PRODUCT SPECIFICATIONS GAS FURNACES ML80DF MERIT SERIES Downflow Bulletin No. 20643 February 208 Supersedes November 207 AFUE - 80% Input - 44,000 to 0,000 Btuh Nominal Add-on Cooling -.5 to 5 Tons MODEL NUMBER IDENTIFICATION ML 80 DF 070 X P 36 A Unit Type ML = Merit Series Stages = Single-Stage AFUE 80 = 80% Configuration DF = Downflow Nominal Gas Heat Input 045 = 44,000 Btuh 070 = 66,000 Btuh 090 = 88,000 Btuh 0 = 0,000 Btuh Cabinet Width A = 4-/2 in. B = 7-/2 in. C = 2 in. Nominal Add-On Cooling Capacity 24 =.5-2 tons 36 = 2-3 tons 48 = 3-4 tons 60 = 4-5 tons Blower P = PSC Multi-Speed Blower Motor Low NO x X = Units meet California Nitrogen Oxides standards Downflow indoor coils with the same letter designation will physically match the furnace supply air opening.
FEATURES CONTENTS Blower Data...0 H Dimensions...7 Dimensions - Furnace/Coil Combined Dimensions... 9 Features...2 Gas Heat Accessories...6 High Altitude Derate...6 Installation Clearances...6 I J Model Number Identification... Optional Accessories...6 Optional Accessory Dimensions...8 Specifications...5 K B L F G E C D NOTE - ML80DF FURNACES ARE NOT AVAILABLE IN CANADA! WARRANTY Duralok Aluminized Steel Heat Exchanger - Limited twenty year warranty in residential applications, ten years in non-residential applications. All other covered components - Limited five year warranty in residential applications, one year in nonresidential applications. Refer to Lennox Equipment Limited Warranty certificate included with equipment for details. APPROVALS Units are Certified by AHRI. Units tested and rated according to US DOE test procedures and FTC labeling regulations. X models approved by the California Energy Commission and meet California Seasonal Efficiency requirements and California Nitrogen Oxides (NO x ) Standards. ISO 900 Registered Manufacturing Quality System. Blower data from unit tests conducted in Lennox Laboratory air test chamber. APPLICATIONS Input capacities of 44,000, 66,000, 88,000 and 0,000 Btuh. Energy efficiency (AFUE) of 80%. Compact cabinet for downflow applications without any internal modifications to the unit. Lennox add-on indoor coils, high-efficiency air cleaners and humidifiers can easily be added to furnace. Shipped factory assembled with all controls installed and wired. Each unit factory test operated to ensure proper operation. ML80DF / Page 2
B C D E F FEATURES HEATING SYSTEM Lennox Duralok Heat Exchanger Assembly Heavy gauge aluminized steel heat exchanger. Crimped seam clamshell type design. Designed for normal expansion and contraction. Minimum resistance to air flow. Heat exchanger has been laboratory life cycle tested in excess of industry standards. Compact size of heat exchanger permits low overall design of furnace cabinet. Inshot Burners Aluminized steel inshot burners provide efficient, trouble-free operation. Burner venturi mixes air and gas in correct proportion for proper combustion. Burner assembly is removable from the unit as a single component for ease of service. SureLight Hot Surface Ignitor Tough, reliable, long-life, trouble-free performance. Silicon nitride ignitor. Gas Control Valve 24 volt redundant combination gas control valve combines manual shut off switch (On-Off), automatic electric valve (dual) and gas pressure regulation into a compact combination control. Combustion Air Inducer Shaded pole heavy duty blower prepurges heat exchanger and safely vents flue products. Pressure switch proves blower operation before allowing gas valve to open. Operates only during heating cycle. G H Flame Rollout Switch Manual reset switch is factory installed on the front of the burner box. Switches provides protection from abnormal operating conditions. Limit