector even chirp. My drafty door and ample soffit vents must be sufficient.

You talking about that small MrBuddy heater or whatever it's called?
 
You talking about that small MrBuddy heater or whatever it's called?

Not the small single tank known to burst into flames mr. Buddy heater. I have the larger model that takes 1 or 2 1lb camping cylinders or you can get a hose and hook it up to a 20 pounder. This one also has a built in convection fan to help circulate heat. You can plug it in or use some d cells, great for use in an ice hut.
 
Not the small single tank known to burst into flames mr. Buddy heater. I have the larger model that takes 1 or 2 1lb camping cylinders or you can get a hose and hook it up to a 20 pounder. This one also has a built in convection fan to help circulate heat. You can plug it in or use some d cells, great for use in an ice hut.

Well if the small one tends to "explode", why wouldn't the big one? ha ha :) Same **** really just the bigger heater uses two cylinders.

So it has a co sensor to warn of gas leaks? what kind of run time do you get out of it, if you have two cylinders and going on full blast?
 
Well if the small one tends to "explode", why wouldn't the big one? ha ha :) Same **** really just the bigger heater uses two cylinders.

So it has a co sensor to warn of gas leaks? what kind of run time do you get out of it, if you have two cylinders and going on full blast?

Im not sure why the small heaters were recalled and the one i have was not, must use some slightly different part. I've had this one for 3 years now and still runs like a top. Also on the list of things im unsure of is the oxygen sensor. It just states in the manual that it has a "low oxygen shut off protection".

As far as run time is concerned with 2 tanks you can get 3-4 hours on high and 12-15 hours on low. The high setting is 18k btu and really kicks out the heat. I only need to run it on high for about 15 mins then I use my electric heater to hold the temp. With a 20lb cylinder according to the manual it's 50h high and 225hr on low. I don't have the hose for the bbq tank, but $20 could heat my garage when im working in it all winter at the rate i use gas, and i spend a fair amount of time in there in the winter
 
Back
Top Bottom