Engineered Systems Magazine

Geothermal heat pumps

April 29, 2010

More than 25 years of research, engineering and manufacturing experience come together in the Legend series of geothermal heat pumps from WaterFurnace International, Inc., a leading manufacturer of residential, commercial, industrial and institutional geothermal and water source heat pumps. All Legend products feature highly efficient, reliable, single capacity scroll compressors paired with five-speed X13 ECM blower motors (or optional three-speed PSC motors) that ensure precisely controlled comfort, quiet operation and energy savings.

 With an 18.5 energy efficiency ratio (EER) and a 3.8 coefficient of performance (COP), the ENERGY STAR®-rated Legend series exceeds ASHRAE 90.1 efficiency standards. The product uses environmentally friendly R-410A refrigerant and is available in capacities ranging from 24,000 through 70,000 Btuh.

 All units are constructed of corrosion resistant galvanized sheet metal with silver metallic powder-coat paint rated for more than 1,000 hours of salt spray. Inside, WaterFurnace’s exclusive FormaShield™ coating on the air coil provides added protection against corrosion and increases equipment life, while ThermaShield™ foam insulation increases the efficiency and consistency of the heat exchangers.

 A simplified microprocessor control sequences components during operation for optimum performance and provides easy-to-use troubleshooting features with fault lights and on-board diagnostics. Unit configurations include vertical top discharge (left or right return) and horizontal units with left or right return, side or end discharge for retrofit and new construction applications.

All Legend series units feature important indoor air quality (IAQ) benefits, including:    
  • A corrosion-free composite double-sloped drain pan to eliminate standing water and prevent bacterial growth    
  • Foil-faced fiber insulation in all air handler compartments to allow cleanability and inhibit bacteria growth    
  • A factory-mounted, four-sided deluxe filter rack that is field switchable from one inch to two inches    
  • A MERV 8, one-inch pleated filter
  In addition, an optional hot water generator allows the Legend series to preheat water in the water heater to save money. In heating mode, water is heated at the efficiency of the unit. In cooling mode, the heat from the home is transferred to the water heater rather than the ground, providing free hot water.