granprixweiss928

I have this little Dayton shop heater, it works awesome in my 600 sq ft non insulated garage. Im in Norcal. I use it when its near freezing at night. Requires 240V

https://www.walmart.com/ip/DAYTON-3V...&wl13=&veh=sem

AirtekHVAC

I have 2 230v electric fan forced heaters in my shop, 21x44, with 14' high bay. Got them at Northern Tool for $100 ea. They work ok, but, being an AC guy, I just acquired a 230v 5-ton gas pack that came off a commercial building. Fixed it, and am waiting to install it and a propane conversion. I will then get a larger than BBQ tank to hook up. Too many projects, too little time.

M. Requin

And if this isn't enough info, head on over to garagejournal.com - this is a perennial topic of discussion and you'll find page after page of experiences and opinions.

Imo000

Step 1: Insulate the walls and doors
Step 2: Get a 120V, 1500W small space heater and set it to +15C and lave it to cycle all the time.

dr bob

Since the move from never-cold SoCal to the 4-seasons central Oregon area, I was concerned about workshop heat. The primary duty falls to a mini-split heat pump, shared with my office/doghouse that shares a wall with the workshop. The heat pump does winter heating duty and can also cool in summer. I've used the AC function a few times but not nearly as much as the heat is used.

Other recommendations:

-- Insulate the heck out of the workspace. It helps a moderate amount of heat do a maximum job for you.

-- Put your overflow refrigerators & freezers in the garage space. In our previous house we had a full butlers' pantry with separate refrigerator and freezer. In the new house here I put them just outside the pantry in the garage, so the heat they generate is put to good use. Think "mini heat pump with food and beverages inside". It saves on electricity both for the food chilling and the garage warming.

-- The house has a high-efficiency condensing gas furnace, which I left in the garage rather than sticking it in a closet inside as the HVAC contractor suggested. This was from my warm-climate experience when most of the duty was cooling. Now the furnace, even though it's well insulated, sheds any excess heat into the garage space.

-- I added a ~~50k BTU Reznor ceiling-mounted condensing gas furnace just for the garage space. It requires a single 4" coaxial stack through the ceiling and the roof, plus a gas line and a 120V outlet for the fan and controls. For days when the ambient temp drops below 0ºF, the heat pump starts to run low on outside heat to pump in. Natural gas costs are less than $2/therm here so while "less efficient" than the SEER 26 heat pump on $0.11 kWh electricity, the gas unit is actually much lower cost to operate. I added two low-temp thermostats to the furnace, one at each end of the garage and the workbay, for freeze protection. I leave them around 50ºF and they don't come on unless there's a lot of heat loss. If I need some extra heat to do some work, I can just bump the thermostat in the workbay to add extra heat when needed.


The permanent-mounted gas furnace is my recommendation if you have the gas available there. The little propane heaters are OK if you ventilate them well, but "ventilation" and "heat loss" go hand in hand with them. The condensing furnace means cold outside air is used to support the actual combustion, with waste exhaust heat going out used to preheat the combustion air coming in. The phase change of the moisture in the exhaust (the 'condensing' part) helps a lot with overall efficiency. A fan blows air across a closed heat exchanger section for space heating, so no CO or CO2 passes into the heated space.

Biggest benefit by far is the thorough insulation. Contractor asked why I needed it during the build, as he wasn't used to having so much. It reduces loss from the garage directly, but also cuts down a lot of loss from the wall of the house at the garage. The garage doors are also well insulated, gasketed and sealed well, so losses through them is less than with just conventional sectional doors.

the flyin' scotsman

interesting comments re use of garage space for freezers/fridges to make use of the heat they put out........we just use our back deck as the freezer during the winter and uplug the electric unit. Just beware the bears etc dont raid the back yard!!!