How to heat a 2-car garage shop

[Chris Atzinger]

Hi,

My shop is in an attached, 2-car garage, about 20'x20', with a single double wide overhead door, and 1 entrance to my house.The ceilings are 8' in most places, and 9' near the door.I am a bit of a tool/wood hoarder so space is at a premium. The garage is not really heated, and it's getting pretty cold. Right now, I am using small electric heaters, or occasionally, a propane heater, neither of these are great long term solutions.

How are you guys heating your shops? Anything you would do differently? what would you recommend?

Thanks!
Chris

[Tom Ewell]

My shop is conditioned already but auto repair needs are cropping up and need to use the unconditioned garage area. Have yet to hook up mine so can't comment on actual performance but depending on available circuits, you might check out electric garage heaters (https://www.google.com/search?q=uniquikely&sourceid=ie7&rls=com.microsoft:en-US:IE-Address&ie=&oe=#q=electric+garage+heaters&rls=com.microsoft:en-US%3AIE-Address) as potential solution.

My intended use is just to make the garage 'workable' as need arises but adding insulation and wall finish might make for a more seasonal heater for shop use.

[Art Mann]

I use a 240VAC, 18A space heater in a free standing shop that is 24 X 28 and it works just fine. Resistance heating is expensive though. If I had it to do over, I would probably either use a vented natural gas heater or better yet, install a mini split heat pump.

Please provide a little more information for the community to help you better. How much do you want to spend? Is the house wiring such that you can easily pull a 240VAC wire to run a heat pump or higher power electric heater? Can you install a unit through a wall or window opening? Are you willing to put up with a forced air "torpedo" style propane or kerosene heater? Do you also want air conditioning in the summer?

[Don Nicholas]

My shop is just under 1000 Sq Ft with 8ft Walls. I searched out a used electric furnace from a mobile home for $25. It requires 220 volt and the unit works just fine. Hopes this helps.

[Kent Smith]

The more insulation you can install in the walls and ceilings the less $ you'll spend on whatever heat source you pick. Extra weather-stripping around the overhead door plus rigid insulation installed in the door (unless it's already insulated) will make a huge difference in keeping heat in and cold out.

[Jim Andrew]

I live in the county so space is not an issue, so I have an outside wood heater, as I am concerned about having a fire in my woodshop. Since I built mine, have found some reasonably priced manufactured units. What I did was build a 6x6 steel building a few feet from my shop, and ran 2 ducts between the building and the shop. Found the return had to be attached to the blower motor on the furnace to work properly, or the blower would suck smoke from the firebox, and after all the work, found that buying a manufactured unit in the 2 to 3 thousand dollar range would be reasonable. We are having a real winter storm here, and the heater is keeping up with the need.

[Chris Atzinger]

Hi Guys,

Thanks for the responses. Just a few clarifications:

-The garage is insulated and has finished drywall. Two walls are interior, 1 exterior (plus the door). There is a bedroom over the garage, so I think the insulation is OK.
-I have 220 electric already, and could run another 50A line out there if necessary. I also have a natural gas line, which I could tap into (i am not sure about building codes, though).
-It doesn't need to be heated 24/7, only when I am out there.
-Cost is always a concern, but I want to do it right, as I am going to be in this house for another 10 yrs at least ( or so I am told!)

Thanks!
Chris

[Keith Outten]

Chris,

I was using a 220 volt heater I purchased from Lowe's until last Summer which did a great job of heating my 24 by 36 foot shop with 9 foot ceilings. I decided I needed to improve my air conditioning for the Summer months now that I am working in my shop full time again so I had a Mitsubishi Mini-Split heat pump installed.

Although the mini-split unit was expensive it is worth every penny and my operating costs are much lower than the electric heater. Whisper quiet and a perfect 70 degrees F in every square foot of my shop space. No ductwork to deal with and no cold air blast like traditional heat pumps. The mini-split doesn't need auxiliary heaters so a 220 volt 20 amp circuit is all that is required for power.