Controls Automatic reset, primary and secondary limits are accurately located. Primary limit factory installed on vestibule panel on all units, secondary limit factory installed on blower housing. Optional Accessories High Altitude Pressure Switch Kit Required on most units for proper unit operation at altitudes from 4,50 to 7500 ft. Natural Gas to LPG/Propane Conversion Kit Required for field changeover from natural gas to LPG/ Propane. LPG/Propane to Natural Gas Conversion Kit Required for field changeover from LPG/Propane to natural gas. BLOWER Multi-Speed direct drive blower. Statically and dynamically balanced. Resiliently mounted. Blower assembly easily removed for servicing. Motor is controlled by the Integrated Furnace Control. Blower speeds are easily changed on the integrated furnace control. See blower performance tables. ML80DF / Page 3
FEATURES I J CONTROLS SureLight Integrated Furnace Control Control contains all necessary controls and relays to operate furnace. Combustion air inducer is operated by the integrated furnace control. Prior to ignition, a pre-purge cycle for 5 seconds is initiated. After the main burners are turned off, a post-purge cycle for 5 seconds is run. Flame sensor assures safe and reliable operation. Should loss of flame occur the integrated furnace control will initiate 4 re-attempts at ignition before locking out unit operation for 60 minutes. Watchguard type circuit automatically resets ignition controls after one hour of continuous thermostat demand after unit lockout, eliminating nuisance calls for service. Fan control consists of adjustable blower timed-off delay (60, 90, 20, 80 seconds - factory setting 20 seconds) and fixed blower timed-on delay (30 seconds). For air-conditioning applications, blower is automatically energized on thermostat demand for cooling. Integrated furnace control has one red LED to indicate status and indicate diagnostic codes. Push button recall of the last 5 diagnostic codes aids in troubleshooting. Integrated furnace control has built-in twinning capability ( TWIN terminal on control) to operate two furnaces simultaneously without any additional controls. A field supplied isolation relay is required to operate the twinned (no thermostat connection) furnace. Two accessory terminals furnished for additional power supply requirements for 20 volt (less than amp) power humidifiers and powered air cleaners. 24 Volt Transformer Furnished and factory installed on outside of control box. 40VA transformer has fuse wired in series. Field Wiring Make-Up Box Furnished for line voltage wiring. Factory installed internally on left side of furnace. Box may be installed on right side of furnace. Optional Accessories Thermostat Thermostat (programmable/non-programmable) is not furnished with unit. See Thermostat bulletins in Controls Section and Lennox Price Book for selection. K L CABINET Low-profile, narrow width cabinet allows easy installation in downflow applications. Heavy-gauge, cold rolled steel construction. Pre-painted cabinet finish. Flanges provided on supply air opening for ease of plenum connection or alignment with indoor coil. Insulated cabinet with foil faced insulation on sides and back of heating compartment. Complete service access. Safety interlock switch automatically shuts off power to unit when blower compartment access panel is removed. Gas piping and electrical inlets are provided in both sides of cabinet. Coil Match-Up All Lennox downflow indoor coils will physically match the furnace supply air opening with the same letter designation (A, B, C, D) as in the furnace model number. Low Leakage Cabinet All models have less than 2% air leakage and meet ANSI/ASHRAE Standard 93-200 