| Advantages
of a Drain Down Solar Water Heating System |
The
Drain Down System provides various advantages. There is no heat
exchanger, which allows efficient heat
transfer directly to the water. It does not use anti-freeze or
non-potable water. The Drain Down System offers freeze protection during
power outages or malfunctioning of the pump or the control systems, as
well as providing better freeze protection than Recirculation
systems in areas of moderate freezing. The system eliminates loss of
stored heat by thermosyphoning or the Recirculation
process. The Drain Down System integrates easily with existing systems.
The system can also be disassembled easily and moved to another
location. |
The
Drain Down system also exhibits a few disadvantages. A drain
down valve and special controls required. Care must be
taken to plumb the supply and return so that they will drain down.
Drained water cannot be recovered, however, a 30 tube Manifold and 50
feet of ½" pipe only holds 5 pints of water. As a result of line
pressures in the solar loop, leaks are potentially more serious. In
areas with hard water, scaling can be a problem for the valve. Providing
valve is cycled daily it should only need de-scaling every few years, a
simple process. |
Disadvantages
of a Drain Down Solar Water Heating System |
