WaterFurnace Envision2 - Manual (Page 12)

12
ENVISION 2 COMPACT INSTALLATION MANUAL
An air outlet collar is provided on vertical top flow units
and all horizontal units to facilitate a duct connection.
A flexible connector is recommended for discharge
and return air duct connections 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
ductwork should be installed. All existing ductwork should
be checked for leaks and repaired if necessary.
Duct System
Water Piping
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.
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 connecting to an open
loop (groundwater) system, thread any copper MPT fitting
into the connector and tighten in the same manner as
described above.
1/2'' Pitch
Drain
1.5 in.
1.5 in. PVC tube stub
PVC coupling
Vent (if needed)
PVC tube stub
1/8 in. per foot
Unit Pitch for Drain Horizontal Drain Connection (Composite Drain Pan)
Condensate Drain
On vertical units, the internal condensate drain assembly
consists of a drain tube which is connected to the drain
pan, a 3/4 in. PVC female adapter and a flexible connecting
hose. The female adapter may exit either the front or the
side of the cabinet. The adapter should be glued to the
field-installed PVC condensate piping. On vertical units, a
condensate hose is inside all cabinets as a trapping loop;
therefore, an external trap is not necessary.
On horizontal units, a PVC stub or stainless steel tube
is provided for condensate drain piping connection. An
external trap is required (see below). If a vent is necessary,
an open stand pipe may be applied to a tee in the field-
installed condensate piping.