Solar Glycol Systems Explained
The following shows a glycol-based system that provides both Solar Domestic Hot Water (SDHW)
and solar radiant heating backed up with a high efficiency boiler (not shown)
The above picture shows "building integrated" collector panels
used in a glycol based system. A glycol based system has the following
characteristics and advantages:
- Less danger of freezing than with a drainback system
is NOT installed by a professional solar installer/designer.
- Somewhat simpler pipe runs to/from collectors (don't
have to worry about tilt).
- Because of lower circulator "head" requirements, the
circulator can easily be run by a photovoltaic panel, resulting in a
"true zero energy use" system.
Solar Storage Tank
Glycol Pump Station
The above picture shows
control panel and storage tank for a glycol based system. Be aware of
the following on glycol based systems:
- Excess heat created in the summertime must be managed
order to minimize damage to glycol.
dumps, hot tubs, etc can be used to "dump" the excess heat; or you can
build an overhanging "shade" structure to cover part of the panels in
- Never use a pure makeup water connection into a
based system. Makeup water systems are good for the boiler plumbing,
but not for solar systems, as they can cause dilution of glycol
solution, and subsequent freezing of the panels.