>
Keith Kaplan writes:
> I'm finishing up getting the
> drywall and insulation up in the walls and ceiling of my 36x24x10
> space, and I'm starting to wonder what I should use for a heater.
I'm working in a 32x26x8 garage that is largely uninsulated. I recently
stapled 4 mil visqueen plastic on all of the rafters. It made a huge
difference and only cost me $12.
I've been very imersed in this subject lately :-(
My garage is external, which is generally good. It gives you a little
more leeway in regard to what is allowed by the building inspectors.
I rent the house and garage I'm living in now. When I moved in last
May the garage had a woodstove. It worked great for a couple of
weeks.
I'd get home from work and fire up my 35,000 Btu torpedo heater
(kerosine). While that made a dent in a cold I'd stoke up the embers
in the wood stove. I'd usually kill the torpedo and head back in the
house to eat, etc. By the time I'd get out there the temps would be
pretty reasonable. When the woodstove is cranking a fan will help
spread the heat.
Unfortunately I have a really crotchety old woman working behind my
house. She called the city and complained about the possible fire
hazzard of whatever was going on with the smoking chimney. The
helpful folks downtown wasted no time letting me know that the
operation of a woodstove is not permitted in a garage. The chimney
came down.
Since then I've been scrambling to get heat in my garage. I've got
a huge amount of car work to do out there by Spring.
> Since it's insulated, I'd think I could get by with a small space
> heater, but it is a lot of space, and I'm usually only out there for a
> few hours in the evening, so I'd like to be able to heat it up in time
> to enjoy the warmth.
The insulation and drywall will significantly reduce your heating
requirements. However you didn't say where you are living and how
cold it gets.
> What about those 'infrared' radiant gas heaters? We have gas heat in
> the house, so I'm assuming it wouldn't be too hard to run a gas line
> the 30 feet or so out to the shop. What I want, in order of importance:
> -- not a fire hazard
> -- heat the place up fast
> -- quiet
> -- efficient
> -- affordable
Natural gas is the least expensive method.
Wood can be great in a garage. Woodstoves excel in large open rooms.
Woodstoves are often illegal in garages because they are considered
"uncontrolled combustion" (you can't turn a woodstove off if you spill
a flamable liquid). I suppose it does make some sense. Of course I
was _much_ more careful with the stove going.
In any case, I've been investigating many alternatives.
Kerosine torpedo heaters are available in many sizes and work fairly
well. They produce fumes and for that reason are not acceptable to
me. Some produce more fumes than others. 110,000 Btu units sell
for $200-$250. I recently saw a 150,000 unit for $300. Major fumage!
They would not likely be tolerable in your insulated space.
There are propane fired torpedo heaters. They usually cost a bit more
than the kerosine versions. The problem is the moisture. For every
pound of propane you burned you get 2 lbs of water. The water rusts
tools and gets in your clothes (particularly bad when you go into the
cold).
Some folks had suggested that propane was only 2X the cost of natural
gas. I didn't find that to generally be the case in the quantities I
would be dealing in. Perhaps if you have a 500 gallon tank you might
get a better price. In 60ish pound quantities I found it to be
roughly 5 to 6 times the cost of natural gas for an equivalent number
of Btus! My $50 house heating bill would have been $297 if I had
used LP at .45/lbs.
Propane is 2550 btu per cubic ft, natural gas is 1050 btu cu/ft.
150,000 Btu of natural gas is 142 cu/ft. My local rate is .375 per
100 cu/ft. It would cost .53/hour to operate a 150K btu gas furnace.
The cost to heat my garage with propane would _very_ quickly outweigh the
cost to install a natural gas line to the garage.
A 150K btu Kerosine heater uses about 1 gallon/hour (the fumes are free!).
I pay about $1.40/gal.
Electric heaters are cheap and extremely efficient. You do need to
have sufficient power in your garage. 1200 watt 99% or so efficient
electric heaters can be found for $10 on sale. I don't have the
electric capacity so I didn't calculate the cost.
Now we get to _real_ heat: natural gas furnaces. Now we're cooking!
There are some _major_ advantages to putting a thermostatically controlled
furnace in your garage.
You can leave the space heated all of the time for not much money. That
is especially true in your case since the space is well insulated.
What temp you set it at is up to you. Even 45 or 50 degrees will do
wonders to maintain your concrete slab and tools at a reasonable temp.
Electronic thermostats are pretty cheap these days. You can program it
to 50 degrees during the day and set it to kick to 70 at 6:00.
Think about it.. If you use torpedo or radiant heaters the air around
you may be warm, but you may be standing on a 20 degree sheet of concrete.
It sucks the heat right out of you! Even with boots on your feet will
get cold and tired. Not to mention when you're under a car on a creeper.
How much you heat the space when you're not there is important in sizing
your furnace. An oversize unit is important if your garage is 20 degrees
during the day and you want it to quickly get to 70 when you want to work.
If you maintain a more reasonable temp all of the time you can get by with
much less capacity.
See part II, "gas furnaces" for more info..
Brian
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bkelley@ford.com
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