Thermo Pride OPA Manual

OUTDOOR COMBINATION OIL-FIRED
FURNACE AND AIR CONDITIONING UNIT
MODEL OPA
INSTALLATION AND SERVICE MANUAL
Please read these instructions prior to installation, initial firing, and before
performing any service or maintenance.
These instructions must be retained by the homeowner for future reference by
qualified heating contractor.
Thermo Products, LLC
PO Box 217
MO-424 North Judson, IN 46366
ECN 4650-MA Phone: [phone] Made In USA
: If the information in this manual is not followed exactly, a
fire or explosion may result causing property damage, personal
injury, or loss of life.
− Do not store or use gasoline or other flammable vapors and liquids in the
vicinity of this or any other appliance.
− WHAT TO DO IF YOU FIND AN OIL LEAK:
• Do not try to light any appliance.
• Immediately call your oil supplier.
• If you cannot reach your oil supplier, call the fire department.
− Installation and service must be performed by a qualified installer, service
agency or the oil supplier. (These entities are referred to in these instructions
as a qualified heating contractor).

All installations and services must be performed by qualified service personnel.
1
Contents
SECTION PAGE
I. SAFETY INFORMATION .............................…………………………………….3
II. GENERAL INSTRUCTIONS ...........................................………………….…..9
III. GENERAL INSTALLATION .....................................................………………. 9
A. Codes and Clearances .......................................................……………. 10
B. Selection of Installation Location .........................................…………… 11
C. Venting Of Combustion Products ............................................………….13
D. Condensate Drain ....................................................................…………14
E. Oil Tank and Piping ..................................................................... ……... 15
F. Oil Filter .......................................................................................……… 17
G. Burner Specifications and Performance .......................................…….. 17
H. Airflow Requirements and Sizing of Ductwork ..............................…….. 19
I. Air Filters ......................................................................................…….. 23
1. Filter Installation ......................................................................…….. 23
2. Use of non-Thermo Pride Filters or Retention Means ..............……. 23
J. Electrical Wiring .............................................................................……. 24
1. Electronic Air Cleaner (EAC) and Humidifier Installation ..........…… 26
2. Thermostat Anticipator Setting.................................................…….. 28
3. Blower Motor Speed Selection .................................................……. 30
IV. STARTUP PROCEDURES.........................................................................…….32
A. HEATING SYSTEM
1. Initial Startup .............................................................................…….32
2. Adjustment of Burner Combustion .............................................…… 34
3. Adjustment of Heat Input Rate ...................................................……37
4. Setting Supply Air Temperature Rise .....................................……... 38
5. Checkout Procedure ................................................................…….. 39
B. COOLING SYSTEM
1. Initial Startup ......................................................................….……... 41
2. Definition of Superheat .......................................................... ……... 42
3. Evaporator Superheat ...........................................................………. 43
4. Definition of Subcooling ..........................................................…….. 44
5. Condenser Subcooling ...........................................................…….. 44
6. Recommendations for Operation at Low Temperatures ............… 45
V. INSTALLER'S INSTRUCTIONS TO USER ..........................................….. 46

All installations and services must be performed by qualified service personnel.
2
Contents
SECTION PAGE
VI. DEALER MAINTENANCE ................................................................ ……... 47
A. General Inspection ...................................................................... ……... 47
B. Heat Exchanger ........................................................................………. 48
1. Disassembly to Access Heat Exchanger ...............................……… 48
2. Reassembly of Unit ................................................................……… 50
3. Operational Check ..................................................................…….. 51
C. Electrical System ...........................................................................……. 51
D. Supply/Return Air Blower .............................................................……... 52
E. Supply/Return Air Filter ................................................................…….. 52
1. Filter Maintenance ...................................................................…….. 52
2. Filter Replacement ...................................................................……. 52
F. Extended Appliance Shutdown ....................................................……... 53
VII. HOMEOWNER/USER INFORMATION AND ROUTINE MAINTENANCE ..55
VIII. TROUBLESHOOTING .........................................................................…… 59
A. Heating System ................................................................................….. 59
B. Cooling System .................................................................................…. 60
IX. REFERENCES .......................................................................................…. 62
X. APPENDIX A: SOURCES FOR REFERENCED STANDARDS .............…. 63
XI. APPENDIX B: CALCULATIONS ...........................................................….. 64
XII. APPENDIX C: ELECTRICAL SCHEMATIC AND CONNECTION DIAGRAM
.................................................................................................................….75
XIII. APPENDIX D: SEQUENCE OF OPERATIONS ....................................….. 76
XIV. APPENDIX E: TROUBLESHOOTING FLOWCHARTS .........................….. 78
XV. APPENDIX F: SPECIFICATION SHEETS .............................................…. 86
XVI. APPENDIX G: REPLACEMENT PARTS ...............................................….. 87
XVII. APPENDIX H: OPA HEATING AND COOLING TEST FORM ...............…. 89
WARRANTY …………………………………………………………………….. 90

