The initial configuration for Solar Hot Water in ApacheHVAC (as of VE 6.4.1) will most often be used in low-temperature heating systems, such as hydronic radiant floors, for which the return water temperature is quite low. This solar HW application is normally paired with a condensing boiler as the backup heat source, so as to maximize the opportunity for actual condensing operation, which also required a moderate return temperature.
Solar hot water panels as a pre-heating system on the HW loop return is also a configuration sometimes used for natatoriums. However, a heat pump or “heat-recovery chiller” may more sense in such cases as means of handling latent loads from pool evaporation on the evaporator side, with condenser heat being rejected to the pool. This is because the majority of heat loss from swimming pools is typically in the form of latent heat and the air then needs to be dried to avoid condensation on windows and other components of the building fabric.
