Installation Instructions
Description
This kit contains the appropriate burner orifices, and/or pres-
sure switch for the application of 90% furnaces in installations
above their maximum (as shipped) rated altitudes. These kits
are not applicable in Canada. Kits apply as shown in the table
below.
Natural Gas
Orifices
Propane Gas
Orifices
Pressure Switch
No Change LPM-06 No Change
Natural Gas
Orifices
Propane Gas
Orifices
Pressure Switch
HANG11 HALP10 HAPS27
Natural Gas
Orifices
Propane Gas
Orifices
ID Blwr
Pressure Switch
HANG12 HALP10 HAPS27
"Standard" and "High Altitude" Kits
7,001 - 9,000 Feet
9,001 - 11,000 Feet
0 - 7,000 Feet (Standard Altitude)
Table 1
Above rated altitude, a derating of the appliance must be fol-
lowed since the CFM moved by the induced draft blower re-
mains almost constant while the pounds of oxygen in that air
is reduced as altitude increases. If this procedure is not fol-
lowed and the fuel input is not reduced the resulting combus-
tion can be inefficient, incomplete, or possibly cause prema-
ture heat exchanger failure due to excessive temperature rise.
HANG11, HANG12, HALP10, HAPS27
HIGH ALTITUDE CONVERSION KIT
INSTALLATION INSTRUCTIONS
The burner orifices in the high altitude kits have been selected
as a result of agency certified testing at high altitude and will
provide the appropriate derating (Table 2). Orifice selection is
based on non-derated gas [about 1000 BTU/Ft
3
for natural
gas, and 2500 BTU/Ft
3
for propane gas]. NOTE: “Point of
use” Btu content will be less due to decreased atmo-
spheric pressure. If the Btu content of your gas supply has
been artificially changed to account for altitude, contact your
gas supplier for orifice sizing.
Altitude (ft)
Natural Gas
Derate
Propane
Gas Derate
7,001 - 9,000 15.3 + 4% X
7,501 - 11,000 32.1 + 4% X
Table 2
Do not derate by adjusting the manifold pressure to a
lower pressure setting than specified on the furnace
nameplate. A lower air density in combination with a lower
manifold pressure at the burner orifice will prevent the orifice
from aspirating the proper amount of air into the burner re-
quired for complete combustion.
In addition to using smaller orifices to reduce the fuel input, a
different pressure switch must be used above the rated altitude
shown in Table 1. A high altitude pressure switch is neces-
sary as a result of the reduction in air density and is required
regardless of the Btu content of the fuel used.
Natural Propane
7 001 - 9 000 #44 X
9001 - 11 000 #45 #56
Burner Orifice Size
Altitude (ft)
Table 3
RECOGNIZE THIS SYMBOL AS A SAFETY PRECAUTION.
ATTENTION INSTALLING PERSONNEL
As a professional installer, you have an obligation to know the product better than the customer.
This includes all safety precautions and related items.
Prior to actual installation, thoroughly familiarize yourself with this Instruction Manual. Pay special attention to all safety warnings.
Remember, it is your responsibility to install the product safely and to know it well enough
to be able to instruct a customer in its safe use.
Safety is a matter of common sense...a matter of thinking before acting.
Most dealers have a list of specific, good safety practices...follow them.
The precautions listed in this Installation Manual are intended as supplemental to existing practices. However, if there is a direct conflict between
existing practices and the content of this manual, the precautions listed here take precedence.
IO-685A
September 2013