Air Compressor Dog House

[Karl_T]

I paid $5 for a 10hp VFD at another auction. Hope you don't think I over paid

An oil plug heater is a good idea, didn't know such a thing was made.

 

[Grumpy Gator]

For what its worth a 300w halogen light in the dog house will keep the compressor warm.
Be sure to put a water separator in your discharge line or loop the air hose over some thing high like a truss. The poor mans way.
******Just Saying**************G******************************************

 

[Silverbullet]

You could wrap heat tape around the compressor crankcase , even one on tank for drainage , you will need lots. Of air circulation at least in warm weather. A fan could be installed for that. The tapes are usually thermostat controlled the fan could be too.

 

[uncle harry]

Thanks for the input, everybody.

What do you all think of this plan?

Put a smaller pulley on for 25% speed reduction and torque increase. Should help with winter starting. I'll put it on a VFD and can run the motor 25% faster for sandblasting, otherwise leave the motor run slow.

FWIW, my son has the same unit outside in his unheated barn and he has trouble with VFD KOs in cold weather. An extremely slow ramp up solves his issue unless its below zero. I use my air compressor a lot in below zero weather.

Another start up approach is to use a centrifugal clutch. This will get the motor spun up before engaging and lets the torque build up.

 

[Karl_T]

ther start up approach is to use a centrifugal clutch. This will get the motor spun up before engaging and lets the torque build up.

Large compressors come with this already. Its called an unloader valve. No air is pumped until up to speed. I've never looked into it, maybe these can be adjusted to let the unit run several more seconds to warm it up.

 

[uncle harry]

Large compressors come with this already. Its called an unloader valve. No air is pumped until up to speed. I've never looked into it, maybe these can be adjusted to let the unit run several more seconds to warm it up.

There are pressure switches that incorporate an unloader valve in their mechanism. The valve is piped in between the tank check valve and the compressor output.

 

[projectnut]

I think you'll need more than just a "dog house" if you expect the compressor to last very long. I have an older Kellogg 2 stage splash oiled compressor. The compressor is specified to use 30W non detergent oil. The owners manual clearly states in bold letters that the compressor shouldn't be run in temperatures below 20*F. In 20*F and colder temperatures not enough oil can be circulated to keep the bearings and cylinder bore properly lubricated.

You'll need a heat source for the cold winter months and plenty of ventilation for the summer months. The recommendations for placement for my compressor are a minimum of 6" between the flywheel and the wall with nothing to impede the air flow on the remaining 3 sides, and at least 2 feet of clear air space above the unit.

 

[projectnut]

I forgot to add a little information about the unloader. The one on the compressor in the picture is a mechanical style. It's similar to a mechanical governor. There's a spring loaded Schroeder valve, activating rod, and weight assembly under the cap on the crankshaft. When the compressor shuts down the weights on the shaft relax. The attached rod is then depresses the Schroeder valve and releases head pressure. When the motor starts the centrifugal force makes the weights move outward and retracts the rod that opens the valve. As soon as the motor is up to speed the unloader is no longer allowing air to exhaust from the high pressure line.

 

[rgray]

I have a 10hp and I put it overhead. My shop has 11 foot walls. I built a platform and the compressor is up in the rafters. My rafters are on 6ft centers so I could get away with that. A 15hp rotary phaze converter runs it and I still had to buy a smaller drive pulley for the motor to gear it down so it would start normal.
My advertised 6 hp (really 3hp) compressor is up there with it and I normally run off of it. I can switch the big one on anytime I'm gonna be running alot of air and need it. The noise level is surprisingly less when they are up that high. It's the warmest place in the shop year around I believe.

 

[TomS]

I have my compressor in a Rubbermaid storage cabinet outside of my shop. I cut holes and put four foundation ventilation grates around the top to get rid of the heat. I live in Redding, California so I deal with 100 degree plus heat continually during the summer. Winters aren't as cold as Minnesota but it does get into the teens. Having it outside keeps the shop quiet enough to have a normal conversation plus saves floor space.

Tom S