Mini split finally humming along in my garage, one winter in

Running mine on a schedule too and it made a huge difference. My shop is a bit smaller, maybe 20 by 22, but I set the thing to hold around 55 all week and bump it up when I know I'll be out there. Garage gets back up to temp in under an hour that way instead of the four or five it took when I tried to warm it from cold. One thing I learned the hard way is where you mount the indoor unit matters. Mine went too low at first, right at the workbench level, and the airflow just blew cold drafts across my legs every time it cycled. Had the installer move it up near the ceiling and the whole space feels way more even now.

The defrost cycles threw me off the first winter. There were a couple mornings in the teens where the outdoor unit steamed like a kettle and I thought something was wrong. Turns out that's just what they do in cold weather, and the manual even mentions it. Wish I'd known before I called the installer in a panic.

Also keep an eye on where the condensate water goes. If that drain line freezes up you'll get water backing into the unit. I ran mine with a slight downhill grade and wrapped a bit of heat tape around it, no issues since.

I went smaller and cheaper on the heating approach with my 24x24 shop and it's worked out fine, for what it's worth. Mine's a Mitsubishi rated for cold weather, but I don't keep it holding temp all week like you two. I set it to 45 when I'm not out there and bump it up when I head out on Saturday mornings. Slab stays cold-ish but the air recovers fast enough that I don't notice, and my electric bill last January was way lower than I expected. The thing that actually bit me was the outdoor unit. First winter it sat on a pad near grade and after a couple heavy storms the snow was up over the bottom half of it. Kept kicking into defrost constantly and the coil iced up. I put it on a wall bracket about chest height the next spring and that solved it. Also keep an eye on where the condensate drains, mine froze solid into an ice mound against the foundation til I rerouted the line.

Curious how you guys dealt with snow around the outdoor units. I put mine up on a couple of wall brackets so it sits above the drift line, since my plow guy tends to bury that side of the garage. Last winter it stayed clear and I never had to dig it out. Before that, at ground level, I was chipping ice away from the fan every other week. Made all the difference for me.

Update: the setback schedule the other guys talked about is working great for me too, garage recovers fast enough that I stopped leaving it warm all week. Still fighting the defrost cycle though, that water dumps off the coil and freezes into a little glacier underneath. To the guy who wall mounted his unit, did you do anything about drainage or does it just drip where it wants?