Table of Contents
Installation
Indoor Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Blower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-14
Blower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Furnace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Routine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26-27
Fall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28-29
8:1 Staged . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
4:1 Modulation . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Indirect Gas-Fired Unit Installations
Units are listed for installation in the United States and
Canada.
• Installation of gas-fired duct furnaces must conform
with local building codes. In the absence of local
codes, installation must conform to the National
Fuel Gas code, ANSI Z223.1 or in Canada, CAN/
CGA-B149 installation codes.
• All electrical wiring must be in accordance with the
regulation of the National Electrical Code, ANSI/
NFPA 70.
®
• Unit is approved for installation downstream from
refrigeration units. In these conditions, condensate
could form in the duct furnace and provision must be
made to dispose of the condensate.
Clearance to Combustibles /
Service Clearances
Floor
Indirect Fired
0 inches
(0 mm)
Units*
Clearance to combustibles is defined as the minimum
distance required between the heater and adjacent
combustible surfaces to ensure the adjacent surface's
temperature does not exceed 90° above the ambient
temperature.
*Reference venting guidelines for combustion blower clearances.
Recommended Minimum Service Clearances
Housing 32
and less
Clearances for component removal (such as evaporative
cooler media) should be 6 in. wider than the width of the
module itself.
Additional IOMs for Reference
For complete furnace information reference the Indirect
Gas-Fired Heat Modules Installation, Operation and
Maintenance Manual. Available turndown control
options include:
4:1- uses modulating valve and furnace
controller
Single Furnace
*High turndown uses a 4:1 modulating
Unit
valve with a proprietary manifold and
furnace controller
8:1- uses one 4:1 modulating furnace with
furnace controller and one 2-stage furnace
4:1 - uses two 4:1 modulating furnaces
controlled in parallel
Two Furnace
*High turndown furnaces in a series
Unit
configuration use one high turndown
furnace and one 2-stage furnace
*High turndown furnaces in a parallel
configuration use two high turndown
furnaces, controlled in parallel
12:1 - uses one 4:1 modulating furnace,
one 2 stage furnace and one 1-stage
furnace
Three Furnace
Unit
*High turndown uses one high turndown
furnace, one 2-stage furnace, and one
1-stage furnace
* High turndown furnace patent pending
8 stage
Single Furnace
2 stage
Unit
1 stage
4-stage uses two 2-stage furnaces
Two Furnace
Unit
2-stage uses two single-stage furnaces
6-stage uses three 2-stage furnaces
Three Furnace
Unit
3-stage uses three 1-stage furnaces
Top
Sides
Ends
0 inches
0 inches
0 inches
(0 mm)
(0 mm)
(0 mm)
42 inches (1067 mm) on the
controls side of the unit
Electronic Modulation
.
Staged
Model IG / IGX Make-Up Air
3
Need help?
Do you have a question about the IG and is the answer not in the manual?