Advanced Distributor Products (ADP) PL Series Premier Indoor Plenum Coils are designed for efficient heating and cooling in a variety of HVAC applications. These coils are engineered for horizontal installation and are compatible with both R-22 and R-410A refrigerants. Their installation requires adherence to specific procedures to ensure optimal performance and system longevity. This guide provides a comprehensive overview of installation steps, refrigerant charging, drainage configuration, and safety considerations based on official documentation from ADP.
Installation Overview
ADP evaporator coils are designed for use with condensing units or heat pump units. These instructions are intended as a general guide and do not supersede local codes in any way. Before proceeding with installation, it is essential to consult with local authorities having jurisdiction to ensure compliance with all relevant regulations.
Pre-Installation Checks
- Shipping Damage Inspection: Upon receipt, check the coil for any signs of shipping damage and verify that all package contents are intact. If damage is discovered, contact the last carrier immediately.
- Performance Verification: Ensure that the coil’s efficiency and performance specifications (such as SEER, EER, and HSPF) align with the matched condensing or heat pump units. This information can be found in the AHRI ratings directory.
- Line Sizing: Consult the outdoor unit manufacturer for proper line sizing to ensure optimal refrigerant flow and system performance.
- Dry Air Holding Charge: Coils are shipped with a 10 psi dry air holding charge. Before removing the plugs, puncture the rubber plug on the suction line to release the charge. Note that the absence of pressure does not confirm the absence of leaks. Always check the coil for leaks before installation or return to the wholesaler.
Refrigerant Line Installation
ADP provides detailed recommendations for refrigerant line installation to minimize contamination and ensure system efficiency:
- Filter Drier and Sight Glass: ADP recommends installing a filter drier and sight glass in the liquid line. These components help remove contaminants and provide visual confirmation of refrigerant flow.
- Brazing Procedures: During brazing operations, purge the system with nitrogen to prevent contamination. This step is critical in maintaining the integrity of the refrigerant lines and preventing system failure.
- TXV Sensing Bulb Placement: For optimal performance, reattach and insulate the TXV sensing bulb at a 10 to 2 o’clock position on the suction line, outside the coil housing, no more than one foot from the connection. When brazing, place a wet rag around the suction line at the cabinet to prevent overheating and potential damage to the sensing bulb.
- System Evacuation: Evacuate the system to 500 microns to ensure proper removal of air and moisture. A deep or triple evacuation method is recommended for best results.
- Service Valve Operation: Open the suction service valve slowly and allow the refrigerant to bleed into the system before opening the liquid service valve. This process helps prevent sudden pressure surges that could damage system components.
Refrigerant Charging
Proper refrigerant charging is essential for system performance and efficiency. ADP provides specific guidelines based on the type of system and refrigerant used:
- Cooling Mode Charging: When charging in cooling mode, the outdoor temperature should be 60°F or higher. Allow the system to operate for a minimum of 15 minutes between adjustments to allow pressures to stabilize. For systems with micro-channel outdoor coils, make small adjustments (1 ounce or less) due to their sensitivity to refrigerant charge.
- TXV Charging Methods: Charging should follow the method recommended by the outdoor unit instructions. Alternatively, ADP recommends charging to 12°F sub-cooling for AC units and 10°F sub-cooling for heat pump units. If the system is equipped with an adjustable valve, adjust to 10°F superheat.
- Non-Bleed TXV Considerations: If the evaporator coil contains a non-bleed TXV and is used with a condensing unit containing a reciprocating compressor, a hard start mechanism will be required on the outdoor unit. This mechanism helps prevent compressor damage during startup.
- Metering Device Compatibility: When changing the metering device, ensure it matches the refrigerant type and capacity of the condensing unit. Failure to do so can result in poor performance and potential compressor damage. All coils must be matched properly as listed in the AHRI directory.
