HTP SSU-119SE - Manual (Page 9)

9
LP-199 REV. 4.15.14
Basic components of the solar water heating system include: the solar collector(s), a solar water heater, a circulator pump, a differential
solar control, and an expansion tank. The types of solar systems in which the solar water heater can be installed include:
Pressurized Closed Loop Systems
– These systems use a glycol/water mix as HTF, which protects the system from freezing. These
systems operate at high pressures.
In systems using a glycol/water mix, freeze protection fluid must be non-toxic propylene glycol, FDA rated as GRAS. To protect the heat
exchanger and other system components, regular scheduled maintenance must be established to monitor and maintain proper HTF pH
levels.
Do not introduce HTF into any fittings on the heater except those clearly marked for that purpose.
The system components should carry temperature and pressure ratings equivalent to the design of the solar collector. To ensure
system is appropriate for the installation climate, the solar collector ratings should be verified against the collector manufacturer
specifications. Collector and storage tank temperatures can be read from the system controllers. Typical tank operating temperatures
range from 40-80
o F on the cold supply line to the 175 o F tank high limit. The collector temperature sensor should be 5-20 o F higher than
the tank sensor during normal charging operation. During idle period, when there is no sun, the collector sensor will read the ambient
temperature; in full sun, the sensor will read as high as 250
o
F. Temperatures vary depending on installation climate.
Using proper concentrations of glycol, solar systems can be operated at ambient temperatures as low as -60
o
F. Freeze tolerance limits
are based upon an assumed set of environmental conditions. Refer to the manufacturer’s specification sheet for recommended
concentrations.
Depending on the controller model, the differential controller uses 10k ohm thermistors or 1k ohm RTDs to monitor the temperature
difference between the collector and the solar water heater. The controller turns on when the collector is 12-20
o
F above tank
temperature and turns off when the differential drops to 4
o
F.
B. SOLAR SYSTEM DESIGN
System design should be completed prior to installation. Solar collectors need to be installed correctly to ensure high efficiency and,
most importantly, safe and reliable operation. Please seek professional advice for the design and installation of your solar heating
system.
NOTE: Only authorized licensed contractors are permitted to install the solar collector.
C. SOLAR COLLECTOR INSTALLATION
NOTE: These solar collector instructions are general in nature. Reference the solar collector manufacture r’s instructions for more
specific and detailed installation information.
The solar collector installation contractor shall obtain all required permits and approvals when installing the solar system. The
installation shall conform to all federal, state and local regulations governing solar water heating system installations. The contractor
shall adhere to sound building safety and trade practices. Special consideration must be given to building code requirements for the
penetration of structural members and fire rated assemblies.
All persons working on roofs should have completed a fall safety course and must be properly outfitted with appropriate safety
equipment. Failure to follow this information could result in property damage, severe personal injury, or death.
Before installation, the contractor shall inspect the condition of the roof and notify the homeowner of any existing roof damage or
necessary repairs. The most important structural consideration is to securely anchor the solar collector and solar strut mounting
hardware to the structural members of the roof with stainless steel hanger or lag bolts. Consult with the collector manufacturer
installation manual for proper guidelines in your application.
Solar collectors should be covered at all times until installation is complete. Failure to follow this information could result in severe
personal injury or death.
Preserving the integrity of the roof membrane is the most important roofing consideration. Ensure that all roof penetrations required to
plumb and mount the solar collector are properly flashed and sealed in accordance with standard roofing practices. The recommended
elastomer for sealing roof penetrations is Tremco “POLYroof”.