ICP 9MPD050F12B1 User manual

90 SingleStage
CategoryIVFurnace
N9MP1 & N9MP2
*9MPD *Denotes Brands (C, H, T)
FAN ASSISTED, DIRECT
VENT GAS FURNACE
SAFETY REQUIREMENTS
Recognize safety information. This is the safety- alert symbolZ.l_. When you see this symbol on the furnace and in instructions manuals be alert to
the potential for personal injury.
Understand the signal words DANGER, WARNING, or CAUTION. These words are used with the safety-alert symbol. DANGER identifies the
most serious hazards, those that will result in severe personal injury or death. WARNING signifies a hazard that could result in personal injury or
death. CAuT__Nis used t_ identify unsafe practices that c_u_d resu_t in min_r pers_na_ injury _r pr_duct and pr__erty damage.
Installing and servicing heating equipment can be hazardous due to gas and electrical components. Only trained and qualified personnel should
install, repair, or service heating equipment.
Untrained service personnel can perform basic maintenance functions such as cleaning and replacing air filters. All other operations must be
performed by trained service personnel. When working on heating equipment, observe precautions in the literature, on tags, and on labels attached
to or shipped with the unit and other safety precautions that may apply.
Follow all safety codes. In the United States, follow all safety codes including the current edition National Fuel Gas Code (NFGC) ANSI
Z223.1-2002/NFPA No. 54-2002. In Canada, refer tothecurrent edition of the National Standard of Canada Natural Gas and Propane Installation
Code (NSCNGPIC) CSA B149.1-00. Wear safety glasses and work gloves. Have fire extinguisher available during start-up and adjustment
procedures and service calls.
These instructions cover minimum requirements and conform to existing national standards and safety codes. In some instances, these instructions
exceed certain local codes and ordinances, especially those that may not have kept up with changing residential construction practices. We require
these instructions as a minimum for a safe installation.
INSTALLER: Affix these instructions
on or adjacent to the furnace.
CONSUMER: Retain these
instructions for future reference.
International Comfort Products, LLC
Lewisburg, TN 37091 U.S.A. Table of Contents
1.SafeInstallationRequirements................. 3
2.Installation................................ 4
3.Combustion&VentilationAir .................. 8
4.Vent&CombustionAir Piping ................ 10
5.GasSupply andPiping...................... 29
6.ElectricalWiring ........................... 33
7.DuctworkandFilter ........................ 35
8. ChecksandAdjustments.................... 38
9.FurnaceMaintenance ....................... 40
10.SequenceofOperation&Diagnostics.......... 41
11.ConcentricVentTermination................. 45
TechSupportand Parts........................ 49
ELECTRIC SHOCK HAZARD
Failure to follow safety
warnings exactly could result
in serious injury, death, and/or
property damage.
Turn Off All Power Before
Servicing.
CARBON MONOXIDE POISNING AND FIRE
HAZARD.
Failure to follow safety warnings exactly could
result in serious injury, death, and/or property
damage.
This furnace is not designed for use in mobile
homes, trailers or recreational vehicles.
PrintedinU.S.A. 07/15/2004 440 01 1020 (04)

START-UP CHECK SHEET
For 90+ Furnace
(Keep this page for future reference)
Dealer Name:
Address:
City, State(Province), Zip or Postal Code:
Business Card Here
Phone:
Owner Name:
Address:
City, State(Province), Zip or Postal Code:
Model Number:
Serial Number:
Type of Gas: Natural: _ LP:
Which blower speed tap is used?
(Heating) (Cooling).
Temperature of Supply Air:
Temperature of Return Air:
(°F)___or(°C)
(°F) or(°C)__
Rise (Supply Temp.-Return Temp.): (°F) or(°C)__
Filter Type and Size:
Fan "Time ON" Setting:.
Fan "Time OFF" Setting:
Manual Gas Shut-Off Upstream
of Furnace/Drip- Leg?
Condensate Drain Connected?
YES
YES
Condensate Drain Trapped? YES
NOE_
NO
NO
Transition Pressure switch hose relocated for U/D/H
Application? YES _ NO
Blower Speed Checked? YES _ NO
All Electrical Connections Tight? YES _ NO
Gas Valve OK? YES _ NO
Measured Line Pressure When Firing Unit:
Calculated Firing Rate:(See Checks and Adjustments Sec-
tion).
