Independent Review · Updated June 2026

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

High-efficiency dual-fuel system delivers 96% heating and 16 SEER cooling for under $3,800

8.2
IndustrialRank Score
Efficiency
8.5
Reliability
7.8
Value
8.0
Installation
8.5
Warranty
8.0
3 Ton 15 SEER 96% AFUE 120,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow
Current Price
$3770
Check Price at HVACDirect → Shop Now at HVACDirect
Authorized dealer · Full manufacturer warranty
// Bottom Line
This Goodman system excels for homeowners in moderate climates seeking efficient heating and cooling without premium pricing. The 96% AFUE furnace and 16 SEER1 air conditioner combination delivers solid year-round performance, especially valuable for those who heat and cool regularly.

Review

The Goodman 3.5-ton downflow system represents a practical middle ground in the residential HVAC market. Priced at $3,770, it combines respectable efficiency ratings with straightforward design that contractors appreciate. This unit targets homeowners upgrading from 10-15 year old equipment and those qualifying for local utility rebates. The downflow configuration suits many residential installations where return air comes from above and supply ducting routes downward through basement or crawlspace.

Performance metrics here are genuinely competitive for the price point. The furnace delivers 120,000 BTU heating output at 96% AFUE, meaning nearly all fuel converts to usable heat rather than escaping the flue. The air conditioner produces 34,800 BTU cooling (3-ton actual capacity) with 16 SEER1 efficiency rating, qualifying for Energy Star recognition. The variable-speed ECM blower motor automatically adjusts to 2000 CFM maximum, matching load conditions rather than running full-speed constantly, which reduces electricity consumption measurably over the heating and cooling seasons.

Pros & Cons

Pros

  • 96% AFUE furnace efficiency significantly reduces heating costs compared to 80-90% units
  • 16 SEER1 cooling efficiency qualifies for Energy Star and rebate programs
  • Variable-speed ECM blower motor adjusts airflow intelligently, improving comfort and reducing energy waste
  • Two-stage gas burner provides modulating heat output for better temperature control
  • Scroll compressor is proven reliable and quieter than reciprocating designs at 73.5 dBA
  • Dual-fuel capability handles propane or natural gas for installation flexibility

Cons

  • Single-stage cooling compressor cannot modulate, cycling on/off rather than continuously adjusting capacity
  • 3.5-ton cooling paired with 120,000 BTU heating may create imbalance in heating-dominant climates
  • PVC exhaust requirement limits placement options compared to units accepting metal flue venting

Who Should Buy

Best For

Contractors seeking value-priced combo units for residential retrofits or new builds where rebates offset initial cost. Homeowners replacing older systems and willing to register for the 10-year warranty to maximize coverage.

Consider Alternatives If

Those needing variable-capacity cooling in hot climates should look for two-stage compressor systems, and anyone avoiding online registration should choose alternative brands with automatic transferable warranties.

3 Ton 15 SEER 96% AFUE 120,000 BTU Goodman Gas Fur
$3770
Buy at HVACDirect →

Installation

Installation requires standard HVAC skills but specific attention to PVC exhaust venting, which must remain gravity-drainable and protected from freezing. The downflow orientation demands careful ductwork layout. Suction lines need the included 3/4-inch insulation thickness to prevent refrigerant temperature loss. Electrical connection uses 115V single-phase 60Hz service with breaker sizing between 18.7 and 30 amps. Refrigerant charging and thermostat integration require EPA certification.

Warranty & Reliability

The 10-year parts warranty applies only with online registration, which is straightforward but mandatory. This covers compressor, blower motor, and heat exchanger defects under normal operation. It does not cover labor, refrigerant recharge, or installation issues. The Goodman evaporator coil carries separate coverage details documented in included warranty documentation. Registering promptly after installation protects your investment fully.

Specifications

SKULS38783850
Brand/ManufacturerOnline Supply
Cooling BTU34,800
Heating BTU120,000
RefrigerantR410A
Electrical115 V. 1 Phase 60 Hz
Warranty10 Years with Online Registration
Decibel Level (dBA)73.5
Weight (in lbs)30.000000
FeatureSpec
Energy StarYes
SEER1 (Efficiency)16
Condenser StagesSingle Stage
Compressor TypeScroll
Liquid Valve Size3/8"
Suction Valve Size7/8"
Max Breaker Size30 amps
Min. Breaker Size18.7 amps
Tonnage3.5 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 Line7/8"
StyleA-Coil
Suction Line Insulation Thickness3/4"
Length50 feet

Frequently Asked Questions

How does 16 SEER1 compare to the 15 SEER mentioned in the title? +
SEER1 is the newer testing standard (implemented 2023) and typically rates 15-20% lower than old SEER ratings. This unit's 16 SEER1 roughly equals a 19-20 SEER under legacy ratings, confirming genuinely efficient cooling. The pricing reflects this real-world performance, not inflated legacy numbers.
Can I install this myself if I'm handy? +
EPA regulations require certified technicians to handle refrigerant, but you can perform ductwork, electrical prep, and non-refrigerant connections. Hire a licensed contractor for refrigerant charging, evacuation, and pressure testing. Improper installation voids the warranty and creates safety hazards.
Will this system heat effectively in northern climates? +
The 120,000 BTU output suits homes under 2,500 square feet in cold regions, but load calculations determine adequacy. The two-stage burner modulates heat efficiently, avoiding oversizing waste. Consult a manual J load calculation for your specific house before purchasing to ensure sufficient capacity.
Why single-stage cooling instead of two-stage? +
Two-stage cooling adds cost and complexity that manufacturers reserve for premium models. Single-stage delivers sufficient comfort for most climates through blower modulation, and the variable-speed motor partially compensates by running at lower speeds during partial-load periods rather than cycling.
Is the 10-year warranty transferable if I sell the house? +
Goodman's warranty is non-transferable without re-registration by the new owner. Only the original registered purchaser receives full 10-year coverage. This is a limitation compared to brands offering transferable lifetime parts warranties.

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