Lennox CHX35 Series User manual

Page 1
THIS MANUAL MUST BE LEFT WITH THE
HOMEOWNER FOR FUTURE REFERENCE
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, personal
injury or loss of life. Installation and service must be
performed by a licensed professional HVAC installer or
equivalent, service agency, or the gas supplier.
IMPORTANT
The Clean Air Act of 1990 bans the intentional venting of
refrigerant (CFCs, HCFCs and HFCs) as of July 1, 1992.
Approved methods of recovery, recycling or reclaiming
must be followed. Fines and/or incarceration may be
levied for noncompliance.
CAUTION
As with any mechanical equipment, contact with sharp
sheet metal edges can result in personal injury. Take
care while handling this equipment and wear gloves and
protective clothing.
IMPORTANT: Special procedures are required for clean-
ing the aluminum coil in this unit. See page 8 in this in-
struction for information.
Shipping and Packing List
Package 1 of 1 contains:
1 – Evaporator coil
Check the components for shipping damage; if found, im-
mediately contact the last carrier.
INSTALLATION
INSTRUCTIONS
INDOOR COILS
507835-01 (067198001)
4/2018
CHX35 Series Coils
General Information
CHX35 horizontal evaporator coils are designed for use
with air conditioners and heat pumps and are supplied
with a factory-installed HFC-410A check/expansion valve.
The coil drain pan has a maximum service temperature
of 500°F. The drain pan must be at least 2" away from a
standard gas-red furnace heat exchanger and at least
4" away from any drum-type or oil-red furnace heat ex-
changer. Closer spacing may damage the drain pan and
cause a leak.
Refer to the Product Specication bulletin (EHB) for the
proper use of these coils with specic furnaces, outdoor
units and line sets.
These instructions are intended as a general guide and
do not supersede local or national codes in any way. Au-
thorities who have jurisdiction should be consulted before
installation.
Table of Contents
Model Number Identication...........................................2
Specications ................................................................2
Releasing Air Charge .....................................................3
Installation .....................................................................3
Refrigerant Line Connections ........................................5
Leak Testing, Evacuating and Charging ........................6
Sealing Ducts ................................................................6
Condensate Drain Connections .....................................6
Blower Speed Selection ................................................7
Maintenance ..................................................................8

Page 2
Model Number Identication
6
X 35 36--F
Unit Type
CH = Indoor Coil - Horizontal
Series
Nominal Cooling Capacity
18 = 1.5 tons
24 = 2 tons
30 = 2.5 tons
36 = 3 tons
42 = 3.5 tons
48 = 4 tons
51 = 4/5 tons
60 = 5 tons
Cabinet Width
A = 14-1/2 in.
B = 17-1/2 in.
C = 21 in.
D = 24-1/2 in.
Cabinet
F = Cased
(Furnaces with the same cabinet width letter designation
will physically match the corresponding indoor coil.)
Metering Device
6 = Factory-Installed Check/Expansion Valve
for HFC-410A Refrigerant (non-bleed port)
CH
Refrigerant Type
X = HFC-410A
A
Specications
18A – 30B
General DataModel No.CHX35
-18A-2F
CHX35
-24A-2F
CHX35
-24B-2F
CHX35
-30A-2F
CHX35
-30B-2F
Nominal size - tons 1.5 2 2 2.5 2.5
Line
Connections
Suction/Vapor o.d. - in. sweat 3/4 3/4 3/4 3/4 3/4
Liquid o.d. - in. sweat3/8 3/8 3/8 3/8 3/8
Condensate drain (fpt) - in. 3/4 3/4 3/4 3/4 3/4
Evaporator
Coil
Net face area - sq. ft.1.75 3.5 3.5 4.33 4.67
Tube diameter - in. 3/8 3/8 3/8 3/8 3/8
Number of rows 2 3 2 3 3
Fins per inch 18 14 19 16 14
Horizontal
Matching
Furnace
Cabinet Designation A A B A B
Coil and Furnace Height 14-1/2 14-1/2 17-1/2 14-1/2 17-1/2
Shipping Data lbs. - 1 package 43 45 47 55 53
36A – 42C
General Data Model No.CHX35
-36A-2F
CHX35
-36B-2F
CHX35
-36C-2F
CHX35
-42B-2F
CHX35
-42C-2F
Nominal size - tons 3 3 3 3.5 3.5
Line
Connections
Suction/Vapor o.d. - in. sweat 3/4 3/4 3/4 7/8 7/8
