Heated Garage ROI?

[mnx]

I was just thinking about different factors that effect efficiency of the car and was wondering if it would make any sense to heat my garage in the winter I currently heat my house with natural gas which is far less expensive than electricity for heating...

ie. If I could keep the garage at ~15C in the cold weather then the cabin heater wouldn't need to do much at the onset of a trip and the battery heater wouldn't kick in either. I do an above average number of short trips and errand running. Since I work at home the car doesn't sit outside in the cold much...

I'm thinking a dedicated natural gas heater in the garage would take forever to pay itself off, but if I could figure out a way to use the house's heat to keep the garage warm then it'd be worthwhile. (I know I can't exchange air between the garage and house due to exhaust fumes from ICE's and it's against code but maybe some kind of heat exchanger would work...)

 

[Doug_G]

First of all, 5C would probably do the trick for the pack heater. I think that would do 95% of the work for substantially less garage heating cost. Since heat loss is proportional to the cube of the temperature difference I suspect this will greatly improve the economic equation.

Another thing to consider - positive temperatures greatly accelerate corrosion. I know the Model S is aluminum but it's also going to be covered in salt for much of the winter, and salt can cause aluminum to corrode.

 

[mknox]

Oops! Posted my thoughts over here.

 

[Doug_G]

Not my section so I can't move it. Suggest either copy-and-pasting into this section and deleting the original, or flagging the post and asking a section moderator to move it over here. Then I can merge.

 

[mitch672]

I think just insulating the garage would be enough in most cases. Just having the car out of the wind/weather will keep the energy usage somewhat lowered on running the pack heater. My garage is insulated, and I have an insulated garage door. I also have a wall unit that runs on natural gas, but the only time I heat the garage is when I'm going to be working on something for an extended period of time.

 

[arg]

I'm surprised nobody has tried insulating the underside of the pack. In an unheated but snow-free garage, you could have a pad of insulating material fixed to the floor, of a thickness to just give clearance to drive over it with suspension in normal: just drive in and then drop suspension to low to close the gap. Obviously this won't keep the pack warm forever, but might help to hold on to some of the heat overnight, especially if charging during that time.

Outdoors, such a thing would be more valuable as it would prevent wind under the car - but maybe impractical to use due to the need to clear snow etc.

 

[Doug_G]

Impractical sounding but it might actually work. The Roadster has a boxy and much less exposed pack, and it takes much longer to chill out.

 

[dsm363]

Would a heated garage floor be enough or cost efficient maybe along with insulation?

 

[Btrflyl8e]

Couldn't something like this work?
Heaters | Powerblanket | Powerblanket Extra Hot Thawing Blankets - GlobalIndustrial.com

 

[green1]

I'm not sure this is the way to go, heating the whole garage is going to be a lot less cost effective than heating just the pack, consider the much larger surface area for heat loss of all the garage walls, roof, floor, and door, vs the much smaller surface area of the pack, even with more efficient heating by gas instead of electricity I think your losses will likely outweigh your gains.

That said, the suggestions for better insulation are good, preventing heat loss is always a good thing, taken to the extreme, a car cover would probably even help a bit (though it is a bit of a pain each time you want to drive)

If looking for auxiliary heating for the pack, I wouldn't try to do the whole garage, but possibly a gas heater on a timer or remote control that aims at the pack, don't worry about the temp of the whole garage, just aim some relatively inexpensive heat at the right spots.

 

[Xenoilphobe]

I insulated my garage with closed cell spray foam insulation and added insulated R18 garage doors. Did the trick.