Method of Test for Determining the Air Tightness of HVAC Equipment. Optional Accessories Downflow Combustible Flooring Base Required for heating only units installed on combustible floors. Not required in add-on cooling applications. See Dimension Drawing. FILTER (not furnished) Filter and provisions for external mounting must be field provided. Optional Accessories Downflow Filter Cabinet Filter cabinet mounts directly on top of furnace. A width cabinet includes one filter. B and C width cabinets have two filters. Filter rails are furnished. Front access for servicing. Cleanable filter(s) are furnished. ML80DF / Page 4
SPECIFICATIONS Gas Heating Performance Model No. Model No. - Low NO x ML80DF045P24A - - - ML80DF045P36A - - - ML80DF070P36A ML80DF070XP36A AFUE 80% 80% 80% Input - Btuh 44,000 44,000 66,000 Output - Btuh 35,000 36,000 53,000 Temperature rise range - F 25-55 5-45 25-55 Gas Manifold Pressure (in. w.g.) Nat. Gas / LPG/Propane 3.5 / 0.0 3.5 / 0.0 3.5 / 0.0 High Static - in. w.g. 0.50 0.50 0.50 Connections in. Indoor Blower Electrical Data Flue connection - in. round 4 4 4 Gas pipe size IPS /2 /2 /2 Wheel nom. dia. x width - in. 0 x 7 0 x 8 0 x 8 Motor output - hp /5 /3 /3 Tons of add-on cooling.5-2 2-3 2-3 Air Volume Range - cfm 40-57 739-524 77-562 Voltage 20 volts - 60 hertz - phase Blower motor full load amps 3. 6. 6. Maximum overcurrent protection 5 5 5 Shipping Data lbs. - package 05 3 28 NOTE - Filters and provisions for mounting are not furnished and must be field provided. Annual Fuel Utilization Efficiency based on DOE test procedures and according to FTC labeling regulations. Isolated combustion system rating for non-weatherized furnaces. SPECIFICATIONS Gas Heating Performance Model No. Model No. - Low NO x ML80DF090P36B - - - ML80DF090P48B ML80DF090XP48B ML80DF0P60C ML80DF0XP60C AFUE 80% 80% 80% Input - Btuh 88,000 88,000 0,000 Output - Btuh 7,000 7,000 89,000 Temperature rise range - F 35-65 25-55 30-60 Gas Manifold Pressure (in. w.g.) Nat. Gas / LPG/Propane 3.5 / 0.0 3.5 / 0.0 3.5 / 0.0 High Static - in. w.g. 0.50 0.50 0.50 Connections in. Indoor Blower Electrical Data Flue connection - in. round 4 4 4 Gas pipe size IPS /2 /2 /2 Wheel nom. dia. x width - in. 0 x 9 0 x 0 -/2 x 0 Motor output - hp /3 /2 Tons of add-on cooling 2-3 3-4 4-5 Air Volume Range - cfm 743-695 97-929 57-2760 Voltage 20 volts - 60 hertz - phase Blower motor full load amps 6. 8.2 0.0 Maximum overcurrent protection 5 5 5 Shipping Data lbs. - package 3 40 60 NOTE - Filters and provisions for mounting are not furnished and must be field provided. Annual Fuel Utilization Efficiency based on DOE test procedures and according to FTC labeling regulations. Isolated combustion system rating for non-weatherized furnaces. ML80DF / Page 5
OPTIONAL ACCESSORIES - ORDER SEPARATELY CABINET ACCESSORIES A Width Models B Width Models C Width Models Downflow Combustible Flooring Base M59 M60 M6 FILTERS Downflow Filter Cabinet 5W06 5W07 5W08 night SERVICE KIT No. and Size of filter - in. () 20 x 20 x (2) 20 x 6 x (2) 20 x 6 x Night Service Kit 68W80 68W80 68W80 Cleanable polyurethane, frame-type filter. GAS HEAT ACCESSORIES Input High Altitude Pressure Switch Kit Natural Gas to LPG/Propane Kit LPG/Propane to Natural Gas Kit Natural Gas High Altitude Orifice Kit 0-4500 ft. 450-7500 ft. 750-0,000 ft. 0-7500 ft. 750-0,000 ft. 0-7500 ft. 750-0,000 ft. 045 No Change No Change 80W5 K49 K44 73W8 73W37 070 No Change 80W52 80W5 K49 K44 73W8 73W37 090 No Change No Change 80W5 K49 K44 73W8 73W37 090X No Change 80W52 80W5 K49 K44 73W8 73W37 0 No Change 80W52 80W5 K49 K44 73W8 73W37 HIGH ALTITUDE DERATE NOTE - Units may be installed at altitudes up to 4500 ft. above sea level without any