POWERPAK Owner’s Manual
5
Issue Date October 2005
SYSTEM OVERVIEW
The Solahart POWER
PAK
system is designed to automatically transfer solar thermal energy collected
by highly efficient Solahart collector panels into a separate (remote) potable water storage system using
two independent transfer circuits.
The primary (or collector) circuit will consist of between 4 and 8 roof or frame mounted Solahart collector
panels connected with insulated copper pipes to the ground-mounted POWER
PAK
energy transfer
module. The primary circuit heat transfer fluid, which consists of potable water with a 20% mix of
Hartgard (propylene glycol mix), is pumped from the POWER
PAK
drain back tank through the solar
collectors to gather energy, then back to a heat exchanger where the collected energy is transferred to
the secondary water circuit.
The secondary circuit is directly connected to a separate hot water storage system using insulated
copper pipes. With the aid of a circulating pump within the POWER
PAK
, potable water is pumped from
the storage system through the POWER
PAK
heat exchanger, where it gathers energy from the primary
circuit, before returning the heated water to the storage system.
The circulation pumps are controlled using a combination of operator-selectable functions and an
overriding temperature comparator system. The temperature comparator system monitors the
temperature at the solar collectors and of the potable water storage system, to determine when useful
energy can be collected for transfer to
the potable water system. When useful
energy is available and required, the
circulator pumps commence circulation
in both circuits. This continues until the
comparator determines that there in
insufficient energy being collected to
justify the systems continued operation.
Using an external switch, the operator
has the option to select one of three
system functions: Off, Manual and
Automatic.
Drain Back Principle:
When the
system is not transferring energy, the
circulation pumps stop. This allows the
fluid within the primary circuit to return
to the drain back tank located within
the POWER
PAK
system. This protects
the fluid from the extremes of
temperature in the collector array when
the system is not operating.
INTERNAL COMPONENT DIAGRAM
System Schematic Diagram
Heat Exchanger
Drain Back Tank
Solar Collectors
Primary Circulation
Pump (Collector)
Primary Circulation
Pump
Secondary
Circulation Pump
Heat Exchanger
Primary and
Secondary Circuit
Connections
Hot Water to
Storage Tank
Cool Water
from Storage
Tank
Drain Back
Tank
POWERPAK
Module
Heat Exchanger
Primary and
Secondary Circuit
Connections
Fill and Level Ports
Temperature
Comparator
Secondary
Circulation Pump
(Potable Water)
