Figure H-14.-Typical air types of space heating systems.

in this manner, the system is usually called a solar-assisted or solar-augmented heat pump (SAHP) system.

Solar-assisted heat pump systems are configured in many different ways.

For example, the solar collectors can be either water or air types; the heat storage medium can be water or a solid material, such as rock or brick; and the heat pump can be of either the air-to-air design or the water-to-air design. But heat pumps have a characteristic that can limit their effectiveness: the efficiency and capacity of a heat pump decrease as the temperature of the heat source (usually outdoor air) decreases. This deficiency can be overcome, however, by using solar collectors to gather the energy of the sun to keep the heat source in the temperature range required for efficient heat pump operation.

Heat Distribution for Air Types of Solar Systems

The pipes and pumps of the liquid types of solar systems are replaced by air ducts and fans. The warm-air system is obviously the best heat distribution system for use with an air type of solar

Figure 15-E-A liquid-to-air heat delivery system.