Keeping an air compressor warm

Old 09-21-05, 05:27 PM
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Question Keeping an air compressor warm

I just bought a Kobalt oil-less 22 gal vertical air compressor, and the manual says it has to be stored indoors during cold weather or the motor might not start and the condensation will freeze in the tank. Yet I want to use it in my unheated garage year round. The temp falls in the winter here to as low as 10 below on occasion. GregH mentioned a "100 watt magnetic heater stuck on the crankcase" worked for him. I'm wondering if that might work for me, where to buy such a heater, and if I need to put the compressor in a shed or something outside the garage to make this work. Or are there any other options? Thanks.
Old 09-21-05, 06:15 PM
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A block heater is an automobile engine kind of thing. Check your nearest automotive supply house. Other ideas are:
- heat tape; normally used on water pipes where the water is not recirculated and could freeze in place.
- hair dryer or heat gun; it might let everything get too cold, but it would be only used before turning it on, Once the pump is compressing air, there will be heat given off in that process
- hot water heater blanket along with some source of heat such as a light bulb to create a heated cavity. would have to be removed before starting to allow proper cooling

Once the compressor has filled the tank, move the block heater from the pump to the area near the drain on the bottom of the tank so that accumulated moisture can flow out. The pump won't need the heat if you are using air fairly steadily.

The block heater will withstand the heat given off by the compressor better than other solutions, so it could be just left in place all the time.
Old 09-21-05, 06:42 PM
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Thumbs up Welcome to the forums bipolarbear.

There is a difference in how a piston and an oiless compressor works.

The piston compressor has a cast iron, oil filled crankcase that allows the oil to absorb heat from the magnetic heater.
The oiless compressor has an aluminum housing and no oil.
The problem with trying to heat your compressor with a magnetic heater is that firstly the magnet won't stick and the heat may not spread to where it is needed.
It is a bit more important that an oiless compressor be warm before using because of the possibility of damage to the rubber (synthetic?) diaphram.

The problem of moisture freezing in the tank is not much of a problem when it is cold because the amount of moisture the air can hold at low temps is not that great.

You could build a large insulated box and heat it or maybe even a small closet.
What ever you do just make sure what ever you use to heat it is safe.
Old 09-22-05, 07:27 AM
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GregH's suggestion of a heated closet is a good one. Besides keeping the comp oil warm you also insulate the noise. When a compressor is in another room it is amazing how quite it becomes.
Draining the water out of the tank should be a regular maintinence routine. IMO this should be done on a daily to weekly basis depending on humidity.
Old 10-07-05, 07:41 AM
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Smile Thank you all.

Thanks to everyone who responded to my question. Lots of good ideas here. I've decided to wait till next year to set up shop in my Ohio garage, so I can put off my final solution till then. I've copied and saved your suggestions so I'll know what to do when the time comes. Thanks again.

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