Carrier 58MCB Operating instructions

-- 1 --
58MCB
4-WAY MULTIPOISE FIXED CAPACITY
CONDENSING GAS FURNACE
Installation, Start-Up, and Operating Instructions
for Sizes 040---140, Series 110 & 120
Visit www.Carrier.com
NOTE: Read the entire instruction manual before starting
the installation.
NOTE: This furnace can be installed as a (2-pipe) direct vent
or (1-pipe) non-direct vent condensing gas furnace.
Special Venting Requirements for Installations in Canada
Installation in Canada must conform to the requirements of CSA
B149 code. Vent systems must be composed of pipe, fittings,
cements, and primers listed to ULC S636. The special vent
fittings and accessory concentric vent termination kits and
accessory external drain trap have been certified to ULC S636 for
use with those IPEX PVC vent components which have been
certified to this standard. In Canada, the primer and cement must
be of the same manufacturer as the vent system -- IPEX System
636, PVC/CPVC Primer, Purple Violet for Flue Gas Venting and
IPEX System 636(1)t, PVC Cement for Flue Gas Venting, rated
Class IIA, 65 deg C. must be used with this venting system -- do
not mix primers and cements from one manufacturer with a vent
system from a different manufacturer. Follow the manufacturer’s
instructions in the use of primer and cement and never use primer
or cement beyond its expiration date.
The safe operation, as defined by ULC S636, of the vent system
is based on following these installation instructions, the vent
system manufacturer’s installation instructions, and proper use of
primer and cement. All fire stop and roof flashing used with this
system must be UL listed material. Acceptability under Canadian
standard CSA B149 is dependent upon full compliance with all
installation instructions. Under this standard, it is recommended
that the vent system be checked once a year by qualified service
personnel.
The authority having jurisdiction (gas inspection authority,
municipal building department, fire department, etc) should be
consulted before installation to determine the need to obtain a
permit.
ama
REGISTERED
ISO 9001:2000
CERTIFIED
Consignes spéciales pour l’installation de ventillation au Canada
L’installation faite au Canada doit se conformer aux exigences du
code CSA B149. Ce systême de ventillation doit se composer de
tuyaux, raccords, ciments et apprêts conformes au ULC S636. La
tuyauterie de ventillation des gaz, ses accessoires, le terminal
concentrique mural ainsi que l’ensemble du drain de condensat
extérieur ont été certifiés ULCS 636 pour l’application des
composantes IPEX PVC qui sont certifiées à ce standard. Au
Canada l’apprêt et le ciment doivent être du même manufacturier
que le systême de ventillation -- IPEX Système 636, Apprêt
PVC/CPVC. Mauve Violette pour conduit en évacuation des gaz
et IPEX Système 636(1)t, ciment pour PVC pour conduit en
évacuation des gaz, évalué CLASSEIIA,65deg.C.doitëtre
utilisé avec ce systèeme d’évacuation -- ne pas mélanger l’apprêt
et le ciment d’un manufacturier avec le systême de ventillation
d’un autre manufacturier. Bien suivre les indications du
manufacturier lors de l’utilisation de l’apprêt et du ciment et ne
pas utiliser ceux--ci si la date d’expiration est atteinte.
L’opération sécuritaire, tel que définit par ULC S636, du système
de ventilation est basé sur les instructions d’installation suivantes,
ainsi que l’usage approprié de l’apprêt et ciment. Tout arrët feu et
solin de toit utilisés avec ce système doivent être des matériaux
listés UL. L’acceptation du standard Canadien CSA B419 est
directement relié à l’installation conforme aux instructions ci--
haut mentionnées. Le standard Canadien recommande l’
inspection par un personel qualifié et ce, une fois par année.
Les autoritées ayant juridiction (inspecteurs de gas, inspecteurs
en bâtiments, département des incendies, etc) devraient être
consultées avant l’installation afin de déterminer si un permis est
requis.
(1) System 636 is a trademark of IPEX Inc.

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Required Notice for Massachusetts Installations
IMPORTANT
The Commonwealth of Massachusetts requires compliance with regulation 248 CMR as follows:
5.08: Modifications to NFPA--54, Chapter 10
2) Revise 10.8.3 by adding the following additional requirements:
a. For all side wall horizontally vented gas fueled equipment installed in every dwelling, building or structure used
in whole or in part for residential purposes, including those owned or operated by the Commonwealth and where
the side wall exhaust vent termination is less than seven (7) feet above finished grade in the area of the venting,
including but not limited to decks and porches, the following requirements shall be satisfied:
1. INSTALLATION OF CARBON MONOXIDE DETECTORS. At the time of installation of the side wall horizontal vented
gas fueled equipment, the installing plumber or gasfitter shall observe that a hard wired carbon monoxide detector with an
alarm and battery back--up is installed on the floor level where the gas equipment is to be installed. In addition, the
installing plumber or gasfitter shall observe that a battery operated or hard wired carbon monoxide detector with an alarm is
installed on each additional level of the dwelling, building or structure served by the side wall horizontal vented gas fueled
equipment. It shall be the responsibility of the property owner to secure the services of qualified licensed professionals for
the installation of hard wired carbon monoxide detectors
a. In the event that the side wall horizontally vented gas fueled equipment is installed in a crawl space or an attic, the hard
wired carbon monoxide detector with alarm and battery back--up may be installed on the next adjacent floor level.
b. In the event that the requirements of this subdivision can not be met at the time of completion of installation, the owner
shall have a period of thirty (30) days to comply with the above requirements; provided, however, that during said thirty
(30) day period, a battery operated carbon monoxide detector with an alarm shall be installed.
2. APPROVED CARBON MONOXIDE DETECTORS. Each carbon monoxide detector as required in accordance with the
above provisions shall comply with NFPA 720 and be ANSI/UL 2034 listed and IAS certified.
3. SIGNAGE. A metal or plastic identification plate shall be permanently mounted to the exterior of the building at a
minimum height of eight (8) feet above grade directly in line with the exhaust vent terminal for the horizontally vented gas
fueled heating appliance or equipment. The sign shall read, in print size no less than one--half (1/2) inch in size, ”GAS
VENT DIRECTLY BELOW. KEEP CLEAR OF ALL OBSTRUCTIONS”.
4. INSPECTION. The state or local gas inspector of the side wall horizontally vented gas fueled equipment shall not approve
the installation unless, upon inspection, the inspector observes carbon monoxide detectors and signage installed in
accordance with the provisions of 248 CMR 5.08(2)(a)1 through 4.
5. EXEMPTIONS: The following equipment is exempt from 248 CMR 5.08(2)(a)1 through 4:
(1.) The equipment listed in Chapter 10 entitled ”Equipment Not Required To Be Vented” in the most current edition of
NFPA 54 as adopted by the Board; and
(2.) Product Approved side wall horizontally vented gas fueled equipment installed in a room or structure separate from
the dwelling, building or structure used in whole or in part for residential purposes.
c. MANUFACTURER REQUIREMENTS -- GAS EQUIPMENT VENTING SYSTEM PROVIDED. When the
manufacturer of Product Approved side wall horizontally vented gas equipment provides a venting system design
or venting system components with the equipment, the instructions provided by the manufacturer for installation
of the equipment and the venting system shall include:
1. Detailed instructions for the installation of the venting system design or the venting system components; and
2. A complete parts list for the venting system design or venting system.
d. MANUFACTURER REQUIREMENTS -- GAS EQUIPMENT VENTING SYSTEM NOT PROVIDED. When
the manufacturer of a Product Approved side wall horizontally vented gas fueled equipment does not provide the
parts for venting the flue gases, but identifies “special venting systems”, the following requirements shall be
satisfied by the manufacturer:
1. The referenced “special venting system” instructions shall be included with the appliance or equipment installation
instructions; and
2. The “special venting systems” shall be Product Approved by the Board, and the instructions for that system shall include a
parts list and detailed installation instructions.
e. A copy of all installation instructions for all Product Approved side wall horizontally vented gas fueled
equipment, all venting instructions, all parts lists for venting instructions, and/or all venting design instructions
shall remain with the appliance or equipment at the completion of the installation.
For questions regarding these requirements, please contact the Commonwealth of Massachusetts Board of State Examiners of Plumbers
and Gas Fitters, 239 Causeway Street, Boston, MA 02114. 617--727--9952.
58MCB