Liquid o.d. - in. sweat 3/8 3/8 3/8 3/8 3/8
Condensate drain (fpt) - in. 3/4 3/4 3/4 3/4 3/4
Evaporator
Coil
Net face area - sq. ft.3.5 4.67 5.83 5.78 5.83
Tube diameter - in. 3/8 3/8 3/8 3/8 3/8
Number of rows 3 2 2 3 3
Fins per inch 12 18 18 12 13
Horizontal
Matching
Furnace
Cabinet Designation A B C B C
Coil and Furnace Height 14-1/2 17-1/2 21 17-1/2 21
Shipping Data lbs. - 1 package 47 48 55 60 60

Page 3
Specications – cont’d
48B – 60D
General DataModel No.CHX35
-48B-2F
CHX35
-48C-2F
CHX35
-51C-2F
CHX35
-60D-2F
Nominal size - tons 3.5 / 43.5 / 4 4 5
Line
Connections
Suction/Vapor o.d. - in. sweat 7/8 7/8 7/8 7/8
Liquid o.d. - in. sweat 3/8 3/8 3/8 3/8
Condensate drain (fpt) - in. 3/4 3/4 3/4 3/4
Evaporator
Coil
Net face area - sq. ft.5.78 5.83 7.22 7.94
Tube diameter - in. 3/8 3/8 3/8 3/8
Number of rows 3 2 3 3
Fins per inch 12 12 13 12
Horizontal
Matching
Furnace
Cabinet Designation B C C D
Coil and Furnace Height 17-1/2 21 21 24-1/2
Shipping Data lbs. - 1 package 60 59 69 78
FOAM
TAPE
FIGURE 1. Insulate Suction Line Inside Cabinet
1 - Left-Hand and Right-Hand Discharge – The
coil must have a 1/2" slope from the rear of the
cabinet to the drain. Position the coil adjacent
to the furnace cabinet and align the six screw
clearance holes in the coil casing with the furnace
engagement holes. Use six eld-provided #8 X 1”
screws to secure the coil casing to the furnace (see
gures 3 and 4).
2 - Right-Hand Air Discharge with Field-Provided
Spacer – The coil must have a 1/2"slope from
the rear of the cabinet to the drain. Position the
coil in the left-to-right conguration on the service
access side of the furnace. Insert a eld-provided
spacer between the furnace and the coil. Use eld-
provided screws to secure the coil casing, spacer
and the furnace together. The spacer should be
long enough to allow room for proper installation
(approximately 6 inches minimum). See gure 5.
Releasing Air Charge
CAUTION
The coil is shipped from the factory pressurized with dry
air. Pierce a hole in the rubber plug that seals the vapor
line to relieve the pressure before removing the plugs.
NOTE - If there is no pressure released when the vapor
line rubber plug is pierced, check the coil for leaks before
continuing with the installation.
The CHX35 coils are shipped with a 9 ± 2 psi dry air hold-
ing charge. Puncture the suction line rubber plug to re-
lease the charge. Remove the rubber plug. Ensure that
the coil is void of pressure.
Installation
WARNING
Risk of explosion or re.
Can cause injury or death.
Recover all refrigerant to relieve pressure before
opening the system.
Install the furnace or air handler according to the installa-
tion instructions provided with the unit.
NOTE – In areas of high humidity, use foam tape to in-
sulate the suction line section in the cabinet as shown in
gure 1.

Page 4
NOTE – When the coil is connected directly with a con-
densing furnace, the coil must be level from return end to
supply end. The front (access side) of the furnace may be
pitched downward up to 1 inch to accommodate a ½-inch
pitched coil.
3 - Secure the supply duct to the coil cabinet.
4 - Refer to the instructions provided with the
condensing unit for leak testing, evacuating and
charging procedures. Always check the entire
system for leaks before charging.
5 - Applications using CHX35-60 D-width unit with
C-width furnace – Figure 2 shows an application
that includes a D-width coil and a C-width furnace.
This application requires construction of an
insulated, eld-supplied block-off plate to cover the
open space on the coil housing
SUPPLY AIR UNIT
FRONT
PLUMBING
CONNECTIONS
SUPPLY AIR
UNIT REAR
TEST HOLE
AIR FLOW
FIELD‐FABRICATED
INSULATED BLOCK-
OFF PLATE
FIGURE 2. D-Width Coil with C-Width Furnace
(Top View)
SUPPLY AIR UNIT FRONT
PLUMBING
CONNECTIONS
SUPPLY AIR UNIT REAR
AIR FLOW
TEST HOLE
SLOPE 1/2”
(13 MM)
90% GAS FURNACE
DRAIN
COIL DRAIN
SUPPLY AIR UNIT
FRONT
BACK
COIL
(SUPPLY AIR END VIEW)
AIR
FLOW
FIGURE 3. Left-Hand Air Discharge
COIL
FRONT
NOTE - Use of this orientation is acceptable for 80% AFUE furnaces.
