Report (65) Table of Contents
1.0 General 2 7.2 Supply Voltage and Wiring 16
1.1 Hazard Labels and Notices 2 7.3 Thermostat and Control Wiring 16
1.2 General Installation Information 2 7.4 Typical Wiring Diagrams 17
1.3 Warranty 3 8.0 Controls 19
1.4 Installation Codes 3 8.1 Fan Control 19
2.0 Furnace Location 3 8.2 Limit Control 19
2.1 General Recommendations 3 8.3 Blocked Vent Switch 19
2.2 Combustion Air Requirements for a Heater 8.4 Gas Controls 19
Located in a Confined Space 4 8.5 Pilot and Ignition Systems 21
3.0 Uncrating and Preparation 4 8.6 Burner Carryover System and Air Adjustment....22
3.1 Uncrating and Inspecting 4 9.0 Commissioning and Startup 23
3.2 Preparing the Furnace for Installation 5 9.1 Check the installation prior to startup 23
4.0 Dimensions and Clearances 6 9.2 Startup 23
4.1 Dimensions 6 9.3 Check installation after startup 23
4.2 Clearances 6 10.0 Maintenance and Service 24
5.0 Suspending or Mounting the Furnace 7 10.1 Maintenance Schedule 24
5.1 Weight 7 10.2 Maintenance Procedures 25
5.2 Suspending the Furnace 7 10.3 Troubleshooting 27
5.3 Mounting the Furnace 7 APPENDIX 28
6.0 Mechanical 7 Converting Model X Duct Furnace for Lower
6.1 Gas Piping and Pressures 7 Temperature Rise/Higher CFM Application 28
6.2 Venting 9 Wiring Diagrams for Match-Lit Pilot Discontinued
6.3 Duct Furnace Airflow 11 in 2003 30
7.0 Electrical Supply and Wiring 16 INDEX 31
7.1 General 16 INSTALLATION RECORD 32
1.0 General 1.1 Hazard Labels and Notices
There are warning labels on the unit and throughout this manual. For your safety, read
the definitions below and comply with all boxes labeled CAUTION, WARNING, and
DANGER during installation, operation, maintenance, and service of this heater.
Definitions of HAZARD INTENSITY LEVELS used in this Manual
1. DANGER: Failure to comply will result in severe personal injury or
death and/or property damage.
2.WARNING: Failure to comply could result in severe personal injury
or death and/or property damage.
3. CAUTION: Failure to comply could result in minor personal injury
and/or property damage.
WARNING
Gas-fired appliances are not designed for use in hazardous
atmospheres containing flammable vapors or combustible dust, in
atmospheres containing chlorinated orhalogenated hydrocarbons,
or in applications with airborne silicone substances. See Hazard
Levels, above.
1.2 General Installation should be done by a qualified agency in accordance with the instructions
Installation in this manual and in compliance with all codes and requirements of authorities having
Information jurisdiction.
The instructions in this manual apply to a Model X duct furnace.
Form I-X,P/N 150491 R8,Page 2
•
1.3 Warranty WARRANTY: Warranty is void if
Refer to the limited warranty
a. Furnaces are used in atmospheres containing flammable vapors or atmospheres
form in the "Literature Bag".
containing chlorinated or halogenated hydrocarbons or any contaminant
(silicone, aluminium oxide, etc.)that adheres to the spark ignition flame sensing
probe.
b. Wiring is not in accordance with the diagram furnished with the heater.
c. Unit is installed without proper clearances to combustible materials or located
in a confined space without proper ventilation and air for combustion. (See
Paragraphs 2.2 and 4.2.)
d. Furnace air throughput is not adjusted within the range specified on the rating
plate.
e. Duct furnace is installed in a process or drying application without factory
authorization. (Any use in a process or drying application voids agency
certification.)
1.4 Installation The duct furnaces covered in this manual are design-certified by the Canadian Stan-
Codes dards Association to ANSI Z83.8a and CSA 2.6 for use with either natural or propane
gas. The type of gas for which the furnace is equipped and the correct firing rate are
shown on the rating plate attached to the unit. Electrical characteristics are shown on
the unit rating plate.
These units must be installed in accordance with local building codes. In the absence
of local codes, in the United States, the unit must be installed in accordance with the
National Fuel Gas Code(latest edition).A Canadian installation must be in accordance
with the CAN/CGA B149.1 and B149.2 Installation Code for Gas Burning Appliances
and Equipment.These codes are available from CSA Information Services, 1-800-463-
6727. Local authorities having jurisdiction should be consulted before installation is
made to verify local codes and installation procedure requirements.
