Independent Review · Updated June 2026

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

High-efficiency 4-ton combo system with 96% heating and 16 SEER cooling.

8.2
IndustrialRank Score
Efficiency
8.5
Reliability
7.8
Value
8.0
Installation
8.5
Warranty
8.0
4 Ton 15 SEER 96% AFUE 100,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow
Current Price
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// Bottom Line
This Goodman system is ideal for contractors and homeowners upgrading older units in moderate climates where balanced heating and cooling performance matters. The 96% AFUE furnace paired with 16 SEER cooling delivers solid year-round efficiency without premium pricing.

Review

Goodman's 4-ton downflow system represents a practical middle ground in the residential HVAC market. This unit combines a 96% AFUE furnace with 16 SEER2 air conditioning in a single matched platform, eliminating mismatched component concerns. The downflow A-coil design works well for homes with furnaces in attics or upper-level closets, where space is tight and ductwork runs downward. It's a workhorse configuration favored by contractors because replacement is straightforward and performance is predictable.

Performance numbers show solid engineering. The furnace delivers a consistent 100,000 BTU across two burner stages, while cooling reaches 45,500 BTU at 16 SEER2 with R410A refrigerant. The variable-speed ECM blower modulates from zero to 2,000 CFM, meaning it uses less electricity during mild weather and ramps up when needed. At 73 dBA during operation, it's audible but not disruptive. Electrical requirements are modest, needing 23.9 to 40 amps, making installation feasible in most existing homes without panel upgrades.

Pros & Cons

Pros

  • 96% AFUE furnace efficiency saves on heating costs, especially in colder months with consistent 100,000 BTU output
  • 16 SEER2 cooling rating achieves Energy Star certification and reduces AC runtime by 15-25% compared to standard units
  • Variable-speed ECM blower motor adjusts airflow from 0 to 2000 CFM for comfort and efficiency across seasons
  • Two-stage burner and single-stage compressor provide smooth operation with minimal wear and predictable performance
  • Downflow/A-coil configuration suits attic or closet installations common in retrofit applications

Cons

  • Specs list conflicting tonnage (4 ton in title, 5 ton in specs), creating potential sizing confusion for installers
  • 73 dBA noise level runs slightly higher than quieter high-end units, noticeable during heating cycles
  • Single-stage cooling means the compressor runs at full capacity until temperature is reached, less efficient than variable-stage alternatives

Who Should Buy

Best For

Contractors and homeowners replacing 10-20 year old systems in homes needing 4-ton cooling and 100,000 BTU heating capacity. Buyers in moderate climates who prioritize fuel savings and want a proven Goodman platform without paying for ultra-premium features.

Consider Alternatives If

Anyone in extreme climates, homes requiring true variable-capacity cooling, or buyers needing sub-70dBA operation should consider higher-tier alternatives.

4 Ton 15 SEER 96% AFUE 100,000 BTU Goodman Gas Fur
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Installation

Installation requires standard furnace and condensing unit connections with 3/8 inch liquid line and 1 1/8 inch suction line, both insulated to 1/2 inch thickness. The 50-foot suction line allows flexible placement. Downflow airflow demands ductwork below the unit. PVC plastic exhaust flue is acceptable. The 48-pound weight is manageable for two-person installation. Proper refrigerant charging and gas line sealing are critical for performance.

Warranty & Reliability

Goodman provides a 10-year parts warranty when you register online within 60 days of installation. This covers compressor, heat exchanger, and coil failures. Labor is not included. Registration is straightforward through Goodman's website. The 10-year term is standard for this price tier and offers reasonable peace of mind for homeowners expecting 15-20 year system life.

Specifications

SKULS381183850
Brand/ManufacturerOnline Supply
Cooling BTU45,500
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
ReplacesGSX16S481
Energy StarYes
SEER1 (Efficiency)16
Condenser StagesSingle Stage
Compressor TypeScroll
Liquid Valve Size3/8"
Suction Valve Size7/8"
Max Breaker Size40 amps
Min. Breaker Size23.9 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

Is this a true 4-ton or 5-ton system? +
The title specifies 4 tons, matching typical home sizes. Specs list 5 tons for the condenser, which is unusual. Contact the supplier for clarification before ordering, as tonnage affects furnace pairing and performance. Cooling capacity is 45,500 BTU, which approximates 3.8 tons of cooling.
Can I install this myself if I have basic HVAC knowledge? +
Not recommended. You need EPA certification to handle R410A refrigerant, EPA Section 608 license for system evacuation and charging, and natural gas or propane licensing depending on fuel type. Hire a licensed contractor to ensure proper installation, safety, and warranty validity.
How does 16 SEER2 cooling compare to older systems? +
A unit from 2005 was likely 10 SEER. This 16 SEER2 system uses roughly 38% less electricity for cooling. Annual savings vary by climate and usage, typically 200-400 dollars in moderate zones. Energy Star certification confirms it exceeds federal minimum standards.
Does the variable-speed blower make a real efficiency difference? +
Yes. The ECM motor uses 75% less electricity than fixed-speed blowers during partial-load operation. In spring and fall, when heating and cooling demand is light, this reduces parasitic fan losses significantly. Over a year, this adds up to meaningful savings.
What happens if I don't register for the warranty? +
Warranty coverage is void without registration. Goodman requires registration within 60 days of installation. The process takes five minutes online. Keep your receipt and AHRI certificate number handy.

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