modifications. At altitudes above 4500 ft. units must be derated to match information in the shaded areas shown below. NOTE - This is the only permissible derate for these units. Input Gas Manifold Pressure (Outlet) in. w.g. 0-4500 Feet 450-7500 Feet 750-0,000 ft. Minimum Natural Gas LPG/ Propane Natural Gas LPG/ Propane Natural Gas LPG/ Propane Natural Gas Line Pressure - in. w.g. LPG/ Propane Maximum 045 3.5 0 3.5 0 3.5 0 4.5 3 070 3.5 0 3.3 0 3.5 0 4.5 3 090 3.5 0 3.3 0 3.5 0 4.5 3 0 3.5 0 3.3 0 3.5 0 4.5 3 Natural Gas High Alitude Orifice Kit required. INSTALLATION CLEARANCES Vent Type Type B Type C NOTE Air for combustion must conform to the methods outlined in the National Sides Rear 0 in. (0 mm) 0 in. (0 mm) in. (0 mm) 0 in. (0 mm) Fuel Gas Code (NFPA 54/ANSI-Z223.). NOTE In the U.S. flue sizing must conform to the methods outlined in the current National Fuel Gas Code (NFPA 54/ANSI-Z223.) or applicable provisions of local building codes. Top in. (25 mm) in. (25 mm) Front 2-/4 in. (57 mm) 2-/4 in. (57 mm) Front (service/alcove) 24 in. (60 mm) 24 in. (60 mm) Floor 2 Combustible 2 Combustible Flue in. (25 mm) 6 in. (52 mm) Left side requires 4 in. if single wall vent is used on 4-/2 in. A width cabinets, 2 in. on 7-/2 in. B width cabinets. 2 Clearance for installation on combustible floor if Optional Downflow Combustible Flooring Base is installed between furnace and combustible floor. Not required in add-on cooling applications if installed in accordance with local codes, National Fuel Gas Code ANSI-Z223. or National Standard of Canada CAN/CSA-B49. and CAN/CSA-B49.2 Installation Code for Gas Burning Appliances. Do not install the furnace directly on carpeting, tile, or other combustible materials other than wood flooring. ML80DF / Page 6
DIMENSIONS - INCHES (MM) 3-/8 (79) 9/6 (4) D B RETURN AIR OPENING FLUE OUTLET (Top) 9-7/6 (494) 9/6 (4) 9/6 (4) TOP VIEW A B 9/6 (4) 3/4 (9) Front Panel 27-3/4 (705) 9-7/6 (494) 9/6 (4) AIR FLOW 33 (838) 5-3/8 (37) Right 2-3/6 (56) Left ELECTRICAL INLET (Either Side) GAS PIPING INLET (Either Side) 6-5/8 (68) Right 7-/8 (8) Left 3/4 (9) C Supply Air FRONT VIEW 3/4 (9) 9-/4 (489) SIDE VIEW Supply Air 3/4 (9) Model No. A B C D in. mm in. mm in. mm in. mm ML80DF045P24A ML80DF045P36A 4-/2 368 3-3/8 340 3 330 4-3/4 2 ML80DF070P36A ML80DF090P36B ML80DF090P48B 7-/2 446 6-3/8 46 6 406 6-/4 59 ML80DF0P60C 2 533 9-7/8 505 9-/2 495 8 203 ML80DF / Page 7
OPTIONAL ACCESSORY DIMENSIONS - INCHES (MM) DOWNFLOW FILTER CABINET A WIDTH FURNACES (Single Filter) B AND C WIDTH FURNACES (Two Filters) 20-/2 (52) 4-/2 (368) 20-/2 (52) 7-/2 (445) B Box 2 (533) C Box FILTER () 2 (533) FILTERS (2) 7-/2 (445) 54 (372) 50-/2 (283 ) 33 (838) 33 (838) FILTER ACCESS DOOR FURNACE FURNACE FILTER ACCESS DOOR NOTE: Return Air Opening (W x D) A Box 3-/2 x 9-5/8 (343 x 498) B Box 6-/2 x 9-5/8 (49 x 498) C Box 20 x 9-5/8 (508 x 498) ML80DF / Page 8
OPTIONAL ACCESSORY DIMENSIONS - INCHES (MM) DOWNFLOW COMBUSTIBLE FLOORING BASE -/2 (38) SUPPLY AIR OPENING DOWN FLOW FURNACE -/2 (38) B 9-3/6 (503) -/2 (38) 27-/4 (692) 2-3/6 (554) Front Of Furnace A -/2 (38) TOP VIEW SIDE VIEW DOWNFLOW COMBUSTIBLE FLOORING BASE FLOOR OPENING Cabinet Width Catalog Number A B C in. mm in. mm in. mm A M59 6-9/6 42 3-9/6 344 5-3/4 400 B M60 9-9/6 497 6-9/6 42 8-3/4 476 C M6 23-/6 586 20-/6 50 22-/4 565 22 (559) C DIMENSIONS - INCHES (MM) - FURNACE/COIL COMBINED DIMENSIONS Furnace Width 33 (838) Coil Height Overall Height Model Number Coil Width Furnace Width Coil Height Overall Height in. mm in. mm in. mm in. mm CR33-8A-F 7-/2 446 4-/2 368 4-/8 359 47-/8 97 CR33-24A-F 7-/2 446 4-/2 368 4-/8 359 47-/8 97 CR33-24B-F 7-/2 446 7-/2 446 4-/8 359 47-/8 97 CR33-30/36A-F 7-/2 446 4-/2 368 6-/8 40 49-/8 248 CR33-30/36B-F 7-/2 446 7-/2 446 6-/8 40 49-/8 248 CR33-30/36C-F 2 533 2 533 6-/8 40 49-/8 248 CR33-48B-F 2 533 7-/2 446 20 508 53 346 CR33-48C-F 2 533 2 533 20 508 53 346 CR33-50/60C-F 24-/2 622 2 533 23-5/8 600 56-5/8 2276 Coil Width ML80DF / Page 9
