Garage heating

[shui5612]

Evening ladies and gents,

I'm wondering what you guys use to heat the garages?

I have two garages which are well insulated (r30 walls and r40 ceiling) in one and In the other, around r24 walls and r30 ceiling). Both are around 14ft by 30ft with 9 feet high ceilings.

Most of my garages have the commercial type forced air heaters (4-5 thousand watts).

Now my idea is to get either a small infra red heater or a small oil heater and run it "all the time" on low instead of relying on the bigger heater.
Do you guys think they would be more efficient? Both garages stay shut for the whole winter and I don't mind what temperature is inside as long as it is above freezing.

(My math behind it is, one 5000w unit running an average of 6 hours a day is 30000w, while a smaller space heater running at 300w x 24 is 7200w. Even a 1000w unit would still consume less power).

The infrared radiant heater could heat up whatever is inside which would heat the air through convection, and the oil heater outputs a stable and decent heat over a large area while consuming less power.

The garages have things like lawnmowers and ride on tractors inside, but also have pipes that run to the house that can't be allowed to freeze.

Basically am I on the right direction that I could be savings on my monthly bill with this technique? Also potentially maintaining a higher temperature?

In either case which of the heating solutions do you personally use in your garages and which would you consider to be more efficient?

Natural gas or propane currently is out of the question. Along with a wood stove..

Thanks again,
Ian

 

[RNeumann]

Using the forced air you already have is the most cost effective. They just need thermostats that will allow you to set them at 35-40° or so- if you want to get real technical you can change the height of the thermostat as well.
The math doesn't add up. Assuming similar efficiency- which all electric heaters share until you get into heat pumps etc- it will take a defined amount of watts to heat a particular space. Spending money to change from one form of electric heat to another form will just cost you money on equipment costs. Going with oil doesn't make sense without knowing more- cost of electricity vs oil so you can do a BTU comparison. Plus I would never recommend an oil unit that wasn't vented properly which means you are typically in the 75-80% efficiency range.
Focus the efforts on the building envelope- that will give you far more bang for the buck and generate a much greater ROI.

I have a Reznor propane heater with a wall thermostat set at 40° f. R50 in the lid with R30 in the walls. Double pane windows and an insulated sectional door. Man doors and shop door all have weatherstripping etc. If I didn't have a propane unit the setup would be the same with an electric unit.

 

[oosik]

RNeumann +1.

 

[wawajake]

I also am under the impression that all electric heaters are equivalent when it comes to heating , BUT some are safer than others by not having open hot red elements. I switched to one of the oil filled electric radiant heaters because no red hot elements to ignite accidental fuel spills. But to keep my garage above freezing I have a woodstove that I use every second or third night to avoid the high electric bills somewhat. Other thoughts would be using any south facing windows to have the sunlight hit flat black materials to absorb the sun heat and radiate it better in the garage on those sunny days. Also I am not sure if they still sell them, but I have a freestanding portable kerosene heater that I bought in the 1980's that still does a good job when I am in a bind for quick heat.

 

[George2615]

I have a mobile home oil fired furnace in my garage. Bought it used and cheap from a local furnace service guy. Its 80,000 BTU and works very well. Through the winter I keep the garage at 45*F and raise to 60* when I need to work in there. Walls and ceiling are insulated with 6" rolled insulation and covered with 15/32 OSB.
Also have a 135,000 BTU torpedo heater bought from local TSC store if needed for faster warmups.
In summer I have 2 - 14,000 BTU window A/C's. I don't get too many days the A/C is needed but its there when I do.
I get the fuel delivered and have 3 - 275 gallon tanks. Fuel is used for the Home furnace, garage furnace, torpedo heater, and tractor.

 

[ray66v]

A given air temperature, will require a certain amount of electric to maintain. That's not going to vary much with different electric heaters.

With an infrared heater, you can save money by feeling warm at a lower air temperature. The way the sun feels on your face, when it's shinning on the winter.

Pipes won't necessarily "feel" that heat, unless the heater is aimed at them. So, a lower air temperature could get you closer to the point where they could freeze.

Have you ever thought about putting heat tape on the pipes, and just heating them?

 

[Toyboy]

My garage has it's own boiler and in floor radiant heat. That has to be figured in when building the garage or pouring the floor.

 

[shui5612]

Heating the pipes is an option but I have not figured out a safe way to do that (all plastic pipes).

By oil heater I meant an oil filled electric heater, sorry for the confusion.

My thinking is, that the big forced induction fan could be set to 40F let's say but the oil filled heater could run constantly, surely it will manage to either heat up or maintain a higher temperature, preventing the big fan from kicking in.

If the 5000w unit runs for roughly 15minutes every hour (hence my figure of 6 hours a day) that's about 1250w over the 15minutes.
If I get a heater that outputs 1000w per hour, it will run nonstop, for the whole hour, and output close to the amount of heat required. However this may reduce the temperature sways and maintain the garage temperature higher than 40-45F (being in a 250w deficit, it would be "saving" on the electrical bill. I think this difference can be offset with the fact that it's on all the time).

The reason for my thinking is that I was helping build a 30ft by 30ft two storey house( open concept), and we had an oil filled heater run all the time, despite needing thousands of watts to heat the house, that little 1500 w heater was able to maintain about 55-60F. Was every corner of the house warm? No but considering that this was before any plinthes or convectors were put in, it did a good enough job.

I'm wanting to stay electric because I could set it and forget it, unlike wood that needs to be added every couple of hours or days etc. A propane HVAC system is an option that's being considered In the long run. To mostly heat the house and help heat garages.

 

[PJSprog]

I like those oil-filled radiators. Been using them for years. If you put one of those near the exposed pipes, even running it on low will keep them warm enough to prevent freezing. We do this in our well house; just turn it on and close the door, then turn it off in the Spring.

 

[Snobdds]

I use infrared heaters that I hang from the ceiling and pointed down. I only turn them on when I am in the shop or very cold days (less than -5) out. They work fantastic and don't create a lot of noise or air circulation, which I like. I have no idea how efficient they are, but since they are radiant and heat the objects and not the air, it seems to be a really comfortable heat. I am usually turning them off around lunch because it gets too hot.