What to do with compressor ac oil?

I have some sitting in the shed in a bucket. What do I do with it ? Take it to a auto place?. What type of oil is it?. Thanks

I don't know what kind of oil they use for the compressor but i do know it's suitable for a waste oil fired hot air furnace.

That's how some of the repair garages around here heat their shop in the winter.

Our Freon removal guy pumps out both the oil and the Freon with his rig. He was saying that the oil he collects goes back to the shop for heating as well.

Originally Posted by alloy2

Refrigeration compressor oil, if the oil is clean and unburnt I keep a gallon on hand for oil top up's and oil changes on my air compressor.

Depending on the manufacture, compressor could be either a synthetic or mineral oil, the latter has been the choice for refrigeration compressors and air, makes for a good cutting oil when drilling metal or using the metal lathe.

When I had the waste oil hot water boiler I used any and all types of oil for fuel. The boiler was a PITA, required a supply of compressed air and the filters needed constant cleaning. Many times would come out to a cold shop because the burner had shut down during the night.

Cool oh wow cold building is never good��. I wonder if it's good to use on sawzall blades?.

Originally Posted by mike1

I wonder if it's good to use on sawzall blades?.

It probably is. Alloy was saying it's good for use as cutting oil when he's drilling metal or using the metal lathe.

I was wondering if the refrigeration compressor oil had some kind of mineral oil base. It's a lot like brake fluid and the hydraulic oil we use at work for our hydraulic machinery.

The trash compactor oil is over $ 80.00 for a five gallon bucket nowadays. I looked up refrigeration compressor oil yesterday and that was over $ 1,200.00 for a five gallon pail. You would think that it would be worthwhile to collect and re-process the refrigeration oil at that price.

Originally Posted by alloy2

When I had the waste oil hot water boiler I used any and all types of oil for fuel. The boiler was a PITA, required a supply of compressed air and the filters needed constant cleaning. Many times would come out to a cold shop because the burner had shut down during the night.

The modern hot air furnaces i've seen are pretty reliable. We had one in a large municipal garage i was working out of years back. Memory is a bit vague but i think the main issue to work around was that the used motor oil was thicker than conventional #2 fuel oil. There weren't any air compressors involved but there might have been a pre-heater to thin the oil out before sending it to the burner.

Another thing that's changed over the years is that the fuel pumps on the burner these days run at much higher pressures. That atomizes the fuel better as it's forced through the nozzle. That gives you a cleaner burn and there's less chance of the furnace sooting up on you.

The other difference is the igniters. Just like a spark plug .... it's electronic ignition nowadays. It's a more reliable system than the earlier transformers from back in the day.

Originally Posted by alloy2

There's a transfer pump at the fuel tank set at 30 psi that supply's oil to a preheater at the burner, ignition was electronic, the issue with waste oil is sludge and foreign liquids ie: ant-freeze and water.


The filter is wire mesh, reusable, I used to chuck the filter onto the metal lathe and give if a quick spin to extradite the crude - a 20 litre bucket over the filter kept the crude off the shop wall.

Waste oil should be processed through a centrifuge to remove moisture and sludge to prevent the issues mentioned above.

Shops use hot air waste oil heaters these are less expensive to purchase, I choose the boiler. In the shop heat was provided using an old cast iron heat exchanger that was five feet long and sat right against the wall. Then another heat exchanger was installed inside the plenum on our forced air furnace in the house..

If the boiler failed to fire up the forced air furnace in the house would simply fall over to its alternative fuel source.

The hot air waste oil furnaces about the time the thermostat is calling for heat you already begin to feel the chill, whereas the boiler has a vast storage of hot water for a supply constant heat.

The shop I built in British Colombia I used a natural gas fired hot water boiler with a heated floor.

I hear you on the contaminants like water & anti freeze. They're pretty careful about that around here. Gasoline mixed in with the oil can be bad. That's something to be avoided.

Most of the residential burner pressures run 100 - 180 psi these days. All of the fuel filters i've done over the years had a felt like element. They seem to do a pretty good job. You just swap them and the nozzle out when you are doing your annual cleaning. That's pretty much the standard if you're burning #2 or kero in this area. It works pretty well. Most of the furnace / boiler calls in the winter are either because an outside tank gelled at the filter or because the annual maintenance hasn't been done in awhile.

I couldn't agree more about the hot air furnaces. They're convective heat. The air gets heated & circulated. Hot water baseboard or heated floor is much better. It's radiant heat. Radiant heat ... heats objects and people. It's much more comfortable because it's even. It's not like constantly cycling from hot to cold you get with a hot air furnace.