York DFAH User Manual
Page 9
107272-UIM-B-1105
Unitary Products Group
9
INSTALLATION OF TAB ATTACHMENT DUCT
CONNECTORS
1.
Make floor cut out as shown in Figure 8.
2.
Determine the depth of the floor cavity from the surface of the floor
to the top of the supply air duct and select the appropriate duct
connector from the chart.
3.
Place locating bracket (supplied with the duct connector) to the
rear of the floor area for the furnace. See Figure 11.
4.
Determine which of the four positions the duct connector best cen-
ters over the supply duct and insert it through the floor cut-out.
5.
Mark cut-out location on the supply duct and remove the duct con-
nector.
6.
Cut out the opening to the supply duct.
7.
Bend tabs down through and back up under the supply duct.
8.
Secure the duct connector to the floor with nails, flat head screws
or staples.
The duct connector is designed for use on ducts down to 12 in (30.5
cm) width. When using the connector on smaller width ducts, there will
not be sufficient clearance to bend the tabs on two sides of the duct
connector.
In such cases the tabs may be attached to the sides of the duct by
using sheet metal screws or other suitable fasteners. Holes for sheet
metal screws are provided in three (3) tabs on each side of the duct
connector. If more than 3 tabs need to be used to provide a more
secure and air tight connection, the remaining tabs can also be fas-
tened to the duct with screws after drilling the required screw hole.
IMPORTANT: The air temperature rise should be taken only after the
furnace has been operating for at least 15 minutes. Temperatures
should be taken 6" (15.2 cm) past the first bend from the furnace in the
supply duct. The return air temperature must be taken at the return air
louvered door. Return static pressures can be taken by pushing probe
through the air filter on the louvered door.
Furnace and Air Conditioner Installations
If an air conditioner is installed which does not use the blower for air dis-
tribution and operates completely independent of the furnace, the ther-
mostat system must have an interlock to prevent the furnace and air
conditioner from operating at the same time. This interlock system usu-
ally contains a heat-cool switch which must be turned to either HEAT or
COOL to activate either heating or cooling operation, or a positive OFF
switch on the cooling thermostat.
When used in connection with a cooling unit the furnace shall be
installed parallel with or on the upstream side of the cooling unit to avoid
condensation in the heat exchanger.
For installations with a parallel flow arrangement, the furnace must be
equipped with a damper to prevent cold air from being discharged up
around the heat exchanger. Cold air causes condensation inside the
exchanger and can cause it to rust out which can allow products of
combustion to be circulated into the living area by the furnace blower
resulting in possible asphyxiation. An air flow activated automatic
damper, is available from furnace manufacturer. See Figure 12.
NOTE: See label on coil panel for conversion and lighting instructions.
Obtain a temperature rise within the ranges specified on the name
plate.
INSTALLATION OF THE FURNACE
1.
Remove the front panels and set the furnace onto the duct con-
nector. Slide it back until the rear of the unit engages the locator
bracket.
2.
Secure the front of the furnace with two screws at the mounting
holes provided. See Figure 13.
3.
Secure the top of the furnace to a structural member using screw
through the strap at the back of the furnace. Strap may be moved
to any of the holes located along the top back of the furnace.
Installer may provide an equivalent method, such as screws
through the casing side.
FIGURE 11: Duct Connector Tab Attachment
TABLE 4: External Static Pressure Range
Input
Output
Nominal
Air Flow
1
1. Std. Blower-High Speed-No Coil.
Ext. Static Pressure
Minimum
Maximum
MBH
kW
MBH
kW
CFM cmm In.W.C kPa In.W.C kPa
66000 19.34 53000 15.55 1050 29.73
.12
.03
.30
.07
84000 24.62 67000 19.63 1250 35.40
.12
.03
.30
.07
Bend Tabs Under Duct
Opening to Secure to the
Supply Duct
Locator Bracket
Nails, Flat Head Screws
or Staples
Floor
Supply Duct
All installations must have a filter installed.
FIGURE 12: Anti-Backflow Damper
FIGURE 13: Installation of Furnace
Automatic
Damper
Supply Duct
Opening
Furnace
Base
Duct
Connector
NOTE: FOR BEST AIR DELIVERY INSTALL DAMPER
WITH BLADES PARALLEL TO SUPPLY DUCT.
Secure Furnace to
Floor with Two Nails
or Screws.
Furnace Seated
Against the
Locator Bracket