Envision Peripherals IM1603 Air Handler Installation, Connection to the Coil, Leak Testing

ENVISION SERIES AIR HANDLER INSTALLATION MANUAL

General Installation Information

Air Handler Installation

The air handler is attached to the shipping pallet with screws. Prior to setting the unit in place remove the ship- ping screws located in the front base right behind the air filter access panel. Also remove the external shipping brack- ets at the rear of the cabinet.

An air filter must always be installed upstream of the air coil on the return air side of the air handler. An air filter is provided with the air handler. If there is limited access to the filter rack for normal maintenance, it is suggested that a return air filter grille be installed. In this instance the filter supplied with the air handler should be removed. Be sure that the return duct is properly installed and free of leaks to prevent dirt and debris from bypassing the filter and plug- ging the air coil.

The cabinet should be sealed so that unconditioned warm air can not enter the cabinet. Warm air will introduce mois- ture into the cabinet which could result in water blow-off problems, especially when installed in an unconditioned space. Make sure that the liquid line, suction line and drain line entry points into the cabinet are well sealed. Use the butyl tape supplied with the air handler to seal around the copper lines entering the cabinet.

All wall penetrations should be sealed properly. The line set should not come into direct contact with water pipes, floor joists, wall studs, duct work, floors, walls and brick.

The line set should not be suspended from joists or studs with a rigid wire or strap which comes into direct contact with the tubing. Wide hanger straps which conform to the shape of the tubing are recommended. All line sets should be insulated with a minimum of 3/8” closed cell insula- tion. The line set insulation should be pliable, and should completely surround the refrigerant line. As in all R-410a equipment, a reversible liquid line filter drier is required to insure all moisture is removed from the system. This drier is factory installed in the Envision Split series compressor section. This drier should be replaced whenever “breaking into” the system for service. All exterior insulation should be painted with UV resistant paint or covering to insure long insulation life.

Connection to the Coil

Connect the refrigerant line set to the ‘A’ coil tubes. Nitro- gen should be bled through the system at 2 to 3 PSI to pre- vent oxidation inside the refrigerant tubing. Use a low silver phos-copper braze alloy on all brazed connections. The air handler txv bulb is secured to the ‘A’ coil for shipping. The Envision Split series compressor section is shipped with a factory charge and the service valves are not to be opened until the line set and air handler have been leak tested, purged and evacuated. A damp towel or heat sink should be used on the service valves to prevent damage caused by excessive heat.

Refer to the Refrigerant Line Sizing table to determine the proper line set configuration for the system being installed. Line sets over 60 feet in length are not recommended. If the line set is kinked or deformed and cannot be reformed,

the bad section of pipe should be replaced. A restricted line set will affect unit performance. Line sets should be routed as directly as possible, avoiding any unnecessary bends and turns.

Important Note:

The bulb will need to be attached to the suction line on the outside of the cabinet once the refrigerant line connections have been made.

Leak Testing

The refrigeration line set must be pressurized and checked for leaks before purging and charging the unit. To pres- surize the line set, attach refrigerant gauges to the service ports and add an inert gas (nitrogen or dry carbon dioxide) until pressure reaches 60 to 90 PSIG. Never use oxygen or acetylene to pressure test the system. Use an electronic leak detector or a good quality bubble solution to detect leaks on all connections made in the field. Be sure to check the service valve ports and stems for leaks. If a leak is found, repair it and repeat the above steps. For safety rea- sons do not pressurize the system above 150 PSIG. Purge pressure from the line set slowly when the pressure test is complete. The system is now ready for evacuation.

System Evacuation

Ensure that the line set and air coil are evacuated before opening service valves. The line set and air coil must be evacuated to 250 microns with a good quality vacuum pump and use a vacuum gauge to ensure that air and moisture are removed. With the system shut off from the vacuum pump a sufficient system vacuum is achieved when a 500 micron vacuum can be held for 30 minutes. A fast rise to atmospheric pressure indicates a leak, while a slower rise to around 1500 microns indicates moisture is still pres- ent in the system and further evacuation is required.

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