Special Installations (Aircraft Hangars/Garages)
Installations in aircraft hangars should be in accordance with ANSI/NFPA No. 409(lat-
est edition), Standard for Aircraft Hangars; in public garages in accordance with ANSI/
NFPA No. 88A(latest edition), Standard for Parking Structures; and for repair garages
in accordance with ANSI/NFPA No. 88B (latest edition), Standard for Repair Garages.
ANSI/NFPA-88 (latest edition) specifies overhead heaters must be installed at least
eight feet above the floor. In Canada, installations in aircraft hangars should be in
accordance with the requirements of the enforcing authorities,and in public garages in
accordance with CSA B149 codes.
WARNING
These duct furnaces are not certified or approved for use in drying or process applications. If a
duct furnace is to be used in a drying or process application, contact the factory for application
guidelines and manufacturer's authorization. Without factory authorization, the warranty is void,
and the manufacturer disclaims any responsibility for the duct furnace and/or the application.
WARNING
To ensure safety, follow lighting instructions located on he outlet box cover.
2.0 Furnace 2.1 General Recommendations
Location A duct furnace is designed for connection to an inlet and an outlet duct and depends
on an external air handler. Location must comply with the clearances listed in Para-
graph 4.2.There are a variety of factors,such as system application, building structure,
dimensions, and weight, that contribute to selecting the location. Read the installation
information in this manual and select a location that complies with the requirements.
WARNING
Avoid installing a furnace in extremely drafty areas. Extreme drafts can
shorten the life of the heat exchanger and/or cause safety problems.
Form I-X,P/N 150491 R8,Page 3
•
2.0 Furnace These duct furnaces are designed to take combustion air from the space in which the
Location furnace is installed. The air that enters into the combustion process is vented to the
outdoors. Sufficient air must enter the equipment location to replace the air exhausted
(cont d) through the vent system. Modern construction methods involve the greater use of insu-
lation, improved vapor barriers and weather-stripping, with the result that buildings
2.2 Combustion Air generally are much tighter structurally than they have been in the past. The combus-
Requirements tion air supply for gas-fired equipment can be affected by these construction conditions
for a Heater because infiltration that would have existed in the past may not be adequate. Exten-
Located in a sive use of exhaust fans aggravates the situation. In the past the filtration of outside
Confined Space air assumed in heat loss calculations (one air change per hour) was assumed to be
sufficient. However, current construction methods may now require the introduction of
outside air into the space through wall openings or ducts.
Requirements for combustion air and ventilation air depend upon whether the unit
is located in a confined or unconfined space. An "unconfined space" is defined as a
space whose volume is not less than 50 cubic feet per 1000 BTUH of the installed
appliance. Under all conditions, enough air must be provided to ensure there will not
be a negative pressure condition within the equipment room or space.A positive seal
must be made in all return-air connections and ducts. Even a slight leak can create a
negative pressure condition in a confined space and affect combustion.
Do not install a unit in a confined space without providing wall openings leading to and
FIGURE 1 -Confined from the space. Provide openings near the floor and ceiling for ventilation and air for
Space: A space whose combustion as shown in FIGURE 1, depending on the combustion air source as noted
volume is less than in Items 1, 2, and 3 below the illustration.
50 cubic feet per 1000 Add total BTUH of all appliances in the confined space and divide by figures below for
BTUH of the installed square inch free area size of each (top and bottom)opening.
appliance input rating 1.Air from inside the building --openings 1 square inchfree area per 1000 BTUH.
Never less than 100 square inches free area for each opening. See (1) in FIGURE 1.
2.Air from outside through duct--openings 1 square inch free area per 2000
(3) (1)� t2) BTUH. See (2) in FIGURE 1.
3.Air direct from outside--openings 1 square inch free area per 4000 BTUH. See
I confined
Space (3) in FIGURE 1.
ihmaimmi=(3) t'� (2) NOTE: For further details on supplying combustion air to a confined space, see the
National Fuel Gas Code ANSI Z223.1a (latest edition ).
WARNING
These furnaces are designed to take combustion air from the space in which the unit is installed
and are not designed for connection to outside combustion air intake ducts.Connecting outside air
duct voids the warranty and could cause hazardous operation. See Hazard Levels, page 2.