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TABLE OF CONTENTS
SAFETY CONSIDERATIONS 3..........................
DIMENSIONAL DRAWING 4...........................
Clearances to Combustibles 5...........................
CODES AND STANDARDS 7...........................
ELECTROSTATIC DISCHARGE (ESD) PRECAUTIONS 8...
INTRODUCTION 8....................................
APPLICATIONS 9.....................................
General 9...........................................
Upflow Applications 9.................................
Downflow Applications 11.............................
Horizontal Left (Supply--Air Discharge) Applications 12.....
Horizontal Right (Supply--Air Discharge) Applications 13....
LOCATION 16........................................
General 16..........................................
Furnace Location Relative to Cooling Equipment 17.........
Hazardous Locations 17...............................
Furnace Location and Application 17.....................
AIR FOR COMBUSTION AND VENTILATION 18..........
INSTALLATION 21....................................
Leveling Legs (If Desired) 21...........................
Installation in Upflow or Downflow Applications 21.........
Installation in Horizontal Applications 21.................
Air Ducts 23.........................................
General 23........................................
Ductwork Acoustical Treatment 24.....................
Supply Air Connections 24...........................
Return Air Connections 25............................
Filter Arrangement 25.................................
Bottom Closure Panel 26...............................
Gas Piping 26........................................
Electrical Connections 27..............................
115--v Wiring 28....................................
24--v Wiring 28.....................................
Accessories 29.....................................
Removal of Existing Furnaces from
Common Vent Systems 29..............................
Combustion Air and Vent Pipe Systems 29.................
Condensate Drain 46..................................
General 46........................................
Application 46.....................................
Condensate Drain Protection 46........................
START-UP, ADJUSTMENT AND SAFETY CHECK 47.......
General 47..........................................
Prime Condensate Trap with Water 47....................
Purge Gas Lines 47...................................
Sequence of Operation 47..............................
Heating Mode 48...................................
Cooling Mode 48...................................
Continuous Blower Mode 48..........................
Heat Pump Mode 48.................................
Component Test 48..................................
Adjustments 49......................................
Set Gas Input Rate 49................................
Set Temperature Rise 55..............................
Adjust Blower Off Delay (Heat Mode) 56................
Set Thermostat Heat Anticipator 56.....................
Check Safety Controls 56..............................
Check Primary Limit Control 56.......................
Check Pressure Switch 56............................
CHECKLIST 57.......................................
UPFLOW
DOWNFLOW
HORIZONTAL
LEFT
AIRFLOW AIRFLOW
AIRFLOW
AIRFLOW
HORIZONTAL
RIGHT
A93041
Fig. 1 -- Multipoise Orientations
SAFETY CONSIDERATIONS
Improper installation, adjustment, alteration, service,
maintenance, or use can cause explosion, fire, electrical shock, or
other conditions which may cause death, personal injury, or
property damage. Consult a qualified installer, service agency, or
your distributor or branch for information or assistance. The
qualified installer or agency must use factory--authorized kits or
accessories when modifying this product. Refer to the individual
instructions packaged with the kits or accessories when installing.
Follow all safety codes. Wear safety glasses, protective clothing,
and work gloves. Have a fire extinguisher available. Read these
instructions thoroughly and follow all warnings or cautions
include in literature and attached to the unit. Consult local
building codes, the current editions of the National Fuel Gas
Code (NFGC) NFPA 54/ANSI Z223.1 and the National Electrical
Code (NEC) NFPA 70.
In Canada, refer to the current editions of the National Standards
of Canada CAN/CSA--B149.1 and .2 Natural Gas and Propane
Installation Codes, and Canadian Electrical Code CSA C22.1
Recognize safety information. This is the safety--alert symbol .
When you see this symbol on the unit and in instructions or
manuals, be alert to the potential for personal injury.
Understand the signal words DANGER,WARNING,and
CAUTION. These words are used with the safety--alert symbol.
DANGER identifies the most serious hazards which will result in
severe personal injury or death. WARNING signifies hazards
which could result in personal injury or death. CAUTION is
used to identify unsafe practices which may result in minor
personal injury or product and property damage. NOTE is used
to highlight suggestions which will result in enhanced
installation, reliability, or operation.
UNIT RELIABILITY HAZARD
Improper installation or misapplication of furnace may
require excessive servicing or cause premature component
failure.
Application of this furnace should be indoors with special
attention given to vent sizing and material, gas input rate, air
temperature rise, unit leveling, and unit sizing.
CAUTION
!
58MCB

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A05053
17
5
⁄ 16 "
24
1
⁄ 2 "
27
9
⁄
16
"
TYP
27
5
⁄
8
"
29
11
⁄ 16 "
TYP
30
13
⁄ 16 "
32
5
⁄ 8 "
TYP
33
1
⁄ 4 "
TYP
CONDENSATE
DRAIN TRAP
LOCATION
(ALTERNATE
UPFLOW)
7
⁄ 8 -IN. DIA
ACCESSORY
POWER ENTRY
7
⁄ 8 -IN. DIA
POWER CONN
CONDENSATE DRAIN
TRAP LOCATION
(DOWNFLOW &
HORIZONTAL LEFT)
26
15
⁄ 16 "
24
1
⁄
2
"
22
5
⁄
16
"
2
-IN. COMBUSTION-
AIR CONN
1
⁄ 2 -IN. DIA
GAS CONN
2 -IN. VENT CONN
1
⁄ 2 -IN. DIA THERMOSTAT
ENTRY
22
11
⁄ 16 "
SIDE INLET
23
1
⁄ 4 "TYP
SIDE INLET
1
1
⁄
4
"
1"E
INLET
11
⁄ 16 "
11
⁄ 16 "
D
13
⁄
16
"
13
⁄
16
"
OUTLET
A
AIRFLOW
OUTLET
26
15
⁄
16
"
28
1
⁄
2
"
22
5
⁄
16
"
19"
13
⁄
16
"
5
⁄
8
"
5
⁄ 16 "
1"
39
7
⁄ 8 "
22
1
⁄ 4 "TYP
11
⁄ 16 "
7
⁄
16
"
24
3
⁄
16
"
BOTTOM INLET
18
1
⁄
4
"
22
11
⁄ 16 "
CONDENSATE DRAIN
TRAP LOCATION
(DOWNFLOW &
HORIZONTAL RIGHT)
OR ALTERNATE
1
⁄ 2 -IN. DIA GAS CONN
2-IN. COMBUSTION-
AIR CONN
1
⁄ 2 -IN. DIA
GAS CONN
7
⁄ 8 -IN. DIA
POWER CONN
1
⁄ 2 -IN. DIA
THERMOSTAT ENTRY
2-IN. VENT CONN
DIMPLE LOCATORS
FOR HORIZONTAL
HANGING
14
1
⁄ 2 "
TYP
SIDE INLET
NOTES: 1. Minimum return-air openings at furnace, based on metal duct. If flex duct is used,
see flex duct manufacturer‘s recommendation for equivalent diameters.
2. Minimum return-air opening at furnace:
a. For 800 CFM 16-in . (406mm) round or 14 1/2 (368mm) x 12-in. (305mm) rectangle.
b. For 1200 CFM 20-in . (508mm) round or 14 1/2 (368mm) x 19 1/2-in. (495mm) rectangle.
c. For 1600 CFM 22-in .(559mm) round or 14 1/2 (368mm) x 23 1/4-in.(591mm)rectangle.
d. For airflow requirements above 1800 CFM, see Air Delivery table in Product Data
literature for specific use of single side inlets. The use of both side inlets, a
combination of 1 side and the bottom, or the bottom only will ensure adequate
return air openings for airflow requirements above 1800 CFM at 0.5“W.C. ESP.
9
7
⁄
16
"
TYP
26
15
⁄ 16 "TYP
CONDENSATE
DRAIN LOCATION
(UPFLOW)
30
1
⁄
2
"
9
⁄
16
"
TYP
CONDENSATE
DRAIN LOCATION
(UPFLOW)
26
1
⁄
4
"
26
1
⁄ 4 "(684mm)
(667mm)
(666mm)
(567mm)
(51mm)
(51mm)
(13mm)
(13mm)
(576mm)
(368mm)
(32mm)
(25mm)
(591mm)
(684mm)
(240mm)
(440mm)
(622mm)
(700mm)
(702mm)
(754mm)
(783mm)
(829mm)
(845mm)
(22mm)
(22mm)
(21mm) (21mm)
(17mm) (17mm)
(464mm)
(775mm)
(565mm)
(614mm)
(25mm)
(11mm)
(17mm)
(1013mm)
(8mm)
(16mm)
(21mm)
(14mm) (483mm)
(567mm)
(667mm)
(694mm)
(724mm)
Dimensions --- IN. (mm)
UNIT SIZE A D E
040--- 08 / 024040 17-1/2 (445) 15-7/8 (403) 16 (406)
040--- 12 / 036040 17-1/2 (445) 15-7/8 (403) 16 (406)
060--- 08 / 024060 17-1/2 (445) 15-7/8 (403) 16 (406)
060--- 12 / 036060 17-1/2 (445) 15-7/8 (403) 16 (406)
060--- 16 / 048060 17-1/2 (445) 15-7/8 (403) 16 (406)
080--- 12 / 036080 17-1/2 (445) 15-7/8 (403) 16 (406)
080--- 16 / 048080 17-1/2 (445) 15-7/8 (403) 16 (406)
080--- 20 / 060080 21 (533) 19-3/8 (492) 19-1/2 (495)
100--- 16 / 048100 21 (533) 19-3/8 (492) 19-1/2 (495)
100--- 20 / 060100 21 (533) 19-3/8 (492) 19-1/2 (495)
120--- 20 / 060120 24-1/2 (622) 19-3/8 (492) 23 (584)
140--- 20 / 060140 24-1/2 (622) 22-7/8 (581) 23 (584)
Fig. 2 -- Dimensional Drawing
58MCB

-- 5 --
335122-201 REV. B LIT TOP
A08435
Fig. 3 -- Clearances to Combustibles
FIRE, EXPLOSION, ELECTRICAL SHOCK AND
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in electrical shock,
fire, personal injury, or death.
Improper installation, adjustment, alteration, service,
maintenance, or use can cause carbon monoxide poisoning,
explosion, fire, electrical shock, or other conditions which may
cause personal injury or property damage. Consult a qualified
installer, service agency, local gas supplier, or your distributor
or branch for information or assistance. The qualified installer
or agency must use only factory-authorized and listed kits or
accessories when modifying this product.
!WARNING
CUT HAZARD
Failure to follow this caution may result in personal injury.
Sheet metal parts may have sharp edges or burrs. Use care and
wear appropriate protective clothing and gloves when
handling parts.
CAUTION
!
The 58MCB Multipoise Condensing Gas-Fired Furnaces are CSA
(formerly AGA and CGA) design-certified for natural and
propane gases (see furnace rating plate) and for installation in
alcoves, attics, basements, closets, utility rooms, crawlspaces, and
garages. The furnace is factory-shipped for use with natural gas.
A CSA listed gas conversion kit is required to convert furnace for
use with propane gas.
See Fig. 3 for required clearances to combustibles.
Maintain a 1-in. (25 mm) clearance from combustible materials to
supply air ductwork for a distance of 36 in. (914 mm)
horizontally from the furnace. See NFPA 90B or local code for
further requirements.
58MCB

