Suntherm MSVT Series User manual

MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 1
Multi-Position DX and Chilled Water Cooling With Hot Water Heating
Models: MSVT Series With Single-Stage Cooling/Heat Pump Airow
MSVE Series with Single and 2-Stage Cooling/Heat Pump Air-Flow
INSTALLATION MANUAL
7 – Line Voltage Wiring............................................................................................16
8 – Thermostat Wiring and Connections ..........................................................18
9 – Blower Performance..........................................................................................21
10 – Blower Motor Speed Selection .....................................................................23
11 – Filling Heating System With Water and System Startup ......................24
12 – Wiring Diagrams................................................................................................ 25
1 – General...........................................................................................................1
2 – Safety..............................................................................................................2
3 – Location, Clearances and Return Air Requirements......................6
4 – Air Handler Orientation and Supply Air Duct Installation ...........7
5 – Air Handler Installation ............................................................................8
6 – Refrigerant/Condensate Piping, TXV, Hot/Chilled Water Piping.....8
LIST OF SECTIONS
LIST OF FIGURES
LIST OF TABLES
SECTION 1: GENERAL
1 – Air Handler Dimensions...........................................................................5
2 – Clearance – Access for Service...............................................................6
3 – Closet Clearances .......................................................................................6
4 – Air Filter Base Accessory for 1”or 2” Air Filters .................................7
5 – Indoor Coil Below Outdoor Unit Piping.............................................8
6 – Typical TXV Connections..........................................................................9
7 – TXV Sensing Bulb Placement ............................................................... 9
8 – Typical Condensate Trap....................................................................... 10
9 – Hydronic Control Box Power Connection Locations .................. 16
10 – Component Locations – Hydronic Heat - No Pump................... 17
11 – Component Locations – Hydronic Heat With Pump.................. 17
12 – Hydronic Heat w/1-Stage Cooling Low Voltage Wiring ............ 19
13 – Hydronic Heat w/1-Stage Heat Pump Low Voltage Wiring.........19
14 – ECM Motor Control Plug Pin Positions.................................................23
15 – ECM Control Board Layout........................................................................23
16 – Constant Torque Motor Terminals..........................................................24
17 – Wiring Diagram: MSVE 18 - 36; ECM Mtr; No Choke; No Pump..25
18 – Wiring Diagram: MSVE 18 - 36; ECM Mtr; w/Pump; No Choke ...25
19 – Wiring Diagram: MSVE 37 - 72; ECM Mtr; w/Choke & Pump .......26
20 – Wiring Diagram: MSVE 37 - 72; ECM Mtr; w/Choke; No Pump ...26
21 – Wiring Diagram: MSVT 18 - 36 / C.T. Mtr; w/Pump; No Choke....27
22 – Wiring Diagram: MSVT 18 - 36 / C.T. Mtr; No Pump; No Choke..27
23 – Wiring Diagram: MSVT 37 - 60; C.T. Motor; w/Choke & Pump....28
24 – Wiring Diagram: MSVT 37 - 60; C.T. Motor; w/Choke/No Pump 28
1 – Hydronic Air Handler Model Specications......................................3
2 – Air Handler Model Number Nomenclature.......................................4
3 – Air Handler Dimensional Data...............................................................5
4 – Clearance to Combustibles and For Service Access.......................6
5 – Chilled Water“A” Coil Cooling Cap. 80/67°F EAT 45°F EWT....... 11
6 – Heating Capacity For Water“A” Coil @ 120°F and 140°F ............ 11
7 – Heating Capacity For Water“A” Coil @ 160°F and 180°F ............ 11
8 – Htg Cap Boiler Loop No Pump 65°F EAT 180 °F EAT 20°F t.... 12
9 – Htg Cap Boiler Loop No Pump 65°F EAT 180 °F EAT 20°F t.... 12
10 – Htg Cap Boiler Loop No Pump 65°F EAT 180 °F EAT 20°F t.... 13
11 – Htg Cap Factory Pump 65°F EAT @ Stated EWT 1.5, 2 Ton ....... 14
12 – Htg Cap Factory Pump 65°F EAT @ Stated EWT 2, 2.5, 3 Ton... 14
13 – Htg Cap Factory Pump 65°F EAT @ Stated EWT 3.0 – 6.0 Ton . 15
14 – Wiring Requirements–115V Hydronic 18-36 KBTU Models..... 16
15 – Wiring Requirements–115V Hydronic 37-72 KBTU Models..... 17
16 – Low Voltage Wire Gauge and Maximum Lengths....................... 18
17 – Typical Heat/Cool T-stat Wire Colors & LowVoltage Connections . 19
18 – Typical Ht PumpT-stat Wire Colors & Low Voltage Connections. 19
19 – MSVT Blower Performance Chart – Constant Torque Motors. 21
20 – MSVE Blower Performance Chart – ECM Motors......................... 22
21 – ECM Motor Control Connector Terminals ...................................... 23
