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508145-01G / 31-5000660

Issue 2220

Page 7 of 38

In addition to providing combustion air, fresh outdoor air 

dilutes contaminants in the indoor air. These contaminants 

may include bleaches, adhesives, detergents, solvents 

and other contaminants which can corrode furnace 

components.

The requirements for providing air for combustion and 

ventilation depend largely on whether the furnace is 

installed in an unconfined or a confined space.

Unconfined Space

An  unconfined  space  is  an  area  such  as  a  basement 

or large equipment room with a volume greater than 50 

cubic feet (1.42 m3) per 1,000 Btu (.29 kW) per hour of 

the combined input rating of all appliances installed in that 

space. This space also includes adjacent rooms which are 

not separated by a door. 

Though  an  area  may  appear  to  be  unconfined,  it  might 

be necessary to bring in outdoor air for combustion if the 

structure does not provide enough air by infiltration. If the 

furnace is located in a building of tight construction with 

weather stripping and caulking around the windows and 

doors, follow the procedures in the air from outside section.

Confined Space

A confined space is an area with a volume less than 50 

cubic feet (1.42 m3) per 1,000 Btu (.29 kW) per hour of 

the combined input rating of all appliances installed in that 

space.  This  definition  includes  furnace  closets  or  small 

equipment rooms.

When the furnace is installed so that supply ducts carry 

air circulated by the furnace to areas outside the space 

containing the furnace, the return air must be handled by 

ducts which are sealed to the furnace casing and which 

terminate outside the space containing the furnace. This 

is especially important when the furnace is mounted on 

a platform in a confined space such as a closet or small 

equipment room. 

Even a small leak around the base of the unit at the platform 

or at the return air duct connection can cause a potentially 

dangerous negative pressure condition. Air for combustion 

and  ventilation  can  be  brought  into  the  confined  space 

either from inside the building or from outside.

Air from Inside

If  the  confined  space  that  houses  the  furnace  adjoins  a 

space  categorized  as  unconfined,  air  can  be  brought  in 

by providing two permanent openings between the two 

spaces. Each opening must have a minimum free area of 1 

square inch (645 mm2) per 1,000 Btu (.29 kW) per hour of 

total input rating of all gas fired equipment in the confined 

space. Each opening must be at least 100 square inches 

(64516 mm2). One opening shall be within 12 inches (305 

mm) of the top of the enclosure and one opening within 12 

inches (305 mm) of the bottom. See Figure 3.

Figure 3. 

Equipment in Confined Space - All Air From 

Inside

NOTE: 

Each opening shall have a free area of at least one square 

inch per 1,000 Btu (645 mm² per .29 kW) per hour of the total 

input rating of all equipment in the enclosure, but not less than 100 

square inches (64546 mm²).

Air from Outside

If air from outside is brought in for combustion and 

ventilation, the confined space must have two permanent 

openings. One opening shall be within 12 inches (305 

mm) of the top of the enclosure and one opening within 

12 inches (305 mm) of the bottom. These openings must 

communicate directly or by ducts with the outdoors or 

spaces (crawl or attic) that freely communicate with the 

outdoors or indirectly through vertical ducts. Each opening 

shall have a minimum free area of 1 square inch (645 mm2) 

per 4,000 Btu (1.17 kW) per hour of total input rating of all 

equipment in the enclosure. See Figure 4 and Figure 5. 

When communicating with the outdoors through horizontal 

ducts, each opening shall have a minimum free area of 1 

square inch (645 mm2) per 2,000 Btu (.56 kW) per total 

input rating of all equipment in the enclosure. See Figure 6.

When ducts are used, they shall be of the same cross 

sectional area as the free area of the openings to which 

they connect. The minimum dimension of rectangular 

air ducts shall be no less than 3 inches (75 mm). In 

calculating free area, the blocking effect of louvers, grilles, 

or screens must be considered. If the design and free area 

of protective covering is not known for calculating the size 

opening required, it may be assumed that wood louvers 

will have 20 to 25 percent free area and metal louvers and 

grilles will have 60 to 75 percent free area. Louvers and 

grilles  must  be  fixed  in  the  open  position  or  interlocked 

with the equipment so that they are opened automatically 

during equipment operation.