Should the need ever arise I could easily move the mini-split to another building or sell it when the time comes to shut down my shop. The only thing I would have to do is plug a 4" hole in the wall.

[Ole Anderson]

45,000 btu ceiling mount natural gas unit heater.

[Dave Kirby]

How do you keep the cast iron tables in your garage shop from sweating and rusting when the temperature changes from heating and then cooling back down. Is there a way to avoid this other than keeping the garage at a constant heated temp? (which I imagine could get expensive unless it's thoroughly insulated.)

[Randy Gazda]

45,000 btu ceiling mount natural gas unit heater. ditto

I put in a Big Maxx by Mr. Heater last year in a very similar garage, it worked great. Did all the work myself except the NG hookup (which the plumber did without shutting off the gas!). If you buy the heater, don't buy the install kit, is cheaper to buy the parts and pieces you need at Home Depot. I put programmable thermostat but probably wouldn't need to do that.

Cost about $750 when all said and done

[Mike Cutler]

If you have NG to the house, put in a NG powered heating unit. With that bedroom over the garage make sure it vents through the wall and you meet all of the air in leakage requirements, or it takes in air from outside. You're garage is only 400 sq/ft. so you won't need a big unit. There are some nice single source wall units that sit between stud bays. Very easy to install.
That bedroom above makes it a little more complicated, and has to be your first priority in choosing a system. It's not just as simple as throwing a unit in to heat a space. Whatever you get, it needs to vent outside.
You may also have to re-sheetrock the ceiling unless you already have the adequate fire rated drywall on the ceilings and walls. Just something to consider.

[Art Mann]

I agree with Mike Cutler unless you also want air conditioning. I expect that would be your cheapest option from a fuel cost perspective.

[Dave Lash]

A friend of mine sucessfully heats his two car attached garage with a 240 volt Fahrenheat electric heater, he is located near Canton Ohio. Before installing the heater, we blew in fibergalss insulation in all outside walls and the ceiling. We also installed 1 1/2 foam insulation on the garage door. The added insulation keeps the garage warmer all winter even when the heater isn't running just from the heat loss from the house, and it is easier to raise the temperature in a 45 degree garage than one at 30 degrees.

[Chris Atzinger]

Just out of curiosity, what's the avg cost of a split heat pump? I have not considered those before.

Thanks!
Chris

[Joe Skinner]

I used to use a propane heater to get the temp up, then an oil filled electric radiator.

2 years ago, I pulled down all the drywall and insulated, then had 12" blown in the attic above the garage. I then tapped into the HAVC plenum and ran a line to the garage. With no return, it does not affect the rest of the house or my power bill. Granted, my HVAC is about 1 ton over sized. The hottest it gets in the summer with 105* is 85*. It has been below freezing the last few days, and it gets down to about 58*. Fire up the propane for about 15 min gets it back up to 65*, and will hold that most of the day.

[James Conrad]

Chris,

I was using a 220 volt heater I purchased from Lowe's until last Summer which did a great job of heating my 24 by 36 foot shop with 9 foot ceilings. I decided I needed to improve my air conditioning for the Summer months now that I am working in my shop full time again so I had a Mitsubishi Mini-Split heat pump installed.

Although the mini-split unit was expensive it is worth every penny and my operating costs are much lower than the electric heater. Whisper quiet and a perfect 70 degrees F in every square foot of my shop space. No ductwork to deal with and no cold air blast like traditional heat pumps. The mini-split doesn't need auxiliary heaters so a 220 volt 20 amp circuit is all that is required for power.

Should the need ever arise I could easily move the mini-split to another building or sell it when the time comes to shut down my shop. The only thing I would have to do is plug a 4" hole in the wall.

Keith, what size is your mini-split?

[David Weaver]

Just out of curiosity, what's the avg cost of a split heat pump? I have not considered those before.

Thanks!
Chris

Cost varies by efficiency and size and brand, but middle of the road cost for one installed (unless your local HVAC is really trying to nail you) is around 3 grand or a little more.