Hazards of Chlorine The presence of chlorine vapors in the combustion air of gas-fired heating equipment
presents a potential corrosion hazard. Chlorine will,when exposed to flame, precipitate
from the compound, usually freon or degreaser vapors, and go into solution with any
condensation that is present in the heat exchanger or associated parts. The result is
hydrochloric acid which readily attacks all metals including 300 grade stainless steel.
Care should be taken to separate these vapors from the combustion process.This may
be done by wise location of the furnace with regard to exhausters or prevailing wind
direction. Remember,chlorine is heavier than air.This fact should be kept in mind when
determining installation locations of heating equipment and building exhaust systems.
3.0 Uncrating and 3.1 Uncrating and Inspecting
Preparation This furnace was test operated and inspected at the factory prior to crating and was in
operating condition. If the furnace has incurred any damage in shipment,document the
damage with the transporting agency and immediately contact an authorized Reznor
distributor. If you are a Reznor distributor, follow the FOB freight policy procedures as
published by Thomas& Betts for Reznor products.
Check the rating plate for the gas specifications and electrical characteristics of the
furnace to be sure that they are compatible with the gas and electric supplies at the
installation site.
Form I-X,P/N 150491 R8,Page 4
•
3.2 Preparing the Read this booklet and become familiar with the installation requirements of your par-
Furnace for ticular furnace. If you do not have knowledge of local requirements, check with the
Installation local gas company or any other local agencies who might have requirements concern-
ing this installation. Before beginning, make preparations for necessary supplies,tools,
and manpower.
Check to see if there are any field-installed options that need to be assembled to the
furnace prior to installation.
Option Parts--Some gas control options will have parts either shipped loose with the
heater or shipped separately. If your unit is equipped with any of the gas control options
listed below, be sure these parts are available at the job site.
Application Opt Shipped Separate Components
Heating-Gas Control AG7 Thermostat, P/N 48033
AG3 Control Switch, P/N 29054
AG8 Control Switch, P/N 29054; Sensor&Mixing Tube, P/N 48041
Control Switch, P/N 29054; Remote Temperature Selector,
Makeup Air-Gas AG9 P/N 48042; Sensor&Mixing Tube, P/N 48041
Control Options Control Switch, P/N 29054; Remote Temperature Selector,
AG15 P/N 115848;Stage Adder Module, P/N 115849; Discharge
Air Sensor Holder, P/N 115850; Discharge Air Sensor Holder
Bracket, P/N 213612
Other shipped-separate options could include a vent damper, a power venter, a gas
shutoff valve, a condensate drain fitting, a thermostat, and/or a disconnect switch.
3.2.1 Instructions for Model X furnaces are equipped with directional air baffles between the heat exchanger
Reversing Airflow by tubes. Facing the control compartment of the furnace,the standard direction of airflow
Changing Directional is from left to right.An installation requiring direction of airflow from right to left when
Air Baffles in the Heat facing the control compartment requires repositioning of the directional air baffles at
Exchanger the installation site. Follow the instructions in FIGURE 2 to change the position of
baffles:
FIGURE 2 - Heat Exchanger Directional Air Baffles Scre B ��, ,SuTopp rt Baffle
a) Remove Screws"A". Individually lift each baffle slightly and slide �•.i` Airflow
forward. Remove all baffles completely from the heat exchanger. f ,• �i�r. Baffles
b) Remove Screws"B"and the top baffle support assembly.
Re-position the assembly to the opposite end of the heat �' I�I
exchanger and attach. '
c) Remove Screws"C"and the assembled bottom baffle support ;
`
o crewsA
and brackets. Plug the holes in the heat exchanger bottom by I "Cto �
re-inserting the screws in the holes. Position the assembly on4 \ "4.
the opposite end of the heat exchanger and attach using field- '� ° ;,I%�
supplied sheetmetal screws. 6 c '�
d) Re-install all of the individual baffles by reversing the procedure in
Bottom
/ SG�6�Gra`9e
Step a)above. Baffle Support \ 'P 1Cs
9ht L Screw c
3.2.2 Change the Vent The vent outlet may be horizontal
Outlet Direction or vertical.
To change orientation (vertical or
FIGURE 3 - Horizontal horizontal) of the flue connection:
or Vertical Flue (1) Remove screws; (2) Reverse � —�
Connection position; (3) Re-fasten.
3.2.3 Install Condensate can form in the heat exchanger of furnaces installed as makeup air units
Condensate Drain, or when installed downstream from a cooling coil. Under these conditions, a drain
Option CS1 flange, Option CS1, may be installed on the furnace bottom as shown in FIGURE 4.