All installations and services must be performed by qualified service personnel.
3
I. SAFETY INFORMATION
This page and the following page contain reproductions of the various
instructions and warning labels placed on the Thermo Pride gas-fired appliances.
Please read and comply with the contents of these labels.

All installations and services must be performed by qualified service personnel.
4

All installations and services must be performed by qualified service personnel.
5
The following warnings and cautions are found throughout the Thermo Pride
Model OPA Installation and Service Manual. Please read and comply with the
statements below.
: IF YOU DO NOT FOLLOW THESE INSTRUCTIONS EXACTLY, A FIRE OR
EXPLOSION MAY RESULT CAUSING PROPERTY DAMAGE, PERSONAL INJURY,
OR LOSS OF LIFE.
: Carefully read and thoroughly understand the following guidelines and
warnings before continuing with the installation of this unit. Failure to follow these
guidelines can cause improper and unsafe operation of this appliance. Unsafe operation
can result in substantial property damage, severe personal injury, or death.
: This unit is not to be used for temporary heating of buildings, or structures,
under construction.
: Maximum gross stack temperature must not exceed 550°F (288°C) under
any circumstances.
:Failure to comply with minimum filter installation requirements may effect the
performance and/or void the warranty on this unit.
: This appliance must be grounded in accordance with local codes or in the
absence of local codes with the National Electrical Code, ANSI/NFPA 70 –1999, or the
latest edition.
: Turn off the electrical power to the appliance before attempting to change
supply air blower speed wiring.
: Personal injury or property damage could result from repair, or service, of
this appliance by anyone other than a qualified heating contractor. The end user may
only perform the service described under the Homeowner/User Routine Maintenance
section of this manual.
: To avoid injury from moving parts or electrical shock, shut off the power to
the appliance before removing supply air blower compartment door and servicing this
appliance.
: When servicing controls, label all wires prior to disconnecting. Reconnect
any wires removed correctly. Wiring errors can cause improper and dangerous
operation. Dangerous operation can result in injury or damage.
: Disconnect electrical power before servicing this unit.

All installations and services must be performed by qualified service personnel.
6
:Waterproof type connectors must be used when connecting electrical power
and control wiring to the unit to prevent moisture from being drawn into the unit during
operation.
: Refrigerant is under pressure. Guard against refrigerant spraying into the
face or on skin. Always wear protective equipment, i.e. safety glasses or goggles and
gloves when working with refrigerant.
: Do not under any circumstances heat the refrigerant cylinder with a torch or
by any other means other than warm water. Excessive pressures generated in this
manner may weaken the refrigerant container and result in an explosion!
: To avoid injury from moving parts, or electrical shock, shut off the power to
the appliance before removing blower compartment door and servicing this appliance.
: When servicing controls, label all wires prior to disconnecting. Reconnect any
removed wires correctly. Wiring errors can cause improper and dangerous operation.
Dangerous operation can result in injury or damage.
: Do not use this appliance if any part has been under water. Immediately call
a qualified service technician to inspect the furnace and to replace any part of the
control system and any gas control that has been under water.
:The area around the appliance, including the top of the unit, must be kept
clear and free of combustible materials, gasoline, and other flammable vapors and
liquids.
:The appliance vent terminal may be hot. If the terminal is hot, allow it to cool
before touching it.
:Shut off unit and disconnect the power source before disassembling the unit.
:Never operate the appliance without clean air filters in place.
: This appliance requires air for combustion, ventilation, and cooling. Do not
block or obstruct air openings in the unit and the air space around the perimeter of the
unit.
: All local codes and ordinances take precedence with regard to selection and
installation of oil storage tank and oil supply (and return) lines. In the absence of local
codes, all tanks and lines must be selected and installed according to the instructions in
this manual and the Standard for the Installation of Oil-Burning Equipment, NFPA 31-
1997, or the latest edition.
: Turn off power to furnace. Before the oil piping system is placed into
service, it must have been leak tested by a qualified heating contractor.