Do not use this orientation for 90% condensing furnaces.
(SUPPLY AIR END VIEW)
SUPPLY AIR UNIT FRONT
PLUMBING CONNECTIONS
SUPPLY AIR UNIT REAR
TEST HOLE
SLOPE 1/2”
(13 MM)
COIL
DRAIN
SUPPLY AIR UNIT
SUPPLY AIR
UNIT FRONT
COIL
AIR FLOW
(Top View)
AIR
FLOW
FIGURE 4. Right-Hand Air Discharge
FIELD-PROVIDED SPACER
(6 IN.)
COIL
BACK
FRONT
SUPPLY AIR UNIT FRONT
PLUMBING CONNECTIONS
SUPPLY AIR UNIT REAR TEST HOLE
SLOPE 1/2”
(13 MM)
COIL DRAIN
SUPPLY AIR
UNIT FRONT
(TOP VIEW)
AIR FLOW
90% GAS FURNACE
DRAIN
(SUPPLY AIR END VIEW)
AIR
FLOW
FIGURE 5. Right-Hand Air Discharge with Spacer

Page 5
Refrigerant Line Connections
LINE SIZES
The refrigerant line sets should be sized according to the
recommendations given in the air conditioner or heat pump
unit installation instructions. Use table 1 to determine cor-
rect braze connection sizes. A eld-provided adapter may
be required to match line set connections.
TABLE 1 Refrigerant Line Connections –
Model CHX35
Model Number Suction Liquid
18-2F
24-2F
30-2F
36-2F
3/4 Inch
3/8 Inch
42-2F
48-2F
51-2F
60-2F
7/8 Inch
REPLACEMENT PARTS
If replacement parts are necessary, order kit 69J46. The
kit includes:
• 10 – Brass nuts for liquid line assemblies
• 20 – Teon rings
• 10 – Liquid line orice housings
• 10 Liquid line assemblies
TEFLON RINGS (20)
BRASS NUTS (10)
LIQUID LINE ASSEMBLIES
(INCLUDES STRAINER) (10)
LIQUID LINE ORIFICE HOUSINGS (10)
LIQUID LINE
ASSEMBLY
COPPER
TUBE
PISTON
RETAINER
STRAINER
FIGURE 6. 69J46 Kit Components
BRAZING GUIDELINES
Use a silver alloy brazing rod (5 or 6 percent silver alloy
for copper-to-copper connections or 45 percent silver al-
loy for copper-to-brass or copper-to-steel connections).
Before making brazed connections, place a eld-provided
heat shield, such as a wet rag, against the unit cabinet
and around the piping stubs, expansion valve and sensing
bulb (or remove the sensing bulb temporarily). The heat
shield must be in place to prevent heat damage during
brazing. See gure 7.
WATER-
SATURATED
RAGS
PLACE A WET RAG AGAINST
COIL CABINET AND AROUND
THE SUCTION LINE
CONNECTION.
BRAZE CONNECTION. ALLOW
PIPE TO COOL BEFORE
REMOVING WET RAG.
1
2
USE A WET RAG TO PROTECT
THE TXV SENSING BULB
(OR REMOVE THE BULB)
WHEN BRAZING THE
SUCTION LINE.
3
FIGURE 7. Braze Refrigerant Lines
SUCTION LINE CONNECTION
Use the following procedure to connect the suction line to
the indoor coil:
1 - Remove rubber plug from the stubbed connection.
2 - Position the properly sized refrigerant piping and
make the brazed connection following the brazing
guidelines.
3 - Do not remove the water-saturated rags from the
cabinet and piping until the piping has cooled
completely.

Page 6
LIQUID LINE CONNECTION
Use the following procedure to connect the liquid line to
the indoor coil:
1 - Remove rubber plug from the stubbed connection.
2 - Position the properly sized refrigerant piping and
make the brazed connection following the brazing
guidelines.
3 - Do not remove the water-saturated rags from the cabinet
and piping until the piping has cooled completely.
Leak Testing, Evacuating and Charging
Refer to the outdoor unit instruction for leak testing, evac-
uating and charging procedures. Always leak check entire
system before charging.
Sealing Ducts
Ensure the duct is secured and all joints are properly
sealed to the coil cabinet anges.
