Independent Review · Updated June 2026

3.5 Ton 15 SEER 96% AFUE 120,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow

High-efficiency dual-fuel system combining 96% furnace heating with 16 SEER cooling at competitive pricing.

8.2
IndustrialRank Score
Efficiency
8.5
Reliability
7.8
Value
8.0
Installation
8.5
Warranty
8.0
3.5 Ton 15 SEER 96% AFUE 120,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow
Current Price
$3136
Check Price at HVACDirect → Shop Now at HVACDirect
Authorized dealer · Full manufacturer warranty
// Bottom Line
This Goodman system works best for homeowners in moderate climates seeking balanced heating and cooling performance without premium pricing. The 96% AFUE furnace and variable-speed blower deliver reliable comfort, though the single-stage air conditioner limits peak efficiency during extreme heat.

Review

The Goodman 3.5-ton dual-fuel system bridges economy and performance, pairing a 96% AFUE furnace with a 16 SEER2 air conditioner. Positioned as a value option for contractors and homeowners, this unit targets the middle market where efficiency matters but premium modulation isn't required. The downflow configuration increases installation flexibility, while the variable-speed blower addresses both heating and cooling needs without oversized ductwork.

Heating delivers 120,000 BTU across two burner stages, preventing rapid on-off cycling that wastes energy. Cooling produces 42,000 BTU at 16 SEER2 using a scroll compressor and R410A refrigerant. The variable-speed ECM blower runs from 0 to 2000 CFM, matching airflow to demand. However, the single-stage air conditioner design means the compressor runs full power even during mild days, losing potential efficiency gains that dual-stage systems achieve.

Pros & Cons

Pros

  • 96% AFUE furnace efficiency reduces heating costs significantly compared to 80-90% units
  • 16 SEER2 cooling rating qualifies for Energy Star, indicating strong AC performance
  • Variable-speed ECM blower motor adjusts output from 0 to 2000 CFM for comfort and efficiency
  • Two-stage burner operation minimizes short cycling and improves temperature consistency
  • Downflow/horizontal configuration fits attic, basement, or closet installations
  • 10-year warranty with online registration covers both furnace and evaporator coil

Cons

  • Single-stage air conditioner cannot modulate capacity, wasting energy during mild cooling days
  • 73 dBA noise level is moderately loud, noticeable in quiet homes during furnace operation
  • Spec sheet lists conflicting tonnage (3.5 Ton title, 5 Ton specification) creating buyer confusion

Who Should Buy

Best For

Homeowners in climates with moderate heating and cooling demands who want solid efficiency without dual-variable-stage equipment. This system suits budget-conscious buyers replacing older furnaces who value the high AFUE rating and Energy Star certification.

Consider Alternatives If

Anyone in extreme heat regions needing aggressive cooling performance should compare dual-stage or variable-capacity air conditioners instead.

3.5 Ton 15 SEER 96% AFUE 120,000 BTU Goodman Gas F
$3136
Buy at HVACDirect →

Installation

The downflow/horizontal A-coil design fits tight spaces where upflow units won't work. Electrical needs are modest: 115V single-phase 60Hz with breaker range from 23.5 to 40 amps. Suction line insulation (1/2 inch, 50 feet) comes included. PVC exhaust flue compatibility suits modern code requirements. Ductwork sizing for 2000 CFM maximum airflow matters for peak performance.

Warranty & Reliability

Online registration unlocks a 10-year warranty covering both furnace and evaporator coil. This is standard industry coverage, protecting against manufacturing defects but not wear items like capacitors or fan motors. Registration is required, so retain documentation. Extended plans may be available through the retailer.

Specifications

SKULS381183850
Brand/ManufacturerOnline Supply
Cooling BTU42,000
Heating BTU120,000
RefrigerantR410A
Electrical115 V. 1 Phase 60 Hz
Warranty10 Years with Online Registration
Decibel Level (dBA)73
Weight (in lbs)48.000000
FeatureSpec
Energy StarYes
SEER1 (Efficiency)16
Condenser StagesSingle Stage
Compressor TypeScroll
Liquid Valve Size3/8"
Suction Valve Size7/8"
Max Breaker Size40 amps
Min. Breaker Size23.5 amps
Tonnage5 Ton
Height30"
Width24.5"
Depth21"
ResourcesCAPT Installation Manual CAPT Specifications Sheet Goodman Evaporator Coil Warranty You will need Adobe® Acrobat® Reader to view PDF documents.
Safety InformationPROPOSITION 65 WARNING This product and many products on our site may contain a chemical know to the state of California to cause cancer or birth defects or other reproductive harm. For more information about Proposition 65 please Click Here.
AHRI Certificate Number7368845
Airflow DirectionDownflow/Horizontal
Exhaust Flue RequirementPlastic / PVC
Product FeaturesRebate Available
Furnace Efficiency / AFUE96%
Blower MotorVariable Speed - ECM
Maximum CFM2000
ConfigurationUpflow / Downflow
Burner StagesTwo
Fuel TypePropane, Natural Gas
Liquid Line3/8"
Suction Line1 1/8"
StyleA-Coil
Suction Line Insulation Thickness1/2"
Length50 feet

Frequently Asked Questions

Does this system qualify for tax credits or rebates? +
Yes, the 16 SEER2 rating and 96% AFUE furnace meet Energy Star standards, potentially qualifying for federal tax credits up to $2000 and state/utility rebates. Check AHRI certificate 7368845 with your installer and local programs for current eligibility.
Can I install this in a basement or attic with limited space? +
The downflow configuration and compact footprint (30 inches tall, 24.5 inches wide, 21 inches deep) work in tight spaces. Ensure 50 feet of pre-insulated suction line reaches the condenser without kinks, and verify PVC exhaust flue can vent safely outdoors.
How does 16 SEER2 compare to higher-rated systems? +
16 SEER2 is solid mid-tier performance. Dual-stage or variable-capacity systems reach 18-21 SEER2 but cost significantly more. This single-stage unit excels in consistent, moderate-load climates but may cycle inefficiently during partial cooling demand.
Does the unit run on natural gas, propane, or both? +
The furnace accepts both natural gas and propane. Confirm your fuel source before ordering. Gas conversion requires minimal adjustments during installation, though orifice sizing differs between fuel types.
What does the 10-year warranty actually cover? +
Coverage includes manufacturing defects in the furnace, air conditioner, and evaporator coil. Online registration is mandatory. Wear items and installation labor are excluded. Review the CAPT specifications sheet for complete terms.

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