Temperature Rise (supply-return temperature):(°F)__
Measured Manifold Gas Pressure:
Static Pressure (Ducts): Supply Air Return
Date of Start-Up:
CO?
CO2 ?
Dealer Comments:
E_ 44001102004

1. Safe Installation Requirements
FIRE, EXPLOSION, AND ASPHIXlATION HAZARD
Improper adjustment, alteration, service,
maintanence or installation could cause serious
injury, death and/or property damage.
Installation or repairs made by unqualified persons
could result in hazards to you and others.
Installation MUST conform with local codes or, in
the absence of local codes, with codes of all
governmental authorities having,jurisdiction.
The information contained in this manual is
intended for use by a qualified service agency that
is experienced in such work, is familiar with all
precautions and safety procedures required in
such work, and is equipped with the proper tools
and test instruments.
NOTE: This furnace is design-certified by the CSA International
(formerly AGA and CGA) for installation in the United States and
Canada. Refer to the appropriate codes, along with this manual,
for proper installation.
• Use only the Type of gas approved for this furnace (see
Rating Plate on unit). Overfiring will result in failure of heat
exchanger and cause dangerous operation. (Furnaces
can be converted to L.P. gas with approved kit.)
• Install this furnace only in a location and position as speci-
fied in "2. Installation"of these instructions.
• Provide adequate combustion and ventilation air to the fur-
nace as specified in "3. Combustion and Ventilation Air" of
these instructions.
Combustion products must be discharged outdoors. Con-
nect this furnace to an approved vent system only, as spe-
cified in "4. Vent and Combustion Air Piping" of these
instructions.
Never test for gas leaks with an open flame. Use a com-
mercially available soap solution made specifically for the
detection of leaks to check all connections, as specified in
"6. Gas Supply and Piping, Final Check"of these instruc-
tions.
Always install furnace to operate within the furnace's in-
tended temperature-rise range with a duct system which
has an external static pressure within the allowable range,
as specified in "Technical Support Manual" of these in-
structions.
• When a furnace is installed so that supply ducts carry air
circulated by the furnace to areas outside the space con-
taining the furnace, the return air shall also be handled by a
duct(s) sealed to the furnace casing and terminating out-
side the space containing the furnace.
• A gas-fired furnace for installation in a residential garage
must be installed as specified in "2. Installation"of these
instructions.
• This furnace is not to be used for temporary heating of
buildings or structures under construction.
• This furnace is NOT approved for installation in mo-
bile homes, trailers or recreation vehicles.
• Seal around supply and return air ducts.
• Install correct filter type and size.
• Unit MUST be installed so electrical components are pro-
tected from direct contact with water.
Safety Rules
Your unit is built to provide many years of safe and dependable
service providing it is properly installed and maintained. However,
abuse and/or improper use can shorten the life of the unit and
create hazards for you, the owner.
A, The U.S. Consumer Product Safety Commission encourages
installation of carbon monoxide alarms. There can be various
sources of carbon monoxide in a building or dwelling. The
sources could be gas-fired clothes dryers, gas cooking
stoves, water heaters, furnaces, gas-fired fireplaces, wood
fireplaces, and several other items.
Carbon monoxide can cause serious bodily injury and/or
death. Carbon monoxide or "CO" is a colorless and odorless
gas produced when fuel is not burned completely or when the
flame does not receive sufficient oxygen.
Therefore, to help alert people of potentially dangerous ca rbon
monoxide levels, you should have a commercially available
carbon monoxide alarm that is listed by a nationally recog-
nized testing agency in accordance with Underwriters Labora-
tories Inc. Standard for Single and Multiple Station Carbon
Monoxide Alarms, ANSI/UL 2034 or the CSA 6.19-01 Resi-
dential Carbon Alarming Devices installed and maintained in
the building or dwelling concurrently with the gas- fired furnace
installation (see Note below). The alarm should be installed as
recommended by the alarm manufacturer's installation in-
structions.
B, There can be numerous sources of fire or smoke in a building
or dwelling. Fire or smoke can cause serious bodily injury,
death, and/or property damage. Therefore, in order to alert
people of potentially dangerous fire or smoke, you should have
fire extinguisher and smoke alarms listed by Underwriters Lab-
oratories installed and maintained in the building or dwelling
(see Note below).