22 – Constant Torque Motor Terminal Connections............................ 24
SAVE THIS MANUAL FOR FUTURE REFERENCE
1. Air handler is rated for 208/240 VAC at 60 Hertz.
2. Air handler size varies by model.
3. Air handler is designed for A/C or heat pump operation.
4. Air handler is designed for upow, downow and
horizontal applications.
5. Air handler must not be operated with the access
panels removed.
6. Air handler is listed by ETL in the United States and Canada.
7. This air handler is for use at elevations of 10,000 ft (3,048m)
or less.
8. This appliance is not to be used by persons (including children)
with reduced physical, sensory or mental capabilities, or lack
of experience and knowledge, unless they have been given
supervision or instruction concerning use of this appliance by
a person responsible for their safety. Children must not be
allowed to play with this appliance.
The following list includes important facts and information regarding the air handler models covered in this manual.
9700771

MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 2
This is a safety alert symbol. When you see this symbol on
labels or in manuals, be alert to the potential for personal injury.
Understand and pay particular attention to the signal words
DANGER, WARNING, or CAUTION.
DANGER: Indicates an imminently hazardous situation, which
if not avoided, will result in death or serious injury.
WARNING:Indicates a potentially hazardous situation, which
if not avoided, could result in death or serious injury.
CAUTION: Indicates a potentially hazardous situation, which
if not avoided, may result in minor or moderate injury. It is
also used to alert against unsafe practices and hazards involving
property damage.
Improper installation may create a condition where the
operation of the product could cause personal injury or
property damage.
Improper installation, adjustment, alteration, service or
maintenance can cause injury or property damage. Refer
to this manual for assistance; or for additional information
consult a qualied contractor, installer, or service agency.
FIRE OR ELECTRICAL HAZARD
Failure to follow the safety warnings exactly could result
in serious injury, death, or property damage. A re or
electrical hazard may result causing property damage,
personal injury or loss of life.
This air handler must be installed in strict compliance with
the installation instructions and any applicable local, state,
and national codes including, but not limited to, building,
electrical, and mechanical codes.
MS Series Multi-Position Air Handler
Safety Requirements
This air handler should be installed in accordance with all national
and local building/safety codes and requirements, local plumbing
or waste water codes, and other applicable codes. In the absence
of local codes, install in accordance with the following codes.
• Standard for the Installation of Air Conditioning and
Ventilating Systems (NFPA 90A)
• Standard for the Installation of Warm Air heating and Air
Conditioning Systems (NFPA 90B)
• National Electrical Code (NFPA 70)
• Canadian Electrical Code, Part I (CSA C22.2) or ANSI/NFPA
No. 70
• All local codes (State, City, and Township)
NOTE: All applicable codes take precedence over any
recommendation made in these instructions.
SunTherm assumes no responsibility for air handlers installed in
violation of any code or regulation.
1. Refer to the air handler rating plate for the air handler model
number and then refer to Figure 1 for return air plenum
dimensions that apply to that model number. The plenum
must be installed according to the above listed codes or the
instructions in this manual.
2. These models are not ETL listed or approved for installation
into a Manufactured (Mobile) Home.
3. Provide clearances from combustible materials as listed under
Clearances to Combustibles.
4. Provide adequate clearances for service access to the control
box, indoor coil, hot water coil and blower.
5. Failure to carefully read and follow all instructions in this
manual can result in malfunction of the air handler, death,
personal injury, and/or property damage.
