Enertech CT024 Instruction manual

Engineering Data and
Installation Manual
CT MODELS COMBINATION WATER-TO-AIR MULTI-POSITIONAL HEAT PUMPS
REVISION: A
*20D082-04NN*
20D082-04NN

Table of Contents:
Section 1: Model Nomenclature
Model Nomenclature,...............................................................................................................4 - 5
Section 2: Installation Introduction
Introduction, Pre-Installation, Components............................................................................6 - 7
Section 3: Installation Considerations
Installation Considerations.............................................................................................................8
Section 4: Installation
Unit Placement................................................................................................................................9
Unit Dimensional and Physical Data....................................................................................10 - 11
Unit Conversion.............................................................................................................................12
Ductwork Installation.............................................................................................................13 - 14
Section 5: Unit Piping Installation
Interior Piping, Water Quality, Buffer Tanks..........................................................................15 - 19
Section 6: Antifreeze
Overview........................................................................................................................................20
Antifreeze Charging............................................................................................................. 21 - 22
Section 7: Desuperheater Installation
Installation...............................................................................................................................23 - 25
Section 8: Unit Controls, Operating Modes and Wiring Diagrams
Controls ..................................................................................................................................26 - 34
Unit Operation Modes, Forced Air & Hydronic Operation................................................35 - 37
Wiring Diagrams.....................................................................................................................38 - 40
Section 9: Accessories
Auxiliary Electric Heat...................................................................................................................41
APSMA Pump Sharing Module....................................................................................................42
Section 10: Equipment Start Up Procedures
Unit Start-Up Checklist and Form.........................................................................................43 - 44
Section 11: Troubleshooting
Troubleshooting, Oil Separator, Superheat/Subcooling Condtions.................................45 - 52
Section 12: Engineering and AHRI Performance Data
Unit Electrical Data................................................................................................................53 - 54
Water Flow and Heating/Cooling Calculations and Correction Factors........................55 - 56
AHRI, Full Load and Hydronic Heat Extended Data Tables..............................................57 - 73
Section 13: Warranty and Revision Table
Warranty Registrationm and Claim Forms..........................................................................74 - 75
Revision Tables...............................................................................................................................76

4
Enertech Global CT Models, Rev.: A
Section 1: GeoComfort®Model Nomenclature
Section 1: Air Handler Model Nomenclature
-

5
CT Models, Rev.: A Enertech Global
Section 1: Uncased “A” Coil Model Nomenclature
H
Section 1: Cased “A” Coil Model Nomenclature
H -
-

6
Enertech Global CT Models, Rev.: A
INTRODUCTION:
This geothermal heat pump provides heating
and cooling as well as optional domestic water
heating capability. Engineering and quality
control is built into every geothermal unit. Good
performance depends on proper application
and correct installation.
Notices, Cautions, Warnings, & Dangers
“NOTICE” Notication of installation, operation
or maintenance information which is important,
but which is NOT hazard-related.
“CAUTION” Indicates a potentially hazardous
situation or an unsafe practice which, if not
avoided, COULD result in minor or moderate
injury or product or property damage.
“WARNING” Indicates potentially hazardous
situation which, if not avoided, COULD result in
death or serious injury.
“DANGER” Indicates an immediate hazardous
situation which, if not avoided, WILL result in
death or serious injury.
Inspection:
Upon receipt of any geothermal equipment,
carefully check the shipment against the
packing slip and the freight company bill of
lading. Verify that all units and packages have
been received. Inspect the packaging of
each package and each unit for damages.
Insure that the carrier makes proper notation
of all damages or shortage on all bill of lading
papers. Concealed damage should be
reported to the freight company within 15 days.
If not led within 15 days the freight company
can deny all claims.
Note: Notify Enertech Global’s shipping
department of all damages within 15 days. It
is the responsibility of the purchaser to le all
necessary claims with the freight company.
Unit Protection:
Protect units from damage and contamination
due to plastering (spraying), painting and
all other foreign materials that may be used
at the job site. Keep all units covered on the
job site with either the original packaging or
equivalent protective covering. Cap or recap
unit connections and all piping until unit is
installed. Precautions must be taken to avoid
physical damage and contamination which
may prevent proper start-up and may result in
costly equipment repair.
⚠ CAUTION ⚠
DO NOT OPERATE THE GEOTHERMAL
HEAT PUMP UNIT DURING BUILDING
CONSTRUCTION PHASE.
Storage:
All geothermal units should be stored inside in
the original packaging in a clean, dry location.
Units should be stored in an upright position
at all times. Units should not be stacked unless
specially noted on the packaging.
Pre-Installation:
Special care should be taken in locating
the geothermal unit. Installation location
chosen should include adequate service
clearance around the unit. All vertical units
should be placed on a formed plastic air
pad, or a high density, closed cell polystyrene
pad slightly larger than the base of the unit.
Flex connectors should also be installed in
between the ductwork and the unit. All units
should be located in an indoor area where
the ambient temperature will remain above
55°F and should be located in a way that
piping and ductwork or other permanently
installed xtures do not have to be removed
for servicing and lter replacement.
Pre-Installation Steps:
1. Compare the electrical data on the unit
nameplate with packing slip and ordering
information to verify that the correct unit
has been shipped.
2. Remove any packaging used to support or
hold the blower during shipping. Remove
and discard the blower motor armature
shaft shipping bracket from the rear of the
blower.
3. Inspect all electrical connections
and wires. Connections must be clean and
Section 2: Installation Introduction

