Lennox Commercial CRX35 Series Downflow Aluminum Coil Instruction Manual

Lennox Commercial CRX35 Series Downflow Aluminum Coil

Product Information

The CRX35 Series Downflow Coils are HVAC equipment designed for cooling purposes. These coils include an externally equalized factory-installed HFC- 410A check/expansion valve. The coils are available in different sizes, ranging from 2 tons to 5 tons, and come with various cabinet widths. The product is shipped in a package that contains the CRX35 evaporator coil, a warranty card, and installation instructions. It is important to check the equipment for shipping damage upon delivery and contact the carrier if any damage is found.

Refer to the Product Specification bulletin (EHB) for specific information on using these coils with furnaces, air handlers, and line sets. The instructions provided in the user manual are a general guide and should not supersede local or national codes. It is recommended to consult with authorities who have jurisdiction before installation.

Product Usage Instructions

1. Step 1: Before installation, ensure that you have read and understood all the instructions provided in the user manual.
2. Step 2: Consult with local or national authorities to ensure compliance with codes and regulations.
3. Step 3: Inspect the equipment for shipping damage. If any damage is found, immediately contact the carrier.
4. Step 4: Follow the instructions provided in the Product Specification bulletin (EHB) to determine the compatibility of the coils with specific furnaces, air handlers, and line sets.
5. Step 5: Install the CRX35 Series Downflow Coils according to standard HVAC installation practices. It is recommended to hire a licensed professional HVAC installer or equivalent, service agency, or the gas supplier for installation and service.
6. Step 6: Take precautions while handling the equipment to avoid personal injury. Wear gloves and protective clothing to protect against sharp sheet metal edges.
7. Step 7: If cleaning of the aluminum coil is required, refer to page 8 of the user manual for special procedures.
8. Step 8: Ensure compliance with the Clean Air Act of 1990, which prohibits the intentional venting of refrigerants. Follow approved methods of recovery, recycling, or reclaiming to avoid fines and/or incarceration.
9. Step 9: Keep the user manual for future reference. It contains important information regarding maintenance and troubleshooting.

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 refrigerants (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 cleaning the aluminum coil in this unit. See page 8 in this instruction for information.

General Information

These instructions are intended as a general guide and do not supersede local or national codes in any way. Authorities who have jurisdiction should be consulted before installation.

CRX35 Series Coils
The CRX35 coil includes an externally equalized 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 2ʺ away from a standard gas-fired furnace heat exchanger and at least 4ʺ away from any drum-type or oil-fired furnace heat exchanger. Closer spacing may damage the drain pan and cause a leak. Refer to the Product Specification bulletin (EHB) for the proper use of these coils with specific furnaces, air handlers, and line sets. These instructions are intended as a general guide and do not supersede local or national codes in any way. Authorities who have jurisdiction should be consulted before installation.

Shipping and Packing List

Package 1 of 1 contains the following:

• 1 – CRX35 evaporator coil
• 1 – Warranty card
• 1 – Installation instructions

Check equipment for shipping damage. If you find any damage, immediately contact the last carrier.

Model Number Identification

Specifications

2 TO 3 TON

General Data| Model No.

Nominal size – Tons

| CRX35-24A-F| CRX35-24B-F| CRX35-30/36B-F| CRX35-30/36C-F
2| 2| 2.5 / 3| 2.5 / 3
Line connections in.| Suction/vapor o.d. – sweat

Liquid o.d. – sweat Condensate drain (fpt)

| 7/8| 7/8| 7/8| 7/8
3/8| 3/8| 3/8| 3/8
(2) 3/4| (2) 3/4| (2) 3/4| (2) 3/4
Indoor| Net face area sq. ft.| 4.08| 4.08| 4.67| 4.67
Coil| Tube diameter – in.| 3/8| 3/8| 3/8| 3/8
 | Number of rows| 3| 3| 3| 3
 | Fins per inch| 14| 14| 14| 14
Shipping weight| lbs.| 44| 51| 52| 60
SPECIFICATIONS|  |  |  | 4 TO 5 TON
---|---|---|---|---
General Data| Model No.