All installations and services must be performed by qualified service personnel.
7
: For initial start-up of the appliance after installation, it may be necessary to
purge the air out of the oil line. A qualified heating contractor should do this.
: If you do not follow these instructions exactly, a fire or explosion may
result causing property damage, personal injury or loss of life.
: Do not run the oil pump dry for more than five minutes, as irreparable
damage may result.
: Before troubleshooting, familiarize yourself with the start up and check out
procedures.
:Never burn garbage or refuse in this appliance. Never try to ignite oil by
tossing burning papers or other material into the combustion chamber.
:Oil-fired appliances produced by Thermo Products are designed for burning
No. 2 distillate (domestic heating) fuel oil. Never use gasoline or a mixture of oil and
gasoline.
I: Do not attempt to make repairs yourself. Contact your local qualified heating
contractor.
:This appliance is designed to directly vent combustion products into
the atmosphere through, and using only, the supplied vent terminal. Do not
attempt to attach a vent connector or a vent system to, or in place of, the supplied
vent terminal.
: Do not attempt to operate the cooling section on a day when outdoor
temperatures are 45°F or cooler.

All installations and services must be performed by qualified service personnel.
8
: Carefully read and thoroughly understand the following guidelines and
warnings before continuing with the installation of this appliance. Failure to
follow these guidelines can cause improper and unsafe operation of this
appliance. Unsafe operation can result in substantial property damage, severe
personal injury, or death.
1. This appliance shall be used with only the type of fuel oil for which it is approved.
Refer to the appliance-rating label for the required type of fuel.
2. This appliance is a single, packaged, oil-fired furnace with air conditioner designed
for outdoor installation on either combustible or non-combustible materials. This
appliance is also approved for rooftop installation on combustible or non-combustible
roofing materials.
3. Ensure that adequate combustion and ventilation air is available to the unit.
4. The airflow resistance of the duct system attached to this appliance must fall within
the allowable external static pressure range for this unit. Refer to the Airflow
Requirements and Sizing of Ductwork section of this manual.
5. Make sure supply and return air ducts are completely sealed to the appliance
casing. Refer to the Airflow Requirements and Sizing of Ductwork section of this
manual.

All installations and services must be performed by qualified service personnel.
9
II. GENERAL INSTRUCTIONS
The entire text of these instructions must be read and understood, before installing the
appliance. It is the installer's responsibility to do the following:
1. Inform and demonstrate to the user, the correct operation and maintenance of
the appliance, as explained in the Homeowner/User Information and Routine
Maintenance section of this manual.
2. Inform the user of the hazards of flammable liquids and vapors and to remove
such liquids and vapors from the vicinity of the appliance.
3. Inform the user of all pertinent warnings and precautions concerning this
appliance.
III. GENERAL INSTALLATION
: This unit is not to be used for temporary heating of buildings, or
structures, under construction. Construction dust may enter the appliance or the duct
system and cause a fire hazard. Certain chemicals used during construction when
burned, form corrosive condensate that can substantially reduce the life of the heating
system heat exchanger.
With exception of the vent terminal, this appliance is shipped completely assembled and
internally wired. All fuel oil and refrigerant piping, refrigerant charge, and electrical wiring
have been factory installed and inspected. At the time of installation, the unit will require
connection to electric power, fuel oil supply, condensate drain, and supply and return air
ductwork. In addition, the vent termination kit will need assembly. In the event of a
shortage of parts or damage, refer to the Dealer Receiving and Freight Claim
Procedure section of the Price Guide.
This unit uses a fan-assisted combustion system, consisting of a pressure atomizing, oil
burner and combustion air blower, used to push the products of combustion through the
heat exchanger system. After installation, the furnace and duct system must be
adjusted to obtain a temperature rise of 50°F to 80°F through the unit. (Refer to the
rating label located on side panel inside the burner compartment). The installation must
conform with local codes or, in the absence of local codes, with the Standard for the
Installation of Oil-Burning Equipment, NFPA 31-1997, or the latest edition, and to these
instructions.

