I want to heat my attached garage. I put my lifting equipment out there (thanks, COVID), and it's a bit too cold in the winter.

It's about 600sqft. Non-insulated garage door. It's drywalled, but not insulated.

I live on the Oregon coast, and 30 degree is pretty cold for around here, doesn't get too far below that very often.

It currently has 2 15-amp circuits, but I'm willing to add more wiring if needed.

Any recommendations would greatly appreciated.

What kind of heating system do you current it have in your house? (I.e. boiler w/ fin tube, furnace, etc)

What kind of fuel does it use? (I.e natural gas, propane, oil)

A mitsubishi ductless heat pump model is always a good alternative but will cost about $8k-$12k installed depending on conditions.

I'm heating my 400sf shop with one of these.
Diesel heater

Got about $150 in it, i run it 24/7 uses about a gallon a day depending on outside temp. Exhausts to outside. Draws combustion air from outside.  Has a thermostat.
Very happy with it.

Regardless of what you use to heat the space, it will be worth the trouble and expense to insulate unless you plan on moving in the near future.

Just get a space heater that won’t blow your 15 amp breaker and call it good.  I use a 15 year old radiant style heater (no blower fan) and turn it on in the garage about 30 minutes before I go out to work on a car.  By the time I go out there it’s plenty warm.  Usually another 30 minutes in and I’m losing the sweatshirt and working in a t-shirt.  I’m sure you’ll warm up much faster working out.  My garage door is also un-insulated.  If you want to spend more on a legit HVAC then by all means please do.  Just spend the money insulating the garage and door as well.  Of course if you do that the space heater will work even better!

Buddy heater or Big Buddy depending on how hot you want it.

I use both in my 800sqft shop with 10 foot walls and it is over 60 after an hour.

1st step insulate your garage, either remove drywall and insulate or leave it and blow it in the walls
Garage door, you may be able to insulate the door, I used rebar wire and plastic sheeting to hold fiberglass insulation to my 16' garage door, it's been on there since 2008

I use a 120v  electric oil filled heater to heat my garage, the heater is set on lowest setting 600 watt at 2.5  out of 10
My garage is 2.5 car 16' door, the walls and ceiling have 3.5" kraft fiberglass  insulation, the walls and most of ceiling is covered with 1/2" wafer board / plywood


My goal was only to keep above freezing, right now outside temp is 8 degrees, inside my garage, temp is 52 degrees

Just heat?  If so I'd just insulate the garage door and buy a mr buddy big buddy heater and hose to hookup to a 20# tank.  It's not gonna get sauna toasty but it'll be warm enough if you're just in there for a workout.  Summers by you aren't that bad IIRC, but it's been almost 20 years and multiple TBIs since I was on the OR coast in summer.  

If you have a natural gas you can put in a ventless heater relatively easily.  If you're on propane bring a line into the garage and hookup the big buddy.

Just have an Anitfa protester from Portland come down and set themselves of fire, should last awile.

Insulated garage door, blowin insulation to the walls, and whatever heater you want.  A ceiling fan (blowing up) nicely disperses the heat and creates uniform warmth.

I’m using a Hot Dawg HD45. It was free.

I had already insulated the walls with rockwool and the ceiling with R-38 pink stuff (with exceptions to the area over the welding bench and furnace with more rockwool, layered crossways for R-30 and R-15 pink cross layered on top of that).

Door isn’t insulated yet.

Garage stays at 55°. Electric use is pulling 3.7A max,  and measured is about $6 a month for the electric to run the blower. Not sure how much NG it’s consuming yet.

I had a natural gas heater in my garage when I lived up north.  It was a large 3 car and worked great.

An electric heater will run up your power bill.

I use this propane heater.  It works great.  I have a 3 car garage with 10 foot ceilings.  It heats it up quickly.





I used to have one of these and I liked it better.  I uses an electric fan to blow the heat.  It got run over.

I wouldn’t bother without insulation and a new door. I finished an existing 2 story 1400 sqft garage last year with reverse cycle mini split.  Finally got the new door on a couple weeks ago.  The old one conducted all the heat straight outside.  I did need 100 amps of new power

The non insulated part means you’ll need more BTUs. I’d be looking at ways to insulate.

A mini split would work well if you want AC out there too. Those low temps are ideal for a mini split.

A temp solution is one of the Buddy heaters or similar vent free heater but they put a LOT of moisture into the air. That’s a problem and can be a bigger problem with a non insulated building.....you get condensation on anything cold (likely including your workout equipment) and lots of it. Avoid vent free heat if at all possible.

Vented heat is the best if you are going to use gas or propane. I heat a 2 car garage with a Mr Heater Big Maxx 45k 81% efficient and we love it. It’s a little oversized for the space but not bad. A 30k would be perfect but would need a more expensive brand to go that small.

I also heat my 30x40x10 shop building with an 80k Mr Heater Big Maxx and love it too. I heated for many years with vent free heat and thought it was nice till I got my vented heaters. I’ll never willingly go back to vent free for a garage, shop, or house. I do have a vent free Buddy heater we take when camping in the cooler months but I don’t use it in the house or shop. Vent free leaves an odor. It’s not horrible but it’s plainly there. If you are using chemicals or scented sprays around a vent free heater, you are gonna end up with funky odors burned into your heater.

I’d like to know some more about this if you are willing. I’m not really interested in it for a shop but more for a camper.

Thanks

The top end Mitsubishi models are expensive but wouldn’t come close to costing that much installed....at least where I live.

You can get a Pioneer system (actually pretty well rated unit) for well under $1000. If you want to/can install the main install yourself (and then pay someone to evacuate and charge your system if you aren’t comfortable doing it yourself) you could have a mini split heat pump installed for less than $2k.

Good idea. They're nice.

Never do it in Michigan, or anyplace where the roads get salted. Warmth + salt coating = instant corrosion over every inch of your car.

This.

When i built my garage i insulated like it was a home and got the 2" foam core sandwich doors.
No regrets, and it stays relatively comfortable even without being directly climate controlled.

My attached garage I leave the door from house open for a couple hours before doing garage stuff.
Mine is insulated and so is door but temps here are a lot lower than OP.

This. All of this. But especially the insulation. My Mr.Heater is an older noisy unit but it cranks out the heat.

This is what I use for now. Same situation as op. I’ll be insulating, getting new doors, and putting in a mini split this summer.