In cold climates, compressor rooms that draw 100% outside air for ventilation face a challenge: how do you prevent freezing temperatures from damaging equipment? The common solution is to install electric heaters.
But while it seems simple, relying on electric resistance heating to temper a compressor room is often a costly mistake — especially when you’re already generating a powerful, free heat source: waste heat from the air compressor itself.
Rotary screw compressors are incredibly inefficient at converting energy into compressed air. In fact, more than 80% of the input electrical energy is turned into heat.
Rather than venting this heat outdoors or letting it build up unnecessarily in summer, that same energy can be recovered and used to warm the compressor room in winter.
There are simple ways to capture and redirect this heat:
- Use ducting to divert the hot cooling air into the room
- Install adjustable louvers to toggle between summer and winter modes
- In liquid-cooled systems, use heat exchangers to capture heat for room or process heating
When compressors operate continuously, the recovered heat is often enough to maintain a safe indoor temperature — even when outside air is frigid and there is more than enough heat to send to the plant to displace unit heater energy. Yet, in many facilities, compressors vent warm air outdoors while expensive electric heaters struggle to warm cold incoming air. This results in redundant energy use and inflated utility bills.

Electric heaters are among the most expensive heating options available. Using them to temper a room that is constantly flooded with sub-zero air is like leaving a space heater on in an open garage — it works, but at a high cost. And all the while, your compressor is already generating more than enough heat to do the job.
By capturing compressor heat, facilities can cut heating costs, reduce their carbon footprint, and improve overall energy efficiency, all while protecting valuable equipment from cold-related damage.
Before you plug in another electric heater, consider this: you’re already paying for the compressor heat. Why not use it?
Filed Under: Air Compressors, Air Preparation, Components Oil Coolers, Compressed Air Technologies, Engineering Basics, Pneumatic Tips