How to heat a 2-car garage shop

[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.

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=CJObj9Hmo7sCFY 47MgodFmsAvg

[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

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/stor...t_Free_Heaters

this little one is inexpensive enough to trial -- http://www.tractorsupply.com/en/stor...ter-18000-btus