42
7
Maintenance
WARNING
Follow the service and maintenance
procedures given throughout this manual
and in component literature shipped
with the solar components. Failure to
perform the service and maintenance
could result in damage to the solar
system. Failure to follow directions in the
manual and component literature could
result in severe personal injury, death or
substantial property damage.
WARNING
The solar heating system should be
inspected annually only by a qualified
service technician. In addition, the
maintenance and care of the solar
collection system explained in the
following pages must be performed
to assure maximum system efficiency
and reliability. Failure to service and
maintain the solar system could result in
equipment failure.
WARNING
Turn off power to electrical components
before any service operation on the solar
system except as noted otherwise in this
instruction manual. Failure to turn off
electrical power could result in electrical
shock, causing severe personal injury or
death.
These maintenance items must be performed annually to
ensure proper operation of the solar collection system.
Address reported problems
1. Inspect any problems reported by the owner and correct
before
proceeding.
Fluid installation
Follow these installation procedures:
1. Clean new or lightly corroded existing systems with a 1% or
2% solution of trisodium phosphate in water prior to the
installation of industrially inhibited propylene glycol fluid.
2. Extensively corroded existing systems should be cleaned by
an industrial cleaning company and all corroded
components should be replace.
3. Use only quality water in solution with the propylene
glycol fluid. Use water with low levels (less than 25 ppm) of
chloride and sulfate, and less than 50 ppm of hard water
ions (Ca++, Mg++). Distilled or deionized water is
recommended.
System design considerations
Avoid use of automatic water make-up systems to prevent
undetected dilution of the propylene glycol and possible
contamination of the water system.
Technical data
Typical Properties of Dowfrost HD Fluid*
Composition (% by weight)
Propylene
Glycol
94
Performance Additives
6
Color
Fluorescent
Yellow
Specific Gravity
15/15°C (60/60°F)
1.053 - 1.063
pH of Solution
(50%
glycol)
9.5
-
10.5
Reserve Alkalinity (min.)
15.0 ml
*Typical properties, not to be construed as specifications.
Complete sales specifications are available on request.
SCH Collectors Installation & Operation Manual
Freezing and boiling points of Aqueous Solutions
Freezing
Temperature, °F
% Glycol
by Volume
Boiling
Temperature, °F
26
10
212
19
20
213
8
30
216
-7
40
219
-28
50
222