Summary of Contents for GE NF80DT

Page 1: ...ry can result from contact with sharp sheet metal edges Be careful when you handle this equipment CAUTION Table of Contents NF80DT Gas Furnace 1 Unit Dimensions 2 Parts Arrangement 3 Shipping and Packing List 4 Safety Information 4 General 6 Combustion Dilution Ventilation Air 6 Downflow Installation 9 Filters 11 Duct System 11 Venting 12 Gas Piping 17 Electrical 19 Integrated Control DIP Switch S...

Page 2: ...TOP VIEW A B C D 3 4 19 27 3 4 705 19 1 4 489 6 5 8 168 Right 7 1 8 181 Left 5 3 8 137 Right 2 3 16 56 Left 33 838 AIR FLOW 3 4 19 19 7 16 494 9 16 14 B Supply Air Supply Air 9 16 14 9 16 14 3 1 8 79 9 16 14 9 16 14 19 7 16 494 3 4 19 Unit Dimensions Capacity A B C D in mm in mm in mm in mm 070 3A 14 1 2 368 13 3 8 340 13 330 4 3 4 121 090 4B 17 1 2 446 16 3 8 416 16 406 6 1 4 159 ...

Page 3: ...38 Parts Arrangement Figure 1 Control Box includes integrated control transformer and door switch Secondary Limit Internal Flue Pipe Assembly Gas Valve Burner Box Assembly Combustion Air Inducer Indoor Blower Heat Exchanger Primary Limit Top Cap ...

Page 4: ...nt National Fuel Gas Code ANSI Z223 1 The National Fuel Gas Code is available from the following address American National Standards Institute Inc 11 West 42nd Street New York NY 10036 Clearances Adequate clearance must be made around the air openings into the vestibule area In order to ensure proper unit operation combustion and ventilation air supply must be provided according to the current Nat...

Page 5: ...operation DO NOT USE THE UNIT FOR CONSTRUCTION HEAT UNLESS ALL OF THE FOLLOWING CRITERIA ARE MET a Furnace must be in its final location The vent system must be permanently installed per these installation instructions b Furnace must be installed as a two pipe system and one hundred percent 100 outdoor air must be provided for combustion air requirements during construction c A room thermostat mus...

Page 6: ...gerous situation In the absence of local codes concerning air for combustion and ventilation use the guidelines and procedures in this section to install these furnaces to ensure efficient and safe operation You must consider combustion air needs and requirements for exhaust vents and gas piping A portion of this information has been reprinted with permission from the National Fuel Gas Code ANSI Z...

Page 7: ...adjoins a space categorized as unconfined air can be brought in by providing two permanent openings between the two spaces Each opening must have a minimum free area of 1 square inch 645 mm2 per 1 000 Btu 29 kW per hour of total input rating of all gas fired equipment in the confined space Each opening must be at least 100 square inches 64516 mm2 One opening shall be within 12 inches 305 mm of the...

Page 8: ...all have a free area of at least 1 square inch per 4 000 Btu 645 mm per 1 17 kW per hour of the total input rating of all other equipment in the enclosure Setting Equipment Do not install the furnace on its front or its back Do not connect the return air ducts to the back of the furnace Doing so will adversely affect the operation of the safety control devices which could result in personal injury...

Page 9: ...PPLY AIR PLENUM OPENING Cabinet Width Front to Rear Side to Side in mm in mm A 14 1 2 19 3 4 502 13 1 4 337 B 17 1 2 19 3 4 502 16 1 4 413 NOTE Floor opening dimensions listed are 1 4 inch 6 mm larger than the unit opening See unit dimensions on Page 2 Table 1 Non Combustible Floor Opening Size Installation on Combustible Flooring Figure 9 1 When unit is installed on a combustible floor a downflow...

Page 10: ...et metal screws from the outside In this case make plenum with a removable front and install screws from the inside see Figure 12 5 Make certain that an adequate seal is made Cabinet Width Front to Rear Side to Side in mm in mm A 14 1 2 22 559 15 3 4 400 B 17 1 2 22 559 18 3 4 476 Table 2 Combustible Floor Opening Size Installation on Cooling Cabinet Figure 10 1 Refer to reverse flow coil installa...