Note: The manufacturer of your furnace does not test any alarms
and makes no representations regarding any brand or type
of alarms.
C,
1.
To ensure safe and efficient operation of your unit, you should
do the following:
Thoroughly read this manual and labels on the unit. This
will help you understand howyour unit operates and the haz-
ards involved with gas and electricity.
Do not use this unit if any part has been under water. Im-
mediately call a qualified service technician to inspect the unit
and to replace any part of the control system and any gas con-
trol which has been under water.
3. Never obstruct the vent grilles, or any ducts that provide
air to the unit. Air must be provided for proper combustion
and ventilation of flue gases.
44001 102004 [_

FrozenWater PipeHazard
WATER DAMAGE TO PROPERTY HAZARD
Failure to protect against the risk of freezing could
result in property damage and/or personal injury.
Do not leave your home unattended for long periods
during freezing weather without turning off water
supply and draining water pipes or otherwise
protecting against the risk of frozen pipes and
resultant damage.
Your furnace is designed solely to provide a safe and comfortable
living environment. The furnace is NOT designed to ensure that
water pipes will not freeze. It is equipped with several safety de-
vices that are designed to turn the furnace off and prevent it from
restarting in the event of various potentially unsafe conditions.
If your furnace remains off for an extended time, the pipes in your
home could freeze and burst, resulting in serious water damage.
If the structure will be unattended during cold weather you should
take these precautions.
1. Turn off the water supply to the structure and drain the water
lines if possible and add an antifreeze for potable water to
drain traps and toilet tanks. Open faucets in appropriate
areas.
-or-
Have someone check the structure frequently during cold
weather to make sure it is warm enough to prevent pipes
from freezing. Instruct them on a service agency to call to
provide service, if required.
-or-
3. Install a reliable remote sensing device that will notify some-
body of freezing conditions within the home.
Winter Shutdown
If you go away during the winter months and do not leave the heat
on in your home, the plastic transition box and the condensate trap
on the furnace must be protected from freeze damage.(See
Figure 9 trough Figure 18)
1. Disconnect the 5/8" OD rubber hose from the vent drain fit-
ting that is located downstream of the combustion blower.
Insert a funnel into the hose and pour four(4) ounces of sani-
tary type (RV) antifreeze into the condensate trap. Recon-
nect the 5/8" OD rubber hose to the stub on the vent drain
fitting. Secure with the hose clamp.
2. Disconnect the 3/4" OD rubber hose from the condensate
trap. Insert a funnel into the hose and and pour four(4)
ounces of sanitary type (RV) antifreeze into the plastic Tran-
sition box. Squeeze the hose together near the end and
quickly reconnect the 3/4" OD rubber hose to the stub on the
condensate trap. Secure with the hose clamp.
When you return home, your furnace will be ready to start, as it is
not necessary to drain the antifreeze from the furnace.
2. Installation
CARBON MONOXIDE POISONING HAZARD
Failure to properly vent this furnace or other
appliances could result in death, personal injury
and/or property damage.
This furnace can NOT be common vented or
connected to any type B, BW or L vent or vent
connector, nor to any portion of a factory-built or
masonry chimney. If this furnace is replacing a
3reviously common-vented furnace, it may be
necessary to resize the existing vent and chimney to
3revent oversizing problems for the other
remaining appliance(s). See Venting and Combus-
tion Air Check in Gas Vent Installation section. This
furnace MUST be vented to the outside.
Location and Clearances
If furnace is a replacement, it is usually best to install the fur-
nace where the old one was. Choose the location or evalu-
ate the existing location based upon the minimum clearance
and furnace dimensions (Figure 3).
FROZEN AND BURST WATER PIPE HAZARD
Failure to protect against the risk of freezing could
result in property damage and/or personal injury.
Special precautions MUST be made if installing
furnace in an area which may drop below freezing.
This can cause improper operation or damage to
equipment. If furnace environment has the potential
of freezing, the drain trap and drainline must be
protected. The use of electric heat tape or RV
antifreeze is recommended for these installations.
(See "Condensate Trap Freeze Protection Section")
1, Refer to Figure 1 or Figure 2for typical installation and ba-
sic connecting parts required. Refer to Figure 4 for typical
horizontal direct vent installation and basic connecting parts
required. Supply and return air plenums and duct are also
required.
