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Critical safety warnings including high voltage, proper use, service personnel, and materials.
Details on connecting supply voltage, including grounding and voltage verification.
Procedure for adjusting the TXV to achieve correct subcooling and superheat.
Details on making low voltage connections to the thermostat and condenser.
This document outlines the installation, operation, and maintenance of Vertical Mount Air Handlers, emphasizing safety, proper setup, and troubleshooting for optimal performance.
Vertical Mount Air Handlers are designed to be integrated into a complete HVAC system, working in conjunction with an outdoor condenser or heat pump to provide heating and cooling for indoor spaces. These units are specifically designed for vertical "upflow" installations, either recessed into a wall or hung. They are equipped with a blower to circulate air, an evaporator coil for heat exchange, and connections for refrigerant lines and electrical supply. Many models include factory-installed, fully adjustable Thermal Expansion Valves (TXVs) to regulate refrigerant flow and ensure efficient operation. The units are designed to accommodate fresh air intake through knockouts on the cabinet sides, allowing for improved indoor air quality. They also feature both primary and secondary condensate drains to manage moisture removal, preventing water damage. The air handlers are designed to operate within specific altitude ranges, from 10,500 feet above sea level to 184 feet below sea level.
The air handlers are designed for flexible installation, supporting both bottom and front return air configurations. For recessed wall installations, the unit can be attached to framing studs using holes along the inside of the front flange. For hanging applications, an offset hanging bracket is provided at the rear of the cabinet. Proper leveling or a slight backward tilt is crucial during installation to ensure effective condensate drainage. The units are shipped with a filter rack and filter, which are essential for maintaining indoor air quality and protecting internal components. Regular inspection, cleaning, and replacement of the filter are recommended monthly.
Electrical connections are made through a knockout on the top or side panel of the air handler, requiring copper conductors and an NEC or CEC approved strain relief. The unit is designed for single-phase electrical supply, and it is critical to ensure that the supply voltage matches the unit's nameplate requirements. Low voltage connections are made to the room thermostat and outdoor unit, with various wiring schemes possible depending on the presence and type of heat kit (single-stage or multi-stage) and outdoor section (air conditioner or heat pump, single-stage or two-stage). The manual provides detailed wiring diagrams and blower charts to guide installers in selecting appropriate fan speeds and ensuring correct electrical hookups.
For models with factory-installed TXVs, the system requires specific adjustments to achieve optimal superheat and subcooling values. This involves running the system in cooling mode for 15 minutes to stabilize refrigerant pressures, connecting service gauges, and using a thermometer to measure liquid and vapor temperatures. Adjustments to the TXV valve stem are made clockwise to increase superheat and counterclockwise to decrease it, with a target range of 7 to 9°F for both superheat and subcooling. The unit is factory-shipped with R410A refrigerant and dry nitrogen mixture gas under pressure, necessitating appropriate service tools and safety procedures during installation and maintenance.
Routine maintenance is crucial for the long-term reliability and efficiency of the air handler. The manufacturer strongly recommends biannual checkups by a qualified servicer before the heating and cooling seasons. Key maintenance tasks include:
The unit's design prioritizes reduced air leakage, with gaskets ensuring that cabinet air leakage remains below 2% at 1.0 inch H2O and below 1.4% at 0.5 inch H2O, as tested in accordance with ASHRAE Standard 193. This contributes to overall system efficiency and performance.
General| Model | AWST18SU14 |
|---|---|
| Type | Air Handler |
| Cooling Capacity (Ton) | 1.5 Ton |
| Series | AA Series |
| Refrigerant | R-410A |
| Voltage | 208/230V |
| Phase | 1 |
| Frequency | 60 Hz |
| Cooling Capacity | 18000 BTU/h |
| Heating Capacity | 20, 000 BTU/hr |
| Static Pressure | 0.5 in. wg |
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