Page 11: ...if a single wall vent is used on 14 1 2 in cabinets or 2 in if a single wall vent is used on 17 1 2 in cabinets The furnace may be installed on a combustible wood floor if an optional additive base is installed between the furnace and the combustible floor Improper installation of the furnace can result in personal injury or death Combustion and flue products must never be allowed to enter the ret...

Page 12: ...ted gas vent Unlined masonry chimneys are prohibited See Figure 17 and Figure 18 for common venting Venting Using a Masonry Chimney The following additional requirements apply when a lined masonry chimney is used to vent this furnace A chimney with one or more sides exposed to the outside of the structure is considered to be an exterior chimney An exterior masonry chimney that is not tile lined mu...

Page 13: ...de a chimney no other appliance can be vented into the chimney The outer wall of type B1 vent pipe must not be exposed to flue products A type B1 vent or masonry chimney liner shall terminate above the roof surface with a listed cap or a listed roof assembly according to the terms of their respective listings and the vent manufacturer s instructions When inspection reveals that an existing chimney...

Page 14: ...fset the maximum common vent capacity listed in the common venting tables should be reduced by 20 the equivalent of two 90 elbows 0 80 x maximum common vent capacity The horizontal length of the offset shall not exceed 1 1 2 feet 46 m for each inch 25 mm of common vent diameter 10 The vent pipe should be as short as possible with the least number of elbows and angles required to complete the job R...

Page 15: ...5 8 28 49 39 98 51 164 64 247 10 0 0 88 0 175 0 295 0 447 2 12 61 17 118 23 194 26 289 5 23 57 32 113 41 187 52 280 10 30 51 41 104 54 176 67 267 15 0 0 94 0 191 0 327 0 502 2 11 69 15 136 20 226 22 339 5 22 65 30 130 39 219 49 330 10 29 59 40 121 51 206 64 315 15 35 53 48 112 61 195 76 301 20 0 0 97 0 202 0 349 0 540 2 10 75 14 149 18 250 20 377 5 21 71 29 143 38 242 47 367 10 28 64 38 133 50 229...

Page 16: ...146 69 220 15 1 21 50 33 89 47 142 64 220 2 22 53 35 96 49 153 66 235 3 24 55 36 102 51 163 68 248 20 1 21 54 33 99 46 157 62 246 2 22 57 34 105 48 167 64 259 3 23 60 35 110 50 176 66 271 30 1 20 62 31 113 45 181 60 288 2 21 64 33 118 47 190 62 299 3 22 66 34 123 48 198 64 309 Table 6 Common Vent Capacity Type B Double Wall Vents with Type B Double Wall Connectors Serving Two or More Category I Ap...

Page 17: ...h as range hoods and bathroom exhausts so they will operate at maximum speed Do not operate a summer exhaust fan Close fireplace dampers 4 Follow the lighting instructions Turn on the appliance that is being inspected Adjust the thermostat so that the appliance operates continuously 5 After the burners have operated for 5 minutes test for leaks of flue gases at the draft hood relief opening Use th...

Page 18: ...essive pressure drop Table 8 lists recommended pipe sizes for typical applications 3 The gas piping must not run in or through air ducts clothes chutes gas vents or chimneys dumb waiters or elevator shafts 4 The piping should be sloped 1 4 inch 6 4 mm per 15 feet 4 57 m upward toward the meter from the furnace The piping must be supported at proper intervals every 8 to 10 feet 2 44 to 3 01 m with ...

Page 19: ...wiring and circuit breaker s per Technical Specification and unit rating plate CAUTION The unit is equipped with a field make up box on the left hand side of the cabinet The make up box may be moved to the right side of the furnace to facilitate installation If the make up box is moved to the right hand side clip the wire ties that bundle the wires together Secure the excess wire to the existing h...

Page 20: ...cuit being connected to one of the provided neutral terminals If a humidifier rated at greater than one amp is connected to this terminal it is necessary to use an external relay Generator Use Voltage Requirements The following requirements must be kept in mind when specifying a generator for use with this equipment The furnace requires 120 volts 10 Range 108 volts to 132 volts The furnace operate...

