Geothermal (ground-source) heat pumps (GHPs) are an efficient alternative to conventional methods of conditioning buildings. However, GHP systems can have relatively high installation costs because of the ground heat exchanger. Proper sizing of the exchanger is critical to performance. Vertical U-tube heat exchangers are commonly used as the ground heat exchanger, but the design and determination of the operating performance is difficult because of the unique heat transfer situation. Proposes a U-tube heat exchanger model based on finite-difference methods that can be used in system design and annual performance simulations.

Units: Dual

KEYWORDS: year 1997, Heat pumps, geothermal energy, calculating, heat exchangers, comparing, heat flow