When using Option CS1, seal all corners and the four square holes in the bottom pan
edge. NOTE:A 4-inch (102mm) minimum clearance is required under the furnace if a
90° street elbow is used.
FIGURE 4 -Condensate Seal holes in bottom pan.Terminate
Bottom of the Furnace Casing
Drain, Option CS1 drain outside of building. Periodic
(P/N 31765) #10 x 1-1/4 Bolt \,= =R�_Gasket cleaning of the condensate collector
and Nut / 3/4"Pipe Waste Nut and disposal system is required.
Form I-X,P/N 150491 R8,Page 5
•
5.0 Suspending or WARNING
Mounting the Unit must be supported level for proper operation. Do not place or add
Furnace additional weight to the suspended unit.
5.1 Weight Before installing the furnace, check the supporting structure to be used to verify that it
has sufficient load-carrying capacity to support the weight of the unit.
Net Weight
Size 75 100 125 150 175 200 225 250 300 350 _ 400
lbs 150 150 163 182 186 224 231 276 286 320 355
kg 68 68 74 83 84 102 105 125 130 145 161
5.2 Suspending the These duct furnaces have two-point suspension. See hanger centerline dimensions in
Furnace FIGURE 5, page 6.
At each suspension point, the furnace is factory-equipped with a free-turning, female,
1" (NPT), pipe hanger. Suspend by connecting the pipe hanger to a 1"threaded pipe.
See FIGURE 6(left side).
As an alternative method, the factory-installed pipe hanger may be removed and the
heater suspended as illustrated on the right in FIGURE 6.
FIGURE 6 - N1"Pipe Flange Washer Nut Assembly
Suspending •
the Furnace
1"Pipe I —3/8"Rod
Washer Nut
Assembly _—(Standard Assembly
II Heater Top —. � Removed)
1 -Access through the side panel.
Standard Assembly Installer Replaced Assembly
5.3 Mounting the A minimum of 3"(76mm)clearance is required from the bottom of the unit to a combus-
Furnace tible surface. See FIGURE 7 for an illustration of field-fabricated supports.
FIGURE 7 - 7------ 1
til4c1 "- 11i ID r'
Field-Fabricated Cabinet Leg "
Support 8 (178mm)
1/4 x 1-1/2 I 1/4"Nuts
Hex Head Lockwashers
\ Bolts Spacers /
Angle Iron Leg
4"(102mm) Drill 9/32"clearance
holes in angle iron
2"x 2"x 1/4" 72-1/4" leg and cabinet leg.
Angle Iron Leg—. i (57mm)
NOTE: Drawing is A A=3"(76mm)minimum height for
6"x 6"x 1/4" clearance to combustibles.The
not proportional; Metal Plate recommended height is 8"(203mm)
comply with dimen- for plumbing and service.
sions as written. .�
6.0 Mechanical 6.1.1 Gas Supply and Connections
6.1 Gas Piping and WARNING
Pressures This appliance is equipped for a maximum gas supply pressure of 1/2
psi, 3.4 kPa, or 14 inches water column. Supply pressure higher than
1/2 psi requires installation of an additional service regulator external
to the unit.
PRESSURE TESTING SUPPLY PIPING
Test Pressures Above 1/2 PSI: Disconnect the heater and manual valve from the
gas supply line which is to be tested. Cap or plug the supply line.
Test Pressures Below 1/2 PSI:Before testing,close the manual valve on the heater.
Form l-X,P/N 150491 R8,Page 7
6.0 Mechanical All piping must be in accordance with requirements outlined in the National Fuel Gas
(cont'd) Code ANSI/Z223.1a (latest edition) or CAN/CGA-B149.1 and B149.2 (See Paragraph
1.4). Gas supply piping installation should conform with good practice and with local
