Figure 15-10.A DHW system with heat exchanger in hot-water storage tanks.
heat exchanger cannot be used effectively in this
Space Heating and DHW Systems
Space heating systems are a simple extension
of the domestic hot-water (DHW) systems (fig.
15-10). The collectors and storage tank need to
be resized to provide greater loads. A heat
delivery system is added and the auxiliary heater
(or existing heater) is connected into the system as
backup. The design of the space heating system,
if a retrofit, depends on the existing system.
Water-to-air heat exchangers may be placed in
unpressurized, unlined tank may be used. This
represents a minimum heating system, as shown in
figures 15-11 and 15-12.
Domestic hot water could be added to the
system shown in figure 10-33 by adding a preheat
coil in the storage tank. Figure 10-31 has the
potential to provide some cooling to the building
by using the collector at night to radiate heat to
the sky and store cool water for use during the
day. A heat pump is another option that could be
used to cool the building, reject the heat to the
storage tank during the day, and then, as before,
cool the tank at night through the solar collectors.
Unglazed collectors are superior to glazed
collectors for this application. There are many
variations that can be used with the configurations
Air types of space heating systems are
receiving increased attention, and a typical system