It cost me $3200 to get the line run from my panel to the heat pump, to buy the heat pump and indoor unit and the line set and get it installed here for a 1 1/4 ton 21 seer mitsubishi unit. I bought the hardware myself and hired the job done as the mitsu dealers wanted to put a smaller heat pump in and they wanted more than $4k to do it. The install was not especially rigorous, and as keith said, with some conditions applied, they don't use much energy.

The only time they would use a fair bit more is if you were using them when it's really really cold (like 0 degrees), or I suppose if it's high 90s or something, though I don't know about the cooling.

Mine will run at any temperature above -13º F, and like Keith, I'm extremely pleased with it.

[Keith Outten]

James,

My mini-split is an 18,000 btu unit, 19.2 SEER Mitsubishi Mr Slim MSZ-GE18NA (http://www.mitsubishipro.com/media/456672/msz-ge18na-8~muz-ge18na-1%20submittal.pdf).

I hired a friend of mine to install mine, he is a certified Mitsubishi installer and my unit has been great. When it was first installed I couldn't believe how quiet it ran. All of the motors are DC / variable speed in both the inside and the outside units and the RPM adjusts to suit demand.

I will never move again so the investment is long term for me....as long as I am healthy enough to continue woodworking. When the heat pump in my shop office upstairs is worn out I intend to replace it with another mini-split and be done with all the problems of a traditional ductwork system.

I should add that dust has not been a problem. The wall mounted unit has two plastic screens that do a good job filtering the shop dust in the air. It takes about five minutes to remove them, use an air hose to clean off the dust and reinstall. Last Summer when the temps were in the upper 90's my shop was 70 degrees and very comfortable. So far this Winter it is the same, the coldest temperature we have seen so far is 28 degrees. My shop is insulated but it has three nine foot wide garage doors. Electricity bills have decreased over the same period last Winter.

Some people might consider this type of system a luxury and it probably is but I sure enjoy working in my shop more when I know it will be comfortable. I don't have to worry about high temperatures shutting down my laser engraver because it is air cooled and I don't have humidity issues. Last but not least my system was a business write off, something I try to take advantage of particularly the last few years as the FED has been allowing us to write off 100%.
.

[Ole Anderson]

Although probably not new information to anyone, using resistance style electric to heat anything is very inefficient and costly compared to using a heat pump which in turn is probably not as cost effective as using natural gas. The upside to resistance electric heaters is the low up front capital cost and fairly easy installation.

[Thomas Wilson]

If you are using the garage exclusively as a shop and plan to be in the house for 10 years, you might want to consider framing the garage door opening and insulating it. It would make the space much warmer and more efficient with any heating solution you choose. You or the next owner can remove the framing and convert back if the need arises.

TW

[Matt Marsh]

I heat my attached 24X32 garage with 12' ceilings with one of these 5KW unit heaters and a remotely mounted line voltage thermostat. I have mine wired to my off-peak panel. The current off-peak rate here with the local electric co-op is now .049 cents/KWH.


http://www.globalindustrial.com/p/hvac/heaters/electric-unit/multi-watt-horizontal-downflow-unit-heater-with-thermostat-208-240v?infoParam.campaignId=T9A&gclid=CJObj9Hmo7sCFY47MgodFmsAvg (http://www.globalindustrial.com/p/hvac/heaters/electric-unit/multi-watt-horizontal-downflow-unit-heater-with-thermostat-208-240v?infoParam.campaignId=T9A&gclid=CJObj9Hmo7sCFY47MgodFmsAvg)

[Chris Friesen]

Where are you? How many heating days do you need, and what's your heat loss? This will tell you how much heating energy you need, which will factor into what energy source makes the most sense.

Usually gas is more expensive up front but cheaper to operate than electrical resistance heat. Usually a heat pump would be even more expensive up front but more efficient to operate.

I'm in the canadian prairies, we usually hit -40 or lower for at least a few days a year. I have an attached 2-car garage with R14 walls, R30 ceiling, and R-16 double-wide overhead door. I heat it with 45KBtu/hr ceiling mounted natural gas unit heater. A 30K would probably be fine. I generally keep it just above freezing and then crank it up if I want to work out there.

