Comfort-Aire HEH Series 2 to 5 Tons - Manual (Page 16)

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Installation, Operation & Maintenance HEV/H SERIES Heat Controller, LLC.
Unit Power
Disconnect
Flow
Controller
Insulated
Hose Kit
P/T Plugs
Thermostat
Wiring
Air Pad or Extruded
polystyrene insulation
board
Figure 12: Typical Ground-Loop Application
GROUND-LOOP HEAT PUMP APPLICATIONS
GROUND-WATER HEAT PUMP APPLICATIONS
Open Loop - Ground Water Systems
Typical open loop piping is shown in Figure 14. Shut off
valves should be included for ease of servicing. Boiler
drains or other valves should be “tee’d” into the lines to
allow acid flushing of the heat exchanger. Shut off valves
should be positioned to allow flow through the coax via
the boiler drains without allowing flow into the piping
system. P/T plugs should be used so that pressure drop
and temperature can be measured. Piping materials
should be limited to copper or PVC SCH80. Note: Due to
the pressure and temperature extremes, PVC SCH40
is not recommended.
Water quantity should be plentiful and of good quality.
Consult table 3 for water quality guidelines. The unit can
be ordered with either a copper or cupro-nickel water
heat exchanger. Consult Table 3 for recommendations.
Copper is recommended for closed loop systems and
open loop ground water systems that are not high
in mineral content or corrosiveness. In conditions
anticipating heavy scale formation or in brackish water, a
cupro-nickel heat exchanger is recommended. In ground
water situations where scaling could be heavy or where
biological growth such as iron bacteria will be present, an
open loop system is not recommended. Heat exchanger
coils may over time lose heat exchange capabilities due
to build up of mineral deposits. Heat exchangers must
only be serviced by a qualified technician, as acid and
special pumping equipment is required. Desuperheater
coils can likewise become scaled and possibly plugged.
In areas with extremely hard water, the owner should be
informed that the heat exchanger may require occasional
acid flushing. In some cases, the desuperheater option
should not be recommended due to hard water conditions
and additional maintenance required.
Water Quality Standards
Table 3 should be consulted for water quality
requirements. Scaling potential should be assessed using
the pH/Calcium hardness method. If the pH <7.5 and the
calcium hardness is less than 100 ppm, scaling potential
is low. If this method yields numbers out of range of those
listed, the Ryznar Stability and Langelier Saturation
indecies should be calculated. Use the appropriate
scaling surface temperature for the application, 150°F
[66°C] for direct use (well water/open loop) and
desuperheater; 90°F [32°F] for indirect use. A monitoring
plan should be implemented in these probable scaling
situations. Other water quality issues such as iron fouling,
corrosion prevention and erosion and clogging should be
referenced in Table 3.
13.