What would happen if you were to put that in the attic of the building? Maybe it wouldn't be as efficient for AC use but it would be a little warmer up there from heat loss and might be more efficient for heating.
Around here as a general principle anything in the attic is considered a bad idea. With a properly insulated, sealed and ventilated roof system the difference between the attic and the outside air temperature is so inconsequential that it will not provide any advantage to the heat pump while operating in heating mode. In the summer the attic can be be hotter than the outside air which only stresses the heat pump even more as it tries to provide air conditioning. Any maintenance required to the heat pump becomes a nightmare because of where it is located. I have heard stories of some contractors who are not even interested in servicing a unit that is in the attic. They just won't take the job. I don't see any benefit to placing it in the attic.
Andrew, since you have a neighbor in the field he should be able to help you with some of the calculations and understanding what options might be best. Does he maybe know how viable an electric boiler would be with in floor heat?
He only does air conditioning and heat pumps. He doesn't do any other kind of heating system so I wouldn't call him a heating contractor. I will be talking to him about it however. Because he is in the business he should know people who can give me opinions on other options.
Also I doubt that the mud they typically use provides any insulation value.
The TV commercial I have seen they say that it is a foam that they inject. I just assumed that if it is a foam it would also provide insulation. I doubt that I will be going that route anyway as I want to add a drain so I will need to dig things up.
You seem to think that electric is your best option, which it may be, I guess the next question though is how much power do you have available in the space? Are you going to have to upgrade power?
I have a 200 amp. entrance to the house and I will installing a 100 amp sub-panel in the garage. I am not concerned about available power.
The main reason why I think that electricity is my best option is because we have really cheap electricity rates here that make it good choice financially. It might not be however. I'll explain why I think it is and maybe you will see it differently in a way that I had not considered.
Montreal is low in the St. Lawrence valley and because of that most of the smog days in Montreal are actually in the winter not the summer. The cold air acts like a roof and holds the smog in. Because of this wood burning appliances have been banned. There is talk now of banning oil burning appliances for the same reason and I can see that happening some time in the future. NG is all around me but for some reason it is not on my street. I suspect the next time the road is re-done it might be added so putting the heating pipes in the concrete is probably a good idea no matter what. Because of the proximity to the neighbour's property I don't have room to put a propane tank on the same side as the garage and the Mrs. doesn't want to know anything about a a "
big ugly tank" stuck in her gardens on the other side. That leaves me with electricity no matter what the type of heat is at least until I have NG available.
Without doing tons of calculation electricity also has to be my cheapest option. Quebec has the cheapest electricity rates in North America. To give you an idea you are probably paying somewhere around 11 or 12 cents USD per KWH. The rate here for a residential customer is 5.9 cents CAD per KWH. But it gets better. Hydro-Quebec has a plan where if you have a dual energy heating system (electric and anything else not electric) you qualify for a special rate. This means that all of the electricity that I consume in the entire house 12 months of the year, not just the electricity used for heating, I am only paying 4.4 cents CAD per KWH as long as the temperature is above -13 Deg. C (8.6 Deg. F). When it is colder than that I pay 25.6 cents CAD per KWH. But the number of days where it is colder than that are not that numerous through the winter and it is generally during the night-time hours not the entire 24 hour period. The portion of my consumption that is billed at this higher rate is really inconsequential as a result.
I am assuming that heating using electricity must be my cheapest option. Before the heat pump all of my heat was provided by an oil fired hot air furnace. Installing a heat pump in the house dropped my heating bills by two thirds because of this dual energy program so the reason I am looking at a heat pump in the garage is because it uses electricity. Since it is also capable of providing me with both the heat and air conditioning that is another bonus. Despite being in a winter climate Montreal gets pretty hot in the summer. Because we are an island surrounded by water and low in the St. Lawrence valley it also gets very humid in the summer.
The only issue that I don't know about is whether or not a heated floor will make a difference as far as being being warm and cosy in the garage as opposed to just not being cold. That is what I don't know.
Garage 101.. BUILD THE LARGEST STRUCTURE YOU CAN ABSOLUTELY AFFFORD! I've built several. still wish i had bigger.. I've got a 60 x 80, a 36 x 42', a 28 x 30'. I still have trouble parking my daily driver somewhere in them. Never have enough room for everything.
Truer words were never spoken. In another life I had a 100' X 60' machine shed, another 60' X 40' storage shed and a 40' X 40' workshop. All of them had high enough ceilings and doors that you could bring in any size piece of equipment. That was heaven.
Dave;
I think that you wrote in an earlier post that you were going to have a large concrete pad extending out from the shop in to your yard. If this is going to be a continuation from the concrete floor from the shop make sure that a really good thermal break is installed between the two. If this is one continuous piece of concrete with no thermal break you will have a hard time keeping the floor in the shop from being cold all the time.