7
MATCHED SYSTEM
The GZ geothermal splits have been tested and rated with Carrier
& Bryant air handlers (fan coils) and evaporator coils (for use with
furnaces).
Use air handler or cased coil from the list below and follow the
Installation Instructions for those components.
Geothermal and Air Handler or Cased Coil Match---Up
Geothermal Split
Air Handler
Cased Coil
GZ024
F(E/V)4***003,
FB*024
C(A/N)P(V/M)P2417
GZ036
F(E/V)4***003,
F(E/V)4***005
C(A/N)P(V/M)P3617
GZ048
F(E/V)4***005
C(A/N)P(V/M)P4821
GZ060
F(E/V)4***006
C(A/N)P(V/M)P6024
GZ072
F(E/V)4***006
C(A/N)P(V/M)P6024
When using the GZ unit with a furnace, it is important to match the
CFM output of the furnace to the requirements of the GHP. For the
GZ072, the selected furnace must achieve at least 2200 CFM.
NOTE
:
The Infinity/Evolution Control may not prevent the
system from accepting a furnace with less airflow than required for
the GZ072. This is the responsibility of the installer.
REFRIGERANT LINES
!
WARNING
PERSONAL INJURY / ENVIRONMENTAL HAZARD
Failure to follow this warning could result in personal injury
or death.
Relieve pressure and recover all refrigerant before system
repair or final unit disposal.
Use all service ports and open all flow–control devices,
including solenoid valves.
CAUTION
!
ENVIRONMENTAL HAZARD
Failure to follow this caution may result in environmental
damage.
Federal regulations require that you do not vent refrigerant to
the atmosphere. Recover during system repair or final unit
disposal.
The installation of the copper refrigerant tubing must be done with
care to obtain reliable, trouble free operation. This installation
should only be performed by qualified refrigeration service and
installation personnel.
Refrigerant lines should be routed and supported so as to prevent
the transmission of vibrations into the building structure. 75 feet as
the maximum length of interconnecting refrigerant lines in split
system heat pumps.
Beyond 75 feet, system losses become
substantial and the total refrigerant charge required can
compromise the reliability and design life of the equipment.
Refrigerant lines should be sized in accordance with those listed in
Table 3. Copper tubing must be clean and free of moisture and dirt
or debris. The suction and liquid lines should be insulated with at
least 3/8” wall, closed--cell foam rubber insulation or equivalent.
Table 3 – Valve Sizing Chart
Valve Sizing Chart
Unit Size
Line Type
Valve Conn.
Size
Allen Wrench
Size
GZ024, 036
Suction
3/4
5/16
GZ048, 060, 072
Suction
7/8
5/16
All Valves
Liquid
3/8
5/16
Some points to consider are:
S
Pressure drop (friction losses) in refrigerant suction lines reduces
system capacity and increases power consumption by as much as
2% or more, depending on the line length, number of bends, etc.
Pressure drop in liquid lines affects system performance to a lesser
degree, provided that a solid column of liquid (no flash gas) is
being delivered to the refrigerant metering device, and that the
liquid pressure at the refrigerant metering device is sufficient to
produce the required refrigerant flow.
S
Oil is continually being circulated with the refrigerant so, oil
return to the compressor is always a consideration in line sizing.
Suction lines on split system heat pumps are also hot gas lines in
the heating mode, but are treated as suction lines for sizing
purposes. If the recommended suction lines sizes are used, there
should be no problem with oil return.
S
Vertical lines should be kept to a minimum. Vertical liquid lines
will have a vertical liquid lift in either heating or cooling, and the
weight of the liquid head is added to the friction loss to arrive at
the total line pressure drop.
S
Wherever possible, the air handler should be installed at a higher
elevation than the condensing section to aid with oil return to the
compressor.
Linear vs Equivalent Line Length
Linear Line Length
-- is the actual measured length of the line
including bends. This is used to calculate the additional refrigerant
charge that must be added to the system.
Equivalent Line Length
-- is the combination of the actual length
of all the straight runs and the equivalent length of all bends valves
and fittings in a particular line. The equivalent length of a bend,
valve or fitting is equal to the length of a straight tube of the same
diameter having the same pressure drop as the particular valve or
fitting. The ASHRAE Fundamentals Handbook provides tables for
determining the equivalent length of various bends, valves and
fittings.
Connecting Refrigerant Lines
S
Use only ACR grade copper tubing and keep ends sealed until
joints are made.
S
For best performance, select routing of refrigerant lines for
minimum distance and least number of bends.
S
Size lines in accordance with Table 5.
S
Cut crimped ends off the air handler suction and liquid lines.
Connect and braze lines to the air handler.
NOTE
: The air handler is factory supplied with a holding charge
of dry nitrogen.
S
Connect and braze lines to service valves on the condensing
section.
CAUTION
!
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
S
Use a brazing shield
S
Wrap service valves with wet cloth or heat sink material.
S
Direct flame away from the valve body.
S
Valve body temperature must remain below 250
_
F to
protect the internal rubber “O” rings and seals.
S
Use nitrogen purge while brazing.
Pressurize the refrigerant lineset and air handler to 150 lbs with dry
nitrogen through the ports provided on the self service valves.
Check lineset and unit connections for leaks. Once system integrity
is verified, evacuate lineset and air handler with a good vacuum
pump to 500 microns and hold for half hour.
IMPORTANT
:
Pumpdown must never be used with heat
pumps.
