Heating my 50x30 but seperated shop.

[bucs012]

Here in Iowa (temps from -10 to 100 degrees) I am having built a wood framed, concrete slab and frost footings (R19 insulation in walls and R25 in ceilings) vinyl sided, 4/12 gable roof with 1' overhangs, 8 foot ceilings when finished, using 16" studs, OSB sheeting walls and roof, 1/2" rock walls and ceiling, tape and spray with orange peel texture. They are also sectionning off a 20x14 foot work shop that will have a 36"x24" window and service door to the exterior and another service door and 8 foot overhead door from the shop area that opens into the larger part of the garage. The main garage will have an 18 foot overhead door on the 30 foot side, service door and another 36"x24" window.

I have read a lot of info on the search option in the forum for heating this area. I am leaning towards the Natural Gas Hot Dawg or Mr Heater type heating.

I would like opinions- It looks like for my shop area of 14x20 a 15,500 BTU will be just fine to keep it a nice 60-70 degrees when working in there, but will keep it 40-50 degrees when not in there. Sound right?

ALSO- There may be times when I want to heat the larger part of the garage also to say around 60-65 degrees over the weekend or keep it at 40-50 degrees all winter for my hot rods.

Would it be best to buy another 40,000 BTU system and hang it in the larger part of the garage to run seperate from the smaller work shop? I know I could buy a LARGE unit, hang in the shop and then OPEN the larger 8 foot overhead door to the shop so air goes out to the rest of the garage but that does not sound as efficient......When I was heating the smaller shop, only, that unit would be way large for that small space.....Is my thinking right?

 

[sledzz]

yea your in a pickle...to bad you are heating the smaller part of your shop. It will be hard to heat the larger side by opening the doors and blowing it in with a smaller heater on the small side of your shop especially come winter...
I have the same arrangement only I heat the large side all the time and the other occasionally and mine is 48 x 32.
the 14x20 might be small enough to use electric and then later on buy a furnace that can heat the large area and then duct the smaller area to heat it.
I bought a used condensing furnace, uses fresh air from the outside to burn and it came with the AC units. I am planning on heating the large part and have the duct work ability to deflect it to the other side. So it is oversized a bit for the main shop but not when you combine them. We'll see how it goes this winter since I am installing it now. I have a old hanger heater in there now...

 

[38Chevy454]

Just an idea, but what about using dampers and adjusting the air flow? Using only one heat unit. It would be way oversize for the smaller portion, with corresponding efficiency losses from short cycling. But maybe the dampers could be adjusted so the main shop stays 45-ish and the office part 65-ish. You would have to play with the dampers, and return air would be a bit more complicated.

 

[rwhite692]

Don't know if it lends any ideas, There are some pics of my Sunstar radiant tube setup, toward the end of the thread (link in my sig, below).