6. The air handler must be installed so the electrical components
are protected from water.
7. Installing and servicing heating/cooling equipment can be
hazardous due to electrical components.
8. Only trained and qualied personnel should install repair or
service heating/cooling equipment. Untrained service .
Untrained service personnel should only perform
basic maintenance functions such as cleaning of exterior
surfaces and replacing the air lters. Observe all precautions
in the manuals and on the attached labels when servicing this
air handler. These instructions cover minimum requirements
and conform to existing national standards and safety codes.
9. In some cases, these instructions exceed certain local codes
and ordinances, especially those who have not kept up with
changing home and/or HUD construction practices.
10. These instructions are to be followed and are the minimum
requirement for a safe installation.
11. The capacity of the air handler should be based on an
acceptable heat loss calculation for the structure such as ACCA
Manual J or other approved methods.
The Clean Air Act of 1990 bans the intentional
venting of refrigerant (CFC’s and HFC’s) as of July
1, 1992. Approved methods of reclaiming must be
followed. Fines and/or incarceration may be levied for
non-compliance.
SECTION 2: SAFETY

MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 3
GENERAL INFORMATION
This air handler provides the exibility for installation in an
upow or horizontal application and may be used with or
without hot water heat. The direct-drive variable speed ECM
or 5-speed constant torque motors provide a wide selection of
air-ow volume to match any application. The air handler can
be positioned for bottom air return in the upow position or
air return through the end of the air handler in the horizontal
position.
NOTE: Refer to the instructions in this manual for instructions on
the proper conversion from the as shipped right-to-left horizontal
conguration to the left-to-right horizontal conguration.
Available Blower Motors
1. Variable Speed ECM
2. 5-Speed Constant Torque
INSPECTION
As soon as the air handler is received, it should be inspected for
possible damage during transit. If damage is evident, the extent
of the damage should be noted on the carrier’s freight bill. A
separate request for inspection by the carrier’s agent should
be made in writing. Before installing the air handler, check the
cabinet for screws or bolts which may have loosened in transit.
There are no shipping or spacer brackets which need to be
removed before startup.
See local Distributor for more information. Mortex Products, Inc.
assumes no liability for freight damage.
Check to be sure all accessories that are required for the
installation are available. Installation of these accessories should
be completed before the air handler is set in place and connected
to wiring, ductwork, and piping.
Hot water from a boiler used to satisfy heating
requirements can be heated to temperatures of 180°F.
Parts containing hot water can scald very quickly.
Use extreme caution when servicing or performing
maintenance on any parts containing hot water.
ALWAYS SHUT OFF ELECTRICITY AT THE DISCONNECT
SWITCH OR TURN OFF THE CIRCUIT BREAKERS IN THE MAIN
ELECTRICAL ENTRANCE BEFORE PREFORMING ANY SERVICE
ON THE AIR HANDLER.
12. Conrm the power supply meets the electrical characteristics
listed on the air handler rating plate. All models must be
connected to a nominal 115 VAC, 1 Phase, 60-Hertz power
supply. DO NOT CONNECT THIS AIR HANDLER TO A 50 HZ
POWER SUPPLY OR A VOLTAGE ABOVE 140 VOLTS.
13. The eld ground wire MUST BE securely fastened to the
ground lug terminal in the air handler control box.