Nominal size – Tons

| CRX35-42B-F| CRX35-48C-F| CRX35-50/60C-F| CRX35-60D-F
3.5| 4| 4 / 5| 5
Line connections in.| Suction/vapor o.d. – sweat

Liquid o.d. – sweat Condensate drain (fpt)

| 7/8| 7/8| 7/8| 7/8
3/8| 3/8| 3/8| 3/8
(2) 3/4| (2) 3/4| (2) 3/4| (2) 3/4
Indoor| Net face area sq. ft.| 5.83| 6.42| 7.00| 7.00
Coil| Tube diameter – in.| 3/8| 3/8| 3/8| 3/8
 | Number of rows| 3| 3| 3| 3
 | Fins per inch| 14| 14| 14| 14
Shipping weight| lbs.| 65| 69| 71| 75

Dimensions

Model Number| A

(Height)

| B

(Width)

| C| D| E| F
---|---|---|---|---|---|---
in.| mm| in.| mm| in.| mm| in.| mm| in.| mm| in.| mm
CRX35-24A-F| 18| 457| 14 -1/2| 368| 13-1/2| 343| 13-1/2| 343| 4-5/8| 117| 3-5/8| 92
CRX35-24B-F| 18| 457| 17-1/2| 445| 16-1/2| 419| 16-1/2| 419| 6-1/8| 155| 3-5/8| 92
CRX35-30/36B-F| 23-1/2| 597| 17-1/2| 445| 16-1/2| 419| 16-1/2| 419| 6-1/8| 155| 4-3/4| 121
CRX35-30/36C-F| 23-1/2| 597| 21| 533| 20| 508| 20| 508| 7-7/8| 200| 4-3/4| 121
CRX35-42B-F| 23-1/2| 597| 17-1/2| 445| 16-1/2| 419| 16-1/2| 419| 6-1/8| 155| 6-3/8| 162
CRX35-48C-F| 27-1/2| 699| 21| 533| 20| 508| 20| 508| 7-7/8| 200| 8-5/8| 219
CRX35-50/60C-F| 27-1/2| 699| 21| 533| 20| 508| 20| 508| 7-7/8| 200| 10| 254
CRX35-60D-F| 27-1/2| 699| 24-1/2| 622| 23-1/2| 597| 23-1/2| 597| 9-5/8| 244| 10-1/2| 267

DIMENSIONS – FURNACE/COIL COMBINED DIMENSIONS

Model Number| Coil Width| Furnace Width| Coil Height| Overall Height
---|---|---|---|---
in.| mm| in.| mm| in.| mm| in.| mm
CRX35-24A-F| 14-1/2| 368| 14-1/2| 368| 18| 457| 51| 1295
CRX35-24B-F| 17-1/2| 445| 17-1/2| 445| 18| 457| 51| 1295
CRX35-30/36B-F| 17-1/2| 445| 17-1/2| 445| 23-1/2| 597| 56-1/2| 1435
CRX35-30/36C-F| 21| 533| 21| 533| 23-1/2| 597| 56-1/2| 1435
CRX35-42B-F| 17-1/2| 445| 17-1/2| 445| 23-1/2| 597| 56-1/2| 1435
CRX35-48C-F| 21| 533| 21| 533| 27-1/2| 699| 60-1/2| 1537
CRX35-50/60C-F| 21| 533| 21| 533| 27-1/2| 699| 60-1/2| 1537
CRX35-60D-F| 24-1/2| 622| 24-1/2| 622| 27-1/2| 699| 60-1/2| 1537

Dry Air Charge Release
The CRX35 coils are shipped with a 10 psi dry air holding charge. Puncture the suction line rubber plug to release the charge. Remove the rubber plug.

