Variable Speed Compressors to Revolutionize Efficiency Standards

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.

As always, to keep up to date with what’s new in HVAC technology, visit our website at airideal.com and follow us on Twitter @airideal and at our Facebook page!

Finally, a Heat Pump for Low Ambient Temperatures

 A couple of the toughest things about living in the northeast is the vagaries of northern weather and the unavailability of natural gas for heating in many suburban and rural areas. This has left many without an option beyond No. 2 fuel oil. Although geothermal heat pumps are a much more efficient and cost effective long term solution, many do not have the discretionary savings to invest in a 5 or 6 year payback period. Air-cooled heat pumps have never been an acceptable alternative because the indoor discharge air temperatures left one shivering in low ambient outdoor conditions.  I installed a variable refrigerant heat pump system in my own home to use as a heat supplement in all but the lowest ambient conditions.

Enter the much ballyhooed variable speed compressor from Copeland. Copeland claims that their new technology will keep homeowners warm with up to 48% greater low ambient heating capacity and no drop off in evap side discharge temperatures. Copeland claims up to 13HSPF (Heating Seasonal Performance Factor) in optimized heat pumps and 29% greater efficiency than any heat pump currently on the market.    Carrier is incorporating the variable compressor in their Infinity line with “Greenspeed Intelligence.”  Other manufacturers should follow suit shortly. This compressor will also be used in WaterFurnace’s new water-to-water geothermal heat pump that will be able to reach 160 degree discharge water temperatures and possibly replace many hot water boilers serving baseboard radiation.

Greater heating performance at lower outdoor ambient temperatures is only one excellent feature. These variable speed compressors should also be able to increase overall efficiency at part loads as well as provide optimum dehumidification, pushing the 20 SEER envelope.

As always, to keep up to date with what’s new in HVAC technology, visit our website at airideal.com and follow us on Twitter @airideal and at our Facebook page!