Do NOT operate furnace in a corrosive atmosphere
containing chlorine, fluorine or any other damaging
chemicals. Refer to Combustion & Ventilation Air section,
Contaminated Combustion Air.
E_ 440011020 04

Typical Upflow Installation
Aluminumornon-rustingshield recommended.(See
VentTerminationShieldingfor dimensions).
Coupling on ends of
*8" Min. _l[q _I_ exhaust pipe. Total
20' Max. Inlet Pipe(not
in same _ _ usedon Single pipe & coupling out-
atmospheric <_ __4t_ Pipemodel) side structure = 8"
zone
VentPipes MUSTbe /]in.
supported
andVertically meatmospheric
* Increase minimum from 8" to 18" for cold climates (sustained temperatures below
0 ° F). 25-23-33
Typical Downflow Installation
See VentTermination
Shieldingin VentSection.
_1 14' *8" Min.
InletPipe _ [_ 20' Max.
(not usedon _ _ in same
SinglePipe _ I,,,_L, atmospheric zone
model) _
Vent Pip MUST bq
support( 4orizonta
andVertically
Coupling on inside
and outside of wall
to restrain vent pipe
Min.
Max.
same
osphericzone
* Increase minimum from 8" to 18" for cold climates (sustained temperatures
below O°F). 25-23-33a
CARBON MONOXIDE POISONING HAZARD.
Failure to follow safety warnings exactly could
result in serious injury, death, or property damage.
Do NOT operate furnace in a corrosive atmosphere
containing chlorine, fluorine or any other damaging
chemicals, which could shorten furnace life.
Refer to 3. Combustion & Ventilation Air section,
Contaminated Combustion Air for combustion air
evaluation and remedy.
Installation Requirements
1. Install furnace level.
2. This furnace is NOT to be used for temporary heat of buildings
or structures under construction.
3. Install the vent pipes as short as practical. (See Gas Vent
Installation section).
4. Do NOT install furnace directly on carpeting, tile or other com-
bustible material other than wood flooring.
5. Maintain clearance for fire safety and servicing. A front clear-
ance of 30" is minimum for access to the burner, controls and
filter. See clearance requirements in Figure 3 or.
6. Use a raised base if the floor is damp or wet at times.
7. Residential garage installations require:
• Burners and ignition sources installed at least 18" (457 ram)
above the floor.
8.
Furnace must be located or physically protected from pos-
sible damage by a vehicle.
If the furnace is to be suspended from the floorjoists in a base-
ment or a crawl space or the rafters in an attic, it is necessary
to use steel pipe straps or an angle iron frame to attach the
furnace. These straps should be attached to the furnace with
sheet metal screws and to the rafters or joists with bolts. The
preferred method is to use an angle iron frame bolted to the
rafters or joists.
I his furnace may be used for construction heat provided that all
the following conditions are met:
The furnace is permanently installed with all electrical wir-
ing, piping, venting and ducting installed according to these
installation instructions. A return air duct is provided, sealed
to the furnace casing, and terminated outside the space
containing the furnace. This prevents a negative pressure
condition as created by the circulating air blower, causing a
flame rollout and/or drawing combustion products into the
structure.
• The furnace is controlled by a thermostat. It may not be "hot
wired" to provide heat continuously to the structure without
thermostatic control.
Clean outside air is provided for combustion. This is to mini-
mize the corrosive effects of adhesives, sealers and other
construction materials. It also prevents the entrainment of
drywall dust into combustion air, which can cause fouling
and plugging of furnace components.
The temperature of the return air to the furnace is no less
than 55 ° F, with no evening setback or shutdown. The use of
the furnace while the structure is under construction is
deemed to be intermittent operation per our installation in-
structions.
• The air temperature rise is within the rated rise range on the
furnace rating plate, and the firing rate has been set to the
rating plate value.
• The filters used to clean the circulating air during the
construction process must be either changed or thoroughly
cleaned prior to occupancy.
• The furnace, ductwork and filters are cleaned as necessary
to remove drywall dust and construction debris from all
HVAC system components after construction is completed.
