York N1VSD10A06 Installation Instruction Download Page 3

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air duct and plenum. This clearance must be maintained
up to 3 feet a long the supply air duct. See Figure 2.

When a discharge plenum forms part of the duct work, it too must
have one inch clearance on all sides.

DUCT CONNECTIONS

NOTE: The electric heat accessory should be installed before the

supply air duct is attached to the supply air openings.

Air supply and return may be handled in one of several ways best
suited to the installation. See Figure 4 for Air Handler inlet and
outlet dimensions. Inlet dimensions of Air Handler are the same
as coil casing outlet dimensions.

The vast majority of problems encountered with combination
heating and cooling systems can be linked to improperly designed
or installed duct systems. It is therefore highly important to the
success of an installation that the duct system be properly de-
signed and installed.

Use flexible duct collars to minimize the transmission of vibra-
tion/noise into the conditioned space. If electric heat is used
non-flammable material must be used.

Where return air duct is short, or where sound is liable to be a
problem, sound absorbing glass fiber should be used inside the
duct. Insulation of duct work is a must where it runs through an
unheated space during the heating season or through an un-
cooled space during the cooling season. The use of a vapor
barrier is recommended to prevent absorption of moisture from
the surrounding air into the insulation.

The supply air opening on the fan unit should be enlarged to the
proper duct size by use of a transition. All ducts should be
suspended using flexible hangers and never fastened directly to
the structure.

Duct work should be fabricated and installed in accordance with local
and/or national codes. This includes the standards of the National
Fire Protection Association for Installation of Air Conditioning and
Ventilating Systems, NFPA No. 90A and Warm Air Heating and Air
Conditioning Systems, NFPA No. 90B.

INDOOR UNIT PREPARATION

Prepare Air Handler for installation as follows:

Each accessory is provided with its own instruction.

1. Attach coil casing to blower section in a way appropriate to

indoor unit application.

See Form 535.01-N5V for G*HC or G*FC Coils and
Form 535.01-N6V for G*HT Coils

Confirm the orifice size before connecting line. The G*HC and
G*FC coils will have an orifice installed in the fitting between the

liquid line connection and distributor. The orifice is identified on a
label next to the liquid connection.

The orifice that is shipped with the coil is based on the “most sold”
combination, but it may have to be changed, depending on the
capacity and efficiency of the outdoor unit, elevation differences,
and/or long total line lengths. See coil instruction and Application
Data (Form 690.01-AD1V) for detailed piping guidelines.

If a thermal expansion valve kit is installed, the orifice must be
removed.

The G*HT coils have a thermal expansion valve installed in the
liquid line. An orifice is not included in this coil. Be sure the G*HT
coil has been listed as a matched coil in the outdoor unit technical
guide.

NOTE: If a humidistat accessory is installed with the system, a

thermal expansion valve kit or G*HT coil must be installed
on the indoor side.

If a two stage (H*DS) outdoor condensing unit is installed with this
variable speed air handler a thermal expansion valve kit must be
installed.

2. Install Combustible Floor Base accessory if applicable. The

floor base is required on blower-heater combinations with
greater than zero clearance in a downflow position on a
combustible floor.

See Form 535.01- N1.5V

NOTE: Instructions for installing accessories are included with the

accessories.

3. Attach Filter Rack Accessory if applicable. The filter rack is

designed for use with G*HC, G*FC or G*HT coil or blower
section.

See Form 535.01- N1.4V

CAUTION: Equipment should never be operated without filters.