-- 6 --
These furnaces SHALL NOT be installed directly on carpeting,
tile, or any other combustible material other than wood flooring.
In downflow installations, factory accessory floor base MUST be
used when installed on combustible materials and wood flooring.
Special base is not required when this furnace is installed on
manufacturer’s Coil Assembly Part No. CNPV, CAPV, CAP or
CAR or CK5, or when Coil Box Part No. KCAKC is used.
The 58MCB 040 through 120 size units are CSA (formerly AGA
and CGA) design-certified for use in manufactured (mobile)
homes when installed as a 2-pipe (direct vent) furnace and a
factory accessory conversion kit is used. The 140 size unit is
NOT design-certified for use in manufactured (mobile) homes.
These furnaces are suitable for installation in a structure built on
site or a manufactured building completed at final site. The
design of this furnace line is NOT CSA design-certified for
installation in recreation vehicles or outdoors.
This furnace is designed for continuous return-air minimum
temperature of 60°F(15°C)db or intermittent operation down to
55°F(13°C)db such as when used with a night setback
thermostat. Return-air temperature must not exceed 80°F(27°C)
db. Failure to follow these return-air limits may affect reliability
of heat exchangers, motors, and controls. (See Fig. 4.)
These furnaces are shipped with the drain and pressure tubes
connected for UPFLOW applications. Minor modifications
are required when used in DOWNFLOW, HORIZONTAL
RIGHT, or HORIZONTAL LEFT (supply-air discharge
direction) applications as shown in Fig. 1. See details in
Applications section.
Install this furnace only in a location and position as specified in
LOCATION and INSTALLATION sections of these instructions.
Always provide adequate combustion and ventilation air as
specified in section Combustion Air and Vent Pipe Systems of
these instructions to the furnace.
Combustion products must be discharged outdoors. Connect this
furnace to an approved vent system only, as specified in the
Combustion Air and Vent piping sections of these instructions.
Never test for gas leaks with an open flame. Use a commercially
available soap solution made specifically for detection of leaks to
check all connections as specified in the GAS PIPING section of
these instructions.
Always install the furnace to operate within the furnace’s
intended rise range with a duct system which has an external
static pressure within the allowable range as specified in the SET
TEMPERATURE RISE section of these instructions and furnace
rating plate.
When a furnace is installed so that supply ducts carry air
circulated by the furnace to areas outside the space containing the
furnace, the return air shall also be handled by ducts sealed to the
furnace casing and terminating outside the space containing
the furnace.
A gas-fired furnace for installation in a residential garage must be
installed as specified in the Hazardous Locations section of
these instructions.
The furnace may be used for construction heat provided that the
furnace installation and operation complies with the first
CAUTION in the LOCATION section of these instructions.
This gas furnace may be used for construction heat provided that:
SThe furnace is permanently installed with all electrical wiring,
piping, air filters, 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.
SThe furnace is controlled by a thermostat. It may not be “hot
wired” to provide heat continuously to the structure without
thermostatic control.
SClean outside air is provided for combustion. This is to
minimize 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.
SThe temperature of the return air to the furnace is maintained
between 55°F(13°C) and 80°F(27°C), 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 instructions.
SThe air temperature rise is within the rated rise range on the
furnace rating plate, and the firing rate has been set to the
nameplate value.
SThe filters used to clean the circulating air during the
construction process must be either changed or thoroughly
cleaned prior to occupancy.
SThe furnace, ductwork and filters are cleaned as necessary to
remove drywall dust and construction debris from all HVAC
system components after construction is completed.
SAfter construction is complete, verify furnace operating
conditions including ignition, input rate, temperature rise and
venting, according to the manufacturer’s instructions.
60
0
(27º C)
(16º C)
A05004
Fig. 4 -- Return-Air Temperature
These furnaces are shipped with the following materials to assist
in proper furnace installation. These materials are shipped in the
main blower compartment.
58MCB

-- 7 --
Installer Packet Includes:
Installation, Startup, and Operating Instructions
Service and Maintenance Instructions
User’s Information Manual
Warranty Certificate
Loose Parts Bag Includes: Quantity
Pressure tube extension 1
Collector Box or condensate trap extension tube 1
Inducer housing drain tube 1
1/2--in CPVC street elbow 2
Drain tube coupling 1
Drain tube coupling grommet 1
Vent and combustion-air pipe support 2
Condensate trap hole filler plug 3
Vent and combustion-air intake hole filler plug 2
Combustion-air pipe perforated disk assembly 1
Vent Pipe Extension 1*
* ONLY supplied with some furnaces.
The furnace shall be installed so that the electrical components
are protected from water.
For accessory installation details, refer to accessory
installation instructions.
CODES AND STANDARDS
Follow all national and local codes and standards in addition
to these instructions. The installation must comply with
regulations of the serving gas supplier, local building, heating,
plumbing, and other codes. In absence of local codes, the
installation must comply with the national codes listed below and
all authorities having jurisdiction.
In the United States and Canada, follow all codes and standards
for the following:
Step 1 -- Safety
SUS: National Fuel Gas Code (NFGC) NFPA 54--2006/ANSI
Z223.1--2006 and the Installation Standards, Warm Air Heating
and Air Conditioning Systems ANSI/NFPA 90B
SCANADA: National Standard of Canada, Natural Gas and
Propane Installation Code (NSCNGPIC) CSA B149.1--05.
Step 2 -- General Installation
SUS: NFGC and the NFPA 90B. For copies, contact the
National Fire Protection Association Inc., Batterymarch Park,
Quincy, MA 02269; or for only the NFGC contact the
American Gas Association, 400 N. Capitol, N.W., Washington
DC 20001.
SA manufactured (Mobile) home installation must conform with
the Manufactured Home Construction and Safety Standard,
Title 24 CFR, Part 3280, or when this standard is not
applicable, the Standard for Manufactured Home Installation
(Manufactured Home Sites, Communities, and Set-Ups),
ANSI/NCS A225.1, and/or CAN/CSA--Z240, MH Series
Mobile Homes
SCANADA: NSCNGPIC. For a copy, contact Standard Sales,
CSA International, 178 Rexdale Boulevard, Etobicoke
(Toronto), Ontario, M9W 1R3, Canada.
Step 3 -- Combustion and Ventilation Air
SUS: Section 9.3 of the NFPA54/ANSI Z223.1--2006, Air for
Combustion and Ventilation
SCANADA: Part 8 of the CAN/CSA--B149.1--05, Venting
Systems and Air Supply for Appliances
Step 4 -- Duct Systems
SUS and CANADA: Air Conditioning Contractors Association
(ACCA) Manual D, Sheet Metal and Air Conditioning
Contractors National Association (SMACNA), or American
Society of Heating, Refrigeration, and Air Conditioning
Engineers (ASHRAE) 2001 Fundamentals Handbook
Chapter 34.
Step 5 -- Acoustical Lining and Fibrous Glass Duct
SUS and CANADA: current edition of SMACNA, NFPA 90B as
tested by UL Standard 181 for Class I Rigid Air Ducts
Step 6 -- Gas Piping and Gas Pipe Pressure Testing
SUS: NFPA 54/ANSI Z223.1--2006; chapters 5, 6, 7, and 8 and
national plumbing codes
SCANADA: NSCNGPIC Parts 4, 5, and 6 A, B, E, and H.
In the state of Massachusetts:
SThis product must be installed by a licensed plumber or gas fitter.
SWhen flexible connectors are used, the maximum length shall not
exceed 36-in. (914 mm).
SWhen lever types gas shutoffs are used they shall not
exceed 36-in. (914 mm).
SThe use of copper tubing for gas piping is not approved by the
state of Massachusetts.
Step 7 -- Electrical Connections
SUS: National Electrical Code (NEC) ANSI/NFPA 70--2008
SCANADA: Canadian Electrical Code CSA C22.1
58MCB