All installations and services must be performed by qualified service personnel.
10
A. Codes and Clearances:
The following items must be considered when choosing the size and location of
the unit.
1. All local codes and/or regulations take precedence over the instructions
in this manual and should be followed accordingly. In the absence of local
codes, installation must conform to these instructions and the guidelines of the
National Fire Protection Association (NFPA). Two applicable NFPA installation
codes are the National Electrical Code, ANSI/NFPA 70-1999, and Standard for
the Installation of Oil-Burning Equipment, NFPA 31-1997. The latest editions of
these codes should be consulted.
2. The selection of a heating unit should be based on a rate of heat loss
calculation for the residence according to the manuals provided by the Air
Conditioning Contractors of America (ACCA) or the American Society of
Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE). The
heating capacity of the unit proposed for installation should meet or slightly
exceed the rate of heat loss for the residence. Oversizing should not exceed
125% of the heat loss calculation.
3. When installed, this unit should be level. If possible, it should be installed in a
central location, with respect to outlet registers of the supply air ductwork.
4. Definitions of "combustible" and "non-combustible" materials as presented in
the 1996 version of the National Fuel Gas Code, ANSI Z223.1-1996/NFPA 70-
1996, are as follows:
a. Combustible material:
“...materials made of or surfaced with wood,
compressed paper, plant fibers, or other materials that
are capable of being ignited and burned. Such materials
shall be considered combustible even though
flameproofed, fire-retardant treated, or plastered.”
b. Non-combustible material:
“...material that is not capable of being ignited and
burned; such as material consisting entirely of, or a
combination of, steel, iron, brick, concrete, slate,
asbestos, glass, and plaster.”

All installations and services must be performed by qualified service personnel.
11
5. Table 1 lists the required minimum clearances to combustible surfaces from
the outer surfaces of the appliance.
Table 1: Minimum Clearances to Combustible Materials
Model
No.
Top
(in.)
Side
(in.)
Rear
(in.)
Front
(in.)
Bottom
(in.)
Vent Terminal
(in.)
OPA - 3 3 3 0 3
The minimum clearances listed in Table 1 are for fire protection purposes
only. Adequate operational and service clearances must be maintained under
all circumstances. A minimum of 36 inches clearance around the
condenser coil should be maintained for adequate airflow to the unit. Any
overhanging material or construction must not block from above the
condenser fan and the vent terminal. The suggested minimum clearances
for servicing the front of the unit and to all points requiring access are at
least 24 inches.
Notice: Access panels for the return air filter and the blower motor are
located on the rear left-hand and right-hand sides of the unit,
respectively.
6. Install this unit outdoors only.
7. This appliance is approved for use as a forced air furnace with cooling unit.
8. This appliance has been designed for use with no. 2 distillate fuel (domestic
heating) oil.
B. Selection of Installation Location
1. The unit should not be placed in a position where it is directly exposed to
sunlight during the majority of the day. Inside corners on the southeast and
southwest sides of the structure should be avoided. Heat build-up due to
solar radiation in such corners would place an increased cooling load on the
unit. Shaded areas on the north side of the structure are preferred.
2. The unit must be located on a level, dry surface in an area, which is free and
protected from excessive drafts or wind. Mount the unit on a sturdy base at
least one inch above the ground or roof surface. A poured concrete slab, or
equivalent, is ideal. If concrete blocks or bricks are used, be sure to use well-
tamped gravel fill beneath the blocks or bricks to prevent settling.
The unit is manufactured with runner supports that raise the unit, about 1.25
inches above the mounting base, allowing air circulation beneath the metal