BLOWER DATA ML80DF045P24A PERFORMANCE (Less Filter) External Air Volume / Watts at Various Blower Speeds Static Medium- Medium- High Low Pressure High Low in. w.g. cfm Watts cfm Watts cfm Watts cfm Watts 0.0 57 399 938 333 764 273 699 243 0.20 20 38 924 322 745 264 677 237 0.30 084 362 890 3 723 258 650 230 0.40 027 349 864 298 695 250 633 224 0.50 975 334 84 283 674 238 605 25 0.60 902 322 764 268 623 225 564 203 0.70 83 305 682 248 549 208 477 86 0.80 73 280 576 228 470 92 40 7 ML80DF045P36A PERFORMANCE (Less Filter) External Air Volume / Watts at Various Blower Speeds Static Medium- Medium- High Low Pressure High Low in. w.g. cfm Watts cfm Watts cfm Watts cfm Watts 0.0 524 567 385 528 44 43 947 366 0.20 465 542 35 490 29 407 943 354 0.30 44 57 293 463 393 950 34 0.40 343 489 236 436 083 37 945 329 0.50 255 464 90 409 038 356 897 3 0.60 205 443 06 380 999 333 870 292 0.70 40 42 059 366 943 37 86 275 0.80 03 388 962 335 870 297 739 252 ML80DF070P36A PERFORMANCE (Less Filter) External Air Volume / Watts at Various Blower Speeds Static Medium- Medium- High Low Pressure High Low in. w.g. cfm Watts cfm Watts cfm Watts cfm Watts 0.0 562 59 386 539 59 436 956 374 0.20 506 553 355 504 49 48 953 36 0.30 459 528 34 473 9 392 94 343 0.40 390 500 264 442 082 374 95 323 0.50 306 477 200 45 048 352 904 305 0.60 23 44 29 39 987 332 849 288 0.70 40 47 066 36 90 304 798 270 0.80 038 395 975 342 836 283 77 244 ML80DF090P36B PERFORMANCE (Less Filter) External Air Volume / Watts at Various Blower Speeds Static Medium- Medium- High Low Pressure High Low in. w.g. cfm Watts cfm Watts cfm Watts cfm Watts 0.0 695 647 43 546 80 468 973 379 0.20 64 6 405 56 62 443 967 368 0.30 595 589 384 492 46 420 958 349 0.40 525 548 344 472 36 399 954 337 0.50 438 55 27 432 0 374 929 39 0.60 370 489 97 400 057 352 886 299 0.70 260 45 9 374 983 328 823 273 0.80 64 425 020 344 900 300 743 249 ML80DF090P48B PERFORMANCE (Less Filter) External Air Volume / Watts at Various Blower Speeds Static Medium- Medium- High Low Pressure High Low in. w.g. cfm Watts cfm Watts cfm Watts cfm Watts 0.0 929 755 794 668 585 572 332 489 0.20 864 77 745 623 544 540 32 463 0.30 779 683 676 588 496 50 296 440 0.40 694 647 600 558 443 473 265 47 0.50 596 607 502 5 363 440 22 393 0.60 483 577 43 485 258 406 48 370 0.70 340 544 273 449 48 374 042 339 0.80 22 505 38 46 08 350 97 307 ML80DF0P60C PERFORMANCE (Less Filter) External Air Volume / Watts at Various Blower Speeds Static Medium- Medium- High Low Pressure High Low in. w.g. cfm Watts cfm Watts cfm Watts cfm Watts 0.0 2760 40 2325 045 888 87 53 686 0.20 2670 362 239 003 937 847 565 679 0.30 2557 292 2257 964 945 832 605 674 0.40 2536 287 2220 949 935 82 622 66 0.50 2384 230 252 9 98 782 626 644 0.60 2273 9 2063 884 884 762 67 630 0.70 297 5 202 875 822 737 574 60 0.80 25 40 950 854 749 708 57 579 ML80DF / Page 0
REVISIONS Sections Optional Accessories Description of Change Removed Universal Service Kit (product discontinued). Visit us at www.lennox.com For the latest technical information, www.lennoxpros.com Contact us at -800-4-LENNOX NOTE - Due to Lennox ongoing commitment to quality, Specifications, Ratings and Dimensions subject to change without notice and without incurring liability. Improper installation, adjustment, alteration, service or maintenance can cause property damage or personal injury. Installation and service must be performed by a qualified installer and servicing agency. 208 Lennox Industries, Inc.