How many BTU's Do I Need To Heat My Garage? [Archive] - Chevelle Tech

: How many BTU's Do I Need To Heat My Garage?


framer
Dec 7th, 03, 8:48 PM
Guys,

I'm looking to purchase a propane heater for my garage so I can work on the Velle over the winter.
The garage is approx 16' x 20', and is drywalled from floor to ceiling.
I just wanted something that I could turn on after work... grab some dinner and go out there an hour or so later and be comfortable. How many BTU's should I be looking for and do I need something with a fan or will radiant heat be sufficient? :confused:

Thanks,

70metgrn
Dec 7th, 03, 9:10 PM
you need one of the 40K btu torpedo REDDY heaters. it will heat it up quick in about 20 minutes. At Home Depot they are around 150.00. and it is portable. the radiant heater is quite but it will not heat that large of an area. also Northern Tools sells a wall mount propane radiant that you can add a blower too. it works very well with the blower. above all be very careful to have ventilation and no open flammables. be safe!!!!!!!

my442ragtop
Dec 7th, 03, 10:07 PM
YEA thats what ya need graemlins/waving.gif

vettefella
Dec 7th, 03, 10:56 PM
Wal, there's another alternative...if you have central heating in your house. Simply plumb a duct into the garage using a louvered vent with a cutoff lever. You can heat the garage if you want. If not simply close the vent.

I've done that on our two houses, so I'm warm in the winter and cool in the summer. It only costs about $30. for the materials and 2-3 hours time. Being in Canada, I suspect your heating system has more than enough reserve to heat a garage for a few hours. Of course, if you don't have central heat, the advice of the other guys might apply.

BillK
Dec 7th, 03, 10:56 PM
Chuck,
Try this site:
http://www.heatershop.com/btu_calculator.htm
Is your garage attached to the house ? Insulated ? if so, you might want to look at an electric heater. The one I have is 5000 watts and will get the garage from 32 deg up to about 65 in 15 minutes. My 22 x 22 attached garage is insulated in the walls, but not the cieling. I have a very nice insulated metal door. With the electric heat there is no smell etc. I use it a few times a week during the winter and really have not noticed any difference in the electric bill. I will see if I can post a picture later.
Only problem is the heater is 220 volts. My electric box is in the garage so it was no problem to mount an outlet and run a circuit to it. I have it mounted pretty close to the breaker box.
This one has very similar specs to mine:
http://www.grainger.com/Grainger/productdetail.jsp?xi=xi&ItemId=1611766906&ccitem=

This one is from the same company as mine, but I dont know if it comes with the wall mount bracket:
http://www.grainger.com/Grainger/productdetail.jsp?xi=xi&ItemId=1611760791&ccitem=
Hope this helps,

Dave
Dec 7th, 03, 11:24 PM
I don't know if you have lp/ng avaliable in your garage. If you do try going with a forced air sealed unit. Vented to the outside, it keeps all the fumes and smell outside. About 60-80,000btu will heat your shop comfortably. I know that grainger sells complete units with ducting and all. Personnally I can't be in a room with a "jet heater" due to headaches. Local hvac guy could plumb it for you, and mounting is pretty basic. If I remember right mine cost me about 300.00 total. But my neighbor hooked up the gas run for me. Just paid for parts and beer, after he hooked up the gas. graemlins/thumbsup.gif It's really nice not to lose the floor space.

baddbob71
Dec 8th, 03, 12:55 AM
a 35 gallon hot water heater, circulation pump, automotive radiator with fan and thermostat to control pump and fan is all you need.

framer
Dec 8th, 03, 12:48 PM
Guys....

I really appreciate all your inputs.
It looks like there isn't an easy soulution here.
Just to provide some additional info:

The garage is part of the house.
It's built into the house with a bedroom above it so the walls and ceiling are insulted and drywalled.