6.1 Gas Piping codes.
and Pressures Capacity of Piping
Cubic Feet per Hour based on 0.3"w.c.Pressure Drop
(cont'd) Specific Gravity for Natural Gas—0.6(Natural Gas--1000 BTU/Cubic Ft)
Specific Gravity for Propane Gas—1.6(Propane Gas—2550 BTU/Cubic Ft)
Length Diameter of Pipe
of 1/2" 3/4" 1" 1-1/4" 1-1/2" 2"
Sizing a Gas Supply Pipe Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane Natural Propane
20' 92 56 190 116 350 214 730 445 1100 671 2100 1281
Lines 30' 73 45 152 93 285 174 590 360 890 543 1650 1007
40' 63 38 130 79 245 149 500 305 760 464 1450 885
50' 56 34 115 70 215 131 440 268 670 409 1270 775
60' 50 31 105 64 195 119 400 244 610 372 1105 674
70' 46 28 96 59 180 110 370 226 560 342 1050 641
80' 43 26 90 55 170 104 350 214 530 323 990 604
90' 40 24 84 51 160 98 320 195 490 299 930 567
100' 38 23 79 48 150 92 305 186 460 281 870 531
125' 34 21 72 44 130 79 275 168 410 250 780 476
150' 31 19 64 39 120 73 250 153 380 232 710 433
175' 28 17 59 36 110 67 225 137 350 214 650 397
200' 26 16 55 34 100 61 210 128 320 195 610 372
Note:When sizing supply lines,consider possibilities of future expansion and increased requirements.
Refer to National Fuel Gas Code for additional information on line sizing.
Duct furnaces for natural gas are orificed for operation with gas having a heating value
of 1000(±50)BTU per cubic ft. If the gas at the installation does not meet this specifica-
tion, consult the factory for proper orificing.
Pipe joint compounds (pipe dope) shall be resistant to the action of liquefied
petroleum gas or any other chemical constituents of the gas being supplied.
Install a ground joint union and manual shutoff valve upstream of the unit control sys-
tem, as shown in FIGURE 8. The 1/8" plugged tapping in the shutoff valve provides
connection for supply line pressure test gauge. The National Fuel Gas Code requires
the installation of a trap with a minimum 3" (76mm)drip leg. Local codes may require a
minimum drip leg longer than 3" (76mm)--typically 6" (152mm).
Gas connection sizes are listed in FIGURE 8.After all connections are made, discon-
nect the pilot supply at the control valve and bleed the system of air. Reconnect the
pilot line and leak-test all connections by brushing on a soap solution.
WARNING
All components of a gas supply system must be leak tested prior to placing equipment in service.
NEVER TEST FOR LEAKS WITH AN OPEN FLAME. Failure to comply could result in personal injury,
property damage or death.
FIGURE 8 -Supply Piping Connection FIGURE 9 -Gas and Electric Connections
Ground Joint Union Thermostat Wire-1'
To Gas Valve-q- I--Manual shutoff i Manual Shutoff Valve
,., Line Voltage(Supply)
���(r with 1/8"NPT plugged
�(L(I'f�; tap must be installed
Drip -4---...„
1 i above the unit casing.
From Gas Supply 0
Leg (horizontal orvertical)
■
Side View
Pipe nipple extending
I
outside the cabinet. Manual shutoff
Junction
To Gas Valve Box 1
--t��_ I. Ground
•!gl♦il IJoint
t Union
Ground
Gas Connection to Joint 1Drip Leg To Gas Controls _,4
Single-Stage Valve Union w and Burner
(Not Gas Supply Line Size) 7/8"(22m)diaa. 1-7/8"x 1-3/8"(48x35mm)
Unit Size 75-250 300-400 Top View 1,7* <.2-3/32"(53mm)
Natural Gas 1/2" 3/4" *1 -4" 102mm
)
Propane 1/2" 1/2" *- <-5-5/8"(143mm)
<-6-7/8"(175mm)
Form I-X,P/N 150491 R8,Page 8
•
6.1.2 Manifold or Measuring manifold gas pressure cannot be done until the heater is in operation. It is
Orifice Pressure included in the steps of the"Check-Test-Start"procedure in Paragraph 9.0.The follow-
Settings ing warnings and instructions apply.
WARNING
Manifold gas pressure must never exceed 3.5" w.c. for natural gas and
10"w.c. for propane gas.
For Natural Gas: When the heater leaves the factory, the combination valve is set so
that the outlet gas pressure of a single-stage valve or high fire of a two-stage valve
is regulated to 3.5" w.c. Low fire on a two-stage valve is set to 1.8" w.c. Inlet supply
pressure to the valve must be a minimum of 5"w.c. or as noted on the rating plate
and a maximum of 14"w.c. NOTE:Always check the rating plate for minimum gas
supply pressure. Minimum supply pressure requirements vary based on the size of
the burner and the gas control option. Most units require a minimum of 5"w.c. of natu-
ral gas as stated above, but Sizes 350 and 400 with electronic modulation require a
minimum of 6" w.c. natural gas supply pressure. Sizes 300 and 350 with mechanical
modulation require 7"w.c.
