Posted on February 29, 2016 by Scott Gibson
in Q&A Spotlight
Jordan Garrow is getting ready to build a new house in New York State, on the cusp between Climate Zones 5 and 6, and he's planning to heat and cool it with a ground-source heat pumpHome heating and cooling system that relies on the mass of the earth as the heat source and heat sink. Temperatures underground are relatively constant. Using a ground-source heat pump, heat from fluid circulated through an underground loop is transferred to and/or from the home through a heat exchanger. The energy performance of ground-source heat pumps is usually better than that of air-source heat pumps; ground-source heat pumps also perform better over a wider range of above-ground temperatures.. His contractor wants to install a horizontal "slinky loop" heat exchangerDevice that transfers heat from one material or medium to another. An air-to-air heat exchanger, or heat-recovery ventilator, transfers heat from one airstream to another. A copper-pipe heat exchanger in a solar water-heater tank transfers heat from the heat-transfer fluid circulating through a solar collector to the potable water in the storage tank., one of several possible options, and Garrow is seeking a second opinion.
A heat load calculation for the house specifies a 4-ton system (one with a capacity of 48,000 BtuBritish thermal unit, the amount of heat required to raise one pound of water (about a pint) one degree Fahrenheit in temperature—about the heat content of one wooden kitchen match. One Btu is equivalent to 0.293 watt-hours or 1,055 joules.
/hour), but the contractor wants the heat exchange loops designed as if they were serving a 6-ton system.