Heat Recovery Systems for Oil-Free Compressors

A heat recovery system captures waste heat from an oil-free air compressor and repurposes it for hot water, process heating, or facility heating. This helps reduce energy costs, lower CO₂ emissions, and improve overall system efficiency.

Benefits of Oil-Free Compressor Heat Recovery

Recovering compressor heat can help make better use of energy already consumed by the compressed-air system. The potential benefits include:

Significant energy-cost savings
Lower CO₂ emissions
Turnkey solution options
Easy installation and operation
Small installation footprint
High reliability
No impact on the compressed-air supply

Your results will depend on your installation. Potential savings and payback are influenced by compressor utilisation, annual operating hours, recoverable-water temperature, available heat demand, existing heating equipment, local energy prices and installation requirements.

Recover_the_heat_generated_by_your_air_compressor

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Calculate Your Savings!

CompAir offers integrated and turnkey heat recovery solutions for selected oil-free compressors, helping businesses turn wasted energy into measurable savings.

How Does Compressor Heat Recovery Work?

A compressor generates heat while producing compressed air. A heat recovery system captures part of this thermal energy and transfers it from the compressor cooling circuit to usable water.

The process can be explained in four steps:

Electrical energy powers the compressor.
Air compression generates heat.
A heat exchanger transfers usable heat to water.
The heated water is supplied to a suitable facility process.

When the facility cannot use all the available heat, a backup cooling system may be required to maintain the compressor’s cooling-water temperature. The E-max system, for example, includes a backup heat exchanger for periods when customer heat demand is insufficient.

Where Can Recovered Compressor Heat Be Used?

Recovered compressor heat can support applications with a regular demand for hot water or low-to-medium-temperature heat. The brochure identifies four principal applications.

Space Heating

Reuse compressor heat to support a suitable facility or building heating circuit.

Industrial Process Heat

Supply recovered thermal energy to compatible industrial processes.

Hot Water Production

Produce usable hot water while reducing demand on separate heating equipment.

Steam Generation Preheating

Preheat water before steam generation to reduce the required heating load.

Turn Compressor Waste Heat into Useful Energy

During compression, most of the electrical energy supplied to an air compressor is converted into heat. Without heat recovery, that energy is removed through the compressor’s air or water-cooling system.

A heat recovery system transfers usable thermal energy from the compressor cooling circuit to water. The heated water can then support another process in the facility, reducing demand on separate heating equipment.

Heat recovery potential: Under ideal circumstances, up to 94% of the compressor’s waste heat may be recovered for reuse. The remaining 6% includes 2% radiated from the compressor and 4% remaining in the compressed air. Actual usable heat depends on the system and operating conditions.

CompAir Oil-Free Heat Recovery Solutions

CompAir offers different heat recovery configurations for selected air-cooled and water-cooled ULTIMA compressors and water-cooled DX-Series compressors.

The appropriate configuration depends on:

Compressor model
Rated power
Air-cooled or water-cooled design
Required water temperature
Available facility heat demand
Need for an integrated or external system

The compressor and compatibility details below are drawn from the CompAir heat recovery brochure.

Download Brochure

Sustainable Heat Recovery Systems for Oil-free Compressors Brochure

ULTIMA™

ULTIMA Heat Recovery Options

The Ultima compressor range offers various heat recovery options to accommodate individual customer needs. The water-cooled models can for example be delivered with just a preparation for external heat recovery, with an additional control of the cooling water outlet temperature (Heat recovery+) or with E-max, an absolute turnkey solution that includes all main components needed in a heat recovery system.

Absolutely unique is the integrated heat recovery option for the air-cooled version of Ultima. In fact, Ultima is the fifirst and only air-cooled oil-free compressor on the market with optional heat recovery, providing usable water temperatures up to 85°C. It’s a turnkey solution with all required components included in the compressor package. This means no additional footprint, no complex installation and thousands of Pounds of potential savings every year.

