Installation Guide

507052-04 Page 11 of 53Issue 1727
Figure 14. Downow Application Installation
Clearances
Top 0
* Front 0
Back 0
Sides 0†
Vent 0
Floor NC‡
* Front clearance in alcove installation must be 24 in. (610
mm). Maintain a minimum of 24 in. (610 mm) for front service
access.
† Allow proper clearances to accommodate condensate trap.
‡ The furnace may be installed on a combustible wood oor if
an optional additive base is installed between the furnace and
the combustible oor.
Installation on Non-Combustible Flooring
1. Cut oor opening keeping in mind clearances listed
on unit rating plate. Also keep in mind gas supply
connections, electrical supply, ue and air intake
connections and sufcient installation and servicing
clearances. See Table 1 for correct oor opening size.
2. Flange warm air plenum and lower the plenum into the
opening.
3. Set the unit over the plenum and seal the plenum to
the unit.
4. Ensure that the seal is adequate.
Table 1. Non-Combustible Floor Opening Size
Cabinet Width
Front to Rear Side to Side
in. mm in. mm
B cabinet (17.5”)
19-3/4 502
16-5/8 422
C cabinet (21”) 20-1/8 511
NOTE: Floor opening dimensions listed are 1/4 in. (6 mm)
larger than the unit opening. See dimension drawing on Page
2.
Figure 15.
Installation on Combustible Flooring
1. When unit is installed on a combustible oor, a
downow combustible ooring base must be installed
between the furnace and the oor. The base must be
ordered separately. See Table 2 for opening size to
cut in oor.
The furnace and combustible ooring base shall not be
installed directly on carpeting, tile, or other combustible
material other than wood ooring.
CAUTION
Table 2. Combustible Flooring Base Opening Size
Cabinet
Width
Catalog
Number
Front to Rear Side to Side
in. mm in. mm
B cabinet
(17.5”)
11M60
22 559
18-3/4 476
C cabinet
(21”)
11M61 22-3/4 578
Figure 16.