How does a heat recovery system work?

Heat recovery systems for air compressors

Air compressors offer a source of power generation that will not only save you money but can help to increase productivity in your business. However, it is a thermodynamic fact that around 96% of this energy will be converted to heat and potentially wasted to the atmosphere. Installing a heat recovery system is a great way of using this excess heat to your advantage and make the process more efficient.

Why businesses should invest in a heat recovery system

Many businesses, especially those with long operating hours, will gain significant financial benefits from installing a heat recovery system. The return on investment for energy recovery can be as short as 1 - 3 years and waste heat can be recovered from all types of air compressors including, rotary screw compressors and oil-free compressors. Wasted heat energy can be recovered in the form of hot air or hot water, which can be particularly beneficial outputs. The types of site and possible applications include:

• Water heating
• Space/air heating
• Process heating and drying

How a heat recovery system will work with your air compressor

When air is compressed heat is formed. Before the compressed air is distributed into the system the heat energy is extracted, preventing it from becoming lost to the atmosphere and wasted. With a heat recovery system in place, 96% of the electrical drive energy fed to the compressor can be reused for heating purposes, with only 2% of the energy lost as radiant heat and the final 2% remaining as heat in the compressed air.

The most efficient and simplest method of heat recovery is when ducting is utilised to deliver the warmed air into nearby storerooms or workshops. If there is no demand for this heat energy, this surplus heat can be released into the atmosphere via a directional damper. Thermostatically controlled dampers control the flow of warm air to maintain consistent temperatures or to support drying processes. The recycled heat can also be used to create hot air curtains or to preheat combustion air for heating systems.

Things to consider before you install a heat recovery system

There are certain factors that should always be considered before installing and using a heat recovery system. HPC’s experienced team is always at hand to advise and discuss options and the main factors to think about are:

1. If your heat recovery system will be used to form hot air, which will be used for space heating, you might need to use automatic controls to ensure overheating does not occur in the building.
2. If your heat recovery system will be used to heat water, especially for pre-heat boiler combustion air, consider whether the fans can cope with the raised temperature.
3. Discuss backpressure with your compressor supplier, looking at ducting and booster fans to prevent any potential issues occurring.

Get in touch with HPC to discuss your heat recovery system and energy-saving options

HPC KAESER has years of experience installing the correct heat recovery system for specific air compressors and business needs. Please do not hesitate to contact HPC today to speak to a member of our expert team about your individual application and the potential energy and cost-saving options available for you.