Towards low carbon homes - A simulation analysis of building-integrated air-source heat pump systems

摘要

A comparative transient simulation analysis for domestic buildings with a floor-embedded heating system coupled to a modern air source heat-pump (ASHP) has been carried out using the TRNSYS numerical modeling environment for various UK locations. The effects of heat-pump control during off-peak electricity tariff periods in conjunction with varying building fabric characteristics were analysed and the results show that for the locations investigated, running costs and CO_2 emissions were lower for the ASHP platform than for a comparative gas boiler heating system. It was also found that by utilizing the thermal mass of a concrete floor slab or by integrating external insulation, acceptable comfort levels during the heating season were maintained when operating the ASHP solely during off-peak tariff periods. A thinner concrete floor slab containing phase change material (PCM) provided a slightly improved comfort level during winter and also reduced overheating during summer in buildings with a high level of insulation. Finally, when utilising a floor-embedded PCM material, it was found that the thermal properties of the PCM material must be carefully matched with case-specific building fabric thermal performance parameters in order to ensure effective internal environmental control.