Cooling Only & Cooling With Hydronic Heat
Models MS**18,24 MS**25,30,36 MSVE**37,42,48,60 MSVT37,42,48,60; MSVE72
Hort Water Coil (Rows) 2,3 2,3,4 2,3,4 2,3,4
Blower Size-Heat (D x W) 10 X 7 (MSVE)
10 X 8 (MSVT)
10 X 7 (MSVE)
10 X 8 (MSVT)
12 X 9 12 X 10
Unit Voltage 115V, 60 HZ, 1 PH
Max. External SP (Duct), In. W.C. 0.60
Thermostat Circuit 24 VAC, 60 Hz, 40VA
Table 1: Hydronic Air Handler Model Specications

MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 4
Table 2: Hydronic Air Handler Model Number Nomenclature
MODEL NUMBER NOMENCLATURE
MS VT 36 15 B 862T AA
I II III IV V VI VII
ISeries
MS = Multi-Position Single-Piece
II
Motor Type
VT = Variable Constant Torque
VE = Variable Speed ECM
III
Unit Size (Capacity in MBTUH)
12 through 24 - Small Cabinet
25 through 36 - Medium Cabinet
37 through 72 - Large Cabinet
OS = No Cooling Small Cabinet
OM = No Cooling Medium Cabinet
OL = No Cooling Large Cabinet
IV
Heating Conguration
00 = Cooling Only
2P = 2 Row Hot Water Coil With Pump
3P = 3 Row Hot Water Coil With Pump
4P = 4 Row Hot Water Coil With Pump
2N = 2 Row Hot Water Coil No Pump
3N = 3 Row Hot Water Coil No Pump
4N = 4 Row Hot Water Coil No Pump
VAir Handler Voltage
A = 115 Volts
VI
SUMMIT Indoor Coil Conguration
862T = DX Coil Geometry And Metering Device
8K2N = CW Coil Geometry, No Metering Device
VII Option Code
AA = Standard Factory Options

DIMENSIONAL DATA MULTI-POSITION AIR HANDLER HYDRONIC HEAT
Model A B C D E F G H J K L M N P R S T
MS**18, 24 17.50 43.00 21.00 15.63 12.50 13.50 11.00 6.75 16.75 14.00 11.00 10.75 2.00 1.50 5.00 16.10 20.20
MS**25, 30, 36 21.00 48.00 21.00 19.00 12.50 14.50 13.00 6.75 20.00 17.00 12.75 10.30 2.30 4.35 5.00 19.90 20.80
MS**37, 42, 48, 60, 72 24.50 58.88 21.75 22.25 14.25 19.75 17.25 6.75 26.00 23.00 16.75 14.35 2.30 4.35 4.50 23.50 20.70
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 5
Figure 1: Air Handler Dimensions
Table 3: Air Handler Dimensional Data

MODEL TOP (in) BACK (in) SIDES (in) FRONT OF FURNACE DUCT (in)
ALCOVE (in) CLOSET (in)
HYDRONIC 0 0 0 30 6 1
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 6
LOCATION
Access for servicing is an important factor in the location of any
appliance. Provide a minimum of 30 inches in front of the air
handler for access to the control box, indoor coil, water pump,
blower, and air lters. This access may be provided by a closet
door or by locating the air handler so that a wall or partition is not
less than 30 inches from the front access panel. The location for
the air handler is usually predetermined. Check with the owner
or user for installation plans. If location has not been decided,
consider the following in choosing a suitable location.
1. Select a location with adequate structural support, space
for service access, clearance for return and supply duct
connections.
2. Normal operating sound levels may be objectionable if the
air handler is placed directly over or under some rooms such as
bedrooms, study, etc.
3. If possible, locate the air handler so ducts are about the same
length to achieve even air distribution of supply and return air
to and from the living spaces.
4. Locate air handler where electrical supply wiring can be easily
routed to main electrical panel and where electrical wiring will
not be damaged.
5. Locate air handler where thermostat wiring can be easily routed
to the thermostat and where the wiring will not be damaged.
6. Locate air handler where refrigerant lines can be easily routed
from the indoor coil to the outdoor unit.
7. Locate the air handler where condensate lines can be easily
routed to the outside or an available drain. Route condensate
drain piping so it does not obstruct access to the air lter or
access panels.
8. When the indoor coil is installed in a draw-through application
such is the case with this air handler, it will create a negative
pressure situation in the condensate drain system. To prevent
condensate from being drawn into the air handlers and blower,
it is recommended to trap the primary (main) and secondary
(overow) drain line. Refer to CONDENSATE DRAIN SYSTEM and
Figure 7 in these instructions. If the secondary drain is not used,
it must be capped.
9. The exterior surface of cabinet will sweat when an air handler
is installed in a non-conditioned space such as an attic or
garage. The installer must provide protection such as full
size auxiliary drain pan for all air handlers installed in a non
conditioned space to prevent damage from condensation
runo. It is recommended that air handlers installed in non
conditioned spaces be insulated on the exterior of the entire
county or local codes for insulation requirement to assure the
installation complies with all codes.