7
CT Models, Rev.: A Enertech Global
tight at the terminals, and wires should not
touch any sharp edges or copper pipe.
4. Verify that all refrigerant tubing is free of
dents and kinks. Refrigerant tubing should
not be touching other unit components.
5. Before unit start-up, read all manuals and
become familiar with unit components
and operation. Thoroughly check the unit
before operating.
⚠ CAUTION ⚠
ALL GEOTHERMAL EQUIPMENT IS
DESIGNED FOR INDOOR INSTALLATION
ONLY. DO NOT INSTALL OR STORE UNIT
IN A CORROSIVE ENVIRONMENT OR IN
A LOCATION WHERE TEMPERATURE AND
HUMIDITY ARE SUBJECT TO EXTREMES.
EQUIPMENT IS NOT CERTIFIED FOR
OUTDOOR APPLICATIONS. SUCH
INSTALLATION WILL VOID
ALL WARRANTIES.
⚠ WARNING ⚠
FAILURE TO FOLLOW THIS CAUTION MAY
RESULT IN PERSONAL INJURY. USE CARE
AND WEAR APPROPRIATE PROTECTIVE
CLOTHING, SAFETY GLASSES AND
PROTECTIVE GLOVES WHEN SERVICING
UNIT AND HANDLING PARTS.
⚠ CAUTION ⚠
BEFORE DRILLING OR DRIVING ANY
SCREWS INTO CABINET, CHECK TO BE
SURE THE SCREW WILL NOT HIT ANY
INTERNAL PARTS OR REFRIGERANT LINES.
Components:
Master Contactor: Energizes Compressor
and optional Hydronic Pump and/or
Desuperheater package.
Logic Board: Logic Board operates the
compressor and protects unit by locking out
when safety switches are engaged. It also
provides fault indicator(s).
Terminal Strip: Provides connection to the
thermostat or other accessories to the low
voltage circuit.
Transformer: Converts incoming (source)
voltage to 24V AC.
Low Voltage Breaker: Attached directly to
transformer, protects the transformer and low
voltage circuit.
Blower Motor Relay: Energizes the blower motor
(PSC motors only).
Reversing Valve: Controls the cycle of the
refrigerant system (heating or cooling).
Energized in cooling mode.
Three Way Valve: Is used with radiant water
heating combination units. Energized in water
heating mode.
High Pressure Switch: Protects the refrigerant
system from high refrigerant pressure, by locking
unit out if pressure exceeds setting.
Low Pressure Switch: Protects the refrigerant
system from low suction pressure, if suction
pressure falls below setting.
Flow Switch (Freeze Protection Device): Protects
the water heat exchanger from freezing,
by shutting down compressor if water ow
decreases.
Electric Heater: Provides auxiliary heat during
cold temperatures and provides electric
backup if unit malfunctions.
Blower Motor (ECM): ECM (Electrically
Communicated Motor) for variable fan speeds.
Compressor (Copeland Scroll): Pumps
refrigerant through the heat exchangers and
pressurizes the refrigerant, which increases the
temperature of the refrigerant.
Oil Separator: Located close to the compressor
to effectively remove oil from the high pressure
gas leaving the compressor increasing unit
efciency and life expectancy. Shown in
refrigerant circuit illustration on page 65.
Section 2: Installation Introduction

