Performance Evaluation of Combined Heat Sources for Innovative Heat Pumps: Ground Source Combined With an Air Coil, Paper ID 650
2013 (English)Conference paper (Refereed)
A significant amount of the Swedish single family houses have installed a ground source heat pump as primary energy source. Many of these installed heat pumps are due for replacement and the new installed heat pumps are generally more efficient. Thus, they extract more heat from the ground at a given heat load of the building. This fact combined with the early “rule of thumb” used by Swedish installers for sizing the borehole length means that many boreholes now are slightly undersized in terms of length.One obvious remedy is to drill some additional meters to the existing borehole. Other alternatives exist to offset this situation as well and two of these are that the borehole is assisted by either a solar collector or an outside air heat collector, similar type used for air-to-air heat pumps. The effect of such a measure is that less energy is extracted from the ground during the heating season, and the heat pump may operate at higher heat source temperatures. In addition, it may prevent or at least delay freezing of the borehole, which may occur late of the heating season for some installations.The present paper investigates the performance of such system and to compare the outcome of these three systems in terms of annual energy extraction rate from the ground. The results indicate that the proposed system indeed may offset the additional heat extraction that a new more efficient heat pump would otherwise cause.
Place, publisher, year, edition, pages
Research subject Energy Technology
IdentifiersURN: urn:nbn:se:kth:diva-178853OAI: oai:DiVA.org:kth-178853DiVA: diva2:878412
CLIMA 201311th REHVA World Congress & 8th International Conference on IAQVEC, Prague, Czech Republic
FunderSwedish Energy Agency