I'd love to run a forced air duct from the house but it would be too much work to do so. The electrical heater that Bill suggested would be great but I don't have 220 in the garage and the electrical panel is in the basement... So, propane it is!
My major concern is the venting.
Just how bad are the fumes? A
Any suggestions on venting???
Is it possible through the side door somehow? Without cutting it! :eek:

What do you think of these units:
Torpedo (http://www.canadiantire.ca/assortments/product_detail.jsp?FOLDER%3C%3Efolder_id=253437430 3514896&ASSORTMENT%3C%3East_id=1408474395348027&bmUID=1070901580775&PRODUCT%3C%3Eprd_id=845524442153235&assortment=primary)

Or will this do....
Radiant (http://www.canadiantire.ca/assortments/product_detail.jsp?FOLDER%3C%3Efolder_id=253437430 3514896&ASSORTMENT%3C%3East_id=1408474395348027&bmUID=1070901580885&PRODUCT%3C%3Eprd_id=845524442153231&assortment=primary)

BTW, Bill, thanks for the link to the calculator.... great info! graemlins/beers.gif

dickf
Dec 8th, 03, 1:03 PM
go to lowes or home depot and get a zero clerance outside vent unit. all you have to do is cut 8" hole thru the wall. it comes with triple insulated pipe and a sleeve to stick thru the vall. does not require and smoke stack. it has a cap that fits on the outside. i also bought the fan kit. it comes on with a thermostat. its quiet and efficient. i do just what you said. i turn in on 15 minutes before i start work. once the chill is off it cycles on and off.

70metgrn
Dec 8th, 03, 9:35 PM
as the fellow stated above the zero clearance from home depot is the way to go. i use all of the above options. we own a custom cabinet shop, we heat with central heat propane furnace. on cold mornings we heat the shop to 75 degrees using the kerosene blower heater and then kick on the furnace. in the paint room after we spray we leave on the central furnace but kick it up a notch with a convection kerosene heater to drop the humidity and raise temp to 85 degress. my paint room is 25x25 with a vaulted ceiling to 12 feet. we use a wall mounted zero clearance in the saw room to supplement the central unit because of the doors being opened and closed. we use a propane forced are in new houses when we do and install where there is no heat, the propane forced air has very little or no fumes just noise.
Sorry for the long reply, but if you are like me you need the most bang for the buck. Decoded more car money!!!

Dean
Dec 8th, 03, 10:34 PM
Originally posted by framer:


I don't have 220 in the garage and the electrical panel is in the basement... So, propane it is!


So Chuck, I assume you don't have natural gas then.

Really, it's not that hard to run a 220 volt circuit from the basement, (probably a lot easier than running a flue pipe) and with an electric heater such as Bill's you have no vent to deal with, no fumes to worry about and no dangerious gas either. Might cost a little more to operate than LP but you wouldn't have to worry about running a gas line or a flue.

If it were me, I wouldn't want to use any gas fired heater in a garage with a bedroom above that doesn't have a flue, vented to the outside - 12" above the roof.
BUT
since any "open flame" in a garage must be at least 18" above the floor, the "sealed combustion" units direct vented through the wall would be ok if they just weren't LP gas.
In my opinion LP gas is just too dangerious because if there is ever a leak, it lays in puddles on the floor since it's heaver than air.

I don't know how cold it gets there or how warm you want the garage to be but you can probably get by fine with around 20,000 btu/hr unless you want the garage to warm up quickly.

Or how about a small heat pump, then you would have A/C in the summer (except I don't think anyone makes one that small)

Confused yet?

427L88
Dec 8th, 03, 10:42 PM
Aw quit your bellyaching Framer, just drink more beer like the rest of us "unheated garage Northerners" do. And wear thin gloves and long underwear.
tongue.gif smile.gif

Ya, and someday I'll get a real garage too!
graemlins/waving.gif

framer
Dec 9th, 03, 1:10 PM
Dean, I hear ya... I'm not so crazy about LP either but it was the easiest solution. I just wanted to do something easy... but after all the great inputs (Thanks Guys) it seems like that isn't going to happen either. I may just get a couple of 1500 watt ceramic heaters to take the chill off things and just suck it up like Gene says, and ware an extra layer of clothing. ;)
Maybe next year I'll look at running a duct into the garage from the house... and solve all my problems... well almost all of them anyways graemlins/clonk.gif