[Tom Bain]

Chris,

I was using a 220 volt heater I purchased from Lowe's until last Summer which did a great job of heating my 24 by 36 foot shop with 9 foot ceilings. I decided I needed to improve my air conditioning for the Summer months now that I am working in my shop full time again so I had a Mitsubishi Mini-Split heat pump installed.




Ditto on the mini-split heat pump, which also cools in the summer which is really nice to have. Depending on the size of the unit, you are probably looking at $3k - $5k installed. It's a significant up front expense, no doubt, but I knew I'm going to be in my new shop for next decade or longer so was willing to bite the bullet. It's amazingly efficient and quiet!

[Chris Atzinger]

How have you guys insulated your garage doors? i know this is an area, which I could probably make a big improvement. Did you just take fiberglass insulation and attach or did you use the Styrofoam stuff? I have seen 1 kit that comes with insulation panels and retainer clips, which seemed pretty easy...

-Chris

[Chris Friesen]

How have you guys insulated your garage doors?

I'm up north, so I bought a factory-insulated door. Double-walled steel with polyurethane foam in between. Claimed R-16 in a 1 3/4" thick panel. There are also gaskets in between the door segments and weatherstripping all around the edges of the door to reduce air leakage.

[Mark Welte]

I am installing a Sterling Garage Guy heater with a concentric vent kit in my garage. It pulls outside air for combustion so it is more efficient and provides clean air to the burner unit. Electricity is very expensive in my town so NG was really my only option. The concentric kit can be mounted horizontally so I can vent through a wall.
Sterling GG Heater (http://www.littlegreenhouse.com/accessory/heaters4.shtml)

Mark

[Julie Moriarty]

Chris, since we have similar winters...

A guy I used to work for worked out of his house and his garage was his shop. He also kept vehicles in the garage and the overhead door was opening and closing as needed. He installed a ceiling hung natural gas heater and it worked beautifully. Bring a truck in the door and the temp drops. After the door closed it only took 5 minutes or so to get it back to temperature again. If I was to install a heater in the garage, that's the way I'd go.

Even though I'm an electrician and could easily install an electric heater, I go that route only as a last resort. I just don't care for electric heat. Personal thing, I guess.

[Stephen Pereira]

I just (15 minutes ago) got done hanging a "Hot Dawg" heater in my shop, It has been a long time coming. I ran a 1/2 " copper line from the 2# natural gas meter to my garage..cut the pressure down to 3.5 WC (or so) with a Maxi troll, hung the heater and I"ve got heat. There were a few tense moments until I discovered I didn't have the thermostat wired correctly. Works wonders when you wire it right..RW..red and white to the board.

I was a bit concerned with disrupting the NG gas supply to my house furnace at -30 F so I waited until it warmed up to -5F and went for it. The "HotDawg" fired up, ran until the thermostat was satisfied and shut down..just like it is supposed to do. I'm a bit nervous about all the gas connections I made in my basement, soaked everything down with leak detector..as the saying goes"no bubbles, no troubles"..no leaks and I'm good to go.

[Bailey John]

simple solution i use for similar garage space -- http://www.tractorsupply.com/en/store/search/natural-gas-heaters-accessories?cm_re=20131211-_-CNTR_D1-_-Store_Event_Christmas_Sale_AD1315_10Percent_Off_Ve nt_Free_Heaters

this little one is inexpensive enough to trial -- http://www.tractorsupply.com/en/store/mr-heaterreg%3B-big-buddytrade%3B-radiant-portable-heater-18000-btus

[Joseph Durnya]

Radiant gas heat... Love it

[Chris Friesen]

Radiant gas heat... Love it

Have you run into any problems? I had read some horror stories about panels warping due to the radiant heat reducing humidity levels on one side while the other side was higher humidity.