-- 8 --
1/2 (13mm)
INDUCER HOUSING
DRAIN CONNECTION
1/4” (6mm)
COLLECTOR BOX TO
TRAP RELIEF PORT
5/8 (16mm)
COLLECTOR BOX
DRAIN CONNECTION
1/2 IN. (13mm) PVC OR CPV
SCREW HOLE FOR
UPFLOW OR DOWN-
FLOW APPLICATIONS
(OPTIONAL)
14
2
78
18
7
SLOT FOR SCREW
HORIZONTAL
APPLICATION
(OPTIONAL)
WIRE TIE
GUIDES
(WHEN USED)
12
1
34
1
34
FRONT VIEW SIDE VIEW
FURNACE
DOOR
FURNACE
DOOR CONDENSATE
TRAP
78
14
26
4
FURNACE
SIDE
FURNACE
SIDE
12
1
14
26
4
34
534 5
4
SIDE VIEW FRONT VIEW END VIEW FRONT VIEW
34
DOWNFLOW AND ALTERNATE
EXTERNAL UPFLOW APPLICATIONS
HORIZONTAL
APPLICATIONS
FIELD
DRAIN
CONN
FIELD
DRAIN
CONN
CONDENSATE
TRAP (INSIDE)
BLOWER SHELF
ALTERNATE DRAIN
TUBE LOCATION
UPFLOW APPLICATIONS
CONDENSATE TRAP
DRAIN TUBE LOCATION
(667mm) (38mm)
(124mm)
(667mm) (19mm)
(146mm) (146mm)
(57mm)
(3mm)
(181mm)
(44mm)
(88mm)
(19mm)
(102mm)
(102mm)
A93026
Fig. 5 -- Condensate Trap
ELECTROSTATIC DISCHARGE (ESD)
PRECAUTIONS
UNIT DAMAGE HAZARD
Failure to follow this caution may damage furnace
components.
Electrostatic discharge can affect electronic components.
Take precautions during furnace installation and servicing to
protect the furnace electronic control. Precautions will
prevent electrostatic discharges from personnel and hand
tools which are held during the procedure. These precautions
will help to avoid exposing the control to electrostatic
discharge by putting the furnace, the control, and the person
at the same electrostatic potential.
CAUTION
!
3. Disconnect all power to the furnace. Multiple disconnects
may be required. DO NOT TOUCH THE CONTROL OR
ANY WIRE CONNECTED TO THE CONTROL PRIOR
TO DISCHARGING YOUR BODY’S ELECTROSTATIC
CHARGE TO GROUND.
4. Firmly touch a clean, unpainted, metal surface of the
furnace chassis which is close to the control. Tools held in
a person’s hand during grounding will be
satisfactorily discharged.
5. After touching the chassis, you may proceed to service the
control or connecting wires as long as you do nothing that
recharges your body with static electricity (for example;
DO NOT move or shuffle your feet, DO NOT touch
ungrounded objects, etc.).
6. If you touch ungrounded objects (recharge your body with
static electricity), firmly touch furnace again before
touching control or wires.
7. Use this procedure for installed and uninstalled
(ungrounded) furnaces.
8. Before removing a new control from its container,
discharge your body’s electrostatic charge to ground to
protect the control from damage. If the control is to be
installed in a furnace, follow items 1 through 5 before
bringing the control or yourself into contact with the
furnace. Put all used AND new controls into containers
before touching ungrounded objects.
9. An ESD service kit (available from commercial sources)
mayalsobeusedtopreventESDdamage.
INTRODUCTION
The model 58MCB 4-way multipoise, Gas-Fired, Category IV,
condensing furnace is available in model sizes ranging from input
capacity of 40,000 to 138,000 Btuh as a direct vent (2-pipe)
application, and in model sizes ranging from input capacity of
40,000 to 120,000 Btuh as a non-direct vent (1-pipe) application.
58MCB

-- 9 --
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
TUBE (GREEN)
INDUCER HOUSING
(MOLDED) DRAIN
TUBE (BEHIND
COLLECTOR BOX
DRAIN TUBE)
COLLECTOR BOX
DRAIN TUBE (BLUE)
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
COUPLING (LEFT
DRAIN OPTION)
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
FIELD-INSTALLED
FACTORY-SUPPLIED
1
⁄ 2 -IN. CPVC STREET
ELBOWS (2) FOR
LEFT DRAIN OPTION
FIELD-INSTALLED
FACTORY-SUPPLIED
DRAIN TUBE
COUPLING (RIGHT
DRAIN OPTION)
CAP
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
PLUG
CONDENSATE
TRAP
A00288
Fig. 6 -- Factory Shipped Upflow Tube Configuration (Shown
With Blower Access Panel Removed)
APPLICATIONS
MINOR PROPERTY DAMAGE
Failure to follow this caution may result in minor property
damage.
Local codes may require a drain pan under entire furnace and
condensate trap when a condensing furnace is used in an attic
application or over a finished ceiling.
CAUTION
!
Step 1 -- General
Some assembly and modifications are required for furnaces
installed in any of the 4 applications shown in Fig. 1. All drain
and pressure tubes are connected as shown in Fig. 6. See
appropriate application instructions for these procedures.
Step 2 -- Upflow Applications
An upflow furnace application is where furnace blower is located
below combustion and controls section of furnace, and
conditioned air is discharged upwards.
COLLECTOR BOX
TUBE (PINK)
CONDENSATE
TRAP
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
DRAIN TUBE (BLUE)
INDUCER
HOUSING
DRAIN TUBE
(VIOLET)
CAP
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
PLUG
A00289
Fig. 7 -- Alternate Upflow Tube Configuration and
Trap Location
CONDENSATE TRAP LOCATION
(FACTORY-SHIPPED ORIENTATION)
The condensate trap is factory installed in the blower shelf and
factory connected for UPFLOW applications. A factory-supplied
tube is used to extend the condensate trap drain connection to the
desired furnace side for field drain attachment. See Condensate
Trap Tubing (Factory-Shipped Orientation) section for drain tube
extension details. (See Fig. 5.)
CONDENSATE TRAP TUBING
(FACTORY-SHIPPED ORIENTATION)
NOTE: See Fig. 6 or tube routing label on main furnace door to
confirm location of these tubes.
1. Collector Box Drain, Inducer Housing Drain, Relief Port,
and Pressure Switch Tubes
These tubes should be factory attached to condensate trap
and pressure switch ready for use in UPFLOW
applications. These tubes can be identified by their
connection location and also by a color label on each tube.
These tubes are identified as follows: collector box drain
tube (blue label), inducer housing drain tube (violet label
or molded), relief port tube (green label), and pressure
switch tube (pink label).
2. Condensate Trap Drain Tube
The condensate trap drain connection must be extended
for field attachment by doing the following:
f. Determine location of field drain connection. (See
Fig. 2 or 6.)
NOTE: If internal filter is used, drain tube should be located to
opposite side of casing from return duct attachment to assist in
filter removal.
g. Remove and discard casing drain hole plug button
from desired side.
58MCB

-- 1 0 --
PLUG
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
COLLECTOR BOX
EXTENSION
DRAIN TUBE
CONDENSATE
TRAP
INDUCER HOUSING
DRAIN TUBE
(VIOLET)
COLLECTOR BOX
EXTENSION TUBE
DRAIN TUBE
COUPLING
COLLECTOR BOX
DRAIN TUBE (BLUE)
CAP
COLLECTOR BOX
EXTENSION TUBE
A00296
Fig. 8 -- Downflow Tube Configuration
(Right-Hand Trap Installation)
h. Install drain tube coupling grommet (factory-supplied
in loose parts bag) in selected casing hole.
i. Slide drain tube coupling (factory-supplied in loose
parts bag) through grommet ensuring long end of
coupling faces blower.
j. Cement 2 factory-supplied 1/2-in. (13 mm) street
CPVC elbows to the rigid drain tube connection on the
condensate trap. (See Fig. 6.) These elbows must be
cemented together and cemented to condensate trap
drain connection.
NOTE: Failure to use CPVC elbows may allow drain to kink
and prevent draining.
k. Connect larger diameter drain tube and clamp
(factory-supplied in loose parts bag) to condensate trap
and clamp securely.
l. Route tube to coupling and cut to appropriate length.
m. Attach tube to coupling and clamp securely.
CONDENSATE TRAP LOCATION (ALTERNATE
UPFLOW ORIENTATION)
An alternate location for the condensate trap is the left-hand side
of casing. (See Fig. 2 and 7.)
NOTE: If the alternate left-hand side of casing location is used,
the factory-connected drain and relief port tubes must be
disconnected and modified for attachment. See Condensate
Trap Tubing (Alternate Upflow Orientation) section for
tubing attachment.
PLUG
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR BOX
TUBE (PINK)
COLLECTOR BOX
DRAIN TUBE (BLUE
& WHITE STRIPED)
COLLECTOR BOX
EXTENSION TUBE
CONDENSATE
TRAP
INDUCER HOUSING
DRAIN TUBE (VIOLET)
COLLECTOR BOX
EXTENSION TUBE
CAP
COLLECTOR BOX
DRAIN TUBE (BLUE)
A00262
Fig. 9 -- Downflow Tube Configuration
(Left-Hand Trap Installation)
To relocate condensate trap to the left-hand side, perform
the following:
1. Remove 3 tubes connected to condensate trap.
2. Remove trap from blower shelf by gently pushing tabs
inward and rotating trap.
3. Install casing hole filler cap (factory-supplied in loose
parts bag) into blower shelf hole where trap was removed.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
Casing hole filler cap must be installed in blower shelf hole
when condensate trap is relocated to prevent combustion
products being drawn in from appliances in the
equipment room.
!WARNING
4. Install condensate trap into left-hand side casing hole by
inserting tube connection stubs through casing hole and
rotating until tabs snap into locking position.
5. Fill unused condensate trap casing holes with plastic filler
caps (factory-supplied in loose parts bag).
CONDENSATE TRAP TUBING (ALTERNATE
UPFLOW ORIENTATION)
NOTE: See Fig. 7 or tube routing label on main furnace door to
confirm location of these tubes.
1. Collector Box Drain Tube
Connect collector box drain tube (blue label) to
condensate trap.
58MCB