44001 102004 [_

|
I
Dimensions & Clearances
17/8
Unit
Capacity
NOMP1050B12A
N9MP1075B12A
NgMP1080F16A
N9MP1100F14A
NgMP1100J20A
NOMP1125J20A
NOMP2050B12A
NOMP2075B12A
NgMP2080F16A
NgMP2100F14A
NOMP2100J20A
NOMP2125J20A
*9MPDO50F12A
*9MPDO75F12A
*9MPDOSOJ16A
*9MPD100J14A
*9MPDIOOJ20A
*9MPD125L20A
TOP
r-- ]
]
LEFT SIDE [-_ _
TRAP(COUNTERFLOW)_
GASt_
VENT )
AIR INTAKE _" )
(ALTERNATE)_ 413/16_
TRAP
UPFLOWtHORIZONTAL_
THERMOSTA_=_ 7-
215/8_ 47/
24
11/4
/ELECTRICAL
11/16
31
2(, f8
3/4
1/1
113/1
_A_ B_
FRONT
Drawing is representative,
but some models may vary
BOTTOM
-- 23118 _,_ 37/8
Cabinet Bottom
ALL DIMENSIONS IN INCHES
MINIMUM CLEARANCES TO
COMBUSTIBLE MATERIALS FOR ALL UNITS
REAR O
FRONT (combustion air openings in 3"
furnace and in structure)
Required For Service *24"
ALL SIDES Of SUPPLY PLENUM 1"
SIDES O
VENT O
TOP OF FURNACE 1"
*30" clearancerecommendedfor casingremoval.
Horizontalposition:Linecontactispermissibleonlybetween
linesformedby intersectionsoftop andtwosidesoffurnace
jacket,andbuildingjoists,studsorframing.
NOTE: Evaporator "A" coil drain pan dimensions
may vary from furnace duct opening size, AIways
consult evaporator specifications for duct size
requirements,
Furnace is designed for bottom return or side
return.
Return air through back of furnace is NOT allowed.
28112
/
16_/ _ 18112
23/8 --
1r/16_ /
/RIGHT SIDE
GAS\ /
//TRAP (COUNTERFLOW)
_I_ELECTRICAL
AIRINTAKE
/(ALTERNATE)
413116_ _'_/VENT
11111_ _ TRAPowIHORIZONTAL
19114
L _
47/8 _=_215/8
24
17/8
25-23-36b
E_ 440011020 04

Installation Positions
This furnace can be installed in an upflow, horizontal (either left or
right) or downflow airflow position. DO NOT install this furnace on
its back. For the upflow position, the return air ductwork can be at-
tached to either the left or right side panel and/or the bottom. For
horizontal and downflow positions, the return air ductwork must be
attached to the bottom. The return air ductwork must never be at-
tached to the back of the furnace.
Furnace Installation Considerations
The installation of the furnace for a given application will dictate the
position of the furnace, the airflow, ductwork connections, vent and
combustion air piping. Consideration must be given to the follow-
ing:
Condensate Trap and Drain Lines
The supplied condensate trap must be attached to the furnace
side panel on either the left or right side. For horizontal installa-
tions, the drain trap is vertically attached to the side panel below
the furnace. A minimum clearance of 6" below the furnace is re-
quired for the condensate trap. Downward slope of the conden-
sate drain line from the condensate trap to the drain location must
be provided. Adequate freeze protection of the drain trap and the
Horizontal Furnace Installation
This furnace can be installed horizontally in an attic, basement,
crawl space, alcove, or suspended from a ceiling in a basement or
utility room. See Figure 4. Do not install furnace on its back or in
the reverse airflow positions as safety control operation will be ad-
versely affected.
Typical Horizontal Installation
Inlet Pipe (not used on Single Pipe model)
Vent
Condensate
Trap
NOTE:6" bottomclearancerequiredfor condensatetrap.
25-23-34
drain line must be provided. See "Condensate Drain Trap"section
for further details.
Leveling
Proper leveling of the furnace must be provided to insure proper
drainage of the condensate from the furnace. The furnace must be
level to within 114"from front to back and from side to side for upflow
and downflow installations or top to bottom for horizontal installa-
tions.
Vent and Combustion Air Connections
On the Dual Certified furnace, the vent and combustion air pipes
attach to the furnace through the top panel for the upflow and hori-
zontal installations. For the downflow installation, the vent and
combustion air pipes attach to the furnace through the alternate
locations on the furnace side panels.
