Abstract
Norway is a member of Annex 32, “Ecomonical Heating and Cooling Systems for Low-Energy Houses” (2006-2008), organized under the umbrella of the International Energy Agency (IEA) and the IEA Heat Pump Programme (HPP). The 9 participating countries are Switzerland (Operating Agent), Austria, Canada, Germany, Japan, the Netherlands, Norway, Sweden and the USA. The Norwegian participation is financed by Enova SF, and SINTEF Energy Research is responsible for planning and carrying out the Norwegian activities. IEA HPP Annex 32 has four tasks: 1) Systems to be investigated, 2) Calculation, comparison and assessment of system solutions, 3) Field testing of integrated heat pump systems, 4) Design guidelines. Task 2.1 – Analysis of centralized heat pump water heater systems for apartment buildings and block of flats of low-energy and passive house standard. Four different heat pump designs were simulated in order to find the maxi¬mum theo¬retical coeffi¬cient of performance (COP). The simulations showed that a heat pump water heater using carbon dioxide (CO2) as working fluid will achieve about 20% higher COP than high-efficiency state-of-the-art heat pump water heater systems. CO2 heat pump water heaters are therefore regarded a very promising alternative for centralized hot water heating in apart¬¬ment buildings and block of flats of low-energy and passive house standard. Task 2.2 – Analysis of integrated CO2 heat pump systems for low-energy and passive houses. Different integrated CO2 heat pump systems have been investigated. It was found that a counter-flow tripartite CO2 gas cooler in combination with an external single-shell hot water tank and a low-temperature heat distribution system, would contribute to the highest possible COP for the CO2 heat pump system. The SPF for a prototype brine-to-water CO2 heat pump was calculated on the basis of laboratory measurements and compared with the performance of a high-efficiency brine-to-water heat pump unit. At DHW heating dema