How many BTUs

[john michael]

I have a 25x25 block 2 1/2 car garage. It isnt insulated. The ceiling is 12ft. I have an apartment above the garage. I also have natural gas already installed. How many btus do i need? What is a good brand heater?

 

[Repsolracer22]

reznor is the ****. prob buy the smallest one they have 35k btu prob be overkill. and you dont want to get more then you need because it will cycle on & off a lot.

 

[Scott V]

Insulated vs non-insulated makes a huge difference-

BTU Calculator:
http://www.calculator.net/btu-calculator.html

 

[CoyoteKyle]

Beat me to it... But here you go.

 

[CNGsaves]

Too little information . . . . . . you say "Un-insulated" but what are the details??

How many doors?? What kind?? Size?? Sieve of free-flowing air to outside??

How many windows?? What kind?? Size??

I'd say rule of thumb is DOUBLE size of heater if you'll never insulate, as effectively you are heating the outside !! So a 80K Btu would do the job.

You'd be better off posting up bunch of pictures, and ask HOW DO I INSULATE this garage !!

However, that still is cart-before-the-horse as rough electrical and other improvements should be done while open stud.

 

[bzinsky]

Well he said he had an apartment above it, which is probably heated. If that apartment is at a comfortable temp he's basically got 0 heat loss from the ceiling.

I had load calcs done by a mechanical engineer for individual apartments in a 3 story building. The apartments are 550sq feet, 0 insulation on walls, the bottom and 2nd story apartments had load calcs around 4000 btu's. Granted there was only 1 exterior wall in each apartment, but it was a big wall with a lot of windows. The 3rd floor apartments were 10kbtu's with r19 above. Just goes to show how much much having a heated space above effects btu load calcs.

 

[bzinsky]

reznor is the ****. prob buy the smallest one they have 35k btu prob be overkill. and you dont want to get more then you need because it will cycle on & off a lot.

I have a 50k btu force air gas heater in my 2 car totally uninsulated garage and I think it's perfect. I don't use it to maintain heat though, I have it on a timer instead of a thermostat. I just turn it to 30 minutes before I'm ready to start working in the garage and I come into a warm garage. I'll turn the dial again after about 2 hours.

Super basic setup, just a duct that goes up and over with a few vent cutouts. Return duct is like 12 inches long, just for a filter.

Only works if you're not trying to maintain a certain temp throughout the winter.

 

[john michael]

The walls are bare block, the overhead door is 16x9 and it is insulated 3 single pane windows. I will not be insulating the walls. My wife parks in there and i wont her to have a warm car in the mornings when she goes to work. I am retired and she is still working so we have insurance.

 

[bzinsky]

The walls are bare block, the overhead door is 16x9 and it is insulated 3 single pane windows. I will not be insulating the walls. My wife parks in there and i wont her to have a warm car in the mornings when she goes to work. I am retired and she is still working so we have insurance.

I've got a much cheaper solution and far more effective at actually having a warm car.

A remote car starter and a power garage door opener with remote.

 

[rodm1]

These sights are a grate help you don't need the LP one but it's interesting.

BTU calculator
http://www.ultimategarageheater.com/...ter/search.php
Sizing your LP tank
http://www.nbmc.com/heaters/lpchart.html