28
Owner’s Information
SOLAR BYPASS
SIMPLE
DRAINBACK
TANK
a long cold winter spell, tank temperature (T2) can be as low as the tap water entering the tank (40-55°
F). During the summer, T2 could reach 180° F. Collector temperatures (T1) can similarly vary. During
T1 can reach 235° F.
When the pump is operational, the delta T (T1-T2) range can be between 3 -20° F. Hot water returning
from the collector loop can exceed 180° F. However, at initial start up, it may require 6-8 hours of solar
resouces to heat the tank.
When utilizing the existing conventional tank as the
backup, a solar bypass, as illustrated in Figure #8, is
closing the solar valves as described in diagrams #1 and
#2 on page 5, the entire solar system can be isolated to
allow for the existing tank to function exactly as it did
prior to the solar system installation.
PROCEDURES FOR ORDINARY AND
PREVENTATIVE MAINTENANCE
The The Simple Drainback system is designed for decades of maintenance free life. Fluid in the tank and
collector loop resides in a closed loop. Contaminants that lead to tank oxidation, calcification or sedimentation
are not continually reintroduced. One result should be exceptionally long system life.
Rust from condensation on the outside of the bottom of the tank represents the single
greatest danger to tank life. Be sure to install the tank up off the floor and
provide some form of thermal break to stop condensation where the hot tank meets the cold floor.
A few simple steps can be taken to prolong system life and efficiency. The collector’s glass cover can be occasionally
cleaned, especially after prolonged periods of no rain. Any insulation exposed to UV should be repainted after the first full
year to extend the insulation life. The optional SHEM insulation blanket (figure #9) improves efficiency.
Calcification of the heat exchanger will occur at approximately the same rate as calcification of house water lines.
Excess calcification can reduce the efficiency of the heat exchanger. Numerous commercial products are available to
reduce calcium deposits. White vinegar can also be used to remove build-up.
Broken collector glass is extremely rare. Hail will often ruin a roof, but not collector glass. If collector
glass does require replacement, simply remove the hex head screws from the top of the collector and remove
the aluminum trim to expose the glass for replacement.
Apply the SHEM stickers helps to clarify the system function.
INDICATORS OF PROPER OPERATION
(CONT’D)