8
Enertech Global CT Models, Rev.: A
Consumer Instructions: Dealer should
instruct the consumer in proper operation,
maintenance, lter replacements, thermostat
and indicator lights. Also provide the consumer
with the manufacturer’s Owner's Manual for the
equipment being installed.
Enertech Global D-I-Y Policy: Enertech Global’s
geothermal heat pumps and system installations
may include electrical, refrigerant and/or water
connections. Federal, state and local codes
and regulations apply to various aspects of the
installation. Improperly installed equipment can
lead to equipment failure and health/safety
concerns. For these reasons, only qualied
technicians should install a Enertech Global built
geothermal system.
Because of the importance of proper installation,
Enertech Global does not sell equipment direct
to homeowners. Internet websites and HVAC
outlets may allow for purchases directly by
homeowners and do-it-yourselfers, but Enertech
Global offers no warranty on equipment that is
purchased via the internet or installed by persons
without proper training.
Enertech Global has set forth this policy
to ensure installations of Enertech Global
geothermal systems are done safely and
properly. The use of well-trained, qualied
technicians helps ensure that your system
provides many years of comfort and savings.
Equipment Installation: Special care should
be taken in locating the unit. All vertical units
should be placed on a level surface on a
vibration absorbing pad (air pad) slightly larger
than the base of the unit. Downow units should
be placed on a non-combustible base. Flex
connectors should also be installed in between
the ductwork and the unit. All units should be
located in an indoor area were the ambient
temperature will remain above 55°F and should
be located in a way that piping and ductwork
or other permanently installed xtures do not
have to be removed for servicing and lter
replacement.
Electrical: All wiring, line and low voltage,
should comply with the manufacturer's
recommendations, The National Electrical
Code, and all local codes and ordinances.
Thermostat: Thermostats should be installed
approximately 54 inches off the oor on an
inside wall in the return air pattern and where
they are not in direct sunlight at anytime.
Loop Pumping Modules: Must be wired to the
heat pump’s electric control box. A special
entrance knockout is provided below the
thermostat entrance knockout. A pump
module connection block, connected to
the master contactor, and circuit breaker is
provided to connect the Pump Module wiring.
Desuperheater Package: Water heating is
standard on all residential units (units may be
ordered without). It uses excess heat, during
both heating and cooling cycles, to provide
hot water for domestic needs. A double wall
desuperheater exchanger (coil) located
between the compressor and the reversing
valve, extracts superheated vapor to heat
domestic water; while satisfying its heating and
cooling needs. The water circulation pump
comes pre-mounted in all residential units, but
must be electrically connected to the master
contactor. Leaving it unconnected ensures that
the pump is not run without a water supply.
The Desuperheater package can make up to
60% (depending on heat pump usage) of most
domestic water needs, but a water heater is still
recommended.
Desuperheater Piping: All copper tubes & ttings
should be 5/8” O.D (1/2” nom) minimum with a
maximum of 50ft separation. Piping should be
insulated with 3/8” wall closed cell insulation.
Note: Copper is the only approved material for
desuperheater piping.
UV Light Usage: The use of a UV light in the unit
return air plenum should be such that the light
does not have a direct line of sight to the air
coil of the unit. UV lights could cause internal
wiring, foam insulation, or other components to
deteriorate. It would be better to place the UV
light in the supply air plenum, or ductwork. This
also helps keep the light cleaner. Additionally, if
a humidier is installed and in line of the sight of
the UV light, consult the humidier install manual
for indication of whether the light will deteriorate
any parts of the humidier (like the pad).
Section 3: Installation Considerations

9
CT Models, Rev.: A Enertech Global
Section 4: Installation
UNIT PLACEMENT:
When installing a geothermal heating and
cooling unit, there are several items the installer
should consider before placing
the equipment.
1. Service Access. Is there enough space for
service access? A general rule of thumb is
at least 2 feet in the front and 2 feet on at
least one side.
2. Unit Air Pad. All vertical geothermal
heating and cooling equipment should be
placed on either a formed plastic air pad,
or a high density, closed cell polystyrene
pad. Downow units should be placed
on a non-combustible base. This helps
eliminate vibration noise that could be
transmitted through the oor.
3. Verify that all applicable wiring, ductwork,
piping, and accessories are correct and on
the job site.
PRE-INSTALLATION:
Before you fully install the geothermal
equipment, it is recommended you go
through this quick checklist before placing the
equipment.
⧠Fully inspect the unit after unpacking.
⧠Open both the air handler section and
compressor section and removed any
packaging material or documentation
included in the unit.
⧠Remove and discard the blower motor
armature shaft shipping bracket from the
rear of the blower.
⧠ Locate the Unit Start-Up form from this
manual and have it available as the unit
installation proceeds.
⧠ Clean the air coil with soap and water
solution to remove any oil or dirt.
⚠ WARNING ⚠
DOWNFLOW UNITS REQUIRE THAT THE
FLOOR OPENING (BETWEEN THE UNIT AND
THE SUPPLY DUCT PLENUM) BE SLEEVED
THROUGH THE FLOOR WITH METAL DUCT.
THIS IS ESPECIALLY IMPORTANT IF THE UNIT
IS SITTING ON A PAD.
⚠ NOTICE ⚠
THE BLOWER SUPPORT BRACKET,
LOCATED ON THE BACK OF THE BLOWER
FOR SHIPPING PURPOSES, MUST BE
REMOVED BEFORE OPERATION. FAILURE
TO REMOVE THE BRACKET COULD RESULT
IN POTENTIALLY NOISY OPERATION AND
EQUIPMENT DAMAGE.
⚠ NOTICE ⚠
THIS UNIT FEATURES A BRAZED-PLATE
HEAT EXCHANGER FOR HYDRONIC
HEATING. TO PREVENT POTENTIAL
EQUIPMENT DAMAGE, A WATER STRAINER
IS PROVIDED AND MUST BE INSTALLED IN
THE WATER INLET CIRCUIT TO PROTECT
THE HEAT EXCHANGER FROM PARTIAL
OR COMPLETE BLOCKAGE. IF ANOTHER
STRAINER IS USED, IT SHOULD FEATURE A
16-20 MESH MINIMUM, 20-40 MESH IS A
BETTER CHOICE.

