10 – Part 3: Solar water heater system installation – VELUX solar system components
VELUX solar system components
Listed below are the components needed for installation of the VELUX water
heating system.
1.
VELUX solar collector: Absorbs the sun’s energy and transfers this energy
into the heat exchanger located on the bottom of the solar storage tank.
2. VELUX collector fl ashings/racking: Integrates the solar collectors into the
roofi ng material for an aesthetic low profi le, water tight installation.
3. Solar storage tank: Transfers sun’s energy to the domestic hot water
through the solar heat exchanger located in the tank. Consists of the
following components:
a. Drain valve (Tank): Used to fl ush sediment which may accumulate on the
bottom of the solar storage tank and also provide a means of draining the
tank.
b. Solar heat exchanger: The solar heat exchanger is designed to transfer
heated energy rapidly from the solar collector into the potable water.
c. Hot water outlet: The solar storage tank has a hot water dip tube outlet
which draws water from the very top of the heater. This helps to keep the
heat trapped inside the highly insulated storage tank.
d. Temperature and pressure relief valve: The relief valve provided complies
with standards for relief valves (ANSI Z21.22). No valve of any type
should be installed between the relief valve and tank. Local codes govern
installation of relief valves. The outlet of the relief valve must be piped
to suitable open drain so that the discharge water cannot contact live
electric parts to eliminate potential damage. Piping used should be
approved for hot water distribution. The valve discharge line must be no
smaller than the outlet of the valve and must be pitched downward from
the valve to allow complete drainage of the relief valve and discharge line.
The end of the discharge piping should be not be threaded or concealed
and should be protected from freezing. No valve of any type, restriction or
reducer coupling should be installed in the discharge line.
e. Back-Up electric element with thermostat (electric back-up systems): The
back electric element will only be activated when the desired minimum
set point temperature set on the back-up thermostat cannot be satisfi ed
by the solar gain achieved from the solar collector.
f. Back-Up burner with thermostat (NG and LP back-up systems): The
back burner will only be activated when the desired minimum set point
temperature set on the back-up thermostat cannot be satisfi ed by the
solar gain achieved from the solar collector.
g. Boiler back-up heat exchanger (boiler back-up systems): The back-
up boiler will only be activated when the desired minimum set point
temperature set on the back-up thermostat can not be satisfi ed by the
solar input from the solar collector.
h. Boiler back-up aquastat (boiler back-up systems): The boiler back-up
aquastat will activate the boiler to circulate the hot water generated
from the boiler into the heat exchanger located on the top section of the
solar storage tank. Once the controller is satisfi ed and has reached its
desired set point, it will shut off the boiler. This back-up portion will only
be activated if the solar gain achieved from the solar collector can not
keep the tank at the minimum desired temperature setting.
VELUX solar collector
VELUX collector fl ashings
Solar storage tank
Solar water heating