-- 1 1 --
NOTE: On 17-1/2-in. (445 mm) wide furnaces ONLY, cut tube
between corrugated sections to prevent kinks from occurring.
2. Inducer Housing Drain Tube
a. Remove and discard LOWER (molded) inducer
housing drain tube which was previously connected to
condensate trap.
b. Use inducer housing drain extension tube (violet label
and factory-supplied in loose parts bag) to connect
LOWER inducer housing drain connection to the
condensate trap.
c. Determine appropriate length, cut, and connect tube.
d. Clamp tube to prevent any condensate leakage.
3. Relief Port Tube
e. Connect relief port tube (green label) to
condensate trap.
f. Extend this tube (if required) by splicing to small
diameter tube (factory-supplied in loose parts bag).
g. Determine appropriate length, cut, and connect tube.
CONDENSATE TRAP FIELD DRAIN ATTACHMENT
Refer to Condensate Drain section for recommendations
and procedures.
PRESSURE SWITCH TUBING
The LOWER collector box pressure tube (pink label) is
factory connected to the pressure switch and should not require
any modification.
NOTE: See Fig. 6 or 7 or tube routing label on main furnace
door to check for proper connections.
UPPER COLLECTOR BOX AND INDUCER
HOUSING (UNUSED) DRAIN CONNECTIONS
Upper Collector Box Drain Connection
Attached to the UPPER collector box drain connection is a
factory-installed corrugated, plugged tube (blue and white striped
label). This tube is plugged to prevent condensate leakage in this
application. Ensure this tube is plugged.
NOTE: See Fig. 6 or 7 or tube routing label on main furnace
door to check for proper connections.
Upper Inducer Housing Drain Connection
Attached to the UPPER (unused) inducer housing drain
connection is a cap and clamp. This cap is used to prevent
condensate leakage in this application. Ensure this connection
is capped.
NOTE: See Fig. 6 or 7 or tube routing label on main furnace
door to check for proper connections.
CONDENSATE TRAP FREEZE PROTECTION
Refer to Condensate Drain Protection section for
recommendations and procedures.
Step 3 -- Downflow Applications
A downflow furnace application is where furnace blower is
located above combustion and controls section of furnace, and
conditioned air is discharged downwards.
CONDENSATE TRAP LOCATION
The condensate trap must be removed from the factory-installed
blower shelf location and relocated in selected application
location as shown in Fig. 2, 8, or 9.
To relocate condensate trap from the blower shelf to desired
location, perform the following:
1. Remove 3 tubes connected to condensate trap.
2. Remove trap from blower shelf by gently pushing tabs
inward and rotating trap.
3. Install casing hole filler cap (factory-supplied in loose
parts bag) into blower shelf hole where trap was removed.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
Casing hole filler cap must be installed in blower shelf hole
when condensate trap is relocated to prevent combustion
products being drawn in from appliances in the
equipment room.
!WARNING
4. Install condensate trap into desired casing hole by
inserting tube connection stubs through casing hole and
rotating until tabs snap into locking position.
5. Fill unused condensate trap casing holes with plastic filler
caps (factory-supplied in loose parts bag).
CONDENSATE TRAP TUBING
NOTE: See Fig. 8 or 9 or tube routing label on main furnace
door to check for proper connections.
1. Collector Box Drain Tube
a. Remove factory-installed plug from LOWER collector
box drain tube (blue and white striped label).
b. Install removed clamp and plug into UPPER collector
box drain tube (blue label) which was connected to
condensate trap.
c. Connect LOWER collector box drain connection to
condensate trap.
(3.) Condensate Trap Located on Left Side of Casing
a. Connect LOWER collector box drain tube (blue
and white striped label) to condensate trap.
Tube does not need to be cut.
b. Clamp tube to prevent any condensate leakage.
(4.) Condensate Trap Located on Right Side of Casing
a. Install drain tube coupling (factory-supplied in
loose parts bag) into collector box drain tube
(blue and white striped label) which was
previously plugged.
b. Connect larger diameter drain tube
(factory-supplied in loose parts bag) to drain
tube coupling, extending collector box drain
tube for connection to condensate trap.
c. Route extended collector box drain tube
directly from collector box drain to condensate
trap as shown in Fig. 9.
d. Determine appropriate length and cut.
e. Connect to condensate trap.
f. Clamp tube to prevent any condensate leakage.
2. Inducer Housing Drain Tube
a. Remove factory-installed cap and clamp from LOWER
inducer housing drain connection.
b. Remove and discard UPPER (molded) inducer housing
drain tube which was previously connected to
condensate trap.
c. Install cap and clamp on UPPER inducer housing drain
connection where molded drain tube was removed.
d. Use inducer housing drain tube (violet label and
factory-supplied in loose parts bag) to connect
LOWER inducer housing drain connection to the
condensate trap.
58MCB

-- 1 2 --
CONDENSATE
TRAP
AUXILIARY "J"BOX
PLUG
CAP
INDUCER HOUSING
DRAIN TUBE (VIOLET)
COLLECTOR BOX
DRAIN TUBE (BLUE)
COLLECTOR BOX TUBE (PINK)
RELOCATE TUBE BETWEEN BLOWER SHELF AND INDUCER HOUSING FOR
040, 060, AND 080 HEATING INPUT FURNACES
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX
DRAIN TUBE
(BLUE AND WHITE STRIPED)
DRAIN TUBE COUPLING
COLLECTOR BOX
TUBE (GREEN)
COLLECTOR
BOX EXTENSION
DRAIN TUBE
A00215
Fig. 10 -- Horizontal Left Tube Configuration
e. Connect inducer housing drain connection to
condensate trap.
(1.) Condensate Trap Located on Left Side of Casing
a. Determine appropriate length and cut.
b. Connect tube to condensate trap.
c. Clamp tube to prevent any condensate leakage.
(2.) Condensate Trap Located on Right Side of Casing
a. Route inducer housing drain tube (violet label)
directly from inducer housing to condensate
trap as shown in Fig. 9.
b. Determine appropriate length and cut.
c. Connect tube to condensate trap.
d. Clamp tube to prevent any condensate leakage.
3. Relief Port Tube
Refer to Pressure Switch Tubing section for connection
procedure.
CONDENSATE TRAP FIELD DRAIN ATTACHMENT
Refer to Condensate Drain section for recommendations
and procedures.
PRESSURE SWITCH TUBING
One collector box pressure tube (pink label) is factory connected
to the pressure switch for use when furnace is installed in
UPFLOW applications. This tube MUST be disconnected and
used for the condensate trap relief port tube. The other collector
box pressure tube (green label) which was factory connected to
the condensate trap relief port connection MUST be connected to
the pressure switch in DOWNFLOW or HORIZONTAL
RIGHT applications.
NOTE: See Fig. 8 or 9 or tube routing label on main furnace
door to check for proper connections.
Relocate tubes as described below.
1. Disconnect collector box pressure tube (pink label)
attached to pressure switch.
2. Extend collector box pressure tube (green label) which
was previously connected to condensate trap relief port
connection by splicing to small diameter tube
(factory-supplied in loose parts bag).
3. Connect collector box pressure tube (green label) to
pressure switch connection labeled COLLECTOR BOX.
4. Extend collector box pressure tube (pink label) which was
previously connected to pressure switch by splicing to
remaining small diameter tube (factory-supplied in loose
parts bag).
5. Route this extended tube (pink label) to condensate trap
relief port connection.
6. Determine appropriate length, cut, and connect tube.
7. Clamp tube to relief port connection.
CONDENSATE TRAP FREEZE PROTECTION
Refer to Condensate Drain Protection section for
recommendations and procedures.
Step 4 -- Horizontal Left (Supply-Air Discharge)
Applications
A horizontal left furnace application is where furnace blower is
located to the right of combustion and controls section of furnace,
and conditioned air is discharged to the left.
CONDENSATE TRAP LOCATION
The condensate trap must be removed from the factory-installed
blower shelf location and relocated in selected application
location as shown in Fig. 2 or 10.
58MCB