Thanks Again,

chester
Dec 9th, 03, 2:00 PM
I have the same setup basically that you describe and was looking for the same solution,
I talked to a lot of people and finally decided to do this
a 20 lb new tank of propane and around radiant heater that bolts onto the top. (home depot)The heat is projected out by the pressure of the tank. I actually have to pull the wifes car out of the garage to get the tank into the corner before I fire it up. It makes it comfortable enough to work in a long sleeve shirt. I run it about 10 min then turn off for about an hour
works for me
hope this helps

terrys
Dec 9th, 03, 3:21 PM
I had raised ranch w/attached 2 car garage with bedrooms over the garage also. I used a cylindrical radiant kerosene heater around 20,000 btu's. You can pick one up at Sears for about $ 150. Clean, quiet, and plenty of heat. Run it about 20 minutes and the garage was comfortable. Even the concrete floor began to warm up for about 6 feet around it.
Just a little cool near the corners of the garage door where it was drafty. So if I wanted to work on the back end I just moved the heater back closer to the garage door and it warmed up pretty quick. One fill of kerosene ran for about 8 hours...
In a power-out emergency it will work in your house to heat a room. People in Japan use these in their homes. They burn slowly, and very efficiently and dont consume all the oxygen in the room.. They usually have electric start, and tip-over shutoffs. No fumes, no pipes, no wiring. Just have to get a 5-gallon kerosene can and a hand siphon-pump, and keep them in the corner of the garage away from the heater. Only fill it when it's cold. Worked for me for many years in Chicago winters.... Good luck.

framer
Dec 9th, 03, 4:10 PM
The plot thickens......

Chester,
I was looking at those radiant units that mount to the top of the propane tank. Did you have to vent the garage at all? If no, how where the fumes?

Terry,
Kerosene...hmmmm, any issues with fumes?

Thanks,

richr
Dec 9th, 03, 4:40 PM
I have the same heater that Bill K has - I had to run a 220 line from the basement as well - I can't tell you how worth it it was to do this. My garage is 21 x 21 attached to the house with an 11 foot cieling. The other day when it was 30 outside and snowing I had it on setting 9 and the garage was 70. No fumes, safe and you can turn it off when your not there. It takes about 20 mins to bring the temp up 30 degrees. Northern Tools sells it cheaper alot cheaper - it's an excellent product the name of it is Farenheat heres the link

http://www.northerntool.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=6970&langId=-1&catalogId=4006970&PHOTOS=on&TEST=Y&productId=595&categoryId=155626

Good luck - I think if you go the hassle for the 220 line you'll be happier in the long run.

Rich

terrys
Dec 9th, 03, 7:35 PM
With the kerosene radiant, no fumes or smell while it's running .... But to shut it off you turn down the knob for the wick, and you usually get a tiny puff of black smoke as the wick extinguishes, which leaves a little smell of kerosene... by this time I'm leaving the garage and smell is gone in couple of minutes... not a big deal.

I liked it because it was totally portable, and required no installation. We did use it once inside the house during a winter power outage to stay warm.

I also used the torpedo type. Boy do they put out heat fast !! You're sweating in 15 minutes; but they burn up all the oxygen and give headaches. You have to open the garage door all the way every 1/2 hour to get some fresh oxygen to stay alive. Torpedos are good on job sites not completely enclosed; but not too safe for home use.

To be completely fair about the subject... I just moved to a new house which came with an electric heater in the master bathroom. It's a built-in 220v unit about 14 inches square.. don't know the rating but on cold mornings the whole bathroom gets nice and toasty pretty quickly..........

I wont be working on the Chevelle this winter cause the garage is still full of boxes from the move; but I need to run some extra wiring to the garage anyway; so for next winter I guess I'll have to give some serious thought to electric heat.....

Nice topic... enjoyed hearing everyone's different experiences on this.