10
Enertech Global CT Models, Rev.: A
Model
Dimensional Data
without Control Box
Dimensional Data
with Control Box
Supply Air
(Top Discharge)
Supply Air
(Bottom Discharge) Return Air
Height
(A1)
Width
(B)
Depth
(C)
Height
(A2) Width Depth Width Depth Width (E)
Height
(D)
024 -
048 56.1 30.3 32.2 62.5 16.0 16.0 13.0 14.0 26.0 28.0
060 -
072 60.1 30.3 32.2 66.5 16.0 16.0 13.0 14.0 26.0 32.0
Notes:
For the source water loop, GeoComfort residential models use 1” double o-ring ttings.
GeoComfort commercial, Hydron Module & TETCO models use 1” FPT ttings
All models use 1” FPT ttings for load water loop connection.
All Desuperheater connections are 3/4” FPT.
All measurements are in inches.
Left View
E
C
.97
5.50
DD
Power Supply 1/2”
High Voltage Supply 1”
Condensate
3/4” FPT
Condensate
3/4” FPT
ASP
ASP
Air Coil
1.13
CAP
BSP
CSP
SAP
SAP
Access
Panels
Low Votage 1/2”
Control Panel
Plug Plate
Filter
Rack Plenum
Flanges
LEGEND:
SAP= Service Access Panel
BSP= Blower Service Panel
CSP= Compressor Service Panel
CAP= Control Access Panel
ASP = Access Service Panel
FPT = Female Pipe Thread
Top View
Top Discharge
8.12
16.00
32.20
16.00
28.01
30.33
Control Box
AIR COIL
SIDE
Front & Back View
B
27.63
A2
A1
.89
CAP
BSP
CSP
D
Bottom Discharge
Bottom View
28.01
30.33
32.20
10.73
14.00
13.005.31
AIR COIL
SIDE
Desuperheater Out
Desuperheater In
Source In
Source Out
Load In
Load Out
Section 4: Unit Dimensional Data

11
CT Models, Rev.: A Enertech Global
Dual Capacity Vertical
Model Number 024 036 048 060 072
Fan Wheel (in.) 10 x 11 10 x 11 10 x 11 10 x 11 10 x 11
Fan Motor ECM
(HP) .5 .5 .75 1 1
Refrigerant Charge (oz.) 62 59 74 84 92
Air Coil
Face Area (Sq.Ft.) 5.55 5.55 5.55 6.17 6.17
Dimensions (in.) 31.8 x 25.1 x 1.0 35.9 x 24.7 x 1.26
Number Of Rows N/A - Micro-Channel
Filter 1” Thick 28 x 30
x 1
28 x 30
x 1
28 x 30
x 1
28 x 34
x 1
28 x 34
x 1
Unit Weight (nominal) - lbs 415 420 435 535 550
Section 4: Unit Physical Data

12
Enertech Global CT Models, Rev.: A
Section 4: Unit Conversion
UNIT CONVERSION:
Units are shipped in the left hand
return air, upow conguration. The
control box is shipped inside the
unit. The control box plugs into the
electrical connection plate on the
top of the unit and mounts with two
screws to the top of the unit.
To convert the unit to right hand return air:
1. Remove the front panels and rear panels.
The panel screws are located under the
band that runs across the middle of the unit.
(GeoComfort & Hydron Module units only)
2. Rotate the unit to the correct position.
3. Move the unit controls connection plate
from its current position (on the top of the
unit) to the opposite side of the top of the
unit. Use the block off plate from that side to
cover the other side.
4. Mount the control box on what is now the
top front of the unit. Plugs are available now
to facilitate this.
5. Replace the front and rear panels onto
the unit.
To convert the unit to downow supply air:
1. Remove the screws holding the blower and
heater housing and drop the
assembly down.
2. Remove the block off plate from the area
under the blower housing on the bottom
blower section panel.
3. Place the block off plate over the opening
where the blower housing was.
4. Install the downow duct kit (instruction
included with kit, which is ordered and
shipped separately) in the compressor
section of the unit.
5. Install the heater and blower housing
assembly onto the downow opening in the
blower section securing it with the screws
removed in step 1.
The source, hot water generator, and
condensate ttings are on the air coil side
of the unit, under the air coil itself. These
connections are easier to facilitate if done prior
to the tting of the return air drop.
Figure 2: Blower Housing Connections
Figure 1: Unit Conversion
NOTE: Do not pry on the "belly band" that runs
across the front of the unit to hide the access
panel screws. Slight pressure on the rounded
portion of the "belly band" will release the catch.
(GeoComfort & Hydron Module units only)