All installations and services must be performed by qualified service personnel.
12
surfaces. This clearance helps to promote air circulation under the base that
allows the unit to be mounted on combustible materials. This clearance also
helps to reduce metal corrosion caused by a buildup of moisture under the
appliance.
3. The cooling system condenser must have an unrestricted supply of air for
efficient cooling.
4. The cooling system fan discharges air, upward through the top grill. For this
reason, this appliance should not be located under an overhang or any other
obstruction to airflow that would redirect the heated discharge air back into
the condenser. The appliance should be located as illustrated in Figure 1,
below.
Figure 1: Selection of Appliance Installation Location
For proper and safe operation of this appliance, ensure that adequate
clearances around air openings into the burner compartment and the

All installations and services must be performed by qualified service personnel.
13
condenser coil area are maintained. These openings are not to be blocked, or
restricted, in any manner.
5. Measures should be taken to prevent the entry of corrosive chemicals
or vapors to the combustion and ventilation air supply. Such chemicals
include, but are not limited to, chlorinated and/or fluorinated hydrocarbons.
These substances are found in refrigerants, aerosol propellants, dry cleaning
fluids, degreasers, and removers. Other harmful compounds may come from
acids, salts, bleaches, air fresheners, cements, and glues. Do not store or
use these chemicals for long periods of time in close proximity to this
appliance.
Vapors from such products can form corrosive compounds when burned in a
flame. These compounds promote rapid corrosion of the burner, combustion
chamber, heat exchanger, and the vent terminal. Rapid or excessive
corrosion will significantly reduce the useful life of the appliance.
6. Refer to the following section, Venting of Combustion Products, for
additional installation location restrictions.
C. Venting of Combustion Products
:This appliance is designed to directly vent combustion products
into the atmosphere through, and using only, the supplied vent terminal.
Do not attempt to attach a vent connector or a vent system to, or in place
of, the supplied vent terminal.
The appliance should be installed in a location such that heavy snow
accumulation will not excessively restrict the flow of flue (combustion) products
from the unit. The vent terminal should not be located in a position where ice
buildup could block the discharge of flue products. If these conditions occur, the
performance of the heating system will be adversely affected.
Choose an installation location where the vent terminal does not discharge over
sidewalks, walkways, and patios. These areas may become slippery when
wetted by water vapor in the flue products.
Combustion products must not be allowed to accumulate within a confined space
and recirculate back into the combustion system. Recirculation of combustion
products promotes poor combustion. In severe cases, it may lead to sooting of
the combustion chamber and heat exchanger, or to nuisance shutdowns of the
heating system.

All installations and services must be performed by qualified service personnel.
14
In addition, long term exposure of building materials to combustion products may
cause discoloration of material surfaces and corrosion or degradation of
materials. The preferred installation location will allow combustion products to
freely escape the immediate area of the appliance and rapidly disperse into the
atmosphere, without being drawn back into the appliance or a nearby structure.
To prevent combustion products from entering a structure, the vent terminal must
expel combustion products away from any point of entry. The minimum
acceptable distances from the vent terminal to points of entry to a building are 4
feet horizontally from, and 1 foot above, or at least 4 feet below, any window,
door, or gravity air inlet into the building. And, 3 feet or more above any forced
air inlet to the building located within 10 feet of the terminal.
Once the unit is installed in a suitable location, the installer must mount the vent
terminal to the appliance. Two sheet metal screws are installed in the unit for this
purpose. Refer to Figure 2 for a sketch of the correctly assembled vent terminal.
FIGURE 2: Vent Terminal Mounting Position
D. Condensate Drain
This appliance is equipped with a ¾ inch, female, NPT coupling for connection of
a condensate line to the evaporator drain pan. A condensate removal line should
be fabricated and attached to the coupling, refer to Figure 3. The condensate
drain line must be pitched downward to drain properly. The drain line can also be
trapped and the condensate pumped to a suitable drain. If the drain line clogs,
when the air conditioner is operating, the condensate tray under the evaporator
coil will fill with water. As a result, water may enter the appliance housing and
the supply air ductwork to the structure.