WARNING
There must be an airtight seal between the bottom of
the air handler and the return air plenum. Use berglass
sealing strips, caulking, or equivalent sealing method
between the plenum and the air handler cabinet to
ensure a tight seal. Return air must not be drawn from a
room where this air handler or any gas-fueled appliance
(i.e., water heater), or carbon monoxide-producing
device (i.e., wood replace) is installed.
IMPORTANT
DUCT SYSTEM SIZING - The duct system should be
properly sized and installed according to the ASHRAE
Standard Manual D. The supply and return air duct
systems should be designed for the cfm and static
requirements of the job. Consult the blower performance
chart in the unit installation instructions to verify that the
blower meets the application requirements.
Condensate Drain Connections
IMPORTANT
After removal of drain pan plug(s), check drain hole(s)
to verify that drain opening is fully open and free of any
debris. Also check to make sure that no debris has fallen
into the drain pan during installation that may plug up the
drain opening.
MAIN DRAIN
Connect the main drain and route downward to drain line
or sump. Do not connect drain to a closed waste system.
See gure 9 for typical drain trap conguration.
OVERFLOW DRAIN
It is recommended that the overow drain is connected to
a overow drain line for all units. If overow drain is not
connected, it must be plugged with provided cap.
BEST PRACTICES
The following practices are recommended to ensure bet-
ter condensate removal:
• Main and overow drain lines should NOT be smaller
than drain connections at drain pan.
• Overow drain line should run to an area where home-
owner will notice drainage.
• It is recommended that the overow drain line be vented
and a trap installed. Refer to local codes.

Page 7
ABOVE
FINISHED
SPACE?
OVERFLOW DRAIN LINE
ALWAYS RUN AN OVERFLOW DRAIN LINE. IF NOT POSSIBLE TO
ROUTE OVERFLOW DRAIN LINE, INSTALL LOW VOLTAGE
OVERFLOW SWITCH KIT. WIRE KIT TO SHUT DOWN
COMPRESSOR PER INSTRUCTIONS.
NO
YES
OEM CATALOG#
X3169 CLEAN OUT
VENT
PRESS IN
(DO NOT GLUE)
VENT MUST EXTEND
ABOVE HEIGHT OF
COIL DRAIN PAN BY
TWO INCHES
1” X 3/4” X 3/4”
REDUCING
TEE WITH
PLUG
OEM CATALOG
NUMBERS* P-TRAP
49P66, J-TRAP #
91P90 OR ANY PVC
SCH 40 P- OR
J-TRAP 3/4”
OVERFLOW
DRAIN
OPTIONAL
SAFETY
PAN
COIL DRAIN PAN
WHEN A COIL IS LOCATED ABOVE A FINISHED SPACE, A 3/4” SECONDARY DRAIN LINE
MUST BE:
● CONNECTED TO SECONDARY DRAIN PAN
OR
●CONNECTED TO THE OVERFLOW DRAIN OUTLET OF THE AIR HANDLER DRAIN PAN.
TRAPS MUST BE DEEP ENOUGH TO OFFSET MAXIMUM STATIC DIFFERENCES —
GENERALLY, TWO INCHES.
DRAIN LINE SHOULD
SLOPE A MINIMUM OF
ONE INCH PER 10 FT.
NOTE — WHEN A AIR HANDLER IS LOCATED ABOVE A FINISHED SPACE THE SECONDARY
DRAIN PAN MUST HAVE A LARGER FOOTPRINT THAN THE AIR HANDLER.
MAIN
DRAIN
TO APPROVED
DRAIN
FOR NEGATIVE PRESSURE COILS (BLOWER
AFTER COIL) TRAPS ARE REQUIRED ON ALL
DRAIN LINES CONNECTED TO COIL.
COMPACT OVERFLOW SWITCH WITH 3/4” FEMALE SLIP INLET
AND MALE ADAPTER, TWO PART DESIGN FOR USE WHERE
OBSTRUCTIONS PREVENT DIRECT THREADING
SECONDARY
DRAIN PAN
2”
(51MM)
TRAP DEPTH
*OEM CATALOG # P-TRAP 49P66 REQUIRES A LARGER INSTALLATION SPACE THAN THE J-TRAP 91P90.
FIGURE 8. Typical Main and Overow Drain Installations
Blower Speed Selection
Proper air volume must be provided over the evaporator
coil. Select a blower motor speed tap that will provide 400
± 50 CFM per 12,000 Btuh of cooling capacity (wet coil).
A static pressure reading must be taken to see if the pres-
sure drop falls within the proper range.