13
CT Models, Rev.: A Enertech Global
DUCT WORK:
All new ductwork shall be designed as
outlined in Sheet Metal and Air Conditioning
Contractors National Association (SMACNA)
or Air Conditioning Contractors of America
(ACCA) or American Society of Heating,
Refrigerating and Air Conditioning Engineers
(ASHRAE) handbooks.
All supply/return plenums should be isolated
from the unit by a exible connector (canvas)
or equivalent to prevent transfer of vibration
noise to the ductwork. The ex connector
should be designed so as not to restrict
airow. Turning vanes should be used on any
run over 500 CFM. If the unit is installed in a
unconditioned space the metal ductwork
should be insulated on the inside with berglass
insulation or similar insulation to prevent heat
loss/gain and to absorb air noise. If the unit
is being installed with existing ductwork, the
ductwork must be designed to handle the air
volume required by the unit being installed.
When running a cooling or heating load on
a building, size ductwork accordingly to the
building design load and heat pump CFM.
Industry Standard: When sizing ductwork use
400 CFM per Ton.
As a general rule, maximum recommended
face velocity for a supply outlet used in a
residential application is 750 FPM. Maximum
recommended return grille velocity is 600 FPM.
Systems with higher velocity, are likely to have
noise problems.
In buildings where ceilings are 8 feet or more,
at least 50 percent of the return air should be
taken back to the heat pump from the ceiling
or high sidewall location and not more than 50
percent from the oor or low sidewall location.
Section 4: Ductwork Installation
Location Supply Return
Main Ducts 900 FPM 600 FPM
Branch Ducts 700 FPM 600 FPM
Grills, Registers, Diffusers 750 FPM 600 FPM
Table 1: Maximum Air Velocities

14
Enertech Global CT Models, Rev.: A
Section 4: Ductwork Installation
Accessible
Filter/Rack
Heat Pump
Flex Connector
Return Air
Flex Connector
Supply Air
Reducer
Never install a takeoff on or near
a reducer or on an end cap, or near
an end cap. Exceptions may apply
Takeoff runs should
never be installed on a
reducer. Takeoffs
should be installed 6"
before a reducer and
at least 24" to 36"
past any reducer.
Return Air Grille
Supply Air Grille
Figure 3: Standard Ductwork Connection Setup
The geothermal unit comes with
an ECM Motor. For maximum
performance, the blower speed
should be set to maintain between
350 and 450 CFM/ton. Use DIP
switch for ECM motor adjustments.
Flex Connector
Accessible
Filter/Rack
Return Air
Supply Air
Flex Connector
Split
Damper
Damper
Motor
Thermostat
No. 1
Thermostat
No. 2
Reducer
Never install a takeoff on or near a reducer or
on an end cap, or near a end cap.
Exceptions may apply.
Takeoff runs should
never be installed on a
reducer. Takeoffs
should be installed 6"
before a reducer and
at least 24" to 36"
past any reducer.
Shift Damper
Supply Air Grille
Note: A bypass damper
is almost always required
for zoning systems.
Bypass
damper
not
shown
Figure 4: Ductwork with Split Damper Connection Setup
NOTE: Maintain duct
size of supply ange
for at least 12”
before transitioning
to size of supply
plenum designed
for duct system.

