I’m moving to a new house and need to figure out how to heat the two car garage size shop. I heard about the Edenpure portable heaters. I can wheel that out in the winter. I don’t think it will put out enough btus though so I was going to instal two electric radiant heaters in the cieling.
I think between the two it should be fine. How do i know it is enough? Talk to a heating person?
Replies
popa,
To calculate the BTU needs, you need to do a heat take-off. That is, figure the heat loss of the structure and the heat differential between outside verses inside temp. I used to do this 40 years ago while working at the plumbing and heating supply company...so that is possibly one source. It might be worth a call to Home Depot also.
For sizing the heating unit, we would double the BTU requirement. This reflects two realities: cold snaps require more heat, no one wants to wait for heat. Once you do all this you'll be matching up needs with whats available...and there's not that much variability relative to size wise out there. So you kinda come full circle to where you current are. You don't indicate where(what town) your moving too, that might help others contribute what they have done in similar environments.
Wheelie Man, if you're in Florida, your heater will be fine. If yer in Alaska, you may need a *tad* more in the thermal dept. ;-)
IE, more info needed. Things to consider: What is your climate? Are your doors insulated? Is this below grade? Wall construction? Insulated? What's your existing home heating? Can it be extended to cover the garage? Is the garage below conditioned space? Freestanding? Windows? All that stuff, and more, will impact your problem.
That said, unless you have hot water heat in your attached home (as in "garage shop w/ attached 3 BR home" ;-) ) that you can extend, you may want to investigate a small direct vented gas heater. I put a small unvented unit in my one-car garage (50K BTU, IIRC. My garage has block walls, uninsulated doors, one small glass block window, below heated space and 1/2 below grade.) It puts out enough heat -- I just worry about the *unvented* thing on occasion. But, unless it's really cold, it doesn't run enough to worry me.
Mike Hennessy
Pittsburgh, PA
Thanks for the responses. I need to get to work. I'ts my last month and I've been goofing off. I'll talk at you this afternoon. Thanks again!
popawheelie,
The solution may be as simple as you state with maybe a suplimental box stove. (those small cast Iron square woodburners to burn your scraps in). I know some are nervious about fires in wood shops but with decent housekeeping and common sense they work fine.
Remember untill well into the 20th century that was all they ever had in wood shops.
Other solutions depend on how well insulated the building is, weather and other factors such as how much equipment you have.. remember it takes a long while for some of that cast Iron to warm up so untill it does that equipment is acting like a refrigerator.
Thermal mass affects things more than most understand.. That stack of wood for example will take a lot of energy to heat up to the point where it no longer is radiating cold. The floor always will be cold unless you do something about it.. that will cause your legs to ache as the blood in them chills.
Your lifestyle or common practice will affect your choices as well. If you open and close the garage doors twice a day, you are effectively purging the area of all heat.. so you will need a much faster recovery time than if it remains closed and is well insulated..
Solar orientation too affects things. Got a few south facing windows? even in the winter on cloudy days they will provide some warming (as well as natural light)
Big subject, don't just turn it over to the experts, they really won't know unless they sell you a whole lot more than you need. (It's called CYA)
I can't see how anyone could give you an intelligent answer without knowing whether or not the space is insulated and what climate you live in, along with a lot of other details. The advice would be radically different if you lived in South Carolina versus somewhere in Northern New England for instance.
Looking at their ads, the Edenpure heaters are just very expensive electric heaters, you could get the same heat output from any electric heater at 1/10th the cost.
John W.
Edited 4/27/2007 11:37 am ET by JohnWW
Right now it is uninsulated as far as I know. I know the cieling isn't. The house inspector went up there and I stuck my head up there also.
The garage is a small two car garage with a 8'? cieling? We move there in a month. So I plan to demo the cieling drywall and raise the cieling in the middle areas. I will also demo the wall drywall if there isn't insulation in there. At that time I will install wiring for lighting, recepticals, and any other utilities I can think of.
So the walls and cieling will be insulated. I'm not sure about the door. I might change it over to two doors if I can.
The house is in Ft Collins CO. Not to far north but it will get cold.
I fixed up the garage in this house a little so I have thought about these issues. In this garage I tapped into the house forced air system. It worked O.K..
I will probably do the same in the next house with a few changes. On this one I built a manifold from the register out to a fan to bring in more air if needed. It didn't work. The fan is designed to move free air. I would need something more like a squirel cage. The idea was to have warm or cold air trickle in so it didn't freeze or get to hot and when I went out to the garage I could turn on the pump and bring it up or down in temp quickly. Basicly I would rob the house of some of it's heat or cold for just a bit.
Maybe I can tap into the house forced air system and put up some radiant cieling fixtures. Btween the two i should be ok. If that doesn't do it i can bring in a portable.
During the cold snaps I can put on a sweater and feed the wood burner. It's not like I'm building for someone else.
I do have a free standing wood burner. I will put it in. All I need is the flue. I like the idea of feeding it scraps.
Here are two pics of the supply fan and the return. A furnace filter is for the return. I also have a piece of 1/2" particle board under there to cover it when I don't want the air going back into the house. If i created some noxious fumes I don't want them in the house. They both fit under a shelf/work table on the back wall.
I'm on my way out for the weekend, so I haven't the time to cover the possibilities for heating a shop, but I feel obligated to point out something very important:
It is both illegal and very dangerous to tie a homes circulating air heating system into a garage, you risk exposing the homes occupants to carbon monoxide and/or pulling in gasoline fumes leading to an explosion. You should permanently disconnect the tie that you created in your current home, preferably right away, certainly before someone unsuspecting moves in.
I'm a former EMT and safety consultant, and I lost a friend to carbon monoxide fumes that seeped into his house from a garage, the risk is very real and kills people in the U.S. every day of the year, I've seen them.
John White, Shop Manager, Fine Woodworking Magazine
I agree John. You make an excellent point. I knew when I hooked up to the hvac system that is was illegal and dangerous. I felt, and still feel, that as long as I was the only person in the shop it was safe. I take personal responsibility for my actions.
I have disconnected the garage from the hvac system of the house we are selling. I would never do this for someone else. They would have to make that decision themselves.
Do you think it was a bad decision to post that info and pics? If the general consensus is that it was a bad thing to post, I apologize.
This forum post is now archived. Commenting has been disabled