Page 21: ...ssue 2220 Page 21 of 38 070 3A 090 4B CUT W914 JUMPER LABELED DEHUM FROM DS TO R AT A92 CONTROL BOARD WHEN USED WITH HUMIDIFICATION CONTROLS Figure 22 Wiring Diagram with Resideo Honeywell Integrated Furnace Control 103132 xx ...

Page 22: ...L BOARD WHEN USED FOR DUAL FUEL APPLICATIONS RATING INSULATION THICKNESS AND TERMINATION K1 K4 K7 K8 8 8 HI W914 W915 2 3 1 43 AMP WHITE RODGERS VALVE CUT W914 JUMPER LABELED DEHUM FROM DS TO R AT A92 CONTROL BOARD WHEN USED WITH HUMIDIFICATION CONTROLS NOTE SEE INSTALLATION INSTRUCTIONS FOR PROCEDURE TO SET CORRECT BLOWER SPEED FOR SPECIFIC COOLING TONNAGE BEING APPLIED AND HEATING TEMPERATURE RI...

Page 23: ... Use DIP switch 2 to set sceond stage heat ON delay OFF 7 minutes ON 12 minutes ON CUT ON BOARD LINK W915 2 STAGE COMPR T STAT FURNACE TERM STRIP OUTDOOR UNIT Not required on all units 1 Heat 2 Cool with t stat with dehumidification mode NOTE Use DIP switch 2 to set sceond stage heat ON delay OFF 7 minutes ON 12 minutes ON CUT ON BOARD LINK W915 2 STAGE COMPR CUT ON BOARD LINK W914 DEHUM T STAT FU...

Page 24: ...ication mode OFF CUT ON BOARD LINK W915 2 STAGE COMPR CUT ON BOARD LINK W914 T STAT FURNACE TERM STRIP OUTDOOR UNIT o Not required on all units 2 Heat 1 Cool with t stat with dehumidification mode OFF CUT ON BOARD LINK W914 T STAT FURNACE TERM STRIP OUTDOOR UNIT o Not required on all units 2 Heat 1 Cool OFF DO NOT CUT ANY ON BOARD LINKS T STAT FURNACE TERM STRIP OUTDOOR UNIT Not required on all un...

Page 25: ... LINK W951 HEAT PUMP T STAT FURNACE TERM STRIP HEAT PUMP 67M41 Y H L Y2 D B L Y2 T T outdoor sensor Dual Fuel Two Stage Heat Pump Thermostat w dual fuel capabilities Capable of 2 stage gas heat control OFF CUT ON BOARD LINK W951 HEAT PUMP CUT ON BOARD LINK W915 2 STAGE COMPR FURNACE TERM STRIP HEAT PUMP out blue 67M41 H L Y2 D B L Y2 T T outdoor sensor T STAT Y2 NOTE Do NOT make a wire connection ...

Page 26: ...RD LINK W914 DEHUM T STAT FURNACE TERM STRIP HEAT PUMP 67M41 Y H L Y2 D B L Y2 T T outdoor sensor Dual Fuel Two Stage Heat Pump Thermostat w dual fuel capabilities Capable of 2 stage gas heat control with dehumidification mode OFF CUT ON BOARD LINK W914 DEHUM CUT ON BOARD LINK W951 HEAT PUMP CUT ON BOARD LINK W915 2 STAGE COMPR T STAT FURNACE TERM STRIP HEAT PUMP 67M41 H L Y2 D B L Y2 T T outdoor ...

Page 27: ...RMOSTAT 2ND STAGE COOL SIGNAL O THERMOSTAT SIGNAL TO HEAT PUMP REVERSING VA LVE L NOT USED DH NOT USED HUM UNPOWERED NORMALLY OPEN DRY CONTACTS LI 120 VAC INPUT TO CONTROL ACC 120 VAC OUTPUT TO OPTIONAL ACCESSORY NEUTRALS 120 VAC NEUTRAL 3 16 QUICK CONNECT TERMINALS FLAME SENSE SIGNAL HI Cool 24VAC HI HEAT 24VAC LO COOL 24VAC LO HEAT 24VAC PARK PARK COMMON 24VAC Flame Sense S4 DIP Switches 24VAC I...