All installations and services must be performed by qualified service personnel.
15
Figure 3: Installation of a Condensate Drainage Line on the Evaporator Coil
Condensate from the evaporator is non-corrosive and may be disposed of in any
appropriate manner. The drain connection should be sealed at the appliance
housing to prevent air leakage from the supply air system. Pipe sealant should
be used sparingly on all male pipe threads. Always consult and conform to the
requirements of local plumbing codes.
E. Oil Tank and Piping
: All local codes and ordinances take precedence with regard to
selection and installation of oil storage tank and oil supply (and return)
lines. In the absence of local codes, all tanks and lines must be selected
and installed according to the instructions in this manual and the Standard
for the Installation of Oil-Burning Equipment, NFPA 31-1997, or the latest
edition.
1. The use of black steel pipe and malleable iron fittings is recommended for
all fuel oil service lines. Never use galvanized steel piping or fittings
for any fuel oil lines.
2. Where practical, provide rigid supports for the piping.
3. If the piping size in a run must be reduced, use reducing couplings only.
Avoid the use of reducing bushings.
4. Remove all pipe thread burrs and inspect the pipe for dirt or other foreign
material prior to connecting. If present, remove any deposits in the piping
and discard any excessively corroded piping.

All installations and services must be performed by qualified service personnel.
16
5. A readily accessible, design-certified, manual oil shutoff valve, with a non-
displaceable rotor member, shall be installed in the fuel oil supply piping
within 6 feet of the appliance.
6. A pipe union, or flanged connection, shall be provided downstream from
the manual oil shutoff valve to permit removal of the appliance oil pump.
Pipe unions must be the ground joint type or flanged-jointed using a
gasket resistant to the corrosive action of fuel oils.
7. Pipe dope or thread sealant design-certified to be resistant to the action of
fuel oils should be used on all threaded joints. Thread sealant should only
be applied to the male member of a joint. The first two threads on the end
of the male member of each pipe joint should be clean and free from
thread sealant.
8. Connection of the oil supply piping to the appliance should be made from
the left-hand side of the burner, facing the burner compartment cover.
9. When tubing is to be used for fuel oil supply lines, use of continuous runs
of heavy wall copper tubing is recommended. Avoid running tubing
against any type of heating unit and across ceiling or floor joists. If
possible, install the tubing under the floor.
10. Where tubing is used for fuel oil supply lines, insure the tubing contains no
kinks, sharp bends, or collapsed regions where the inside cross-sectional
area of the tube is greatly reduced. These will excessively reduce the flow
of oil.
11. Flared fittings should be used at all tube joints, when tubing is used for
fuel supply lines. Do not use compression fittings. Avoid the use of
tube fittings in inaccessible locations.
Burners are equipped with a single-stage, fuel pump. This type of fuel pump,
when connected with a supply line only, is satisfactory where the fuel supply is
level with, or above the burner thus permitting gravity flow of oil to the burner. If
the tank is above the burner, and gravity oil feed to the burner is permitted, a
single line system may be used. The line should have a gradual slope downward
of approximately 1/2 inch per foot, or more, from the tank to a point directly below
where it is connected to the pump. Pitching the line upward toward the tank will
help prevent the formation of air pockets in the line.
NOTICE: An oil safety valve or a delayed-action, solenoid valve should be
installed in the oil supply line of all gravity-fed systems.
When the oil tank is located below the level of the burner, it is necessary to “lift”
the oil to the burner. A return line should be connected between the fuel pump