-- 1 3 --
To relocate condensate trap from the blower shelf to desired
location, perform the following:
1. Remove 3 tubes connected to condensate trap.
2. Remove trap from blower shelf by gently pushing tabs
inward and rotating trap.
3. Install casing hole filler cap (factory-supplied in loose
parts bag) into blower shelf hole where trap was removed.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
Casing hole filler cap must be installed in blower shelf hole
when condensate trap is relocated to prevent combustion
products being drawn in from appliances in the
equipment room.
!WARNING
4. Install condensate trap into desired casing hole by
inserting tube connection stubs through casing hole and
rotating until tabs snap into locking position.
5. Fill unused condensate trap casing holes with plastic filler
caps (factory-supplied in loose parts bag).
CONDENSATE TRAP TUBING
NOTE: See Fig. 10 or tube routing label on main furnace door to
check for proper connections.
1. Collector Box Drain Tube
a. Install drain tube coupling (factory-supplied in loose
parts bag) into collector box drain tube (blue label)
which was previously connected to condensate trap.
b. Connect large diameter drain tube and clamp
(factory-supplied in loose parts bag) to drain tube
coupling, extending collector box drain tube.
c. Route extended tube (blue label) to condensate trap
and cut to appropriate length.
d. Clamp tube to prevent any condensate leakage.
2. Inducer Housing Drain Tube
a. Remove and discard LOWER (molded) inducer
housing drain tube which was previously connected to
condensate trap.
b. Use inducer housing drain extension tube (violet label
and factory-supplied in loose parts bag) to connect
LOWER inducer housing drain connection to the
condensate trap.
c. Determine appropriate length, cut, and connect tube.
d. Clamp tube to prevent any condensate leakage.
3. Relief Port Tube
a. Extend collector box tube (green label) which was
previously connected to the condensate trap by
splicing to small diameter tube (factory-supplied in
loose parts bag).
b. Route extended collector box pressure tube to relief
port connection on the condensate trap.
c. Determine appropriate length, cut, and connect tube.
d. Clamp tube to prevent any condensate leakage.
CONDENSATE TRAP FIELD DRAIN ATTACHMENTS
Refer to Condensate Drain section for recommendations
and procedures.
PRESSURE SWITCH TUBING
The LOWER collector box pressure tube (pink label) is factory
connected to the pressure switch for use when furnace is installed
in UPFLOW applications. This tube MUST be disconnected,
extended, rerouted, and then reconnected to the pressure switch in
HORIZONTAL LEFT applications.
NOTE: See Fig. 10 or tube routing label on main furnace door to
check for proper connections.
Modify tube as described below.
1. Disconnect collector box pressure tube (pink label)
attached to pressure switch.
2. Use smaller diameter tube (factory-supplied in loose parts
bag) to extend tube disconnected in item 1.
3. Route extended tube:
a. Behind inducer housing.
b. Between blower shelf and inducer housing.
c. Behind inducer motor bracket.
d. Between inducer motor and pressure switch.
4. Determine appropriate length, cut, and reconnect tube to
pressure switch connection labeled COLLECTOR BOX.
CONDENSATE TRAP FREEZE PROTECTION
Refer to Condensate Drain Protection section for
recommendations and procedures.
CONSTRUCT A WORKING PLATFORM
Construct working platform where all required furnace clearances
are met. (See Fig. 3 and 11 or 12.)
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent
unit operation.
The condensate trap MUST be installed below furnace. See
Fig. 5 for dimensions. The drain connection to condensate
trap must also be properly sloped to an open drain.
CAUTION
!
NOTE: Combustion-air and vent pipes are restricted to a
minimum length of 5 ft. (1.5 M) (See Table 11.)
NOTE: A 12-in. (305 mm) minimum offset pipe section is
recommended with short (5 to 8 ft (1.5 to 2.4 M)) vent systems.
This recommendation is to reduce excessive condensate droplets
from existing vent pipe. (See Fig. 11, 12 or 41.)
Step 5 -- Horizontal Right (Supply-Air Discharge)
Applications
A horizontal right furnace application is where furnace blower is
located to the left of combustion and controls section of furnace,
and conditioned air is discharged to the right.
MINOR PROPERTY DAMAGE
Failure to follow this caution may result in minor
property damage.
Local codes may require a drain pan under entire furnace and
condensate trap when a condensing furnace is used in attic
application or over a finished ceiling.
CAUTION
!
NOTE: In Canada, installations shall be in accordance with
current NSCNGPIC Installation Codes and/or local codes.
NOTE: The auxiliary junction box (J-Box) MUST be relocated
to opposite side of furnace casing. (See Fig. 13.) See Electrical
Connection section for J-Box relocation.
CONDENSATE TRAP LOCATION
The condensate trap must be removed from the factory-installed
blower shelf location and relocated in selected application
location as shown in Fig. 2 or 13.
58MCB

-- 1 4 --
COMBUSTION - AIR
INTAKE VENT
MANUAL
SHUTOFF
GAS VALVE
SEDIMENT
TRAP CONDENSATE
TRAP
DRAIN
ACCESS OPENING
FOR TRAP
30″(762 mm)MIN
WORK AREA
A 12-IN. (305 mm) MIN HORIZONTAL PIPE
SECTION IS RECOMMENDED WITH
SHORT (5 TO 8 FT / 1.5 TO 2.4 M) VENT
SYSTEMS TO REDUCE EXCESSIVE
CONDENSATE DROPLETS FROM
EXITING THE VENT PIPE.
5
3
/
4
″ (146 mm)
NOTE: LOCAL CODES MAY REQUIRE A DRAIN PAN UNDER THE
FURNACE AND CONDENSATE TRAP WHEN A CONDENSING
FURNACE IS INSTALLED ABOVE FINISHED CEILINGS.
A93031
Fig. 11 -- Attic Location and Working Platform for Direct Vent (2-pipe) Application -- All Sizes
VENT
MANUAL
SHUTOFF
GAS VALVE
SEDIMENT
TRAP CONDENSATE
TRAP
DRAIN
ACCESS OPENING
FOR TRAP
30-IN. (762mm) MIN
WORK AREA
A 12-IN. (305mm) MIN HORIZONTAL PIPE
SECTION IS RECOMMENDED WITH
SHORT (5 TO 8 FT / 1.5 TO 2.4M) VENT
SYSTEMS TO REDUCE EXCESSIVE
CONDENSATE DROPLETS FROM
EXITING THE VENT PIPE.
A 3-IN.(76mm) MINIMUM CLEARANCE
TO COMBUSTION-AIR INTAKE
IS REQUIRED.
5
3
/
4
IN. (146mm)
NOTE: LOCAL CODES MAY REQUIRE A DRAIN PAN UNDER THE
FURNACE AND CONDENSATE TRAP WHEN A CONDENSING
FURNACE IS INSTALLED ABOVE FINISHED CEILINGS.
COMBUSTION AIR
INTAKE
A96184
Fig. 12 -- Attic Location and Working Platform for Non-Direct Vent (1-pipe) Applications-Sizes 040 Through 120 Only
58MCB

-- 1 5 --
PLUG
COLLECTOR BOX DRAIN TUBE
(BLUE AND WHITE STRIPED)
INDUCER HOUSING
DRAIN TUBE (VIOLET)
COLLECTOR BOX
EXTENSION TUBE
COLLECTOR BOX TUBE (GREEN)
CAP
COLLECTOR BOX DRAIN TUBE (BLUE)
COLLECTOR BOX TUBE (PINK)
CONDENSATE
TRAP
COLLECTOR BOX EXTENSION TUBE
AUXILARY “J” BOX RELOCATED HERE
A00214
Fig. 13 -- Horizontal Right Tube Configuration
To relocate condensate trap from the blower shelf to desired
location, perform the following:
1. Remove 3 tubes connected to condensate trap.
2. Remove trap from blower shelf by gently pushing tabs
inward and rotating trap.
3. Install casing hole filler cap (factory-supplied in loose
parts bag) into blower shelf hole where trap was removed.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
Casing hole filler cap must be installed in blower shelf hole
when condensate trap is relocated to prevent combustion
products being drawn in from appliances in the
equipment room.
!WARNING
4. Install condensate trap into desired casing hole by
inserting tube connection stubs through casing hole and
rotating until tabs snap into locking position.
5. Fill unused condensate trap casing holes with plastic filler
caps (factory-supplied in loose parts bag).
CONDENSATE TRAP TUBING
NOTE: See Fig. 13 or tube routing label on main furnace door to
check for proper connections.
1. Collector Box Drain Tube
a. Remove factory-installed plug from LOWER collector
box drain tube (blue and white striped label).
b. Install removed clamp and plug into UPPER collector
box drain tube (blue label) which was previously
connected to condensate trap.
c. Connect LOWER collector box drain tube (blue and
white striped label) to condensate trap. Tube does not
need to be cut.
d. Clamp tube to prevent any condensate leakage.
2. Inducer Housing Drain Tube
a. Remove factory-installed cap and clamp from LOWER
inducer housing drain connection.
b. Remove and discard UPPER (molded) inducer housing
drain tube which was previously connected to
condensate trap.
c. Install cap and clamp on UPPER inducer housing drain
connection where molded drain tube was removed.
d. Use inducer housing drain extension tube (violet label
and factory-supplied in loose parts bag) to connect
LOWER inducer housing drain connection to
condensate trap.
e. Determine appropriate length, cut, and connect tube to
condensate trap.
f. Clamp tube to prevent any condensate leakage.
3. Relief Port Tube
Refer to Pressure Switch Tubing section for
connection procedure.
CONDENSATE TRAP FIELD DRAIN ATTACHMENT
Refer to Condensate Drain section for recommendations
and procedures.
58MCB

-- 1 6 --
UPFLOW OR DOWNFLOW
HORIZONTAL
FRONT FRONT
LEVEL (0”)
TO 1/2” (13mm)
MAX MIN 1/4” (7mm)
TO 1/2” (13mm)
MAX
A02146
Fig. 14 -- Furnace Location for Proper Condensate Drainage
PRESSURE SWITCH TUBING
One collector box pressure tube (pink label) is factory connected
to the pressure switch for use when furnace is installed in
UPFLOW applications. This tube MUST be disconnected and
used for the condensate trap relief port tube. The other collector
box pressure tube (green label) which was factory connected to
the condensate trap relief port connection MUST be connected to
the pressure switch in DOWNFLOW or HORIZONTAL
RIGHT applications.
NOTE: See Fig. 13 or tube routing label on main furnace door to
check for proper connections.
Relocate tubes as described below:
1. Disconnect collector box pressure tube (pink label)
attached to pressure switch.
2. Extend collector box pressure tube (green label) which
was previously connected to condensate trap relief port
connection by splicing to small diameter tube
(factory-supplied in loose parts bag).
3. Route extended collector box pressure tube behind inducer
motor bracket then between inducer motor and
pressure switch.
4. Connect collector box pressure tube (green label) to
pressure switch connection labeled COLLECTOR BOX.
5. Use remaining smaller diameter tube (factory-supplied in
loose parts bag) to extend collector box pressure tube
(pink label) which was previously connected to
pressure switch.
6. Route this extended tube (pink label) to condensate trap
relief port connection.
7. Determine appropriate length, cut, and connect tube.
8. Clamp tube to relief port connection.
CONDENSATE TRAP FREEZE PROTECTION
Refer to Condensate Drain Protection section for
recommendations and procedures.
CONSTRUCT A WORKING PLATFORM
Construct working platform where all required furnace clearances
are met. (See Fig. 3 and 11 or 12.)
FRONT
BACK
FRONT
B
A
C
K
A93043
Fig. 15 -- Installation on Back is Prohibited
UNIT MAY NOT OPERATE
Failure to follow this caution may result in intermittent
unit operation.
The condensate trap MUST be installed below furnace. See
Fig. 5 for dimensions. The drain connection to condensate
trap must also be properly sloped to an open drain.
CAUTION
!
NOTE: Vent pipe(s) and combustion-air pipe (when applicable)
are restricted to a minimum length of 5 ft. (See Table 11.)
NOTE: A 12-in. (305 mm) minimum offset pipe section is
recommended with short (5 to 8 ft) vent systems. This
recommendation is to reduce excessive condensate droplets from
existing vent pipe. (See Fig. 11, 12 or 41.)
NOTE: The 140 size unit may NOT be installed in non-direct
vent (1-pipe) application.
LOCATION
Step 1 -- General
This furnace must
Sbe installed so the electrical components are protected
from water.
Snot be installed directly on any combustible material other than
wood flooring (refer to SAFETY CONSIDERATIONS).
Sbe located so combustion-air and vent pipe maximum lengths
are not exceeded. Refer to Table 11.
Sbe located where available electric power and gas supplies
meet specifications on the furnace rating plate.
Sbe attached to an air distribution system and be located as close
to the center of the distribution system as possible. Refer to Air
Ducts section.
Sbe provided with ample space for servicing and cleaning.
Always comply with minimum fire protection clearances
shown on the furnace clearance to combustibles label.
NOTE: For upflow/downflow applications install furnace so that
it is level or pitched forward within 1/2-in. (13 mm) for proper
furnace operation. For horizontal applications pitch 1/4-in. (6
mm) minimum to 1/2-in. (13 mm)maximum forward to ensure
proper condensate drainage from secondary heat exchangers.
(See Fig. 14.)
58MCB