To ensure accuracy, static pressure must be read from the
air entry side of the coil to the air exit side of the coil. See
gure 9 for an example to obtain an accurate reading.
LEFT-HAND AIR DISCHARGE (TOP VIEW)
SUPPLY AIR UNIT FRONT
SUPPLY AIR UNIT REAR
AIR
FLOW
TEST HOLE 1
TEST HOLE
2
SUPPLY
AIR DUCT RETURN AIR
DUCT
FIGURE 9. Static Pressure Test
CAUTION
Take care when drilling test holes into the furnace ange
and the duct. Drill holes away from refrigerant piping.
Test holes should be drilled where specied in order to
avoid unit damage.
1 - Drill a 5/16" test hole in the coil case 1" from the
furnace ange (test hole 1, gure 9).
2 - Drill a 5/16" test hole into the supply air duct (test
hole 2, gure 9).
3 - Connect the zero end of the draft gauge scale to the
furnace end of the coil. Insert the hoses so that 1/4"
extends inside the duct or end seal. Seal around
holes with Permagum.
4 - Turn on electrical power to the furnace and set the
thermostat to initiate a cooling demand.
5 - Table 2 lists the range of air volumes and equivalent
draft gauge readings for this unit. Observe the draft
gauge reading. If the reading is below the required
air volume, increase the blower speed; if the reading
is above the required air volume, decrease the
blower speed. Refer to the furnace wiring diagram
for blower speed settings.

Page 8
CLEANING THE COIL
1 - Remove the coil from the cabinet or plenum, and
take the coil to an appropriate place to clean it.
2 - Vacuum or brush the coil to remove matted
and surface debris from the ns. Use vacuum
attachments and /or brushes that are non-
destructive to ns.
3 - If oil deposits are present, spray the coil with a mild
coil cleaner with a pH in the range of 5 to 9 to soften
deposits. Do not leave the coil cleaner on the coil
for more than 10 minutes. Flush the coil thoroughly
with potable water.
4 - Spray the coil at a vertical angle of 30 to 45 degrees
with a constant stream of water at moderate
pressure. A pressure washer with a fan nozzle will
work best. Do not spray the coil from a horizontal
direction.
5 - Direct the spray so that any debris is washed out of
the coil. For most residential units, hot water is not
necessary.
NOTE - Attempting to back ush from the inside of the coil
will require removing parts from the unit, and it may be
very difcult to ush the whole coil surface. Attempting to
blow water through a coil will slow the water stream and
reduce the ushing action of the outer n surface.
6 - Replace the coil into the cabinet or plenum. Ensure
that you have followed the proper procedure for
routing and securing the refrigerant tubing.
IMPORTANT
Ensure that the distributor lines are not rubbing together
or kinked. All tubes must have enough clearance
from other metal parts. Use wire ties to secure tubes
to prevent movement that could cause the refrigerant
tubing to fail.
6 - When the required draft gauge readings are
obtained, remove the draft gauge lines and insert
snaphole plugs into the test holes.
TABLE 2. Air Volume / Static Pressure Drop Across Coil
Cabinet
Vol: CFM
Drop: in. w.g.
CHX35
Model Width in. Dry Wet
-18A-2F 14-1/2 600 .09 .11
-24A-2F
-24B-2F
14-1/2
17-1/2
800
800
.15
.09
.19
.11
-30A-2F
-30B-2F
14-1/2
17-1/2
1000
1000
.24
.14
.27
.16
-36A-2F
-36B-2F
-36C-F
14-1/2
17-1/2
21
1200
1200
1200
.30
.16
.15
.39
.21
.18
-42B-2F
-42C-2F
14-1/2
17-1/2
1400
1400
.26
.18
.31
.21
-48B-2F 17-1/2 1400 .25 .29
-48C-2F 21 1600 .27 .30
-51C-2F 21 1600 .25 .29
-60D-2F 24-1/2 2000 .24 .30
Maintenance
NOTICE !
Failure to follow instructions will cause damage to
the unit.
This unit is equipped with an aluminum coil. Alu-
minum coils may be damaged by exposure to solu-
tions with a pH below 5 or above 9. The aluminum
coil should be cleaned using potable water at a mod-
erate pressure (less than 50psi). If the coil cannot
be cleaned using water alone, Lennox recommends
use of a coil cleaner with a pH in the range of 5 to 9.
The coil must be rinsed thoroughly after cleaning.
A trained technician or service agency must perform main-
tenance and service on equipment. At the beginning of
each heating or cooling season, indoor coils should be
inspected to determine whether the coil requires cleaning.