Outbuilding heat question

Patrick_North

Hi all,
I’ve seen questions similar to this one on the Wall, but not with my particulars, so…
I’m looking at renovating the second floor of a 30X40 two-story garage for use as a rec room (about 2/3 of the space) and wood shop The two spaces would be divided to contain woodshop mess. Renovation would include loads of insulation- including the floor- and replacing windows. I’m in central PA. So it’s a modestly sized space, well insulated, with moderately cold winters.
Being a detached garage there is no gas line or oil tank, and adding them seems like overkill at this point. Perhaps not- you’re the experts. At any rate I’m only thinking of electric heat at this point. A mini-split has AC appeal, but I don’t like forced air particularly, and it’s not a good match with the dusty woodshop environment. (Aside: it crossed my mind that with an uninsulated partition, the woodshop side may remain passably warm with only indirect warm air heat, but I digress. A guy rationalizes.) Being that there is no concrete slab I’m guessing electric floor radiant is out, but again I don’t know. Electric radiant with open or very hot elements is also out- at least in the wood shop portion- because of the risk of fire.
Any thoughts on how to heat such a space? The rec room space definitely gets comfort priority. I’m in the plotting and dreaming stages here so wild guesses are welcome.
Thanks,
Patrick

*Edit: I'm moving this to the Main Wall because I don't want to assume radiant is the only answer here. Admin- please delete if I'm doubling up on the posting. Thanks.

bmwpowere36m3

Without running an oil line, putting in a tank, or running a gas line... your choices probably would be electric, wood, solar or geothermal. First step would be calculating your heat loss. Second, are you planning on constantly heating the space or only when its occupied?

Electric can get expensive (running costs), but it would depend on local rates and how high your heat load is.

Patrick_North

Wood is definitely out. I would consider geothermal or solar if initial cost wasn't too far beyond my budget and offered a reasonable ROI, but I'm guessing that in this case, fresh-from-the-grid electric is the ticket.
I'm sure we'd use the space more with a reliable heating strategy, but even then the space will probably only be used a few times a week.
Thanks,
Patrick

Harvey Ramer

Who is your electric company?

Patrick_North

My power company is Alleghney Power.

Patrick_North

An online heatloss calculator puts it at about 17700 btu/hr, if that changes anything.
Thanks,
Patrick

Harvey Ramer

Alleghney Power is a First Energy company. I am not aware of any load control programs they have for cheaper rates. You do have a fairly small load though, and if you are only using it weekends and such, the electric usage shouldn't be to bad. If that is how you plan to use it, you'll want to have a system with a fast response time.

Patrick_North

Thanks for the input. Any thoughts on a system with quick(ish) response time? I love radiant but it definitely seems best at "low and slow." I'm guessing all delivery modes are not created equal.
Thanks,
Patrick

SWEI

Low mass radiant responds quite quickly. Keep the tubes out of the concrete if you want fast response.

Patrick_North

So electric in-floor radiant - over insulation, but not over or in a slab- might be appropriate? This is a second floor- insulated floor above an unheated garage space. I'm guessing tile flooring is a must in this case? My (ignorant, layperson) impression of electric in-floor radiant is that it's a nice addition in say a bathroom but often not adequate for a sole heat source. Or by "low mass radiant" were you referring to electric bb?
Thanks,
Patrick

Harvey Ramer

Above floor electric radiant with tile flooring would be a very nice system for you. As long as you don't have any plumbing in the building, you won't need to maitain a minimum temp to keep pipes from freezing. The floor should have a reasonable recovery.

Spence

What will be the R-values of your floor, wall, and ceiling insulation?

Patrick_North

Thanks Harvey. For my layperson clarification, by "above floor" do you mean electric baseboard and such or does this mean electric radiant just under tile (versus in a slab)? Unless tile was helpful for the heating system, I'd probably use wood flooring.
Spence- the tentative R-values would be about 36 in the floor and 21 in the walls.
Thanks,
Patrick

Harvey Ramer

Sorry, I meant electric radiant.

Spence

If you can get to R-40 wall and R-60 ceiling, with your excellent choice of floor R-value, an Easy-Bake oven will heat nicely.