Fort Polk Installation Demonstrates Retrofit Potential of Geothermal Heat Pumps
A recent independent study prepared for the U.S. Department of Energy by Oak Ridge National Laboratory (Hughes, et al, 1998) demonstrates that geothermal heat pumps (GHPs) provide substantial benefi ts to the end user, the electric utility industry and the environment. A comprehensive 4,003-home retrofi t project was conducted at Fort Polk, Louisiana where the existing heating and cooling systems (560 gas furnace/electric air-conditioner systems and 3443 air-source heat pump systems) were replaced by GHPs with desuperheater water heaters. In addition existing incandescent lighting fi xtures were replaced by high-effi ciency fl uorescent or compact fl uorescent fi xtures, and existing shower heads were replaced by low-fl ow shower heads. Evaluation of this massive retrofi t showed that it reduced electrical consumption in the 4003 residences by 26 million kWh (33%) while altogether eliminating consumption of 27,425,000 MJ of natural gas. Peak demand was reduced by 7.5 MW (43%), and the power factor was increased from 0.52 to 0.62 . Emissions of CO2 have been reduced by an estimated 20,321,000 kg per year at the Ft Polk site. The GHPs alone are credited with 66% of the electricity savings and all of the natural gas savings (Hughes and Shonder, 1998) accounting for about 14,900,000 kg of the total annual CO2 emissions reduction.

Retrofit Heat Pumps for Building
In the majority of European countries, the present heat pump market for space and water heating and cooling is largely concentrated on new buildings, particularly single and two-family houses. However, there is a very large potential in the retrofi t market for replacement of old conventional oil-, gas- and coal-fired heating systems with high energy-efficient and environmentally sound heat pumps.

High temperature heat pump for the retrofit market in France
The retrofit of heating systems represents a significant market in France. Nowadays, high-temperature heat pumps make an interesting alternative to boilers, with real advantages in term of CO2 emission and energy efficiency. Another advantage of heat pumps lies in the energy that can be saved over a year. The HSPF (heat seasonal performance factor) is therefore the most appropriate parameter for relating to actual heating energy bills. HSPF is the ratio of the total heat delivered over the heating season to the total energy input over the heating season. In the study, field test results on a French house will be presented, as results of simulations calculating the HSPF.

Air-to-air heat pumps in Norway
In Norway, air-to-air heat pumps have become the most popular way for house-owners to reduce their energy bills. By the end of 2006, heat pumps of this type will make up about 13 % of all those that have been installed, with almost all having been installed during the last five years.

Air-to-air heat pumps evaluated for nordic circumstances
Twelve variable-speed capacity controlled air-to-air heat pumps have been evaluated by laboratory measurements and the results have been compared to similar investigations made in 2001 (variable-speed capacity control) and 1991 (single-speed compressors). The heat pumps were evaluated in terms of efficiency, performance of defrost system and ability to operate in a cold climate. The results show that heat pumps have become more efficient since 1991 and 2001. On average, the coefficient of performance (COP) has increased by 7-24 % since 1991. The defrost systems have also improved, although there are still systems that in practice operate under simple time control, and thus perform unnecessarily many defrost cycles, which reduces performance and probably also equipment life.