Drainage Configuration
Proper drainage is critical to prevent water damage and ensure system efficiency. ADP provides multiple configuration options for primary and secondary drain lines:
- Drain Line Routing: The condensate drain line should be routed to avoid freezing temperatures and must not interfere with accessibility to the coil, air handling system, or filter. The drain should be pitched downward at a rate of 1 inch per 10 feet, with a 2-inch trap as close to the coil as possible. If a second trap or an extended run is required before termination, a vent tee should be installed after the trap closest to the pan.
- Secondary Drain Installation: If the coil is located in or above a living space where damage may result from condensate overflow, a separate ¾” drain must be provided from the secondary drain connection. This drain should be routed to a location that complies with local installation codes and is easily noticeable when the unit is operational. Condensate flowing from the secondary drain indicates a clogged primary drain.
- Trap and Flow Testing: Prime the trap with water and test the line for leaks. Test water flow with the unit in operation to ensure proper drainage. A secondary drain pan should also be installed under the unit as specified by most local building codes.
- Drain Pan Options: ADP provides three configuration options for drain pans, as outlined in the installation manual. These options include routing the primary and secondary drains to designated areas or connecting them with a TEE to a secondary drain pan. Local codes must be followed in all cases.
Coil Support and Mounting
The coil must be properly supported to ensure structural integrity and optimal performance:
- Furnace Attachment: To attach the coil to the furnace, align the bottom edges of the coil and furnace. The included furnace mount bracket can be attached to the coil with two screws. The coil should then be attached to the furnace flanges using sheet metal screws. Ensure that the coil is sealed according to local codes.
- Coil Support Options: The coil can be supported from the bottom using furnace stands or by attaching hanging straps to the back end of the sheet metal. In all cases, the coil should be level or pitched slightly toward the drain connections to facilitate proper drainage.
Piston Size and Adjustment
For systems using a piston as the metering device, proper sizing is essential:
- Piston Sizing: The piston should be sized to match the recommendation from the outdoor unit manufacturer. If no specific recommendation is provided, refer to the piston size chart included in the installation manual.
- Piston Replacement Procedure: To change ADP pistons, follow these steps:
- Loosen the hex nut located on the liquid line and separate it from the distributor assembly.
- Remove the existing piston from inside the distributor assembly.
- Insert the desired piston into the distributor assembly.
- Inspect the Teflon O-ring and replace it if damaged. Ensure that the O-ring is in place.
- Re-install the hex nut to the body and torque it to 10 ft-lbs.
Safety Considerations
Several safety precautions must be followed to ensure safe installation and operation:
- Refrigerant Handling: The Clean Air Act of 1990 prohibits the intentional venting of refrigerants (CFCs and HFCs). Approved methods of reclaiming must be followed. Non-compliance may result in fines and/or incarceration.
- Leak Detection: The absence of pressure in the coil does not confirm the absence of leaks. Always check for leaks before installation or return to the wholesaler.
- Local Codes Compliance: Consult with local authorities to ensure that all installation practices comply with applicable building and safety codes.
Warranty and Support
ADP provides a limited warranty for its PL Series Premier Indoor Plenum Coils:
- Warranty Term: The warranty covers defects in material and workmanship under normal use and service for a period of five (5) years from the date of installation, not to exceed six (6) years from the date of manufacture.
- Warranty Registration: For information on warranty terms, extended warranty registration, or filing a claim, visit www.ADPwarranty.com. In states or provinces where registration requirements are prohibited, failure to complete registration does not diminish warranty rights.
Conclusion
The ADP PL Series Premier Indoor Plenum Coils are engineered for high performance and reliability in HVAC applications. Proper installation, refrigerant charging, and drainage configuration are essential to ensure optimal system performance and longevity. By following the detailed procedures outlined in the manufacturer’s documentation, technicians and DIY users can install these coils safely and effectively. It is important to always verify local codes and consult with professionals when necessary to avoid potential system issues or safety hazards.