Plant & Works Engineering
The answer to this month’s trouble shooter is provided by BOGE. Q: How can I recover heat from my air compressor?
Published:  04 June, 2015


All compressors generate heat. In fact, most of the energy consumed by a typical compressor is converted to heat during the compression process; and where there’s heat, there’s cost and an opportunity for savings by using what is otherwise wasted energy.

At a basic level, heat recovery can be as simple as redirecting hot compressor exhaust air into surrounding areas as a means of space heating, such as in a workshop. Alternatively, adding hot air ducting can, for example, enable nearby offices to be heated. It is also possible to extract waste heat from a compressor to heat water for boilers, cleaning processes, plating operations or heat pumps.

In most applications the most efficient method of heat recovery is to use a specialised heat recovery device. These systems are designed for oil injected screw compressors and connect directly into the oil circuit. They are generally compact, easy to retrofit to existing compressors of any make and can offer a relatively fast payback; sometimes in twelve months or less.

Before investing in heat recovery it’s worth carrying out an assessment to establish the likely returns. Bear in mind that small compressors or those with only infrequent use are unlikely to offer a suitable payback. Most compressor specialists can help you calculate the potential energy and savings in electricity, oil or gas costs. They should also be able to help you establish where recovered heat can best be used and prepare an effective installation plan.