15
CT Models, Rev.: A Enertech Global
Open Loop Piping
Placement of the components for an open
loop system are important when considering
water quality and long term maintenance. The
water solenoid valve should always be placed
on the outlet of the heat pump, which will keep
the heat exchanger under pressure when the
unit is not operating. If the heat exchanger is
under pressure, minerals will stay in suspension.
Water solenoid valves are also designed to
close against the pressure, not with the pressure.
Otherwise, they tend to be noisy when closing.
A ow regulator should be placed after the
water solenoid valve. Always check the product
specication catalog for proper ow rate. A
calculation must be made to determine the
ow rate, so that the leaving water temperature
does not have the possibility of freezing.
Other necessary components include a strainer,
boiler drains for heat exchanger ushing, P/T
ports and ball valves. Ball valves allow the
water to be shut off for service, and also help
when velocity noise is noticeable through the
ow regulator. Spreading some of the pressure
drop across the ball valves will lessen the
velocity noise. Always double check ow rate
at the P/T ports to make sure the ball valve
adjustments have not lowered water ow too
much, and essentially taken the ow regulator
out of the equation. It’s a good idea to remove
the ball valve handles once the system is
completed to avoid nuisance service calls.
Hose kits are optional, but make for an easier
installation, since the P/T ports and connections
are included. The hose also helps to isolate the
heat pump from the piping system.
Since the heat pump can operate at lower
waterow on rst stage, two stage units
typically include two water solenoid valves
to save water. The ow regulators should be
sized so that when one valve is open the unit
operates at rst stage ow rate, and when
both valves are open, the unit operates at
full load ow rate. For example, a 4 ton unit
needs approximately 4 GPM on rst stage, and
approximately 7 GPM at full load. The ow
regulator after the rst valve should be 4 GPM,
and the ow regulator after the second valve
should be 3 GPM. When both valves are open,
the unit will operate at 7 GPM.
Section 5: Unit Piping Installation
Figure 5: Open Loop Piping Example
IN
OUT
S
HEAT PUMP
Single
Speed
Units
S
S
Two-
Stage
Units
Boiler Drain
for Heat
Exchanger
Maintenance
(2 required)
P/T Port
(2 required) Strainer
Ball Valve
(2 required)
Flow Regulator**
Water
Solenoid
Valve
**See product specification
catalog for flow rates.
Optional
Hose Kit*
*Hose kit is used for piping
isolation, and includes
fittings for P/T ports.
From Well
Discharge Line
Note: All GCT/HCT/TCT units
are two-stage units.
Not recommended for
3 ton and smaller. Use
single solenoid and
ow regulator.

16
Enertech Global CT Models, Rev.: A
Water Quality
The quality of the water used in geothermal
systems is very important. In closed loop systems
the dilution water (water mixed with antifreeze)
must be of high quality to ensure adequate
corrosion protection. Water of poor quality
contains ions that make the uid “hard” and
corrosive. Calcium and magnesium hardness
ions build up as scale on the walls of the system
and reduce heat transfer. These ions may also
react with the corrosion inhibitors in glycol based
heat transfer uids, causing them to precipitate
out of solution and rendering the inhibitors
ineffective in protecting against corrosion. In
addition, high concentrations of corrosive ions,
such as chloride and sulfate, will eat through any
protective layer that the corrosion inhibitors form
on the walls of the system.
Ideally, de-ionized water should be used for
dilution with antifreeze solutions since de-
ionizing removes both corrosive and hardness
ions. Distilled water and zeolite softened water
are also acceptable. Softened water, although
free of hardness ions, may actually have
increased concentrations of corrosive ions and,
therefore, its quality must be monitored. It is
recommended that dilution water contain less
than 100 PPM calcium carbonate or less than
25 PPM calcium plus magnesium ions; and less
than 25 PPM chloride or sulfate ions.
In an open loop system the water quality is
of no less importance. Due to the inherent
variation of the supply water, it should be tested
prior to making the decision to use an open
loop system. Scaling of the heat exchanger
and corrosion of the internal parts are two of
the potential problems. The Department of
Natural Resources or your local municipality
can direct you to the proper testing agency.
Please see Table 2 for guidelines.
Potential
Problem Chemical(s) or Condition Range for Copper Heat Exchangers
Range for Cupro-Nickel Heat
Exchangers
Scaling Calcium & Magnesium Cabonate Less than 350 ppm Less than 350 ppm
Corrosion
pH Range 7 - 9 5 - 9
Total Disolved Solids Less than 1000 ppm Less than 1500 ppm
Ammonia, Ammonium Hydroxide Less than 0.5 ppm Less than 0.5 ppm
Ammonium Chloride, Ammonium Nitrate Less than 0.5 ppm Less than 0.5 ppm
Calcium Chloride / Sodium Chloride Less than 125 ppm Less than 125 ppm - Note 4
Chlorine Less than 0.5 ppm Less than 0.5 ppm
Hydrogen Sulde None Allowed None Allowed
Biological
Growth
Iron Bacteria None Allowed None Allowed
Iron Oxide Less than 1 ppm Less than 1 ppm
Erosion Suspended Solids Less than 10 ppm Less than 10 ppm
Water Velocity Less than 8 ft/s Less than 12 ft/s
Notes:
1. Harness in ppm is equivalent to hardness in mg/l.
2. Grains/gallon = ppm divided by 17.1.
3. Copper and cupro-nickel heat exchangers are not recommended for pool applications for water outside the range of the table.
Secondary heat exchangers are required for applications not meeting the requirements shown above.
4. Saltwater applications (approx. 25,000 ppm) require secondary heat exchangers due to copper piping between the heat exchanger
and the unit ttings.
Table 2: Water Quality
Section 5: Unit Piping Installation

