Ask Atlas Copco: How Can I Use Recovered Heat?

Did you know that 80 to 93 percent of an industrial air compressor’s electrical energy is converted into heat? A properly designed heat recovery unit can recover 50 to 90 percent of available thermal energy and use it to heat air or water. 

Typical uses for recovered heat include:

• Supplemental space heating
• Industrial process heating
• Water heating
• Makeup air heating
• Boiler makeup water preheating                                                 

Heat recovery systems are available for both air- and water-cooled compressors.

Using heat recovery with air-cooled compressors

Packaged, air-cooled rotary screw compressors are conducive to heat recovery for space heating. Ambient atmospheric air is heated as it passes across the system’s aftercooler and lubricant cooler. The atmospheric air extracts heat from both the compressed air and the lubricant used to cool the compressor.

The hot air can be used for:

• Space heating
• Industrial drying
• Preheating aspirated air for oil burners
• Other applications requiring warm air

Using a heat exchanger makes it possible to extract waste heat from the lubricant coolers found in packaged water-cooled reciprocating or rotary screw compressors. The heat exchanger also helps produce hot water. Depending on design, heat exchangers can produce non-potable or potable water.

The hot water can be used in:

• Central heating or boiler systems
• Industrial cleaning processes
• Plating operations
• Heat pumps
• Laundries
• Other applications requiring hot water 

Using heat recovery with water-cooled compressors

Oil-free water-cooled screw compressors can recover the maximum amount of heat because they operate at much higher temperatures. With these compressors, it’s possible to achieve almost 90 to 95 percent heat recovery, and at some conditions, even more. Water temperatures can reach up to 194°F for use in various applications, including boiler makeup, preheating water and more.

Investing in the right compressed air heat recovery system can help reduce your facility’s energy consumption by reusing the heat in various applications. If you’re interested in learning more about heat recovery, please reach out to an Atlas Copco expert.