For Propane: When the heater leaves the factory,the combination valve is set so that
the outlet gas pressure of a single-stage valve or high fire of a two-stage valve is 10"
w.c. Low fire on a two-stage valve is set to 5"w.c. Inlet pressure to the valve must be
a minimum of 11"w.c. and a maximum of 14"w.c.
Before attempting to measure or adjust manifold gas pressure, the inlet(supply) pres-
sure must be within the specified range for the gas being used both when the heater is
in operation and on standby. Incorrect inlet pressure could cause excessive manifold
CAUTION: DO NOT gas pressure immediately or at some future time.
Instructions to Check Manifold Pressure:
bottom out the gas 1)With the manual valve (on the combination valve)positioned to prevent flow to the
valve regulator main burners, connect a manometer to the 1/8"pipe outlet pressure tap in the valve.
adjusting screw. NOTE:A manometer(fluid-filled gauge)is recommended rather than a spring type
This can result gauge due to the difficulty of maintaining calibration of a spring type gauge.
in unregulated 2)Open the valve and operate the heater. Measure the gas pressure to the manifold.To
measure the low stage pressure on units equipped with a two-stage valve, disconnect
manifold pressure the wire from the"HI"terminal on the valve. (Be sure to reconnect wire.)
causing excess Normally adjustments should not be necessary to the factory preset regulator. If adjust-
overfire and heat ment is necessary, set pressure to correct settings by turning the regulator screw IN
exchanger failure. (clockwise)to increase pressure.Turn regulator screw OUT(counterclockwise)to
decrease pressure.
Consult the valve manufacturer's literature provided for more detailed information.
6.2 Venting
DANGER
Failure to provide proper venting could result in death, serious injury, and/or property
damage. This furnace must be installed with a vent connection and proper vent to the
outside of the building. Install vent in accordance with Part 7, Venting of Equipment,
of the National Fuel Gas Code, ANSI Z223.1 (latest edition) or applicable provision of
national, state or local codes. A Canadian installation must be in accordance with the
CSA B149.1 and B149.2, Installation Code for Gas Burning Appliances and Equipment,
and applicable local codes. Also, comply with venting requirements in this Paragraph.
Safe operation of any gravity-vented gas-fired equipment requires a properly operating
vent system, correct provision for the combustion air (See Paragraph 2.2) and regular
maintenance and inspection. See Hazard Levels, page 2.
6.2.1 Venting 1. Provide a minimum clearance of 18" between the drafthood relief opening and any
Requirements obstruction. Do not expose the relief opening to wind drafts from any source such
as from an overhead door or adjacent air handling equipment.
Form I-X,P/N 150491 R8,Page 9
•
6.0 Mechanical 6.2.1 Venting Requirements (cont'd)
(cont'd) 2. The unit is equipped with a built-in draft diverter, consequently an external draft
diverter MUST NOT be installed in the vent connector or any internal alterations
6.2 Venting (cont'd) made. Do not install a manual damper or other fixed restriction in the vent
connector.
3. Vent pipe should be a minimum of 26-gauge galvanized steel or other non-
corrosive material. Double-wall, Type B vent pipe such as Metalbestos or
Amerivent is recommended. (NOTE: Double-wall pipe is not available in 9"
diameter.)Where it is necessary to run the vent pipe through an exterior wall of
combustible materials, a suitable thimble must be used.The vent pipe shall have
a clearance of at least six inches (152mm)from combustible materials or as is
specified by the double-wall vent pipe manufacturer.
4. With the outlet on the heater in the horizontal position, it is recommended that a
12-18" (305-457mm) piece of straight pipe be connected to the flue collar before
installing an elbow.The horizontal vent pipe run should have a uniform rise of at
least 1/4" per foot of horizontal run in the direction of discharge.The length of the
lateral run must not exceed lengths shown in the vent tables of the National Fuel
Gas Code or the Canadian Installation Code for Gas Burning Appliances (See Vent
Tables below).
5. Support horizontal runs every six feet(1.8M). Support vertical runs of type
"B"double-wall vent pipe in accordance with the requirements of the pipe
manufacturer. Support single-wall vertical pipe in accordance with accepted
industry practices. Do not rely on the heater for support of either horizontal or
vertical pipes. Use non-combustible supports.
6. Vent connectors serving Category I heaters shall not be connected into any portion
of a mechanical draft system operating under positive pressure.
7. Where it is necessary to use a long run of vent pipe, or where the vent pipe is
exposed to cold air, condensation within the pipe may occur.There are two ways
to overcome or eliminate this problem.
(a) Prevent condensation by insulating the pipe so that the temperature of the flue
products never drops below 250°F.