CDN SS
Dec 10th, 03, 12:16 AM
Chuck ... every car guy here ( and you know it gets cold here !! ) with an attatched insulated double garage all use a 220 electric heaters running a 220 wire to the panel in the basement is no big deal .... new breaker and a 220 plug on wall in garage where you need it ... alot safer !!! BTW you may want to consider a small fan on the ceiling to push the heat back down .... I keep my garage heater on all the time one to keep the garage about 50* and have a secound heater I crank up when I go out to work there but with the first heater always on it takes very little to bring the garage up to a comfort level and cheaper than reheating a cold garage when you want to work out there have a t least 6 friends all doing same thing

von
Dec 10th, 03, 5:49 AM
Of course you can leave the door open between the living quarters and garage while working out there to help heat it too. Maybe a fan in the doorway too. Especially if using electric heat (no odor or fumes) in the garage. That and a couple 1500 watt electric heaters might do it.

SS_Dave
Dec 11th, 03, 9:53 AM
Originally posted by CDN SS:
Chuck ... every car guy here ( and you know it gets cold here !! ) with an attatched insulated double garage all use a 220 electric heaters running a 220 wire to the panel in the basement is no big deal ....This has got to do amazing things to your electric meter. Like on National Lampoons Christmas where Chevy plugs in the lights and the little pointers on the meter become a blur. :eek: What are you guys paying to run those heaters? My electric bill is already over 100 dollars a month.

Dave

CDN SS
Dec 11th, 03, 10:19 AM
You forget these heaters run on 220 the cost is very low , yes if it were 110 then it would cost a fortune ... 220 is the key and I guess depends on what you pay for electric power also how well your garage is insulated, especially the ceiling ... this am it is -24F going to a high of -15 and the heater still only cycles on and off like normal once the garage is warmed up it does not take alot to keep it that way.

Peter F.
Dec 11th, 03, 7:08 PM
Umm, there is no difference whatsoever in electrical consumption between a 120V heater and a 220V heater if they are the same wattage rating. None whatsoever. Power (electrical usage) is measured in wattage, not voltage.

Chuck, Those round propane radiant heaters do work quite well and they burn quite cleanly so that fumes aren't a big deal. The kerosene heaters are good when they are working but will make your eyes water when you shut them off. I was using one and wouldn't shut it off even if I was too hot just because of this. I would not ever use a "tube" heater of any kind because the fumes will kill you.

I use a 2000W baseboard heater in my garage. I leave it on low most of the time and turn it up when I want to work. I noticed the hydro going up by about $50 for the worst bill. My garage has old windows and had a badly insulated/sealed door that I have since replaced. Overall, electric isn't really any more expensive than any other form of heat here, at least for now until we see what the government is going to do in the spring. I leave it on all the time to keep it dry out there.

Kerosene was costing me $60+/month just to turn it on when I wanted it and the moisture was rusting all my tools and destroying everything else.

My recommendation would be a 2-head propane radiant or wire a baseboard into the garage.

Peter

BB_Mike
Dec 11th, 03, 11:28 PM
Why do you need to work on your car? :confused: Was the spot in Chevelle World not justification enough. graemlins/sad.gif

Anywho, glad to see the black car is doing fine, dog dishes and all. smile.gif

ColoradoMalibu
Dec 12th, 03, 2:50 AM
I have an attached insulated 2 car.
I use a 19,800 btu kerosene heater.
No noticable fumes, keep a door cracked for ventilation.
Works great, I can't justify spending money to do anything different.
I leave after shutting it down, so I do not notice the fumes when it is burning out.

von
Dec 12th, 03, 6:02 AM
Originally posted by BB_Mike:
Why do you need to work on your car? :confused: Was the spot in Chevelle World not justification enough. graemlins/sad.gif

smile.gif Maybe he wants to put the rallys and red lines back on it so that it looks better. ;)

HOTRODSRJ
Dec 12th, 03, 9:03 AM
Even if you have the perverbial 120 wires, a couple of small electric or baseboard heating units is all you need if you are sealed up real good. 4000 watts should keep it okay even in the dead of winter, but opening the gdoor will provide a task to rewarm quickly.

