Originally Posted by Flint (Post 304250)

So I needed to reduce from male 1/2" something on this end to something like 5/8" something on the other end.

Originally Posted by tw (Post 304328)

A heat pump works by trying to cool outside air - thereby heating inside air. However as outside temperature drops below 40F, the heat pump has little outside heat to pump inside. Therefore (and unlike other heating systems) a heat pump must also have the 'emergency heat' function. That is typically electric heat - very expensive. Thermostat must have extra functions to control that 'emergency heat' function.

Heat pumps generally are most efficient at latitudes and temperatures of North Carolina.

Originally Posted by Wikipedia

Because a ground-coupled heat pump in heating mode draws heat from the ground or groundwater, which below a depth of about eight feet is at a relatively constant temperature year-'round, its COP is often higher on average than for an air-coupled heat pump—its COP is more constant year—'round. The tradeoff for this improved performance is that a ground-coupled heat pump is usually more complicated due to the need for wells or buried coils, and thus is also usually much more expensive to install than an air-coupled heat pump.