(b) Use double-wall,Type B vent pipe which is recommended for the reduction or
elimination of condensate problems. Where extreme conditions are present
and condensate is anticipated, install a trap for collecting condensate.
8. The vent connection may be made into a suitable permanent chimney or into a
gas vent.The effective area of the vent connector, gas vent or chimney when
connected to a single appliance shall not be less than the area of the appliance
drafthood outlet or in accordance with approved venting methods.The effective
area of the gas vent or chimney when connected to more than one appliance shall
not be less than the area of the largest vent connector plus 50% of the areas of
additional vent connectors or in accordance with approved venting methods.
Minimum permissible height of the vertical vent is 5 feet(1.5M) providing no
horizontal vent pipe connector is used. If a horizontal vent connector is necessary,
consult Tables below or the National Fuel Gas Code or the Canadian Installation
Code for Gas Burning Appliances,for the maximum permissible length of a
horizontal pipe run (vent connector)for a given vertical height of gas vent.
The gas vent or chimney should extend at least 3 feet(1 M)above the highest point
where it passes through a roof of a building and at least 2 feet(.6M) higher than
any portion of a building or obstruction within a horizontal distance of 10 feet(3M).
Install a Reznor Option CC1 vent cap on the end of the vent pipe to prevent rain
or snow from entering the open end. (NOTE: When installing a Size 125, run the
required 7"vent pipe and use a field-supplied increaser to attach an 8"vent cap.)
9. If the heater is installed in a space served by a large exhaust fan, be sure that the
exhaust fan does not affect the operation of the heater or the satisfactory venting
of its products of combustion.
If a negative pressure exists, as evidenced by a downdraft, a factory-designed
mechanical motor drive venter(Option CA)should be installed. In severe negative
pressure conditions, makeup air equipment may be necessary.
Form I-X,P/N 150491 R8,Page 10
6.0 Mechanical 6.3 Duct Furnace Airflow (cont'd)
(cont'd) 6.3.1 Pressure Drop and Temperature Rise by Size (cont'd)
Model X-Pressure Drop Table for 80%Thermal Efficient Duct Furnace
Size 75 100 125 150 175 200 225 250 300 350 400
Temp CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D. CFM P.D.
Rise
50°F 1105 0.2 1475 0.4 1840 0.5 2210 0.4 2580 0.5 2945 0.4 3315 0.5 3685 0.4 4420 0.6 5160 0.7 5895 0.7
60°F 920 0.2 1225 0.3 1535 0.3 1840 0.3 2150 0.4 2455 0.3 2765 0.4 3070 0.3 3685 0.4 4300 0.4 4915 0.5
70°F 790 0.1 1050 0.2 1315 0.3 1580 0.2 1840 0.3 2105 0.2 2370 0.3 2630 0.2 3160 0.3 3685 0.3 4210 0.3
80°F 690 0.1 920 0.2 1150 0.2 1380 0.2 1610 0.2 1840 0.2 2070 0.2 2300 0.2 2765 0.3 3225 0.3 3685 0.3
90°F 610 0.0 815 0.1 1020 0.2 1225 0.1 1430 0.2 1635 0.1 1840 0.2 2045 0.2 2455 0.2 2865 0.2 3275 0.2
The duct furnace must be installed on the positive pressure side of the field supplied
blower. The air throughput must be within the CFM range stated on the heater rating
plate.The air distribution must be even over the entire heat exchanger.Turning vanes
should be used in elbows or turns in the air inlet to ensure proper air distribution (See
Paragraph 6.3.2).
If it is determined that the blower CFM is greater than allowed or desirable, see Para-
graph 6.3.3 for instructions on determining the correct size of bypass duct required or
see the APPENDIX, page 28, for instructions on converting the furnace for a higher
CFM application.
6.3.2 Duct Furnace Proper arrangements of blower and duct furnace with respect to angle of approach of
Blower Connections the duct connection and the arrangement of the discharge opening of the blower are
shown in FIGURES 11 A, B, and C. Blowers should be bottom horizontal discharge
when coupled to the duct furnace. If a top horizontal discharge blower is connected to
the duct furnace, be sure that sufficient length of duct is provided to permit even flow
FIGURE 11A-Straight
Through Air Blower
0 , 15°
Connection Direct-� O
Coupling
Remote
Slanted Transition _i6"(152mm)
24"
Suggested blower connections for straight through airflow. (616mm)
minimum
Use either method for good air coverage and efficient operation.