CLEARANCES
This air handler is approved for 0 inches of clearance to
combustible material to any part of the air handler exterior
cabinet. Refer to Figure 2 and 3 and Table 4 for clearance to
combustibles and for service access clearances.
SECTION 3: LOCATION, CLEARANCES AND
RETURN AIR REQUIREMENTS
Figure 2: Clearance – Access for Service Figure 3: Closet Clearances
Table 4: Clearances to Combustibles and Service Access

MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 7
RETURN AIR REQUIREMENTS
For the air handler to work properly, a closet or alcove must have
a certain total free area opening for the return air.
For A/C and HP Air Handlers 1/3 HP Blower Motor On MSVE,
MSVT18 & 24
• Minimum 200 in© free area opening
• Use Return Grille or Coil Cabinet
For A/C and HP Air Handlers 1/2 HP Blower Motors On MSVE,
MSVT25, 30, & 36
• Minimum 250 in free area opening
• Use Return Grille, A/C Coil Cabinet, or any return grille
• with a minimum 250 in² free area opening.
For A/C and HP Air Handlers with Hydronic Heat use 1.0 HP
Blower Motor On MSVE/MSVT 37, 42, 48, & 60
• Minimum 390 in² free area opening
• Use Return Grille, or A/C Coil Cabinet, or any return grille
with a minimum 390 in² free area opening.
For A/C and HP Air Handlers use 1.0 HP Blower Motor On
MSVE72
• Minimum 430 in² free area opening.
• Use return grille, or indoor coil cabinet, or any return
grille with a minimum 430 in² free area opening.
Provisions must be made to permit air in the rooms and living
spaces to return to the air handler. Failure to comply may
cause a reduction in the amount of return air available to the
blower, causing reduced air ow and improper cooling and
heating of the living space.
Return Air Filters
A return air lter is necessary to prevent dust, lint, and other
contaminants from accumulating on the indoor coil and interi-
or surfaces of the air handler. Return air lter options include
a return air lter grille that attaches to a wall, door, or ceiling
or a lter frame that attach directly to the return opening of the
air handler.
Recommended Return Air Filter Grille Size - Bottom Re-
turn Only
800 CFM – 20 X 20 Grille – 324 in²
1000 CFM – 20 X 25 Grille - 414 in²
1200 CFM – 25 X 25 Grille - 414 in²
1400 CFM – 25 X 30 Grille - 644 in²
1600 CFM – 25 X 30 Grille - 644 in²
1800 CFM – 30 X 30 Grille - 784 in²
2000 CFM – 30 X 35 Grille - 924 in²
2400 CFM – 30 X 40 Grille - 1064 in²
Air Filter Base Accessory
The SunTherm Air Filter Base Accessory is available as an
alternative to a return air lter frame. The Air Filter Base
Accessory can be used on the return air end of the air handler
when congured in upow position. The air lter base accessory
is placed over the return plenum in the oor or closet platform
opening and sealed to the plenum or platform using sealant,
caulking material, and/or tape. The air handler is placed on top
of the air lter base and sealed around its perimeter to prevent
air leaks.
NOTE: Filter size adjustment knobs are located on both sides of
the frame. Make sure the ow arrow on the air lter is pointing
towards the air handler.
Figure 4: Air Filter Base Accessory for 1” or 2” Air Filters.
SECTION 4: AIR HANDLER ORIENTATION AND SUPPLY
AIR DUCT INSTALLATION
FILTER BASE ASSEMBLY KIT – FIELD INSTALLED
86ET0002 – 16”X 20” X 2” Small Cabinet
86ET0001 – 20” X 20” X 2” Medium Cabinet
86ET0003 – 20” X 24” X 2” Large Cabinet
Miniumum Air Filter Size
The minimum lter size vs. CFM of airow is shown below
800 CFM = 20 x 20 x 1
1000 CFM = 20 x 25 x 1
1200 CFM = 20 x 30 x 1
1400 CFM = 25 x 30 x 1
1600 CFM = 25 x 30 x 1
1800 CFM = 30 x 30 x 1
2000 CFM = 30 x 40 x 1 or two 30 x 20 x 1
2400 CFM = 30 x 40 x 1 or two 30 x 20 x 1
Pleated Air Filter @ 500 ft/min or Less
800 CFM = 16 x 16 x 1
1000 CFM = 18 x 20 x 1
1200 CFM = 20 x 20 x 1
1400 CFM = 20 x 20 x 1
1600 CFM = 20 x 25 x 1
1800 CFM = 20 x 30 x 1 or two 20 x 15 x 1
2000 CFM = 20 x 30 x 1 or two 20 x 15 x 1
2400 CFM = 25 x 30 x 1 or two 14 x 30 x 1
The air handler is shipped from the factory congured to be
installed in the upow or horizontal right-to-left air-ow position.