4000 watts takes about 33+ amps, so if you have a couple of 30 amp circuits like I do your in like flint! Like you said, get a couple of heavy duty ceramic heaters and go to it!

I just don't like any open flames or smelly stuff in the work space. Just me...even tho the propane units will heat quickly.

Dean
Dec 12th, 03, 10:03 AM
Originally posted by HOTRODSRJ:
Even if you have the perverbial 120 wires, a couple of small electric or baseboard heating units is all you need if you are sealed up real good. 4000 watts should keep it okay even in the dead of winter, but opening the gdoor will provide a task to rewarm quickly.

4000 watts takes about 33+ amps, so if you have a couple of 30 amp circuits like I do your in like flint! Like you said, get a couple of heavy duty ceramic heaters and go to it!

I just don't like any open flames or smelly stuff in the work space. Just me...even tho the propane units will heat quickly. I can't even imagine a 33+ amp 120 volt circuit WOW now that would be something to try to install.

I also can't imagine messing around with a stinky kerosene heater, going after fuel, storing fuel, filling, spilling, maintaining, running out of fuel, stumbling over.
:rolleyes:

Peter is right, watts is watts.

chester
Dec 12th, 03, 11:08 AM
framer,
sorry it took so long to post a reply
I really do not smell anything when it runs.
I usually crack ther garage door about an inch but that is a habit that i was doing way before i got the heater

TSN100
Dec 12th, 03, 1:16 PM
So no one uses a propane convection heater? I use one to heat a 1200 sq. ft. shop. 275,000 btu, takes about 5 minutes to heat the place. Can't leave it on very long, Ice forms on the outside of a 5 gallon tank, and I don't believe it would be safe to heat your home with it. Bought mine through Grainger several years ago for about $150.00 & several friends with machine shops, after seeing how well it works, purchased them too. One tank will last about a week, but its never constantly on. It's also very loud. Sounds like a roofer's tar kettle, but for me it does the job.
Terry

framer
Dec 12th, 03, 4:42 PM
Originally posted by BB_Mike:
Why do you need to work on your car? :confused: Was the spot in Chevelle World not justification enough. graemlins/sad.gif

Anywho, glad to see the black car is doing fine, dog dishes and all. smile.gif Hey Mike!
I was quite surprised to see the old black car in Chevelle World.... Aces1 must be partial to those red lines as they used to be on one of his cars a few years back graemlins/thumbsup.gif
Von,
One of these days you're gonna get used to the puppies! ;)
As for the heater... now I'm more confused than ever... seriously guys, there has been some great input here. I'm starting to lean towards one of those tank mount propane radiants. The question now is.... is 24K BTU enough or should I go for the 45K BTU. :confused: Again, the garage is approx. 16 x 20 with 10ft ceilings.

Thanks,

JYD71_454
Dec 12th, 03, 5:20 PM
I've run just about every heat option out there. My first setup was a 50,000 btu propane torpedo heater. Soon after, I upgraded to a 150,000 propane space heater like they use in new construction. Then I discovered what the main byproduct of combusting propane is; water. Everything in the garage was soaked, my tools in the box drawers were even wet. Not good. I switched to a kerosene torpedo heater. Kerosene has very little water production but unless it is running really good, there's a fume issue. Venting the fumes pretty much offset the output of the heater. Since my garage was detached and only had 120V service, I bought a used oil furnace. I rigged the pump up to be selfpriming and used an old outboard gas tank with a gauge as the fuel container. A simple thimble through the wall and some ducting completed the setup. It cost me less than the original torpedo heater I bought ($175) to do the furnace. It was 80 degrees in that garage without any insulation in less than 1/2 hour. Sipped fuel too. Anyway, be careful with propane. If you burn enough without venting, water is an issue....

