Page 114 - Low Temperature Energy Systems with Applications of Renewable Energy

Effective use of heat pumps for various heating applications 103

Fig. 3.18 Temperature changes of air in the elements of the system in Fig. 3.17. C HP , heat pump
condenser; E HP , heat pump evaporator.

since the costs for heating the ambient air are reduced. The energy spent on heating the
inflow air during the cold period can be reduced to 60e85%, compared to the usual
inflow plant [7].
Recirculation is also widely used when air is cooled in summer. It can be seen from
Fig. 3.19 that the flow of exhaust air is divided into two streams: one part, after passing
through a filter, is combined in a mixing chamber with the inflow air; the other is
directed to the heat recovery unit and HP. Due to the recovery unit and the HP, air leav-
ing the room is transferred to the fresh air coming from the environment.

Fig. 3.19 Ventilation system using a heat recovery unit and recirculation of exhaust air. F, filter;
L, heat pump compressor driver; MC, mixing chamber.