FIGURE 11B -With Elbows Turning Vanes FF
Up or Down „ _ __
__f -- _ __- =
`XI Bm�J I .44>7,Ti.,��,7��\�;,1, iiii�i'nti '•EMI
y No air 1'' ,. ` 1
I I 'x
i fliall
I I I' z man
NOTE:"X"should 15° I , NOTE:"X"should N GTE:Ang e" 'never be less than -
never be less M�l'� ,. should never b,
1/2"Y" 6, than 112"Y" more than 15'
(152mm) 0
GOOD POORO POOR
FIGURE 11C -With Elbows AFF
Right or Left Turning Vane _ ____, - ,==-.
___-�* - '
•
of air at the end of the duct. Or, baffles may be inserted between the blower and the
heater to assure an even flow of air across the heat exchanger.
WARNING
The furnace MUST be installed on the positive pressure side of the air-
circulating blower. See Hazard Levels, Page 2.
6.3.3 Constructing When the CFM of air throughput is greater than desirable or permissible for the unit,
Bypass Duct a bypass duct may be constructed. Follow these instructions to determine the correct
size of the bypass duct.
FIGURE 12 - Bypass Duct Bypass CFM
Control Side "A"Width Pressure Drop through the Furnace
inches mm 0.10 0.15 0.20 0.25 0.30 0.35 0.40 0.45 0.50
Top View 3" 76 490 530 610 700 780 830 900 960 1010
of Furnace 4" 102 630 750 870 980 1090 1160 1250 1310 1400
5" 127 850 1010 1190 1300 1410 1520 1640 1730 1810
6" 152 1050 1290 1480 1650 1800 1940 2090 2200 2320
7" 178 1250 1510 1760 1960 2180 2320 2500 2650 2800
f 8" 203 1490 1810 2100 2350 2560 2760 2940 3110 3290
I.—18" 457mm —. Bypass Duct A 9" 229 1700 2100 2400 2700 2970 3200 3400 3600 3800
( ) I j 1 —18"(457mm)–.I 10" 254 1920 2350 2760 3090 3650 4020 4300 4550 4800
Directions for Sizing Bypass Duct the answer in Step 2).
1) From the tables in Paragraph 6.3.1, find the pressure EX: Go to P.D. column .40; move down to 900
drop (RD.)and the allowable CFM for the duct 4) Move to the left column to find out the required size
furnace that is being installed. of the bypass duct.
EX: Size X150 @ 50°F Temperature Rise; P.D. 38; EX: Bypass Duct should be 3" (76mm).
CFM 2210 Locate the bypass duct on the side of the furnace oppo-
2) Subtract the allowable CFM from the actual CFM of site the controls and 2" from the heat exchanger side
the installation to determine how much air must be
panel. Extend the bypass18" (457mm) beyond the
diverted through the bypass duct. duct y
furnace on both the inlet and outlet ends.
EX:Actual Blower CFM is 3000; 3000 minus
allowable CFM of 2210=790 NOTE: Not all capacities are covered in this chart. If
3) Go to the column in the bypass CFM chart that is your installation is not covered, consult your Reznor
closest to the pressure drop through the heater. Move representative or the factory to determine the appropriate
down in that column until you find the CFM closest to size of the bypass duct.
6.3.4 Duct
Connections
re 18(457) 75 150 200 250FIGURE 13 - DuctSize100 125175 225 300 350 400
Connection Dimensions 3/4(19) 12-1/2 15-1/4 20-3/4 26-1/4 34-1/2 40 45-1/2
- inches (mm) 3/4 (318) (387) (527) (667) (876) 1016 (1156)
(19)�
IMPORTANT NOTE: A minimum horizontal duct length of 18 inches (457mm) is required at the furnace discharge
before any vertical rise is made in front of the drafthood relief opening.This is required to prevent interference with the
built-in drafthood.
Requirements and • Type of Ductwork-The type of duct installation to be used depends in part on the
Suggestions for type of construction of the roof(whether wood joist, steelbar joist, steel truss, pre-
Connecting and cast concrete)and the ceiling (whether hung, flush, etc.).
• Ductwork Material - Rectangular duct should be constructed of not lighter than
Installing Ducts No. 26 U.S. gauge galvanized iron or No. 24 B&S gauge aluminum.
• Ductwork Structure -All duct sections 24 inches or wider, and over 48 inches
in length, should be cross broken on top and bottom and should have standing
seams or angle-iron braces. Joints should be S and drive strip, or locked.
Form l-X,P/N 150491 R8,Page 13