[Clint Olver]

Chris,

I have the exact same situation (2 car attached, 1 external wall + double wide door, room over garage...) My door is factory-insulated door. Double-walled steel with polyurethane foam in between. I heat my garage with a $15 space heater from HD. Today is supposed to get up to 19 degrees F, and the heater barely runs to keep the shop around 67 F. Even when it drops to -15 F it doesn't run all that much. I keep the shop around 57 F when I'm not in it for a few days. To heat it up quicker, I just open the door to the house an hour before I go in. Insulation is the way to go for sure. It doesn't hurt to put in flooring to raise everything off the concrete slab, and the more "stuff" you have in there, the more heat it will hold.

(Heater is on the bench top)

C

[Mark Blatter]

Do you get much moisture out of these heaters or are they vented outside?

[Justin Jump]

I second (or third) the minisplit idea.....

You can, with enough knowledge install it yourself, though hire out the final purge/charge refrigerant hook up. Most unit come pre-charged, and can be up and running fairly quickly.

A link to my minisplt install below...



http://www.sawmillcreek.org/showthread.php?199370-The-heat-is-on-finally!!&highlight=

[Jeremy Killingbeck]

I insulated my garage door at my old house with ridged foam sheets from Menards. I bought the white 4x8" sheets, cut them to size & put them into the pannel area on the garage door (I had a lip so I did not have to use any glue). Adding the insulation to the door kept the garage around 10-15° warmer in the winter. The cost of the 4x8 sheets were about 1/2 of the garage door insulation kit & they were also thicker, so they insulated better.

As for heating I used a 5KW electric heater for my 20x20 garage. It is not the most efficient way of heating, but you don't have to vent anything. I think the total cost for the heater & installation was around $300 vs $700 for installing a gas heater. The heater took about 30min to warm the shop from 40° to 60°. With only weekend work & a couple nights a week I think it raised my electric bill by by around $15-20/month.

That being said in my new shop (30x25' very well insulated) I have a 45K BTU natural gas heater & I love it. I keep my shop heated at 55° all the time & I have not noticed much of an increase in my gas bill. Gas will also warm the shop up a lot quicker if you don't plan to keep it on all the time.

If I had the money & was starting from scratch I would probably look at a split unit so I could cool the shop in the summer.

[Jason White]

When I lived in Boston, I insulated the ceiling and walls and used a pellet stove controlled by a wall thermostat. Worked great! The only thing cold was the concrete floor.



Hi,

My shop is in an attached, 2-car garage, about 20'x20', with a single double wide overhead door, and 1 entrance to my house.The ceilings are 8' in most places, and 9' near the door.I am a bit of a tool/wood hoarder so space is at a premium. The garage is not really heated, and it's getting pretty cold. Right now, I am using small electric heaters, or occasionally, a propane heater, neither of these are great long term solutions.

How are you guys heating your shops? Anything you would do differently? what would you recommend?

Thanks!
Chris

[Joseph Durnya]

Have you run into any problems? I had read some horror stories about panels warping due to the radiant heat reducing humidity levels on one side while the other side was higher humidity.


sorry I haven't been on .. no ..no warping... I wont bring the temp up fast... as the unit seems to heat everything in the garage quickly... if I know I will be out there I will turn the heater on ( at the lowest temp) when I get home from work... then by the time I have dinner and get out there move it up to 70 or so... its a 3 car garage.. insulated with insulated overhead doors

HTH Joe

[Drew Pavlak]

I am in the process of building a pole barn shop, Working on insulating and drywall. This is a joint effort with my brother-in-law. We decided to go with a Radiant tube heater that hangs from the ceiling. Natural Gas fired. Mfg - SpaceRay (SunStar is also made by the same company, they offer all kinds of options). I would definitely recommend Radiant of some kind. My father-in-law had a auto shop for 40 years and this is what he had heating his shop. Heats objects not he air. When you open you garage door, you are going to lose some heat no matter what you are using, difference is that the objects will help heat the room, so it will come back to Temp a lot quicker and the heater will not have to work as hard or run as long to get back up to temp.

Currently my heaters are not installed, but looking at them I am not disappointed that I went with SpaceRay. unit is well built. looking forward to getting them installed, it's been a little cold in Michigan lately.