How Many BTU's?

[OverkillYJ]

I have a 700sqft garage with 15ft ceilings. It is concrete block construction. I live in Philadelphia and am looking for a heater. I have no idea though how many BTU's I will need. I see things that are like 55,000 BTU's, or 80,000 BTU heaters. I just want it around 55 degrees in the dead of winter, which here is usually not lower then 25 degrees on the coldest of days. I am replacing insulation in the roof shortly. I just dont want to waste money on something that doesnt heat it for ****, and I dont have the cash to put out for an infrared radiant heater right now.

 

[rshadd]

A simple formula that can be used to determine heater BTU requirements:

Cu. Ft. of Area X .133 X Desired Temp. Rise °F = BTU Size Needed.

Example:
Area: 50' X 25' x 10' = 12,500 Cu. Ft.
Desired Temp Rise: 30°

12,500 (Cu. Ft.)
X .133 (Factor)
1662.5
X 30 (Temp Rise)
49,875 (Proper Heater Size)

Answer: A 50,000 BTU heater should be selected for this application.

Or plug your numbers into this BTU calculator:
http://www.calculator.net/btu-calculator.html

 

[CNGsaves]

Any plans to insulate the concrete block walls?? Could be 1" wood strips with styrofoam between, then topped with sheetrock.

Pics you might want to share??

You have natural gas or propane available??

 

[OverkillYJ]

I have Natural gas available. It did have water lines coming off the furnace in the house. I removed them since the runs were about 100ft, and I would have had to let it stay on all winter long to stop the water from freezing if I turned it off. I need something more on demand that I can turn on when I want and have the place workable in 30 min or so. I was told non-radiant innfrared is the best way to go since everything near the heater will get warm, but not hot to the touch as it would with radiant infrared? I was also told I can hook that up to my gas line.

 

[OverkillYJ]

A simple formula that can be used to determine heater BTU requirements:

Cu. Ft. of Area X .133 X Desired Temp. Rise °F = BTU Size Needed.

Example:
Area: 50' X 25' x 10' = 12,500 Cu. Ft.
Desired Temp Rise: 30°

12,500 (Cu. Ft.)
X .133 (Factor)
1662.5
X 30 (Temp Rise)
49,875 (Proper Heater Size)

Answer: A 50,000 BTU heater should be selected for this application.

Or plug your numbers into this BTU calculator:
http://www.calculator.net/btu-calculator.html

Nice formula. I know with most things though they lose efficiency when you push them to the limit since they are working at the max they were intended for. Would it save me money on gas if I went with something that was capable of heating my garage to 80 degrees if I wanted it to? In the long run I would like something that will get it up to 65-70 degrees when I know I will be in there all day. Right now I am looking on craigslist for a kerosene heater for this first winter with my garage though.

 

[CNGsaves]

Wow, great lift in that old garage !!

For your situation, sounds like Bigger heater is better. I'd go 80K Btu Big Maxx (Mr Heater) that are around $450 to $500 and natural gas should be cheapest fuel in your situation.

Mr Heater also makes a portable heater (Big Buddy) that can be ran from 20 lb BBQ bottle of propane that puts out up to 18K Btu. These are around $100 to $150 with the hose kit. These can be operated indoors with no problems as they have low oxygen sensor that will shut them off automatically.

I'd avoid the kerosene torpedo heaters unless you get one dirt cheap, as fumes are a problem with those (thus good ventilation is needed).

 

[OverkillYJ]

Thanks on the garage.

What do you mean fumes are a problem with those? I thought they were safe indoors? I see them on CL for $100 and thought it would be a good investment to make it through this winter.

 

[CNGsaves]

You might get by with kerosene torpedo heater since garage has open ceiling and lots of air infiltration, plus cracked doors/window. Cheap propane torpedo heater would be much safer IMHO.

I've used my Big Buddy 18K Btu propane heater (3 heat settings Low/Med/High) in as small confined space as clamshell camper. Heck, fisherman in Michigan use these Big Buddy heaters in fishing huts on frozen lakes. They are 100% safe for indoor use.

Curious how far you've got to run black pipe steel to get natural gas supply over to where you want to hang heater?? Unistrut would make hanging that heater real easy.

 

[OverkillYJ]

Gas line is already run underground from house to garage by the previous owner. I just need to make sure it is still air tight and reconnect it in my basement. It actually runs within feet of where I will hang an infrared heater.

 

[Charles (in GA)]

Thanks on the garage.

What do you mean fumes are a problem with those? I thought they were safe indoors? I see them on CL for $100 and thought it would be a good investment to make it through this winter.

Torpedo heaters DO produce carbon monoxide, no matter how well they are adjusted and how clean they burn. You will need ventilation, and more than just loose building leakage. I ran my 85K btu quite a bit in Jan/Feb or 2011 while I was assembling my used oil heater, and even in my 60x60x16 steel building, with several air leaks (that I have now slowed or closed) I was getting a headache after a couple of hours (from the CO, not the noise).

Good natural gas heater, regular suspended garage type would do well for you.

This thread http://www.garagejournal.com/forum/showthread.php?t=47200 will help you with proper calculations.

Discussion on air infiltration. http://www.garagejournal.com/forum/showthread.php?t=149646

Charles

 

[OverkillYJ]

I was just looking on craigslist and see a ton of used gas furnaces on there for less than $400. Some are forced air, some water boilers. If I got a 90k BTU forced air and threw a couple of ducts up so it heated evenly would that work? Would there be any downsides to it?

 

[zmaxmotorsports]

I was just looking on craigslist and see a ton of used gas furnaces on there for less than $400. Some are forced air, some water boilers. If I got a 90k BTU forced air and threw a couple of ducts up so it heated evenly would that work? Would there be any downsides to it?

Id be really careful with used gas furnaces,for a couple hundred dollars more you can buy a new furnace and know its history.

 

[OverkillYJ]

Thats not a concern. More like what is more efficient. Infrared or forced air. I have a friend who can inspect and make sure anything is working fine before buying or getting it up and running. I have also done more business on Craigslist than probably any store I go to over the past couple of years. Been happier with the craigslist finds too.

 

[mygarageone]

Infrared is by far the best way to go . It heats objects not the air. There by giving you a much more even heat. and much more comfortable.
Unless you have to use forced air because of costs , I would never have a forced air system in my garage.. The floors are never warm , Never !

 

[anthony666]

hey man, you have a build thread for that yj ???

 

[jomobco]

ahhh Yuengling! Have two for me

 

[neel2008]

I know this is a little late, but I use this calculator to get an idea on btu's needed for a certain space http://www.calculator.net/btu-calcu...=50&temperatureunit=f&calctype=heat&x=50&y=14 seems to be pretty close to others I have used as well...

 

[OverkillYJ]

ahhh Yuengling! Have two for me

LOL Yeah. I used to live in Denver, never found Yuengling out there.

 

[OverkillYJ]

OK guys. Thanks for all your help. I cam across a 170k BTU torpedo heater on craigslist for $200. I bought it last night so I would have something immediate since it got cold here early this year and I have a lot of work to do in my garage. Might have been a mistake. I started a new thread for it.

http://www.garagejournal.com/forum/showthread.php?t=221372

@ anthony666. I am on wranglerforum for the Jeep stuff. Same handle/name on there. It is a Spring Over setup with a lot more to it.