My fur shed is my attached garage. It’s insulated and I have a kerosene heater as the only heat source. What my dilemma is I don’t want to leave the heater run while I’m not home to keep an eye on it. If I run it at say 60 degrees when I’m home and shut it off when I leave is there any downside to drying with fluctuating temps? I don’t care about dry time or how long it takes. Thanks for any feedback

You should be fine.

I have an attached garage, the three outer walls aren’t insulated.

I don’t run heat unless I’m out there, I do run a fan to circulate air though.
I probably don’t have the same cold temps you do though.

You will be fine as long as you have good air circulation.

Air flow is more important than temp. But the fluctuation won't affect anything.

Why don’t you run an electric heater with a thermostat?

I don't know about Wisconsin but the electric bill here would be outrageous.
Electric heaters really suck the juice

Electric heaters will cost you an extra $200 each month. Don’t ask how I know.

I won't run electric heat, way to pricey for me. I'd put a fan on low moving some air and let them dry.

At some point I’d like to put in a natural gas heater but right now $50 a year in kerosene is fine by me

it really doesnt have much to do with the temperature.I like to dry beaver at 10c in a cold room.But we have very low humidity here in winter.
You need low humidity to dry pelts regardless of temperature.
Heat in low humidity will speed it up,if you are drying a lot of pelts in a small area they may not dry.The pelts will put a lot of humidity into the air as they dry.

Boco said it. And remember old timers got by with much less than us.

I use a box fan, even in cooler conditions the air circulation makes a significant difference.

I bought a ventless natural gas heater for my fur room

Heaters that burn gas or kerosene can actually put moisture into the air slowing down the drying process. Better to have dry cold air movement than warm moist air.

Tackman, do you have a basement?

If so, you could skin in the garage and finish fleshing and drying in the basement. That's what I have done, with a fan set on low to circulate air.

All you need is a fan to circulate the air on your pelts

Air circulation with a small amount of heat will dry it out and be good in about 2-3 days.