Use a Floating Head & Low Pressure

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Affordability

Multiple compressor applications, such as supermarkets, are appropriate for this technology.  It would be cost prohibitive to retrofit to smaller systems.

Cost savings

Savings can be dramatic and investments recovered quickly. A study at a U.S. ice arena concluded that a $1,000 investment in a control change was paid back in energy cost savings in less than two months.

Environmental considerations

A floating head system will reduce wear on parts of your equipment so they last longer. Replacing parts less often reduces the need for more production and shipping and reduces material in the landfill.

What you need to know

• Set your equipment so that the pressure of the vapour coming out of the compressor (the "head pressure") will float – that is, drop with reduced ambient temperatures. This requires an expansion valve capable of operating at lower pressures and flow rates. Such valves are commercially available. 
• In one field test, operating a system with floating head pressure reduced annual electricity costs by 4.9% relative to operating with fixed head pressure.
• The formation of vapour, also called flash gas, in the liquid refrigerant line causes inefficiency in the refrigeration cycle. Keep refrigerant pressure high enough to avoid "flashing”.
• You will save money when you get more energy efficient. Learn about starting a workplace Green Team and Hiring an Energy Manager to reduce your energy use and costs.

FAQ

I have a compressor that I am not ready to replace. Is it possible to retrofit my existing equipment to reduce pressure in lower temperatures?
Yes. If your compressor is greater than 50 hp, the necessary expansion valves are commercially available and can be installed fairly easily.