Abstract
The space heating demand in near zero energy houses is reduced due to increased insulation thickness. As a
result, the demand for heating of domestic hot water (DHW) has become a more significant part of the total
energy demand in these buildings. Ordinary heat pumps perform inefficiently when covering heating,
cooling and ventilation due to the high temperature requirements for DHW, thus a high temperature
difference in the condenser. In this article an innovative design heat pump for near zero energy houses is
discussed.
The objective of this work is to carry out simulations and presentation of a CO2 heat pump which uses the
exhaust air from the ventilation system as heat source to provide space heating (SH), heating of ventilation
air and DHW. As the CO2 heat pump is used for these three demands the coefficient of performance factor
(COP) of the whole unit increases as the return CO2 temperature decreases. Results show that the simulation
of the CO2 heat pump gave a COP of 4.4 when operating in winter modus. In addition, CO2 is a natural
working fluid with no ozone depletion potential (ODP) and a global warming potential (GWP) of only 1. Copyright © 2014 IIR/IIF. All rights reserved.
result, the demand for heating of domestic hot water (DHW) has become a more significant part of the total
energy demand in these buildings. Ordinary heat pumps perform inefficiently when covering heating,
cooling and ventilation due to the high temperature requirements for DHW, thus a high temperature
difference in the condenser. In this article an innovative design heat pump for near zero energy houses is
discussed.
The objective of this work is to carry out simulations and presentation of a CO2 heat pump which uses the
exhaust air from the ventilation system as heat source to provide space heating (SH), heating of ventilation
air and DHW. As the CO2 heat pump is used for these three demands the coefficient of performance factor
(COP) of the whole unit increases as the return CO2 temperature decreases. Results show that the simulation
of the CO2 heat pump gave a COP of 4.4 when operating in winter modus. In addition, CO2 is a natural
working fluid with no ozone depletion potential (ODP) and a global warming potential (GWP) of only 1. Copyright © 2014 IIR/IIF. All rights reserved.
