Almost every manufacturer of HVAC equipment is currently scrambling to bring to market variable speed units with either Copeland or Danfoss inverter driven compressors. Variable speed geothermal heat pumps being manufactured by WaterFurnace (7-Series) and Climatemaster (Trilogy 40) will purportedly reach previously unattainable efficiency levels and have COPs (Coefficient of Performance) between 6 and 7 and EERs (Energy Efficiency Ratio) above 40. In air-cooled heat pump situations, variable speed technology will increase HSPFs (Heating Seasonal Performance Factor) by more than 15%, allowing for better performance at lower outdoor ambient temperatures. Carrier’s Infinity heat pump with “Greenspeed” offers HSPFs up to 13.
Variable speed compressors also offer the advantage of much lower starting amperage and improved power factors, which will lessen the impact of power draw on the grid by reducing transformer load and grid losses. Capacity modulation upon demand will significantly reduce air conditioning power requirements and help prevent demand spikes that occur in standard on/off cycles. Of course, rotary variable speed compressors have been available for some time in VRF systems, but the advent of a variable speed scroll compressor will open the technology to a much wider market in U.S. manufactured equipment. Americans constitute 5% of the world’s population but consume 24% of the world’s energy. 73% of the energy we consume is in the form of electricity and 20% of our electricity goes to power air conditioning systems. In general, variable speed air conditioners are 15-40% more energy efficient than comparable single speed air conditioners, so the impact will be tremendous.