Carrier CNPHP - User Manual

The CNPHP is a horizontal, multi-use furnace coil designed for heating and cooling applications. It is available in sizes ranging from 024 to 060 and is equipped with a factory-installed TXV (Thermal Expansion Valve) for use with Puron® (R-410A) refrigerant systems. These furnace coils can also be applied to other similar horizontal furnaces on the market with the use of a field-supplied transition duct.

Function Description:

The CNPHP coil is designed to optimize system performance and comfort by efficiently transferring heat. In cooling mode, it extracts heat from the indoor air, which is then carried away by the refrigerant. In heating mode (when paired with a heat pump), it can transfer heat to the indoor air. The integrated TXV helps regulate the flow of refrigerant, ensuring optimal performance across the system's operating range. The coil also manages condensate produced during the cooling process, directing it to a drain.

Important Technical Specifications:

Refrigerant: Puron® (R-410A)
Coil Sizes: 024 through 060
TXV: Factory-installed, hard-shutoff, designed only for R-410A refrigerant. Preset superheat settings, not field-adjustable.
Nitrogen Precharge: 15 PSIG (pounds per square inch gauge) at the factory. This pressure must be released through the center of the rubber plugs before removing the plugs.
Coil Connection Tube Sizes (Liquid/Suction):
- CNPHP2417ALA: 3/8 in (10 mm) / 5/8 in (16 mm)
- CNPHP3017ALA: 3/8 in (10 mm) / 3/4 in (19 mm)
- CNPHP3617ALA: 3/8 in (10 mm) / 3/4 in (19 mm)
- CNPHP4221ALA: 3/8 in (10 mm) / 7/8 in (22 mm)
- CNPHP4321ALA: 3/8 in (10 mm) / 7/8 in (22 mm)
- CNPHP4821ALA: 3/8 in (10 mm) / 7/8 in (22 mm)
- CNPHP6024ALA: 3/8 in (10 mm) / 7/8 in (22 mm)
- CNPHP6124ALA: 3/8 in (10 mm) / 7/8 in (22 mm)
Condensate Drain Connections: Two 3/4-in. female threaded pipe connections are provided in each coil condensate pan.
Airflow: Generally, 350 to 400 cfm/ton during normal cooling operation. Heat pump applications require airflow in a particular direction for best performance.

Usage Features:

Installation Flexibility: The CNPHP can be installed in multiple configurations, including horizontal-left and horizontal-right orientations. It can be mounted on a work platform, secured to roof trusses in the attic, suspended from hangers on floor joists in a crawl space, or installed on blocks.
Pan Extension: For 43, 60, and 61 size coils, a pan extension is supplied and required for both horizontal-left and horizontal-right installations. This ensures proper condensate management and prevents blow-off into the ductwork. The pan extension is slotted to fit onto the condensate pan edge and extends into the supply plenum.
Furnace Compatibility: While designed as a multi-use furnace coil, it is important to note that CNPHP furnace coils are NOT designed to be installed with furnaces that measure wider than the coil itself. Attachment plates and a filler plate are provided for secure connection to the furnace.
Refrigerant Line Connections: The coil can be connected to outdoor units using accessory refrigerant line sets or field-supplied lines of refrigerant grade. The filter dryer should be placed just before the indoor unit.
Condensate Management: The coil is designed to dispose of accumulated water through built-in condensate drain fittings. PVC fittings are recommended for the condensate pan. A trap is not always necessary on the condensate line, but local codes should be consulted. If a trap is required, it should be installed as close to the coil as possible, at least 3 inches (76 mm) deep, and no higher than the bottom of the unit condensate drain opening. The condensate line should pitch 1 inch (25.4 mm) for every 10 ft. of length to an open drain or sump.
Secondary Condensate Pan: When installing over a finished ceiling and/or living area, a field-fabricated secondary condensate pan should be installed under the entire unit to prevent property damage from condensate overflow. A float switch can be installed to shut off the unit if water in the secondary pan gets too high. Alternatively, some localities may allow a separate 3/4-in. (19 mm) condensate line to a noticeable place.
Safety Features: The manual emphasizes safety considerations, including wearing safety glasses, protective clothing, and work gloves during installation and service. It also highlights the importance of turning off main power before servicing and using factory-authorized kits or accessories for modifications.

Maintenance Features:

Periodic Maintenance: To ensure high performance and minimize equipment failure, periodic maintenance is essential, ideally at least annually. This should be performed by a qualified service agency.
Filter Replacement/Cleaning: The only consumer service recommended or required is filter replacement or cleaning on a monthly basis.
Brazing Precautions: When brazing, it is crucial to avoid overheating the TXV valve (temperatures exceeding 212°F / 100°C can harm valve performance) by using a wet cloth or heat sink. A 1/2 psig Nitrogen purge should be used in the suction and out the liquid line during brazing.
TXV Bulb Placement: Ensure the TXV bulb is securely fastened and wrapped in the indentation on the vapor line tube for proper operation.
Refrigerant Line Care: Place the liquid filter dryer near the indoor unit to reduce the risk of debris clogging the TXV valve. Evacuate tubing and reclaim refrigerant when making connections or flaring tubing. Leak check connections before insulating the entire suction line.
Environmental Responsibility: Federal regulations require that refrigerant not be vented to the atmosphere. Recovery is necessary during system repair or final unit disposal. All components or materials (oil, refrigerant, etc.) should be removed and recycled before final unit disposal.