Horizontal right-to-left means that when facing the front of the
air handler and the air handler is laid on its side, the supply air
opening is on the left and the return opening is on the right. The
air handler can be eld converted to the horizontal left-to-right
air-ow position using the procedure below.
For eld conversion to left-to-right horizontal applications:
1.Remove the air handler access panels.
2.Remove the indoor coil.
3.Move the condensate drain pan to the right side.
4.Reinstall the indoor coil.
5.Connect the condensate drains and refrigerant lines.
6.Reinstall air handler access panels.
UPFLOW APPLICATIONS
For upow installations, the discharge air outlet is at the top of

CONDENSING UNIT
LIQUID LINE
SUCTION LINE
EVAPORATOR COIL
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 8
SECTION 5: AIR HANDLER INSTALLATION
Prior to installing the air handler, make sure the holes are cut into
the oor for the refrigerant tubing, the drain line, the electrical
wiring, the thermostat wiring and the outdoor unit control wiring.
1. Remove the top shipping cover and corner posts.
2. Remove the bottom shipping cover.
3. Remove the blower and control box access panel.
4. Remove the coil compartment access panel.
5. Place the air handler into position.
6. Connect the electrical supply wires to the line voltage terminal
block and connect the thermostat cable wires to the low
voltage terminal block or low voltage pigtails. Re-install the coil
compartment access panel.
7. Connect the refrigerant lines to the coil.
8. Re-install the blower and control box access panel.
9. Turn the power on to the air handler by following the
the air handler. The air handler must be installed level to permit
proper condensate drainage.
Typical upow installations will be in a closet or basement.
If installed in a closet, the closet should have a platform at least
12 inches in height framed in with an opening centered in the
closet that matches the return air opening on the bottom of
the air handler or an air lter frame if one is installed. The return
air opening can be located in the oor, on a closet door, or in a
side wall next to the air handler cabinet or a return duct can be
attached directly to the platform next to the air handler. If the
return air opening is located in the closet door or side wall above
the platform, the front of the platform must be left open and
a minimum of 6 inches of clearance between the front of the
platform and the closet door must be provided to allow adequate
air-ow from the return air opening into the cavity below the
platform. The 6 inches of clearance is not required if the return
opening is installed completely below the platform allowing the
return air to enter directly into the cavity below the platform or
if the return duct is connected directly to the platform beside the
air handler.
Joints between the air handler, air lter frame, and platform must
be sealed to prevent air leakage. A return air lter grille may be
used instead of a lter frame.
Connect the supply air outlet to a plenum to the top of the air
handler and secure it with screws. If the air handler is installed in
a basement, run supply and return duct work in accordance with
local codes. Use a non-tape sealant such as mastic or an aerosol
sealant to seal between the air handler and ducts to prevent air
leakage.
HORIZONTAL APPLICATIONS
Horizontal applications will normally be used in an attic or crawl
space. This type of installation requires the supply air plenum or
duct to be connected to the supply duct anges and a return air
plenum or duct be attached to the air handler return air inlet.
The supply ducts will be connected to the supply air plenum and
routed through the attic to a register in each room. The opposite
end of the return air duct is attached to a return lter grille
housing. The lter grille is usually located in a wall, just below the
ceiling or the ceiling in a hallway. Use a non-tape sealant such as
mastic or an aerosol sealant to prevent leaks in the ducts and the
plenum.
procedure in the Users Information Manual.
10. Set the thermostat to the desired operating mode and
temperature.
