7
NSZ/NDZ INSTALLATION MANUAL
Coil uses a TXV. No capillary or fixed orifice systems
•
should be used
A life expectancy of more than 7 years remaining for the
•
air handler and components
Flush air coil and line set
•
When utilizing the existing air coil or line set, only flushing
compounds that vaporize should be used; which means
they are packaged in a pressurized disposable cylinder. It is
preferable to use a flushing agent that removes oil, water,
and acid, plus, is biodegradeable and non-toxic. The flushing
agent should be safe to use with both HCFC and HFC
refrigerants. Once a flushing agent has been selected, follow
the instructions provided with the product.
The first step should be purging the lines or air coil with
nitrogen. Purging with nitrogen first will remove some of
the particulate and residual oil which will allow the flushing
agent to work better. Never blow the flushing agent
through a compressor, filter drier, or txv as it will cause the
components to fail.
When flushing is complete and the final system is assembled,
an acid check should be preformed on the system. Acid test
kits are available from most HVACR distributors.
Connection to Air Coil
Figures 1 and 2 illustrate typical Envision Split installations.
Reference the Line Set Sizes table for typical line set
diameters and maximum length. Line sets over 60 feet 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.
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 should be replaced whenever “breaking
into” the system for service. All line sets should be insulated
with a minimum of 1/2 in. closed cell insulation. All exterior
insulation should be painted with UV resistant paint or
covering to ensure long insulation life.
Air Handler Installation
Air handlers used with dual capacity units must be capable
of operating with a minimum of 2 blower speeds. Refer to
the manufacturer’s instructions for the blower coil unit for
details on installing the air handling portion of the system.
All blower coil units/air coils must be installed as specified
by the manufacturer’s installations instructions. However,
the following recommendations should be considered to
minimize noise and service problems.
An air filter must always be installed upstream of the air coil
on the return air side of the air handler or furnace. If there
is limited access to the filter rack for normal maintenance,
it is suggested that a return air filter grille be installed. Be
sure that the return duct is properly installed and free of
leaks to prevent dirt and debris from bypassing the filter and
plugging the air coil.
Ensure that the line set size is appropriate to the capacity of
the unit (refer to Line Set Sizes table). Line sets should be
routed as directly as possible, avoiding unnecessary bends
or turns. All wall penetrations should be sealed properly. Line
set should not come into direct contact with water pipes,
floor joists, wall studs, duct work, floors, walls and brick.
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 strips which conform to the shape of
the tubing are recommended. Isolate hanger straps from line
set insulation by using metal sleeves bent to conform to the
shape of insulation. Line set insulation should be pliable, and
should completely surround the refrigerant line.
NOTES:
Improper installation of equipment may result in
undesirable noise levels in the living areas.
Disconnect
Thermostat Wire
From Air Handler
Vibration Absorbing Pad or Air Pad
P/T Plugs
Water Out
Water In
Lineset To
Air Handler
Insulated Suction Line
Supply
Duct
Wire To
Thermostat
Return
Duct
Condensate Drain
(must be trapped)
To Drain
Remote Air Handler
(Maximum Recommended Distance is
60' Between Units)
DHW In
DHW Out
Figure 1: Typical Split System Application with
Remote Blower Coil
General Installation Information cont.
