30 September 2015
Direct-exchange ground-source – DX – heat pumps with horizontally installed ground collectors had a market share of 65 % in Austria in the mid nineties. They were the most efficient heat pump type achieving SPFs between 4 and 5. Currently, air source heat pumps dominate the market; the share of DX heat pumps is in the range of 5 %. The problem of polluting the groundwater in the case of a leakage has been solved and the required space for ground collectors reduced while compressors with continuous capacity control have been improved significantly. In terms of efficiency, DX heat pumps are still the most efficient solution for heating homes.