SECTION 6: HYDRONIC HEATING / COOLING
AND REFRIGERANT PIPING
DX Refrigerant Piping:
Air handlers with DX type evaporator coils require liquid
and suction piping sized in accordance with outdoor unit
manufacturer’s instructions. The evaporator coils have sweat
copper connections. Refrigerant lines should be soldered with
silver solder or high temperature brazing alloy. The suction
line must be insulated to avoid condensate from forming and
dropping o. Armaex (or equivalent) with 3/8” (1 cm) minimum
wall thickness is recommended. In severe conditions such as hot
or high humidity areas, 1/2”(1.3 cm) minimum wall thickness
may be required. If the outdoor unit is installed above the indoor
coil, oil traps are required at equal intervals along suction line
as shown in Figure 5. Horizontal suction lines should slope
downward 1 inch for every 20 feet toward outdoor unit. Flow dry
nitrogen through refrigerant lines during soldering operation to
prevent oxidation of the interior of the copper tubes.
• Install 1 oil trap for a height dierence of 15 ft to 25 ft
(4.6 m to 7.6 m) between indoor and outdoor units.
• Install 2 oil traps for a height dierence of 26 ft to 50 ft
(7.9 m to 15.2 m) between indoor and outdoor units.
• Install 3 oil traps for a height dierence of 51 ft to 100 ft
(15.5 m to 30.5 m) between indoor and outdoor units.
• Install 4 oil traps for a height dierence of 101 ft to 150 ft
(30.8 m to 45.7 m) between indoor and outdoor units.
Figure 5: Evaporator Below Outdoor Unit Piping
Thermal Expansion Valves (TXV)
Introduction
SunTherm air handlers can have a factory installed thermal
expansion valve (TXV) or a TXV may be eld installed. The factory
and eld installed TXV’s for this air handler have an internal check
valve making them compatible for both heat pump and cooling
only applications. The TXV has an external pressure equalizer,
non-adjustable superheat, and has a bleed rate of 15%.

HEX NUT
TXV
LIQUID LINE
FEED TUBES
TO COIL
TEFLON SEAL
FOR BODY
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 9
Coil is pressurized with nitrogen from the factory. Relieve
pressure before installing TXV by depressing the Shrader
valve on the coil manifold.
Field Installed TXV Instructions
The TXV assembly is to be installed between the owrator
distributor and the existing liquid line attached to the owrator
distributor as shown in Figure 6.
1. After the coil pressure has been relieved, turn the female swivel
nut counter-clockwise to remove.
2. Remove the piston from the owrator distributor tting using
a small diameter wire or paper clip. (ALWAYS REMOVE PISTON
FROM DISTRIBUTOR BODY WHEN TXV IS INSTALLED).
3. Attach the TXV by connecting the female swivel nut on TXV
outlet to the owrator distributor (aligning Teon seal rst) and
torque swivel nut to 10-30 ft. lbs.
4. Attach liquid line with female swivel nut to male rotolock tting
on TXV inlet (Aligning Teon seal rst) and torque swivel nut to
10-30 ft. lbs.
5. Remove the cap from the male Schrader valve port on the coil
manifold. Attach equalizer tube with 1/4”female are nut
that includes a valve depressor to the male Schrader valve port.
Torque the are nut to 10-30 ft. lb.
Field and Factory Installed TXV Instructions – Sensing Bulb,
Leak Check, Evacuation
1. Install the TXV bulb on the suction line just outside the air
handler cabinet using the two bulb clamps furnished with kit.
2. The bulb should be installed on the upper portion of a
horizontal section of the suction line between 10:00 o’clock and
2:00 o’clock as shown in Figure 7.
3. If the bulb must be installed on a vertical run, the bulb should
be located at least 6 inches from any bend, and on the tubing
side opposite the plane of the bend. On vertical bulb
installations, the bulb should be positioned with the bulb
capillary tube at the top.
4. The bulb must be insulated using thermal insulation to protect
it from the eect of the surrounding ambient temperature.
5. After completing the installation of the TXV (including equalizer
tube), leak check the coil and evacuate the coil through the
liquid and suction line valves on the outdoor unit.