Note: On the Direct Vent furnace, the vent pipe attaches to the fur-
nace through the side panels. The combustion air pipe attaches to
the top panel or to the alternate location on the side panel.
On the Single Pipe furnace, the vent pipe attaches to the furnace
through the furnace side panels.
Note: Repositioning of the combustion blower is required for the
vent pipe connection to the furnace through the "right side" panel.
See "Vent and Combustion Air Piping"section for further details.
If the furnace is to be suspended from the floor joists in a crawl
space or the rafters in an attic, it is necessary to use steel pipe
straps or an angle iron frame to rigidly attach the furnace to prevent
movement. These straps should be attached to the furnace with
sheet metal screws and to the rafters or joists with bolts. The pre-
ferred method is to use an angle iron frame bolted to the rafters or
joists. (Take caution to allowdoor panels to be removed for mainte-
nance)
If the furnace is to be installed in a crawl space, consult local
codes. A suitable concrete pad or blocks are recommended for
crawl space installation on the ground.
NOTE: 6" bottom clearance required for condensate trap.
Thirty (30) inches between the front of the furnace and adjacent
construction or other appliances MUST be maintained for service
clearance.
Keep all insulating materials clear from Iouvered door. Insulating
materials may be combustible.
The horizontal furnaces may be installed directly on combustible
wood flooring or supports as long as all required furnace clear-
ances are met. See Figure 4.
This furnace MUST NOT be installed directly on carpeting or tile or
other combustible material other than wood flooring or supports.
For horizontal installation over a finished living space. A field fabri-
cated auxiliary drain pan with drain pipe is required to prevent
damage by overflow due to blocked condensate drain.
44001 102004

3. Combustion & Ventilation Air
For Single Pipe Installation
CARBON MONOXIDE POISONING HAZARD
Failure to provide adequate combustion and
ventilation air could result in death and/or personal
injury.
Use methods described here to provide combustion
and ventilation air.
Furnaces require ventilation openings to provide sufficient air for
proper combustion and ventilation of flue gases. All duct or open-
ings for supplying combustion and ventilation air must comply with
National Fuel Gas Code, NFPA54/ANSI Z223.1, 2002 (or current
edition) and applicable provisions of local building codes.
This furnace can NOT be common vented or connected to any
type B, BW or Lvent or vent connector, nor to any portion of a facto-
ry- built or masonry chimney. Ifthis furnace is replacing a previous-
ly common-vented furnace, it may be necessary to resize the
existing vent and chimney to prevent oversizing problems for the
other remaining appliance(s). See "Venting and Combustion Air
Check"in this section, This furnace MUST be vented to the out-
side.
Air Openings and Connecting Ducts
2,
3.
Total input rating for all non direct vent gas appliances
MUST be considered when determining free area of open-
ings.
Connect ducts or openings directly to outside.
When screens are used to cover openings, they MUST be
no less than 1/4" mesh.
The minimum dimension of rectangular air ducts MUST
NOT be less than 3".
5. When sizing grille or louver, use the free area of opening. If
free area is NOT stamped or marked on grill or louver, as-
sume a 20% free area for wood and 60% for metal.
Confined Space Installation
NOTE: A confined space is defined as an area with less than 50
cubic feet per 1,000 BTUH input rating for all gas appliances
installed in the area.
Requirements
Provide confined space with sufficient air for proper com-
bustion and ventilation of flue gases using horizontal or ver-
tical ducts or openings.
Figure 5 illustrate how to provide combustion and ventila-
tion air. A minimum of two permanent openings, one inlet
and one outlet, are required.
Outside Air (This is ONLY a guide. Subject to codes of country having jurisdiction.)
Gas Vent
CableVent This installation NOT approved in Canada GasVen_.
.Jx. c,,en .... ,dNI a___aOut,et
Outlet Air (1) Soffit Vent /
') I I _;_.-u,atio.'>_ .ir(1)I JL__.q3 II II
II 11I II II
r-q I I ]- OutletAir'l' _] ISoffitVent In.let _4........I I_;:;:,1 ___.L_U, tnlet
I I A _ _ -- _II I MinimumOnelnletandOneOutletAirSupplyisRequired
I I II I May bein any Combination Shown
Inlet _ ,r_o, I_"_1 I I I Inlet Air Opening Must be Within12" of floor
alternate lnlet Air (1) AIr(l) _ Iq [_:_"r_r _ilrei2)OutletAirOpeningMustbeWithinl2"ofceiling
(1)1SquareInchper4000BTUH
(2)1SquareInchper2000B]-UH
3. One opening MUST be within 12" of the floor and the sec-
ond opening within 12" of the ceiling.