DUKE 69
Dec 14th, 03, 10:32 AM
Chuck,
I have a reconditioned mobile home furnace in my shop and I burn kerosene in it. The vent stack goes thru the side of the building. Kero.burns clean, and the heat output is great! The shop is 24X32 w, 10' ceiling and is insulated w. 1" insulating board all around. I can go from 20 degrees (F) to 65 degrees (f) in less than 15 min.- sweet! I really like it and it is easy on fuel-10-15 gals. for the entire winter, depending on how much I am out there. I live betw. Rochester and Syracuse NY so my winter weather is similar to yours.
BTW, congrats on your car's pic in CW. It looks great there, but much better in person. See you next Aug. in Niagara Falls.

George Mitchell- DUKE 69

Dean
Dec 14th, 03, 10:40 AM
Originally posted by DUKE 69:
The vent stack goes thru the side of the building. Just a FYI warning for people that might think you can terminate a vent stack below the roof line.

NO you can't (unless you want to take a chance on back drafting carbon monizide)

All natural draft flues must go at least 12" above anything within 4' horizontally of the pipe.

HOTRODSRJ
Dec 14th, 03, 10:49 AM
Hey Dean.....your comment.."I can't even imagine a 33+ amp 120 volt circuit WOW now that would be something to try to install"

I think you missed my original post/comment... "4000 watts takes about 33+ amps, so if you have a couple of 30 amp circuits like I do your in like flint! Like you said, get a couple of heavy duty ceramic heaters and go to it!"

I have three 30 amp circuits in my garage to run everything from air, large power tools etc. They are really quite common and a 320 amp main service to go with. I am sure you missed the couple part tho! Right? :confused:

Dean
Dec 14th, 03, 11:03 AM
Yeah I guess so because a circuit is either a 120 volt single circuit or a 230 volt single circuit.

A 230 volt single circuit is not a "couple of circuits" although it does have a couple of hot conductors.

I thought you meant a couple of 120 volt circuits when you really ment a couple of single 230 volt circuits I guess

I was thinking one heater - one circuit not realizing you were talking about air compressers or other things not related to heating a garage. redface.gif

sorry

graemlins/beers.gif

monkeyboy
Dec 14th, 03, 11:26 AM
I spoke with a plumber/friend and he said that he could easily install one of those heaters that hang from the ceiling. It would be fed by hot water right from my boiler. I already have baseboard/hot water heat. It has a radiator and a fan behind it. I would need a thermostat and some electrical work. Also, the garage temp can't go below freezing or the pipes would freeze. Cost - approx. $1,500. It seems like the safest way. No fumes or kerosene. Not cheap. I don't know how cost efficient it would be to run. Any thoughts?

Dean
Dec 14th, 03, 11:56 AM
I guess it would depend on the effeciency your hydronic boiler.

It's sorta along the same lines of what baddbob71 recomended.

Like you said the only downfall is the possibility of freezing pipes but you could have him install a continuious loop with a three way water valve that shuts off the hot water to the heater but keeps it circulating through the bypass loop to keep the pipes warm when the heater is off. Naturally, the pipes must be insulated.

Adding a three way valve would probably ad a couple of hundred of dollars to the installation though.

If I still had my hydronic heat (I took it out because it was very ineffecient and I wanted ducts for A/C and humidifing), that's the route I would take. In fact if it wasn't so much trouble to run a flue pipe from the basement, through the roof, I would install a regular 40 gallon water heater in the basement to use as a boiler and use antifreeze in it since it would be a closed system.

I've built several of these systems using a water heater, a small circulating pump and baseboard fin tube heaters for people that have added on a room and there is no way to get ductwork to it.

framer
Dec 14th, 03, 12:51 PM
Originally posted by DUKE 69:
BTW, congrats on your car's pic in CW. It looks great there, but much better in person. Thanks George :D
Looks like I'm just gonna go with one of those radiant heaters that mounts on top of a propne tank. It's the most cost effective way to go for now. I really don't have much to do this winter... just some detail stuff to get ready for next year.

See you in the falls graemlins/thumbsup.gif