A hard start capacitor on the outdoor unit is normally not
required when a 15% bleed TXV is used, but may be necessary
if compressor starting issues are encountered.
Field Installed TXV Kit Information
R72DB0053HX: R-410A, 1.5 – 2.5 Ton, 15% Bleed,
Inlet: Male Rotolock, Outlet: Female Swivel Nut
R72DB0054HX: R-410A, 3.0 – 5.0 Ton, 15% Bleed,
Inlet: Male Rotolock, Outlet: Female Swivel Nut
Figure 6: Typical TXV Connections
Figure 7: TXV Sensing Bulb Placement
CONDENSATE DRAIN PIPING
The air handler indoor coil drain pan has two ¾”NPT female
primary and two secondary connections (left or right hand). The
horizontal pan has two ¾”NPT female, one primary and one
secondary. Condensate piping from each tting must have a 2”
minimum trap (See Figure 8) and the piping must be routed to
provide enough slope for adequate drainage to a visible area. Do
not pipe these two ttings together into a common drain. If a
secondary drain is not installed, the secondary drain connection
must be capped.

Air handler must be located so that if any connections
should leak, water will not cause damage to the adjacent
area. When such locations can’t be avoided, a suitable
drain pan should be installed under the air handler, not
over 1½”deep, with minimum length and width at least
2” greater than the air handler dimensions and connected
to an adequate drain. Under no circumstances is the
manufacturer to be held liable for any water damage in
connection with this air handler.
2˝ MIN.
DRAIN TRAP
VENT
ANTI-SYPH0N
AIR VENT
2˝ MIN.
2˝ MIN.
MORTEX PRODUCTS INC. 501 TERMINAL RD FORT WORTH, TX 76106 Page 10
CHILLED AND HOT WATER PIPING
All water pipes must be supported independent of coils to
prevent vibration and stress on coil headers. Swing joints or
exible ttings must be provided to absorb expansion and
contraction strains. Rigid piping reduces the eectiveness of
vibration isolators. Coil water pipes must be adequately vented
in order to prevent air binding. Air handlers are provided with
manual air vents mounted through the manifold panel.
Chilled Water Piping
Supply and return chilled water piping to the coil should be ¾”ID
up to 42,000 BTU/Hr, 1”on air handlers greater than 42,000 BTU/
Hr. Water piping must always be connected so that the entering
water is on the leaving air side of the coil.
Hot Water Piping
If a residential water heater is used for space heating water, do
not exceed a distance of 70 feet between the air handler and the
water heater. The water heater should be the quick recovery type.
Air handler and water heater must be located indoors and not
subject to freezing temperatures.
Total hot water piping should not exceed 140 feet. All hot water
piping to the coil should be copper and ¾”ID and 7/8” OD. CPVC
or PEX piping may be used in applications where the water
temperature does not exceed 150°F. It is recommended that a
water isolation valve and a union be placed in the water lines to
and from the coil that is near the coil for serviceability, repair or
replacement of the coil.
A thermal expansion tank is recommended on any closed loop
system to relieve thermal expansion due to pressure increase.
NOTE: Refer to SECTION 9: FILLING HEATING SYSTEM WITH
WATER AND SYSTEM STARTUP for instructions on lling the
system with water, purging the air from the system, and checking
for leaks once the air handler installation has been completed.
Chilled Water Piping:
Supply and return chilled water piping to the coil should be ¾”ID
up to 42,000 BTU/Hr, 1”on air handlers greater than 42,000 BTU/
Hr. Water piping must always be connected so that the entering
water is on the leaving air side of the coil.
“Massachusetts requires an electronically controlled
pump timer that activates the pump every 6 hours for 60
seconds and limits the distance between the water heater
and air handler to 50 feet max.”
Figure 8: Typical Condensate Trap
When system requires water at temperatures higher than
required for other uses, a means such as a mixing valve
shall be installed to temper the water for those uses in
order to reduce the potential for a scald hazard.
For personal safety, turn the electrical power “OFF” at
the main electrical panel and at the air handler control
box circuit breakers before attempting any service or
maintenance operations. Homeowners should never
attempt to perform any maintenance which requires
opening any of the air handler access panels.