Duct system, Water piping – Envision Peripherals R-410A User Manual

Page 6

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ENVISION RESIDENTIAL INSTALLATION MANUAL

Duct System

An air outlet collar is provided on vertical top air discharge units and all horizontal units to facilitate a duct connection

(vertical bottomflow units have no collar). A flexible connector is recommended for discharge and return air duct connec-

tions on metal duct systems. Uninsulated duct should be insulated with a minimum of 1-inch duct insulation. Application of

the unit to uninsulated ductwork in an unconditioned space is not recommended as the unit’s performance will be adversely

affected.

If the unit is connected to existing ductwork, check the duct system to ensure that it has the capacity to accommodate

the air required for the unit application. If the duct is too small, as in the replacement of heating only systems, larger duct-

work should be installed. All existing ductwork should be checked for leaks and repaired if necessary.

The duct system should be sized to handle the design airflow quietly and efficiently. To maximize sound attenuation of

the unit blower, the supply and return plenums should include an internal duct liner of fiberglass or constructed of ductboard

for the first few feet. On systems employing a sheet metal duct system, canvas connectors should be used between the

unit and the ductwork. If air noise or excessive airflow is a problem, the blower speed can be changed.

Water Piping

The proper water flow must be provided to each unit whenever the

unit operates. To assure proper flow, use pressure/temperature ports

to determine the flow rate. These ports should be located at the supply

and return water connections on the unit. The proper flow rate cannot

be accurately set without measuring the water pressure drop through

the refrigerant-to-water heat exchanger.

All source water connections on commercial units are fittings that

accept a male pipe thread (MPT). Insert the connectors by hand, then

tighten the fitting with a wrench to provide a leakproof joint. When con-

necting to an open loop (groundwater) system, thread any copper MPT

fitting into the connector and tighten in the same manner as described

above.

All source water connections on residential units are swivel piping

fittings (see Figure 4) that accept a 1-inch male pipe thread (MPT) .

The swivel connector has a rubber gasket seal similar to a rubber hose

gasket, which when mated to the flush end of any 1-inch threaded

pipe provides a leak-free seal without the need for thread sealing tape

or compound. Check to ensure that the rubber seal is in the swivel

connector prior to attempting any connection. The rubber seals are

shipped attached to the waterline. To make the connection to a ground

loop system, mate the brass connector (supplied in CK4L connector kit)

against the rubber gasket in the swivel connector and thread the female

locking ring onto the pipe threads, while maintaining the brass connec-

tor in the desired direction. Tighten the connectors by hand, then gently

snug the fitting with pliers to provide a leak-proof joint. When connecting to an open loop (ground water) system, thread any

1-inch MPT fitting (SCH80 PVC or copper) into the swivel connector and tighten in the same manner as noted above. The

open and closed loop piping system should include pressure/temperature taps for serviceability.

Never use flexible hoses smaller than 1-inch inside diameter on the unit. Limit hose length to 10 feet per connection.

Check carefully for water leaks.

Figure 4: Swivel Connections

(Residential Units)

Locking
Ring

Stainless
Steel
Snap Ring

Gasket
Support
Sleeve

Gasket
Material

CAUTION: Be sure to remove the shipping material from the blower discharge before con-

necting ductwork.

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