2
SAFETY INFORMATION .............................................5
REQUIREMENTS AND CODES ..................................5
GENERAL INSTRUCTIONS ........................................6
Combustion Air Quality ............................................6
Operation of Furnace During Construction ..............6
Installation in a Garage ............................................7
Heating
Load
...........................................................7
Clearances to Combustible Materials ......................7
COMBUSTION AIR REQUIREMENTS ........................7
General
Information
.................................................7
Conventional Furnaces - Confi ned Spaces .............8
Outdoor Air Using Vertical Ducts ........................8
Outdoor Air Using Horizontal Ducts ....................8
Outdoor Air from a Crawl Space or
Vented
Attic
.........................................................8
Air Directly Through an Exterior Wall .................8
Alternate Method of Providing air from
Outside
...............................................................9
Air From Inside ....................................................9
Conventional Furnaces - Unconfi ned Spaces .......10
Direct
Vent
Furnaces
.............................................10
VENTING REQUIREMENTS ......................................11
Vent Pipe Material .................................................11
Vent Pipe Length and Diameter .............................11
Vent Pipe Installation .............................................12
Outdoor Terminations - Horizontal Venting ............12
Outdoor Terminations - Vertical Venting .................12
Vent Freezing Protection .......................................13
Condensate
Disposal
............................................13
Existing
Installations
..............................................14
FURNACE INSTALLATION .......................................14
General
Requirements
..........................................14
Vent and Inducer Assembly Options .....................14
Inducer Assembly Rotation ...................................14
Pressure Switch Relocation ..................................15
Special Instructions for SC038-23A
Furnaces
..........................................................15
Condensate Drain Lines ........................................16
Direct Vent (2 - Pipe) Applications ........................16
Upfl
ow
Installation
.................................................16
Side Return Air Inlet ........................................16
Bottom Return Air Inlet ....................................16
Horizontal
Installation
...........................................16
Bottom Panel Removal ....................................17
Downfl
ow
Installation
............................................17
Installation on a Concrete Slab ..........................18
CIRCULATING AIR REQUIREMENTS ......................18
Plenums and Air Ducts ..........................................18
Supply Air Connections ........................................19
Upfl
ow/Horizontal
Furnaces
............................19
Downfl
ow
Furnaces
.........................................19
Return Air Connections ........................................19
Upfl
ow/Horizontal
Furnaces
..............................19
Side Return Installations ..............................19
Bottom Return Installations ..........................19
Downfl
ow
Furnaces
...........................................19
Acoustical
Treatments............................................19
GAS SUPPLY AND PIPING .......................................20
Leak
Check
.........................................................20
High-Altitude
Application
......................................20
Conversion to LP/Propane ...................................21
TABLE OF CONTENTS