4. Size openings and ducts per Table 1.
5. Horizontal duct openings require I square inch of free area
per 2,000 BTUH of combined input for all gas appliances in
area (see Table 1).
6. Vertical duct openings or openings directly to outside re-
quire 1 square inch of free area per 4,000 BTUH for com-
bined input of all gas appliances in area (see Table 1).
E_ 440011020 04

Free Area
BTUH MinimumFreeArea Requiredfor Each Opening
Input HorizontalDuct VerticalDuctoropenings RoundDuct
Rating (2,000 BTUH) to outside(4,000BTUH) (4,000BTUH)
50,000 25 sq. in. 12.5sq. in. 4"
75,000 37.5sq. in. 1825 sq. in. 5"
100,000 50sq. in. 25sq. in. 6"
125,000 62.5sq. in. 3125 sq. in. 7"
150,000 75 sq. in. 37.5sq. in. 7"
EXAMPLE: Determining Free Area
Appliance 1 Appliance 2 Total Input
100,000 + 30,000 = (130,000 + 4,000) = 32.5 Sq. In. Vertical
Appliance 1 Appliance 2 Total Input
100,000 + 30,000 = (130,000 + 2,000) = 65 Sq. In. Horizontal
One permanent opening, commencing within 12" of the top of the
enclosure, shall be permitted where the equipment has clear-
ances of at least 1" from the sides and back and 6" from the front of
the appliance. The opening shall directly communicate with the
outdoors or shall communicate through a vertical or horizontal
duct to the outdoors or spaces (crawl or attic) that freely communi-
cate with the outdoors, and shall have a minimum free area of:
• 1 sq. in per 3000 Btu per hr. of the total input rating of all
equipment located in the enclosure, and
• Not less than the sum ofthe areas of all vent connectors in
the confined space.
Unconfined Space Installation
CARBON MONOXIDE POISONING HAZARD
Failure to supply additional air by means of
ventilation grilles or ducts could result in death
and/or personal injury.
An unconfined space or homes with tight
construction may not have adequate air infiltration
for proper combustion and ventilation of flue gases.
Most homes will require additional air.
BTUH Input
Rating
50,000
78,000
114,000
155,000
An unconfined space is defined as an area having a minimum vol-
ume of 50 cubic feet per 1,000 Btuh total input rating for all gas ap-
pliances in area. Refer to Table 2 for minimum area required.
I Unconfined Space
Minimum Area in Square Feet
Minimum Area in Square Feet
312
49O
712
968
EXAMPLE: NOTE: Square feet is based on 8 foot ceilings.
28,000 BTUH X 50 Cubic Ft. = 1,400 = 175 Sq. Ft.
1,000 8' Ceiling Height
NOTE: Refer to definitions in section titled Unusually Tight
Construction, If any one of the conditions apply, the space MUST
be considered confined space regardless of size.
1. Adjoining rooms can be considered part of an unconfined
area if there are openings without doors between rooms.
2. An attic or crawl space may be considered an unconfined
space provided there are adequate ventilation openings di-
rectly to outdoors. Openings MUST remain open and NOT
have any means of being closed off. Ventilation openings to
outdoors MUST be at least 1" square of free area per 4,000
BTUH of total input rating for all gas appliances in area.
3. Install air intake a minimum of 12" above maximum snow
level and clear of any obstruction. Duct or ventilation open-
ing requires one square inch of free area per 4,000 BTU H of
total input rating for all gas appliances in area.
4. Air inlet MUST be screened with not less than 1/4" mesh
screen.
Unusually Tight Construction
In unconfined spaces, infiltration may be adequate to provide air
for combustion, ventilation and dilution of flue gases. However, in
buildings with unusually tight construction, additional air MUST be
provided using the methods described in section titled Confined
Space Installation:
Unusually tight construction is defined as: Construction with
1. Walls and ceilings exposed to the outside have a continu-
ous, sealed vapor barrier. Openings are gasketed or sealed
and
2,
3. Doors and openable windows are weather stripped and
Other openings are caulked or sealed. These includejoints
around window and door frames, between sole plates and
floors, between wall-ceiling joints, between wall panels, at
penetrations for plumbing, electrical and gas lines, etc.
