Our town garage is looking at purchasing a oil furnace fueled with used motor oil. We change oil on a regular basis on about 10 pieces of equipment. We would also be looking for residents to donate oil. Probably a supplement to current heat. Any experiences?

They are popular overseas.
Same as our kero/oil furnace with different nozzle.
Make sure the "free" oil is not contaminated
with antifreeze.
Learn how to service/clean.
Don't tell the alphabet agency.

Friend of mine has one at his service station.

He gets our used oil, normally around 600gal plus his and doesn't usually have enough for the year. (guessing he burns 1200gal total.)

If you had enough supply of oil and a backup if you run out you'll be ok.

If you are going to take oil donations, make dang sure that it's been stored inside and is moisture free.

You don't want oil that's been sitting outside in a drain pan for months and has been rained or snowed on

I don't have experience myself but a local implement dealer has one. Their foreman says as long as he cleans the filter every day, it works flawlessly. Sounds like the cleaning process is fairly simple. He's very happy with it.

many places only accept oil in clear containers now because water is such an issue

you could easily make a settling barrel let the water separate out and drain it off, but a lot better to not have to deal with it in the first place.

filters and filtration are an issue , son worked for a mechanic shop for a while that had one their old shop , it would develop a clog and they would come into no heat Monday morning , and spend a half hour cleaning it to make it run again then be cold for a couple hours waiting for it to heat back up
they built a new shop and said no oil burner too much of a time suck, but then I think heat was more of a money suck so tradeoffs

I think that is not the best Idea and they closed and sold the place since , a LP or natural gas furnace set to 5 degrease below where you like to keep the oil heat at so that you come in to a shop that is 5 degrease cooler than it should be and you have 2 forms of heat.

heck you might be able to charge people a dollar a gallon for providing you heat that you can use to fund filters and make a pump with a filter adapter that re-used some of your most common truck oil filters would be perfect , change it on the truck , put it on the barrel pump and run a couple hundred gallons through it then swap for the next one.

what would be really nice in the winter is a wash bay with a oil furnace not far away and you could pull in a truck or peice of equipment , hit it with hose wash it down and the heat to get it dry before working on it or putting it away. roll out to plow snow with a warm truck

the hardest thing on engines is the minutes to get to operating temperature , it causes the most wear on an engine , gas or diesel , so if you keep your equipment at 55 degrees in the building you are making it last , if you can also keep it from rusting out even better.