Independent Review · Updated June 2026

3.5 Ton 15 SEER 96% AFUE 100,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow

High-efficiency dual-fuel system with 96% AFUE and 16 SEER1 for year-round comfort

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 100,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow
Current Price
$0
Check Price at HVACDirect → Shop Now at HVACDirect
Authorized dealer · Full manufacturer warranty
// Bottom Line
This 5-ton Goodman system excels for homeowners upgrading older equipment or building new construction in regions with moderate heating demands. The 96% AFUE furnace and 16 SEER1 air conditioner deliver strong utility bill savings, while dual-fuel capability supports natural gas and propane.

Review

The Goodman 5-ton downflow system positions itself in the mid-to-premium segment of residential HVAC equipment. Online Supply offers this dual-fuel unit at competitive pricing, making high-efficiency heating and cooling accessible to contractors managing diverse customer budgets. Goodman's brand recognition stems from reliable performance across commercial and residential applications. This particular configuration targets homes needing simultaneous heating and cooling capacity with downflow ductwork architecture.

Performance metrics exceed baseline expectations. The 96% AFUE furnace converts nearly all natural gas or propane into usable heat, minimizing wasted energy up the exhaust flue. Cooling delivers 42,000 BTU at a 16 SEER1 rating, surpassing the advertised 15 SEER specification. The variable-speed ECM blower motor ramps between 0-2000 CFM, allowing soft-start operation that reduces initial energy spikes. Two burner stages prevent energy-wasting short cycles during mild weather.

Pros & Cons

Pros

  • 96% AFUE furnace efficiency reduces heating costs significantly compared to 80-90% units
  • 16 SEER1 cooling rating outperforms the advertised 15 SEER specification
  • Variable-speed ECM blower motor adjusts output from 0-2000 CFM for comfort and efficiency
  • Two-stage burner system minimizes short-cycling and cycling losses
  • Energy Star certified with 10-year warranty covering parts when registered online
  • Scroll compressor is proven durable across thousands of Goodman installations

Cons

  • 73 dB noise level may be noticeable in quiet residential settings during operation
  • Single-stage cooling compressor cannot modulate capacity for variable-load efficiency
  • 5-ton capacity oversizes many homes and increases first costs unnecessarily
  • Requires 40-amp maximum electrical service, limiting some older home installations

Who Should Buy

Best For

Contractors and homeowners upgrading 15-25 year old systems who want proven reliability with strong efficiency gains. This system makes sense for homes where 5-ton cooling capacity matches actual load calculations and dual-fuel flexibility is valuable.

Consider Alternatives If

Budget-conscious buyers seeking entry-level equipment should explore lower-tonnage options. Those in harsh climates may prefer two-stage cooling compressors for better part-load efficiency.

3.5 Ton 15 SEER 96% AFUE 100,000 BTU Goodman Gas F
$0
Buy at HVACDirect →

Installation

This downflow A-coil unit requires PVC or plastic exhaust venting, standard for modern installations. Electrical service demands a 23.5 to 40-amp circuit at 115V single-phase, manageable for most homes. The 3/8 inch liquid line and 1 1/8 inch suction line with 1/2 inch insulation thickness follow industry standard configurations. Pre-charged refrigerant lines simplify field connections for experienced technicians.

Warranty & Reliability

Online Supply backs this unit with a 10-year comprehensive parts warranty upon online registration. This coverage protects compressor, heat exchanger, and sealed components, typical for Goodman equipment. Registration is essential, as failures without proof of registration may face partial coverage limitations. Extended warranties are available through some distributors for additional cost.

Specifications

SKULS381183850
Brand/ManufacturerOnline Supply
Cooling BTU42,000
Heating BTU100,000
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
Height34.5"
Width21"
Depth28.75"
ResourcesGoodman Brochure Goodman Installation Instructions Goodman Parts Manual Goodman Service Manual Goodman Specifications Goodman Technical Information Goodman User Information Goodman 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.
ConfigurationDownflow/Horizontal
Liquid Line3/8"
Suction Line1 1/8"
StyleA-Coil
AHRI Certificate Number7368844
Airflow DirectionDownflow/Horizontal
Exhaust Flue RequirementPlastic / PVC
Product FeaturesRebate Available
Furnace Efficiency / AFUE96%
Blower MotorVariable Speed - ECM
Maximum CFM2000
Burner StagesTwo
Fuel TypePropane, Natural Gas
Suction Line Insulation Thickness1/2"
Length50 feet

Frequently Asked Questions

How does the 16 SEER1 rating compare to the advertised 15 SEER specification? +
The actual unit delivers SEER1 16, which is the newer DOE-standardized efficiency metric replacing legacy SEER. This represents approximately 6-7% better real-world efficiency than the original 15 SEER marketing claim. Real efficiency gains depend on regional cooling patterns and indoor thermostat settings.
Is this system right for a 3.5-ton requirement, given it's rated 5 tons? +
No. This unit oversizes most 3.5-ton load calculations, increasing equipment costs and cycling less efficiently. Contractors should always right-size systems based on Manual J calculations. Oversizing wastes capital and can reduce dehumidification performance in humid climates.
Can I use this with propane or only natural gas? +
This Goodman system accepts both natural gas and propane fuel sources. Your HVAC contractor must configure the burner assembly and pressure regulators for your specific fuel type during installation. Field conversion between fuels requires recalibration.
What is the 73 dB noise level in practical terms? +
73 dB equals normal conversation volume, noticeable but not disruptive for most homes. High-efficiency units generate more sound than older models. Two-stage burner operation minimizes compressor runtime, reducing average noise exposure compared to single-stage competitors.
Does online registration really matter for the 10-year warranty? +
Yes. Goodman requires online registration within 30-60 days of installation to activate the full 10-year coverage. Without registration, warranty defaults to 5 years. Keep your AHRI certificate number 7368844 and proof of installation handy.

Affiliate disclosure: IndustrialRank earns a commission on qualifying purchases at no extra cost to you. We only recommend products we have independently reviewed.