	Water-cooled			Air-cooled
	Preparation for external heat recovery*	Heat recovery+	E-max	Integrated Heat recovery
Internal thermal management to achieve cooling water outlet temperatures up to 90°C	●			●
Control of the cooling water outlet temperature		●	●	●
Control of the heat recovery temperature on customer side			○
Control of backup cooling water flow			○	●**
Heat exchanger for heating the customer’s water			●	●
Backup heat exchanger			●	●
Visualization of the current and accumulated heat recovered			●	●
Water pump			●	●
Compressed air aftercooler	○***	○***	○***	○***

● Standard Option ○ Optional Add-on

* For the Ultima, this option is part of the standard scope of supply
** The two radial fans of the air-cooled Ultima serve as additional / emergency coolers if necessary
*** In many cases the Ultima already has a sufficiently low air discharge temperature, so an external aftercooler will not be needed

Explore ULTIMA Compressors

See ULTIMA Heat Recovery in Practice

See how Hochwald Sprudel uses ULTIMA compressor technology as part of an energy-efficient compressed air installation, including effective heat recovery.

Read the Hochwald Sprudel Case Study

D-Series

Water-cooled DX-Series compressors

All water-cooled D-Series compressors, from 37 kW to 315 kW, are available with preparation for external heat recovery. Depending on the model, recovered heat can be used to provide hot water at temperatures of up to 75°C or even 90°C.

Models up to 200 kW are also compatible with E-max, the turnkey heat recovery solution.

Explore DX-Series Oil-Free Compressors

E-Max

E-Max: turnkey heat recovery system for oil-free compressors

Scope of supply

Heat recovery heat exchanger to heat up your usable water
Backup heat exchanger, operated in times when the heat demand is not sufficient to cool down the cooling water to the requested max. inlet temperature for the compressor
Speed regulated pump to control the cooling water temperature before the heat recovery heat exchanger
Intuitive coloured touch screen controller providing a quick and comprehensive performance overview, including visualisation of current and cumulated recovered heat

Broad range of further options:

Electrical valve kit 1: To control the water outlet temperature on the customer side of the heat recovery heat exchanger
Electrical valve kit 2: To control the external cooling water flow through the backup cooler in order to reduce water consumption when the backup cooler is not needed
Additional backup pump
Connecting kit comprising ball valves and adapters from Victaulic to 1" internal threads for all water connections
Compressed air aftercooler (provided loosely. The E-max box as a standard includes inlet and outlet connections for the aftercooler's cooling water)

U-Cooler/E-Cooler - a perfect extension for E-max

Highly efficient V-shaped cooling module for trouble-free waste heat removal from the ULTIMA cooling cycle. A complete package of cooling module, pump station and control integrated into the compressor. Easy to install, easy to operate and virtually maintenance-free.

Compare CompAir Oil-Free Heat Recovery Options

Solution	Compressor configuration	Heat recovery approach	Temperature
ULTIMA integrated heat recovery	Air-cooled ULTIMA	Components integrated into the compressor package	Usable water up to 85°C
ULTIMA external heat recovery preparation	Water-cooled ULTIMA	Prepared for connection to an external system	Configuration dependent
ULTIMA Heat Recovery+	Water-cooled ULTIMA	Additional cooling-water outlet-temperature control	Configuration dependent
ULTIMA with E-max	Water-cooled ULTIMA	External turnkey heat recovery system	Application dependent
DX-Series external heat recovery	Water-cooled DX-Series, 90-355 kW	Preparation for external heat recovery	Up to 75°C or 90°C, model dependent
E-max	Compatible oil-free compressors	Packaged heat exchangers, pump and controller	Compressor and application dependent

Frequently Asked Questions About Compressor Heat Recovery

Compressor heat recovery captures thermal energy produced during air compression and transfers it to a usable heating circuit. The recovered heat can support space heating, industrial process heat, hot-water production or preheating for steam generation.

Heat Recovery Systems for Oil-Free Air Compressors