Btu requirements?

[borderboy1971]

Can someone please calculate my heating requirements for my shop? All the online calculators might as well be written in Greek, because they make no sense to my little peanut brain.

Shop is 60' x 64' x 16' ceiling. Has 2" styro under slab with in floor piping spaced every foot. Walls are structural insulated panels that are 8" thick rated at r32. Has 2 14'x14 sectional garage doors rated at r25. Has 6 south facing 4'x4 dual pane windows. Ceiling will be blown in to r50 or r60 range.

Presently considering a oil fired boiler.

Thanks for any help.

Oops, I should add that in winter here it can get to as low as -40 Celsius without wind (Fahrenheit temperature is pretty much same at -40), and as hot as plus 40 Celsius in summer ( very uncommon for summers like this though). Average winter temps are -20c.

 

[Shiftless]

You sir, have an amazingly well insulated space. In many climates you would be able to heat the place with the waste heat from your lights, your flat screen TV, and your beer fridge.
Solar heat gain from those windows might overheat the place from time to time.
I know that winters in Canada can be brutal so of course you will need some hot water circulating through your hydronic in floor heat tubing. Get it right and it will be SO comfortable you might just move in there.
I can't calculate your BTU needs but somebody can. I can just give you encouragement!

 

[2011laramie]

where did you find r25 garage doors?

 

[borderboy1971]

I don't remember the brand name of the doors, but model name is t300. If you google that, I'm sure it'll come up.

 

[jvitez]

Honestly, pay a commercial HVAC contractor or even a mechanical engineer to do a proper Manual J heat loss calc. It'll money very well spent. Rule of thumb numbers will be so far off your fabulous sounding but very unique space that you'll be kicking yourself forever for a poorly performing system.

I remember finding some online sites where you can pay for a onetime heat loss calc, might be worth a try.

 

[George-V]

You could just google BTU calculator and do it yourself.

 

[George-V]

http://www.hearth.com/calc/btucalc.html

Try this calculator.

 

[chrispyny]

Have you considered an outdoor wood fired boiler ? I knew someone several years ago who built a garage/shop with high bay door large enough for a school bus to fit, and he used a wood fired boiler to run hot water thru his concrete floor. I had an opportunity to work in his shop once during a cold winter day. It was amazing, laying on my back in a t shirt working on a vehicle, and the garage was toasty and the floor was clean, dry and warm. Just amazing.

 

[TooMuchHair]

Sounds awesome BB. Very similar to my 60'x60' ICF wall building with R60 in the ceiling. I only have one 16' wide x 13-6" high RAYNOR T300 OH door. They are awesome doors, 3" thick, but manufacturer only claims 17.05 R-value. I'll be watching closely as i'm trying to decide how many candles I will need to stay warm this winter in the St.Louis area. Ha

 

[Ironhorse74]

http://www.hearth.com/calc/btucalc.html

Try this calculator.

For what it is worth, I am not a fan of that calculator. It was written with old inefficient hearth products in mind. My bet is that a modern boiler is much more efficient than a B-vent fireplace.

Brad

 

[George-V]

For what it is worth, I am not a fan of that calculator. It was written with old inefficient hearth products in mind. My bet is that a modern boiler is much more efficient than a B-vent fireplace.

Brad

It's just the first one of many I picked out.

 

[Shiftless]

Yeah, don't spend six figures on your garage and go with anything less than a professional analysis of heating needs.

 

[DonPowers]

The calculation for heat loss is Q=U x A x ∆T
Where:
Q= BTU per Hour
U= 1/R
A= Area in sq ft
∆T= Temperature Difference between inside and outside

So if R=24 and the wall area = 1,120 and ∆T = 86°
Q=(1/24) x (1120) x (86°)
Q= 4,013 BTU per Hr

Do the same for ceiling, floor, doors and windows then add up all the Q’s.

There a lot of other considerations to factor into a heat loss calculation but this will give you a ballpark idea of your heat loss. If you set it up on a spreadsheet you can model options.

 

[2011laramie]

real effective R values of walls and air infiltration/turn over always throw off the calcs when i try those calculators.

 

[darkside91]

You are probably looking for something more accurate but the general rule of thumb I hear people using for garages is 50 BTU/square foot.

 

[borderboy1971]

First off, thanks for all the suggestions and help. I did give my info to a heating guy and he came back today with a recommendation of a propane boiler rated at 82,000 btu, which he said is actually slightly oversized but without knowing how much the doors will be opened it should be good to be oversized. His price however scared me at $8200. This is a supply boiler and pumps and associated with only....no installation which I planned to do anyways. So now I'm on the lookout for a propane or oil fired boiler in that 80,000 btu range.

Regarding an outdoor boiler, I haven't completely given up on that thought yet, but not sure if I have the extra time for maintenance and cleaning and filling etc. Maybe my life will slow down as I get older?

The doors are thermatite t300 by the way for those interested.

 

[brewchief]

What's the nearest big city? Without a bunch of minor details it's hard to get exact numbers but I came up with a little under 60k btu using Saskatoon as the location.

 

[borderboy1971]

What's the nearest big city? Without a bunch of minor details it's hard to get exact numbers but I came up with a little under 60k btu using Saskatoon as the location.

Closest city is Estevan (sunshine capital of Canada, but believe me when I say that sunshine does not necessarily mean warmth). But as far as bigger cities go, Regina, Saskatchewan or Minot, North Dakota would be closest references. Saskatoon (300 miles north) weather is pretty much the same as here so that will work.