17
CT Models, Rev.: A Enertech Global
Section 5: Unit Piping Installation
Interior Piping
All interior piping must be sized for proper ow
rates and pressure loss. Insulation should be
used on all inside piping when minimum loop
temperatures are expected to be less than
50°F. Use the table below for insulation sizes with
different pipe sizes. All pipe insulation should
be a closed cell and have a minimum wall
thickness of 3/8”. All piping insulation should
be glued and sealed to prevent condensation
and dripping. Interior piping may consist of the
following materials: HDPE, copper, brass, or
rubber hose (hose kit only). PVC is not allowed
on pressurized systems.
Table 3: Pipe Insulation
Typical Pressurized Flow Center Installation
The ow centers are insulated and contain
all ushing and circulation connections for
residential and light commercial earth loops
that require a ow rate of no more than 20
gpm. 1-1/4” fusion x 1” double o-ring ttings
(AGA6PES) are furnished with the double
o-ring ow centers for HDPE loop constructions.
Various ttings are available for the double
o-ring ow centers for different connections.
See gure 6 for connection options. A typical
installation will require the use of a hose kit.
Matching hose kits come with double o-ring
adapters to transition to 1” hose connection.
Note: Threaded ow centers all have 1” FPT
connections. Matching hose kits come with the
AGBA55 adapter needed to transition from 1”
FPT to 1” hose.
Piping Material Insulation Description
1” IPS Hose 1-3/8” ID - 3/8” Wall
1” IPS PE 1-1/4” ID - 3/8” Wall
1-1/4” IPS PE 1-5/8” ID - 3/8” Wall
2” IPS PD 2-1/8” ID - 3/8” Wall
Figure 6: Typical Single Unit Piping
Connection (Pressurized Flow Center)
Air Coil
Source Water In
Source Water Out
~
~
Flow
Center
Hose
Kit
To/From
Loop Field
P/T Ports
Equipment Pad
2” Polyethylene Foam
Note: P/T ports should be angled
away from the unit for ease of
gauge reading.
Load Side Hydronic Buffer or Storage Tanks
Virtually all water-to-water heat pumps used
for hydronic applications require a buffer tank
to prevent equipment short cycling, and to
allow lower ow rates through the water-to-
water unit than through the hydronic delivery
system. The following are considerations for
buffer tank sizing.
• The size of the buffer tank should be deter-
mined based upon the predominant use of
the water-to-water equipment (heating or
cooling).
• The size of the buffer tank is based upon the
lowest operating stage of the equipment.
For example, a water-to-water heat pump
with a two-stage compressor or two com-
pressors may be sized for rst stage capac-
ity, reducing the size of the tank (two-stage
aquastat required).
• Pressurized buffer tanks are sized differently
than non-pressurized tanks (see guidelines
listed below).

18
Enertech Global CT Models, Rev.: A
Typical Non-Pressurized Flow Center Installation
Standing column ow centers are designed to
operate with no static pressure on the earth
loop. The design is such that the column of
water in the ow center is enough pressure to
prime the pumps for proper system operation
and pump reliability. The ow center does have
a cap/seal, so it is still a closed system, where the
uid will not evaporate. If the earth loop header
is external, the loop system will still need to be
ushed with a purge cart. The non-pressurized
ow center needs to be isolated from the ush
cart during ushing because the ow center
is not designed to handle pressure. Since this
is a non-pressurized system, the interior piping
can incorporate all the above-mentioned pipe
material options (see interior piping), including
PVC. The ow center can be mounted to the
wall with the included bracket or mounted on
the oor as long as it is properly supported.
Figure 7: Typical Single Unit Piping Connection (Non-Pressurized Flow Center)
Section 5: Unit Piping Installation
Figure 8: Typical Single Combination Unit Piping Connection













 


 




