Ventilation Air
Some provincial codes and local municipalities require ventilation
or make-up air be brought into the conditioned space as replace-
ment air. Whichever method is used, the mixed return air tempera-
ture across the heat exchanger MUST not fall below 60°F or flue
gases will condense in the heat exchanger. This will shorten the
life of the heat exchanger and possibly void your warranty.
Venting and Combustion Air Check
NOTE: When an existing Category I furnace is removed or re-
placed, the original venting system may no longer be sized to prop-
erly vent the attached appliances, and to make sure there is
adequate combustion air for all appliances, MAKE THE FOL-
LOWING CHECK.
Vent Check
Vent Pipe----_,l I 7 Draft Hood
Typical Gas f _'_
WaterHeate / i i Match
I I
If flame pulls towards draft hood, this indicates sufficient
venting.
44001 102004 [_

CARBON MONOXIDE POISONING HAZARD
Failure to follow the steps outlined below for each
appliance connected to the venting system being
placed into operation, could result in carbon
monoxide poisoning or death:
The following steps shall be followed for each
appliance connected to the venting system being
placed into operation, while all other appliances
connected to the venting system are not in
operation:
1. Seal any unused openings in the venting system.
2. Inspect the venting system for proper size and horizontal
pitch, as required in the National Fuel Gas Code, ANSI
Z223,1/NFPA 54 or CSA B149, 1, Natural Gas and
Propane Installation Code and these instructions. Deter-
mine that there is no blockage or restriction, leakage,
corrosion and other deficiencies which could cause an
unsafe condition.
3. As far as practical, close all building doors and windows
and all doors between the space in which the appliance(s)
connected to the venting system are located and other
spaces of the building.
4. Close fireplace dampers.
5. Turn on clothes dryers and any appliance not connected
to the venting system. Turn on any exhaust fans, such as
range hoods and bathroom exhausts, so they are
operating at maximum speed. Do not operate a summer
exhaust fan.
6. Followthe lighting instructions. Place the appliance being
inspected into operation. Adjust the thermostat so
appliance is operating continuously.
7. Test for spillage from draft hood equipped appliances at
the draft hood relief opening after 5 minutes of main burner
operation. Use the flame of a match or candle. (Figure 6)
8. If improper venting is observed, during any of the above
tests, the venting system must be corrected in
accordance with the National Fuel Gas Code, ANSI
Z223,1/NFPA 54 and/or CSA B149. 1, Natural Gas and
Propane Installation Code.
9. After it has been determined that each appliance
connected to the venting system properly vents when
tested as outlined above, return doors, windows, exhaust
fans, fireplace dampers and any other gas-fired burning
appliance to their previous conditions of use.
For Two Pipe Installation
This furnace can NOT be common vented or connected to any
type B, BW or Lvent or vent connector, nor to any portion of a facto-
ry-built or masonry chimney. Ifthis furnace is replacing a previous-
ly common-vented furnace, it may be necessary to resize the
existing vent and chimney to prevent oversizing problems for the
other remaining appliance(s). See "Venting and Combustion Air
Check"in this section, This furnace MUST be vented to the out-
side.
4. Vent and Combustion Air Piping
CARBON MONOXIDE POISONING HAZARD.
Failure to properly vent this furnace could result in
death and/or personal injury.
Use methods described here to provide combustion
and ventilation air.
SinglePipe(N9MP1Models)
This furnace is certified as a category [V appliance. This furnace
requires ventilation openings to provide air for proper combustion
and ventilation of flue gases. All duct or openings for supplying
combustion and ventilation air must comply with the gas codes or
in absence of local codes, the applicable national codes.
When the installation is complete, see the" Venting and Combus-
tion Air Che¢l_' in this manual.
Direct Vent (N9MP2 Models)
This furnace is certified as a category ]V appliance. This furnace
uses outside air for combustion ONLY, it MUST be taken from the
same atmospheric pressure zone as the vent pipe. See Confined
Space Installation in the Combustion and Ventilation Air in this
manual.
Dual Certified (*9MPD Models)
This furnace is certified as a category ]V appliance. This furnace
can be installed as a direct vent furnace using outside air for com-
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