Page 28: ...open dry contacts ACC one 120VAC output terminal for optional accessory L1 three 120VAC line terminals Neutrals five 120VAC neutral terminals THERMOSTAT CONNECTIONS DS Dehumidification signal W2 Heat demand from 2nd stage Tstat W1 Heat demand from 1st stage Tstat white R Class 2 voltage to thermostat G Manual fan from Tstat green C Tstat signal ground connected to transformer Ground TR Chassis gro...

Page 29: ...g Mode Blower Off Delay The blower on delay of 30 seconds is not adjustable The blower off delay time that the blower operates after the heating demand has been satisfied can be adjusted by moving switches 3 and 4 on the integrated control The unit is shipped from the factory with a blower off delay of 90 seconds The blower off delay affects comfort and is adjustable to satisfy individual applicat...

Page 30: ...NG Before attempting to perform any service or maintenance turn the electrical power to unit OFF at disconnect switch CAUTION BEFORE LIGHTING smell all around the appliance area for gas Be sure to smell next to the floor because some gas is heavier than air and will settle on the floor The gas valve on this unit will be equipped with a gas control switch Use only your hand to move the switch Never...

Page 31: ...2 cu ft Dial 1 cu ft Dial 2 cu ft Dial 070 55 110 136 272 090 41 82 102 204 Natural 1000 btu cu ft LP 2500 btu cu ft Table 13 Furnace should operate at least 5 minutes before checking gas flow Determine time in seconds for two revolutions of gas through the meter Two revolutions assures a more accurate time Divide by two and compare to time in Table 13 If manifold pressure matches Table 15 and rat...

Page 32: ...g 0 4 500 ft Manifold Pressure in wg 4 501 7 500 ft Manifold Pressure in wg 7 501 10 000 ft 2 Supply Line Pressure in wg Low Fire High Fire Low Fire High Fire Low Fire High Fire Min Max 070 Natrual 1 7 3 5 1 5 3 2 1 7 3 5 4 5 13 0 LP Propane 3 4 5 10 0 4 5 10 0 4 5 10 0 11 0 13 0 090 Natrual 1 7 3 5 1 5 3 0 1 7 3 5 4 5 13 0 LP Propane 3 4 5 10 0 4 5 10 0 4 5 10 0 11 0 13 0 1 This is the only permi...

Page 33: ...ontrol speed terminal 7 Resecure blower access panel 8 Turn on electrical power to furnace 9 Recheck temperature rise Heating Sequence of Operation Electronic Ignition The two stage variable speed integrated control used in NF80DT units has an added feature of an internal Watchguard control The feature serves as an automatic reset device for ignition control lockout caused by ignition failure Afte...

Page 34: ... switch does not close the combustion air inducer will switch to high fire After a 15 second pre purge the high fire pressure switch will close and the unit will begin operation on high fire After 10 to 20 seconds of high fire operation the unit will switch to low fire 3 After the pre purge is complete a 20 second initial ignitor warm up period begins The combustion air inducer continues to operat...

Page 35: ...n to check for gas leaks CAUTION Annual Furnace Maintenance At the beginning of each heating season and to comply with the GEA Limited Warranty your system should be checked as follows 1 Check wiring for loose connections voltage at indoor unit and amperage of indoor motor 2 Check the condition of the belt and shaft bearings if applicable 3 Inspect all gas pipe and connections for leaks 4 Check th...

Page 36: ...sure switch Ignitor Primary limit control Flame rollout switch s Secondary limit Repair Parts List The following repair parts are available through independent GEA dealers When ordering parts include the complete furnace model number listed on the CSA International nameplate All service must be performed by a licensed professional HVAC installer or equivalent service agency or gas supplier Cabinet...

Page 37: ...ssure in w c Air Volume Watts at Various Blower Speeds High Black Medium High Brown Medium Blue Medium Low Yellow Low Red cfm watts cfm watts cfm watts cfm watts cfm watts 0 10 1700 423 1495 293 1380 233 1295 202 1165 156 0 20 1665 436 1455 307 1330 248 1245 211 1110 166 0 30 1620 452 1415 319 1295 257 1195 221 1055 175 0 40 1585 464 1365 328 1225 269 1140 230 985 185 0 50 1560 471 1325 343 1185 2...

Page 38: ...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 n...

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