NOTE
If there is no pressure when the rubber plug is punctured, check the coil for leaks before installing the coil. Loosen and remove the liquid line compression fitting. Remove and discard the plug which is in the distributor body.

Plenum Installation

See Table 1 for the dimensions of the floor opening required to accommodate the supply air opening and the plenum. If the unit is installed against a wall, the rear edge of the opening must be at least 1ʺ (25 mm) from the wall. Cut an appropriately sized opening.

1. Lower plenum through floor opening – Align the base of the unit with the matching plenum, then lower the unit over the plenum. The coil cabinet must be either level or sloped slightly toward the drain outlet and secured and sealed to the plenum. If the furnace and coil cabinet are the same size, skip to step 3.
   TABLE 1. Floor Opening Dimensions

   • CAUTION
     Do not install screws through the drain pan.

   • CAUTION
     If the furnace flange height is greater than 5/8ʺ (16 mm), damage may occur to the coil. Notch flange so that it does not contact coil slabs.

   • WARNING
     There must be an airtight seal between the top of the furnace and the return air plenum. Use fiberglass sealing strips, caulking, or equivalent sealing method between the plenum and the furnace cabinet to ensure a tight seal. Return air must not be drawn from a room where this furnace or any gas-fueled appliance (i.e., water heater), or carbon monoxide-producing device (i.e., wood fireplace) is installed.

2. Sealing – Seal between the furnace cabinet and the coil cabinet to prevent air leaks.

3. As you lower the furnace onto the coil, align the flanges of the furnace and the coil cabinet.

Air Leakage
All indoor cabinets MUST be taped after installation to seal against any air leaks. System performance and effi-ciency will be reduced if air leakage exists.

Refrigerant Line Connections

The refrigerant line sets should be sized according to the recommendations given in the condensing unit or heat pump installation instructions (see table 2 for sweat con-nection sizes). A field-provided adapter may be required to match line set connections.

TABLE 2. Refrigerant Line Connection Sizes – in (mm)

NOTE – Some applications may require a field-provided 7/8” to 1-1/8” adapter

NOTE
When installing refrigerant lines longer than 50 feet, see the Lennox Refrigerant Piping Design and Fabrication Guidelines, CORP. 9351-L9, or contact Lennox Technical Support Product Applications for assistance.

Brazing Coil Connections

1. Place a field-provided heat shield, such as a wet rag, against the piping plate and around the piping stubs, and sweat in the suction line. The heat shield must be in place to guard against heat damage to the paint.
2. Slide the liquid line compression nut onto the provided liquid line stub. Insert the field-supplied liquid line into the liquid line stub for brazing.
3. Braze liquid line and coil connections. Use a silver alloy brazing rod (5 or 6 percent silver alloy for copper-to-copper connections or 45 percent silver alloy for copper-to-brass or copper-to-steel connections).
4. Remove the heat shield after brazing and allow the connections to cool.

Metering Device Installation

CRX35 coils include a factory-installed HFC-410A check/ expansion valve metering device. Connect the properly sized field-provided liquid line to the liquid line stub as shown in figure 5 using one of the following procedures:

1. Position the properly sized refrigerant piping and make the brazed connection following the brazing guidelines.
2. Do not remove the water-saturated rags from the cabinet and piping until the piping has cooled completely. OR
3. Cut the copper liquid line on a vertical or horizontal section. Use a field-provided coupling to join the properly sized field-provided refrigerant piping and and the liquid line stub on the coil. Follow the brazing guidelines.
4. Do not remove the water-saturated rags from the cabinet and piping until the piping has cooled completely.

Condensate Drain Installation

IMPORTANT
After removal of drain pan plug(s), check drain hole(s) to verify that the 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 the drain line or sump. Do not connect the drain to a closed waste system.
• See Figure 4 for a typical drain trap configuration.

OVERFLOW DRAIN

• The overflow drain MUST be connected and routed to an overflow drain line
• If the overflow drain is not connected, it must be plugged with a field-provided cap or plug.