-- 1 7 --
When a furnace is installed so that supply ducts carry air
circulated by the furnace to areas outside the space containing the
furnace, the return air shall also be handled by duct(s) sealed to
furnace casing and terminating outside the space containing the
furnace to ensure there will not be a negative pressure condition
within equipment room or space.
UNIT DAMAGE HAZARD
This gas furnace may be used for construction heat
provided that:
--The furnace is permanently installed with all electrical
wiring, piping, air filters, 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
minimize 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
maintained between 55°F(13°C) and 80°F(27°C), 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 instructions.
--The air temperature rise is within the rated rise range on the
furnace rating plate, and the firing rate has been set to the
nameplate 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.
--After construction is complete, verify furnace operating
conditions including ignition, input rate, temperature rise and
venting, according to the manufacturer’s instructions.
CAUTION
!
FIRE, INJURY OR DEATH HAZARD
Failure to follow this warning could result in fire, property
damage, personal injury, or death.
Do not install furnace on its back. Safety control operation
will be adversely affected. Never connect return-air ducts to
back of furnace. (See Fig. 15.)
!WARNING
Step 2 -- Furnace Location Relative to Cooling
Equipment
The cooling coil must be installed parallel with or on downstream
side of furnace to avoid condensation in heat exchanger. When
installed parallel with a furnace, dampers or other means used to
control flow of air shall be adequate to prevent chilled air from
entering furnace. If dampers are manually operated, they must be
equipped with a means to prevent operation of either unit unless
damper is in full-heat or full-cool position.
A07911
Fig. 16 -- Freeze Protection
UNIT DAMAGE HAZARD
Failure to follow this caution may result in minor property or
unit damage.
If this furnace is installed in an unconditioned space where
ambient temperatures may be 32°F(0°C)or lower, freeze
protection measures must be taken. (See Fig. 16.)
CAUTION
!
Step 3 -- Hazardous Locations
FIRE, EXPLOSION, INJURY OR DEATH HAZARD
Improper location or inadequate protection could result in fire
or explosion.
When the furnace is installed in a residential garage, the
burners and ignition sources must be located at least 18-in.
(457 mm) above the floor. The furnace must be located
or protected to avoid physical damage by vehicles. When
the furnace is installed in a public garage, airplane hangar, or
other building having a hazardous atmosphere, the furnace
must be installed in accordance with the NFGC or
NSCNGPIC. (See Fig. 17.)
!WARNING
Step 4 -- Furnace Location and Application
DIRECT VENT (2-PIPE) APPLICATION
Furnace may be located in a confined space without special
provisions for dilution or ventilation air.
18-IN. (457.2 mm)
MINIMUM TO BURNERS
A93044
Fig. 17 -- Installation in a Garage
58MCB

-- 1 8 --
Table 1 – Minimum Free Area Required for Each Combustion Air Opening or Duct to Outdoors
FURNACE
INPUT
(BTUH)
TWO HORIZONTAL DUCTS
(1 SQ. IN./2,000 BTUH) (1,100 SQ. MM/KW)
SINGLE DUCT OR OPENING
(1 SQ. IN./3,000 BTUH) (734 SQ. MM/KW)
TWO OPENINGS OR VERTICAL DUCTS
(1 SQ. IN./4,000 BTUH) (550 SQ. MM/KW)
Free Area of
Opening and Duct
Sq. In. (mm)
Round Duct
Dia.
In. (mm)
Free Area of Opening
and Duct
Sq. In (mm)
Round Duct
Dia.
In. (mm)
Free Area of Opening
and Duct
Sq. In (mm)
Round Duct
Dia.
In. (mm)
44,000 22 (14194) 6 (152) 14.7 (9494) 5 (127) 11 (7097) 4 (102)
66,000 33 (21290) 7 (178) 22 (14193) 6 (152) 16.5 (10645) 5 (127)
88,000 44 (28387) 8 (203) 29.3 (18903) 7 (178) 22 (14193) 6 (152)
110,000 55 (35484) 9 (229) 36.7 (23677) 7 (178) 27.5 (17741) 6 (152)
132,000 66 (42581) 10 (254) 44 (28387) 8 (203) 33 (21290) 7 (198)
154,000 77 (49677) 10 (254) 51.3 (33096) 9 (229) 38.5 (24838) 8 (203)
EXAMPLE:Determining Free Area
FURNACE WATER HEATER TOTAL INPUT
110,000 + 30,000 = (140,000 divided by 4,000) = 35.0 Sq. In. for each two Vertical Ducts or Openings
66,000 + 40,000 = (106,000 divided by 3,000) = 35.3 Sq. In. for a Single Duct or Opening
88,000 +30,000 =(118,000 divided by 2,000) =59.0 Sq. In. for each of two Horizontal Ducts
Table 2 – Minimum Space Volumes for 100% Combustion, Ventilation and Dilution Air from Outdoors
OTHER THAN FAN-ASSISTED TOTAL
(1,000’S BTUH GAS INPUT RATE)
FAN-ASSISTED TOTAL
(1,000’S BTUH GAS INPUT RATE)
ACH 30 40 50 44 66 88 110 132 154
SpaceVolumeFt
3(M3)
0.60 1,050
(29.7)
1,400
(39.6)
1,750
(49.5)
1,100
(31.1)
1,650
(46.7)
2,200
(62.2)
2,750
(77.8)
3,300
(93.4)
3,850
(109.0)
0.50 1,260
(35.6)
1,680
(47.5)
2,100
(59.4)
1,320
(37.3)
1,980
(56.0)
2,640
(74.7)
3,300
(93.4)
3,960
(112.1)
4,620
(130.8)
0.40 1,575
(44.5)
2,100
(59.4)
2,625
(74.3)
1,650
(46.7)
2,475
(70.0)
3,300
(93.4)
4,125
(116.8)
4,950
(140.1)
5,775
(163.5)
0.30 2,100
(59.4)
2,800
(79.2)
3,500
(99.1)
2,200
(62.2)
3,300
(93.4)
4,400
(124.5)
5,500
(155.7)
6,600
(186.8)
7,700
(218.0)
0.20 3,150
(89.1)
4,200
(118.9)
5,250
(148.6)
3,300
(93.4)
4,950
(140.1)
6,600
(186.8)
8,250
(233.6)
9,900
(280.3)
11,550
(327.0)
0.10 6,300
(178.3)
8,400
(237.8)
10,500
(297.3)
6,600
(186.8)
9,900
(280.3)
13,200
(373.7)
16,500
(467.2)
19,800
(560.6)
23,100
(654.1)
0.00 NP NP NP NP NP NP NP NP NP
NON-DIRECT VENT (1-PIPE) APPLICATION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in intermittent
unit operation.
Do not install furnace in a corrosive or contaminated
atmosphere. Make sure all combustion and circulating air
requirements are met.
CAUTION
!
Refer to the AIR FOR COMBUSTION AND VENTILATION
section for details.
AIR FOR COMBUSTION AND
VENTILATION
Provisions for adequate combustion, ventilation, and dilution air
must be provided in accordance with:
SU.S. Installations: Section 9.3 of the NFPA 54/ANSI
Z223.1--2006, Air for Combustion and Ventilation and
applicable provisions of the local building codes.
SCanadian Installations: Part 8 of the CAN/CSA--B149.1--05,
Venting Systems and Air Supply for Appliances and all
authorities having jurisdiction.
FURNACE CORROSION HAZARD
Failure to follow this warning could result in reduced furnace
component life.
Air for combustion must not be contaminated by halogen
compounds, which include fluoride, chloride, bromide, and
iodide. These elements could corrode heat exchangers and
shorten furnace life. Air contaminants are found in aerosol
sprays, detergents, bleaches, cleaning solvents, salts, air
fresheners, and other household products.
!WARNING
The following types of furnace installations may require
OUTDOOR AIR for combustion due to chemical exposures:
SCommercial buildings
SBuildings with indoor pools
SLaundry rooms
SHobby or craft rooms, and
SChemical storage areas
If air is exposed to the following substances, it should not be
used for combustion air, and outdoor air may be required
for combustion:
SPermanent wave solutions
SChlorinated waxes and cleaners
58MCB

