Rec: Temp winter heater for the garage

[itsablurr]

I'm looking for a rec on a temporary/portable heater for an uninsulated attached garage, approx 925 sq ft.

The garage will be getting finished and heated next summer, but with a resto project coming in a few weeks, I'd like to have a somewhat comfortable means of doing work over this winter. 110v is currently what's in there.

Anything fuel or elec that's a go-to for this type of situation?

 

[Rookie2]

The big box stores handle a propane fired torpedo heater. works good !

 

[theoldwizard1]

A lot of it depends on where you live ! (Update your profile)

I have this 30,000 BTU heater.

In a un-insulated garage, at 20F, it will fry your **** while your front side is freezing. It might raise the temp in the garage a couple of degrees.

This unit is 70,000 BTU and is very highly rated on YouTube.

 

[laser3kw]

The big box stores handle a propane fired torpedo heater. works good

I have been heating my 1200 sqft with a propane heater. I have the forced air torpedo but it is deafening. I went to a 30k to 80k "construction" heater (looks like a small metal trashcan) with a 100 lb propane tank and it works great - and quiet! But! I would go with a 40 lb propane, the 100 lb is heavy to deal with.

 

[Spudland_Dave]

.....for an uninsulated attached garage, approx 925 sq ft.

??? where you are...but that right there translates to ******* into a stiff breeze....BTDT....I feel your pain....so if your gonna shop for something like that, I'd suggest going with a big azz mofo kerosene powered torpedo heater, something with some serious BTU's... took almost 200k BTU to "warm" my 30x50 when it was uninsulated. The year after it was all insulated and a small 60K LP fired torpedo heater made it comfy enough to work in a t-shirt.

PERSONALLY, my honest to goodness suggestion would be to not waste any money on temp heater...use the money to insulate. No clue on your design, but if its a traditional truss/rafter design...insulate & seal the ceiling first for your biggest bang for the buck.

 

[Stuart in MN]

Unvented heaters pump a ton of moisture into the room, so you may have issues with condensation. They also pump a ton of carbon monoxide into the room, so be careful about that as well.

 

[laser3kw]

They also pump a ton of carbon monoxide into the room, so be careful about that as well.

That subject has come up before and discussed at length. I went as far as buying a Carbon Monoxide detector with a readout. In my case, a 30 x 40 x 10 well insulated garage, running either the 130,000 btu forced air propane heater or the 80,000 btu construction heater, the CO detector reading went from "000"ppm to may be "018"ppm after 6 hours of continual use. According to the CO detector instructions, "Concentrations of CO between 1 and 30 PPM can often occur in normal,everyday conditions."
Now, when I fire up a snow blower, within minutes the alarm sounds and records peak readings anywhere between 300 ~500 ppm. Time to open doors.
If you choose this type of heating, I urge you to get a CO detector as well, good peace of mind.
PS an "unvented" heater can not pump moisture that is not all ready there. They just make it noticeable as the temp changes.

 

[Two Sheds]

PS an "unvented" heater can not pump moisture that is not all ready there. They just make it noticeable as the temp changes.

Combustion of propane turns propane and oxygen into CO2 and water vapor, and plenty of it. If it isn't burning cleanly, you also get carbon monoxide.

C3H8 + 5 O2 → 3 CO2 + 4 H2O + heat

Therefore, you need some other form of ventilation when using an unvented heater.

ref:
https://en.wikipedia.org/wiki/Propane#Properties_and_reactions