BEST PRACTICES
The following practices are recommended to ensure better condensate removal:

• Main and overflow drain lines should NOT be smaller than drain connections at the drain pan.
• The overflow drain line should run to an area where the homeowner will notice drainage.
• It is recommended that the overflow drain line be vented and a trap installed. Refer to local codes.

Blower Speed Adjustment

Proper air volume MUST be provided over the evaporator coil. To ensure that the static pressure is within the proper range, take a draft gauge reading as follows:

CAUTION
The access panel must be removed before drilling air test holes.

1. Remove the access panel.
2. Drill two 5/16” (8 mm) air test holes in the right front access panel; hole locations are shown in Figure 5. Replace the panel.
3. Connect draft gauge. The zero end of the draft gauge scale connects to air entering the hole of the coil. Insert gauge hoses into test holes about 5/16” (8 mm). Seal around holes with premium.
4. Turn off power to the outdoor unit, then set the thermostat for high-stage cooling.
5. Table 3 lists the range of air volumes and equivalent draft gauge readings for this unit. Observe draft gauge reading. If the reading is above the required air volume, decrease the blower speed. Refer to the furnace wiring diagram for changing the direct drive blower speed. Do not exceed the maximum air volume as indicated in the diagram blower speed table.
6. After required draft gauge readings are obtained, remove draft lines and seal air test holes.
7. Set the room thermostat to the desired temperature.

Maintenance

NOTICE!

• Failure to follow instructions will cause damage to the unit.
• This unit is equipped with an aluminum coil. Aluminum coils may be damaged by exposure to solutions with a pH below 5 or above 9. The aluminum coil should be cleaned using potable water at moderate pressure (less than 50 psi). If the coil cannot be cleaned using water alone, Lennox recommends the 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 maintenance 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.

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 fins. Use vacuum attachments and/or brushes that are non-destructive to fins.

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 flush from the inside of the coil will require removing parts from the unit, and it may be very difficult to flush the whole coil surface. Attempting to blow water through a coil will slow the water stream and reduce the flushing action of the outer fin 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.

Air Resistance

CRX35

-24A-F

| 400| 0.08| 0.09
600| 0.16| 0.18
800| 0.29| 0.33
1000| 0.45| 0.49
CRX35

-24B-F

| 600| 0.11| 0.13
800| 0.18| 0.19
1000| 0.27| 0.29
1200| 0.35| 0.39
1400| 0.47| 0.51
CRX35

-30/36B-F

| 600| 0.1| 0.12
800| 0.15| 0.18
1000| 0.24| 0.27
1200| 0.32| 0.36
1400| 0.43| 0.47
CRX35

-30/36C-F

| 600| 0.05| 0.08
800| 0.09| 0.12
1000| 0.13| 0.17
1200| 0.17| 0.23
1400| 0.24| 0.30
Model No.| Air Volume| Total Resistance
---|---|---
Dry Coil| Wet Coil
cfm| in. w.g.| in. w.g.
CRX35

-42B-F

| 600| 0.08| 0.10
800| 0.12| 0.14
1000| 0.18| 0.22
1200| 0.25| 0.30
1400| 0.34| 0.39
1600| 0.43| 0.49
CRX35

-48C-F

| 800| 0.09| 0.10
1000| 0.11| 0.13
1200| 0.15| 0.18
1400| 0.21| 0.23
1600| 0.26| 0.30
1800| 0.34| 0.37
2000| 0.4| 0.44
CRX35

-50/60C-F

| 800| 0.09| 0.11
1000| 0.12| 0.14
1200| 0.16| 0.20
1400| 0.22| 0.24
1600| 0.27| 0.32
1800| 0.33| 0.38
2000| 0.4| 0.46
CRX35

-60D-F

| 800| 0.09| 0.08
1000| 0.13| 0.13
1200| 0.18| 0.16
1400| 0.16| 0.21
1600| 0.2| 0.26
1800| 0.24| 0.32
2000| 0.29| 0.39

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