-- 1 9 --
SChlorine based swimming pool chemicals
SWater softening chemicals
SDe-icing salts or chemicals
SCarbon tetrachloride
SHalogen type refrigerants
SCleaning solvents (such as perchloroethylene)
SPrinting inks, paint removers, varnishes, etc.
SHydrochloric acid
SCements and glues
SAntistatic fabric softeners for clothes dryers
SMasonry acid washing materials
All fuel-burning equipment must be supplied with air for fuel
combustion. Sufficient air must be provided to avoid negative
pressure in the equipment room or space. A positive seal must be
made between the furnace cabinet and the return-air duct to
prevent pulling air from the burner area and from draft
safeguard opening.
CARBON MONOXIDE POISONING HAZARD
Failure to follow this warning could result in personal injury
or death.
The operation of exhaust fans, kitchen ventilation fans, clothes
dryers, attic exhaust fans or fireplaces could create a
NEGATIVE PRESSURE CONDITION at the furnace.
Make-up air MUST be provided for the ventilation devices, in
addition to that required by the furnace. Refer to the Carbon
Monoxide Poisoning Hazard warning in the venting section of
these instructions to determine if an adequate amount of
make-up air is available.
!WARNING
The requirements for combustion and ventilation air depend upon
whether or not the furnace is located in a space having a volume
of at least 50 cubic feet per 1,000 Btuh input rating for all gas
appliances installed in the space.
SSpaces having less than 50 cubic feet per 1,000 Btuh require
the OUTDOOR COMBUSTION AIR METHOD.
SSpaces having at least 50 cubic feet per 1,000 Btuh may use
the INDOOR COMBUSTION AIR, STANDARD or
KNOWN AIR INFILTRATION METHOD.
Outdoor Combustion Air Method
1. Provide the space with sufficient air for proper
combustion, ventilation, and dilution of flue gases using
permanent horizontal or vertical duct(s) or opening(s)
directly communicating with the outdoors or spaces that
freely communicate with the outdoors.
2. Fig. 18 illustrates how to provide TWO OUTDOOR
OPENINGS, one inlet and one outlet combustion and
ventilation air openings to the outdoors.
a. One opening MUST commence within 12-in. (305
mm) of the ceiling and the second opening MUST
commence within 12-in. (305 mm) of the floor.
b. Size openings and ducts per Fig. 18 and Table 1.
c. TWO HORIZONTAL DUCTS require 1 square inch of
free area per 2,000 Btuh (1,100 mm2/kW) of combined
input for all gas appliances in the space per Fig. 18
and Table 1.
d. TWO OPENINGS OR VERTICAL DUCTS require 1
square inch of free area per 4,000 Btuh (550 mm2/kW)
for combined input of all gas appliances in the space
per Fig. 18 and Table 1.
3. ONE OUTDOOR OPENING requires:
a. 1 square inch of free area per 3,000 Btuh
(734 mm2/kW) for combined input of all gas
appliances in the space per Table 1 and
b. Not less than the sum of the areas of all vent connectors
in the space.
The opening shall commence within 12-in. (305 mm) of
the ceiling. Appliances in the space shall have
clearances of at least 1-in. (25 mm) from the sides and
back and 6-in. (152 mm) from the front. 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
communicate with the outdoors.
Indoor Combustion Air©NFPA & AGA
Standard and Known-Air-Infiltration Rate Methods
Indoor combustion air is permitted for combustion, ventilation,
and dilution, if the Standard or Known-Air-Infiltration Rate
Method is used.
CARBON MONOXIDE POISONING HAZARD
Failure to supply outdoor air via grilles or ducts could result in
death and/or personal injury.
Many homes require air to be supplied from outdoors for
furnace combustion, ventilation, and dilution of flue gases.
The furnace combustion air supply must be provided in
accordance with this instruction manual.
!WARNING
The Standard Method:
1. The space has no less volume than 50 cubic feet per
1,000 Btuh of the maximum input ratings for all gas
appliances installed in the space and
2. The air infiltration rate is not known to be less than 0.40
air changes per hour (ACH).
The Known Air Infiltration Rate Method shall be used, if the
infiltration rate is known to be:
1. Less than 0.40 ACH and
2. Equal to or greater than 0.10 ACH
Infiltration rates greater than 0.60 ACH shall not be used. The
minimum required volume of the space varies with the number of
ACH and shall be determined per Table 2 or Equations 1 and 2.
Determine the minimum required volume for each appliance in
the space and add the volumes together to get the total minimum
required volume for the space.
Table 2 -- Minimum Space Volumes were determined by using
the following equations from the National Fuel Gas Code NFPA
54/ANSI Z223.1--2006, 9.3.2.2:
1. For other than fan-assisted appliances, such as a draft
hood-equipped water heater
A04002
2. For fan-assisted appliances such as this furnace:
A04003
58MCB

-- 2 0 --
1 SQ IN.
PER
4000
BTUH*
DUCTS
TO
OUTDOORS
1 SQ IN.
PER 4000
BTUH*
CIRCULATING
AIR DUCTS
VENT
THROUGH
ROOF
D
B
A
C
E
1 SQ IN.
PER 4000
BTUH*
DUCT
TO
OUTDOORS
CIRCULATING AIR DUCTS
1 SQ IN.
PER 2000
BTUH*
1 SQ IN.
PER 2000
BTUH*
DUCTS
TO
OUTDOORS
12″MAX
12″MAX
12″MAX
12″
MAX
12″
MAX
OUTDOORS
1 SQ IN.
PER
4000
BTUH*
F
G
CLEARANCE IN FRONT
OF COMBUSTION AIR
OPENINGS SHALL BE
AT LEAST 3 IN.
(305mm)
(305mm)
(305mm)
(305mm)
(305mm)
(76mm)
*Minimum dimensions of 3 in. (76 mm).
NOTE: Use any of the following combinations of openings:
A&BC&DD&EF&G
A03174
Fig. 18 -- Air for Combustion, Ventilation, and Dilution
for Outdoors
If:
Iother=combined input of all other than fan-assisted appliances
in Btu/hr
Ifan=combined input of all fan-assisted appliances in Btu/hr
ACH = air changes per hour (ACH shall not exceed 0.60.)
The following requirements apply to the Standard Method and to
the Known Air Infiltration Rate Method.
1. Adjoining rooms can be considered part of a space if:
a. There are no closable doors between rooms.
b. Combining spaces on same floor level. Each opening
shall have free area of at least 1-in.2/1,000 Btuh
(2,000 mm2/kW) of the total input rating of all gas
appliances in the space, but not less than 100-in.2
(0.06 m2). One opening shall commence within 12 in.
(305 mm) of the ceiling and the second opening shall
commence within 12-in. (305 mm) of the floor. The
minimum dimension of air openings shall be at least
3-in. (76 mm). (See Fig. 19.)
c. Combining space on different floor levels. The
volumes of spaces on different floor levels shall be
considered as communicating spaces if connected by
one or more permanent openings in doors or floors
having free area of at least 2 in.2/1,000 Btuh
(4,400 mm2/kW) of total input rating of all
gas appliances.
2. An attic or crawlspace may be considered a space that
freely communicates with the outdoors provided there are
adequate permanent ventilation openings directly to
outdoors having free area of at least 1-in.2/4,000 Btuh of
total input rating for all gas appliances in the space.
CIRCULATING AIR
DUCTS
6" MIN
(FRONT)Ü
CIRCULATING AIR DUCTS
VENT THROUGH ROOF
1 SQ IN.
PER 1000
BTUH* IN DOOR
OR WALL
12" MAX
1 SQ IN.
PER 1000
BTUH* IN DOOR
OR WALL
12" MAX
UNCONFINED
SPACE
INTERIOR
HEATED
SPACE
CLEARANCE IN FRONT OF COMBUSTION AIR
OPENINGS SHALL BE AT LEAST 3 IN.
(305mm)
(152mm)
(305mm)
* Minimum opening size is 100 sq in. with minimum dimensions of 3 in. (76
mm)
† Minimum of 3 in. (76 mm) when type-B1 vent is used.
A03175
Fig. 19 -- Air for Combustion, Ventilation, and Dilution
from Indoors
3. In spaces that use the Indoor Combustion Air Method,
infiltration should be adequate to provide air for
combustion, permanent ventilation and dilution of flue
gases. However, in buildings with unusually tight
construction, additional air MUST be provided using
the methods described in the Outdoor Combustion Air
Method section.
Unusually tight construction is defined as
Construction with:
a. Walls and ceilings exposed to the outdoors have a
continuous, sealed vapor barrier. Openings are
gasketed or sealed and
b. Doors and openable windows are weatherstripped and
c. Other openings are caulked or sealed. These include
joints 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.
NOTE: In determining the free area of an opening, the blocking
effect of the louvers, grilles, and screens must be considered. If
the free area of a louver or grille design is unknown, it may be
assumed that wood louvers have a 20 percent free area, and metal
louvers or grilles have a 60 percent free area. Screens, when used,
must not be smaller than 1/4-in. (6 mm) mesh. Louvers and
grilles must be constructed so they cannot be closed.
When combustion air ducts are used, they must be of the same
cross sectional area as the free area of the openings to which they
connect. The minimum dimension of ducts must not be less than
3-in. (76 mm).
58MCB