19
CT Models, Rev.: A Enertech Global
Condensation Drain Connection
Connect the EZ-Trap to the equipment
condensate drain drain connection as shown
in gures 9a through 9d. The condensate line
must be trapped a minimum of 1.0” as shown
on diagram. The condensate line should be
pitched away from the unit a minimum of
1/4” per foot. The condensate line from the
unit drain connection to the P-trap should be
sloped downward. For moreinformation on
installing EZ-Trap, see installationsheet that
comes with the EZ-Trap Kit. Always install the air
vent after the trap.
Note: Connect the drain through the trap to
the condensation drain system in conformance
to local plumbing codes.
Part Number Description
ACDT1A EZ-Trap ¾” Kit
ACDT2A EZ-Trap 1” Kit
Figure 9a: Condensation Drain Connection
Figure 9d: Right Overow Sensor Connection
Figure 9c: Left Overow Sensor Connection
Note: Make Sure the condensate overow
sensor is mounted to the side closest to the
drain being used as shown in gures 9c and 9d
below.
Section 5: Unit Piping Installation
⚠ NOTICE ⚠
THIS UNIT FEATURES A BRAZED-PLATE
HEAT EXCHANGER FOR HYDRONIC
HEATING. TO PREVENT POTENTIAL
EQUIPMENT DAMAGE, A WATER STRAINER
IS PROVIDED AND MUST BE INSTALLED IN
THE WATER INLET CIRCUIT TO PROTECT
THE HEAT EXCHANGER FROM PARTIAL
OR COMPLETE BLOCKAGE. IF ANOTHER
STRAINER IS USED, IT SHOULD FEATURE A
16-20 MESH MINIMUM, 20-40 MESH IS A
BETTER CHOICE.
Figure 9b: Condensation Drain Drop

20
Enertech Global CT Models, Rev.: A
Antifreeze Overview
In areas where minimum entering loop
temperatures drop below 40°F, or where piping
will be routed through areas subject to freezing,
antifreeze is required. Alcohols and glycols
are commonly used as antifreeze. However,
local and state/provincial codes supersede
any instructions in this document. The system
needs antifreeze to protect the coaxial heat
exchanger from freezing and rupturing. Freeze
protection should be maintained to 15°F
below the lowest expected entering source
loop temperature. For example, if 30°F is the
minimum expected entering source loop
temperature, the leaving loop temperature
could be 22 to 25°F. Freeze protection should
be set at 15°F (30-15 = 15°F). To determine
antifreeze requirements, calculate how much
volume the system holds. Then, calculate
how much antifreeze will be needed by
determining the percentage of antifreeze
required for proper freeze protection. See
Tables 4 and 5 for volumes and percentages.
The freeze protection should be checked
during installation using the proper hydrometer
to measure the specic gravity and freeze
protection level of the solution.
Antifreeze Characteristics
Selection of the antifreeze solution for closed
loop systems require the consideration of
many important factors, which have long-term
implications on the performance and life of
the equipment. Each area of concern leads to
a different “best choice” of antifreeze. There
is no “perfect” antifreeze. Some of the factors
to consider are as follows (Brine = antifreeze
solution including water):
Safety: The toxicity and ammability of the brine
(especially in a pure form).
Cost: Prices vary widely.
Thermal Performance: The heat transfer and
viscosity effect of the brine.
Corrosiveness: The brine must be compatible
with the system materials.
Stability: Will the brine require periodic change
out or maintenance?
Convenience: Is the antifreeze available and
easy to transport and install?
Codes: Will the brine meet local and state/
provincial codes?
The following are some general observations
about the types of brines presently being used:
Methanol: Wood grain alcohol that is
considered toxic in pure form. It has good heat
transfer, low viscosity, is non-corrosive, and is mid
to low price. The biggest down side is that it is
ammable in concentrations greater than 25%.
Ethanol: Grain alcohol, which by the ATF
(Alcohol, Tobacco, Firearms) department
of the U.S. government, is required to be
denatured and rendered unt to drink. It has
good heat transfer, mid to high price, is non-
corrosive, non-toxic even in its pure form, and
has medium viscosity. It also is ammable with
concentrations greater than 25%. Note that
the brand of ethanol is very important. Make
sure it has been formulated for the geothermal
industry. Some of the denaturants are not
compatible with HDPE pipe (for example,
solutions denatured with gasoline).
Propylene Glycol: Non-toxic, non-corrosive,
mid to high price, poor heat transfer, high
viscosity when cold, and can introduce micro
air bubbles when adding to the system. It
has also been known to form a “slime-type”
coating inside the pipe. Food grade glycol is
recommended because some of the other
types have certain inhibitors that react poorly
with geothermal systems. A 25% brine solution is
a minimum required by glycol manufacturers,
so that bacteria does not start to form.
Ethylene Glycol: Considered toxic and is not
recommended for use in earth loop applications.
GS4 (POTASSIUM ACETATE): Considered highly
corrosive (especially if air is present in the
system) and has a very low surface tension,
which causes leaks through most mechanical
ttings. This brine is not recommended for use in
earth loop applications.
Section 6: Antifreeze