|Provided By Sierra Solar Systems
|Domestic Hot Water And Space Heating
In this active, closed-loop system, incoming potable water is
routed to the solar storage tank, but never into the collectors.
A water and antifreeze mixture circulates from the collectors
through a coil of pipe in the solar tank, and then is pumped
back through the collectors. (In most climates, a 50/50
propylene glycol and water mixture will keep collectors from
freezing.) The potable water is warmed by heat transfer
through contact with the pipe.
These systems require an expansion tank and a few other
auxiliary components for filling, venting, and maintaining the
system. A definite advantage to antifreeze systems is that
the collectors can be mounted anywhere. These systems are
pretty much the only choice in very cold climates.