All installations and services must be performed by qualified service personnel.
17
and tank. This requires insertion of the "by-pass" plug into the fuel pump. If the lift
(vertical distance between the supply line inlet and the burner) exceeds
approximately 10 feet, a two-stage pump should be installed with a return line.
When a return line is used with either single or two-stage pumps, in-line air is
automatically returned to the tank, making the oil pump and lines self-purging.
Underground tanks should be located outside the building. Installation of above
ground tanks is permitted inside buildings, under certain conditions, as well as
outside. Consult the Standard for Installation of Oil-Burning Equipment for
restrictions. If permitted, connect the burner oil supply line near the base of the
tank, opposite of the fill end. Connection at this point tends to flush older oil
through and out of the tank. This helps to prevent the accumulation of rainwater
and condensed water vapor in the tank, which can cause the tank to corrode.
If the oil supplier does not already use oil additives, it is recommended that
additives be used to emulsify any water accumulation in the oil.
F. Oil Filter
It is strongly recommended that an oil filter assembly be installed in the oil supply
line to the unit. Use an oil filter with the capacity to trap a 40-50 micron particle
for all installations. Install the filter between the oil manual shutoff valve and the
burner.
The filter cartridge should be replaced at least once a year. The filter body should
be thoroughly cleaned before installing a new cartridge.
G. Burner Specifications And Performance
The appliance is supplied with two oil burner nozzles, one for the high-fire and
one for the low-fire heat input rate. The model OPA has the low-fire, oil nozzle
already installed in the burner by the factory. Table 2 gives the burner
specifications and the estimated performance of the appliance operating under
high and low fire conditions.

All installations and services must be performed by qualified service personnel.
18
Table 2: Burner Specifications and High and Low Fire Heating Performance
* Based on #2 fuel (domestic heating) oil having higher heating value of 140,000
BTU per gallon.
** Based on an assumed steady state, thermal efficiency of 80%.
For more specific burner information, consult the Model AFG Oil Burner
Instruction Manual or contact Thermo Products, LLC. P.O. Box 217, North
Judson, IN 46366. Phone no. 574-896-2133.
Heating
Mode
Oil Pump
Pressure
(PSIG)
Oil Flowrate
@ Nozzle
(GPH)
Heat Input
Rate*
(BTUH)
Heat Output
Rate**
(BTUH)
Burner Model
Number
Air Tube
Combination
Nozzle
Type
High Fire 130 0.75 105,000 85,000
Low Fire 120 0.6 85,000 67,000
AFG-TP1501 AF35 BOSS
Simplex, 80
deg., hollow
cone

All installations and services must be performed by qualified service personnel.
19
H. Airflow Requirements and Sizing of Duct Work
The duct system must be sized and installed by a qualified installer or service
person, following the design standards of the Air Conditioning Contractors of
America (ACCA) or the American Society of Heating, Refrigeration, and Air
Conditioning Engineers (ASHRAE). This furnace has been designed to
operate against a maximum external static pressure of 0.4 in. W.G. This is
equivalent to .2 in. W.G. supply and .2 in. W.G. return pressure drops.
1. Supply and return air ducts have to be furnished by the installer and run
between the appliance, which must be installed outdoors, and the interior of
the structure the appliance serves. These ducts must be sealed to the casing
of the appliance.
2. To reduce the transmission of vibration and noise to the duct system and to
reduce flexure of the duct system due to thermal expansion and contraction, it
is recommended that flexible joints be installed at the supply and return duct
connections to the unit.
3. The return air duct system must equal the supply air duct system in the flow
capacity (CFM) for a given pressure drop. Use a supplier's catalog for proper
sizing of outlet and return air registers and grills to ensure that they meet the
flow requirements of the run to which they are connected.
4. The duct system shall be sized to provide the maximum air flowrate (CFM)
required of the installation. Two common rules for determining minimum
airflow in heating and cooling systems follow:
a. For heating, 14 CFM of airflow are required per 1000 BTU/hr of heat
output, based on steady state operation and a 50° to 80° temperature rise.
b. For cooling, 400 CFM of airflow are required per ton of air conditioning.
(For reference, a ton of A/C = 12,000 BTU/hr removed from the space.)
Refer to Example 1, in Appendix B: Calculations of this manual, for a
sample calculation of how to determine the required minimum air flowrate.
5. Duct sizing is based upon both air velocity and pressure drop considerations.
When possible, current practice favors designing ductwork for lower air
velocities. (For residences, a maximum air velocity of 800 FPM is suggested.)
This results in quieter duct systems, systems which require less fan power
(reduced operating costs), and less carefully constructed ductwork (lower
initial costs).
However, lower air velocities also result in larger duct sizes than necessary at
higher velocities. In some cases, space restrictions may limit the ductwork to
smaller than optimal sizes.