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 Goodman combo delivers 96% heating and 16 SEER cooling in one unit

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
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// Bottom Line
This Goodman system works best for homeowners replacing aging furnace-AC combos who want reliable efficiency without premium pricing. The 96% AFUE furnace and 16 SEER condenser hit sweet spots for both heating and cooling performance in moderate climates.

Review

Goodman's 3.5/5 ton combined furnace-air conditioner system lands squarely in the practical middle market for residential HVAC. This isn't a premium variable-capacity unit, but it delivers solid efficiency ratings backed by manufacturer stability. The unit ships as a downflow A-coil configuration, making it suitable for attic or basement installations where space is tight. Energy Star certification and a reasonable price point make it appealing for contractors managing multiple replacement jobs.

The heating side produces 100,000 BTU output at 96% AFUE efficiency, meaning minimal fuel waste and measurable savings on gas bills. The cooling side rates at 16 SEER1 with 42,000 BTU capacity from a scroll compressor. The two-stage burner and variable-speed ECM blower motor allow the system to ramp down during mild conditions, improving comfort and efficiency compared to fixed-output competitors. At 73 dB, noise levels are moderate and typical for this class, though sensitive listeners may notice operation.

Pros & Cons

Pros

  • 96% AFUE furnace efficiency means lower winter heating bills, especially in gas-dependent regions
  • 16 SEER1 cooling rating is well above the 13 SEER minimum for Energy Star qualification
  • Two-stage burner and variable-speed ECM blower allow modulated operation for comfort and efficiency
  • PVC exhaust compatibility simplifies venting in retrofit applications and older homes
  • Scroll compressor design is industry-standard reliable with lower failure rates than rotary types
  • 10-year warranty with online registration provides solid peace of mind on major components

Cons

  • Single-stage condenser limits cooling modulation compared to two-stage models, reducing part-load efficiency
  • 73 dB operating noise is moderately loud, noticeable in quiet neighborhoods or during evening operation
  • Title lists 3.5 ton with 5 ton specs, creating confusion about actual system capacity and matched tonnage

Who Should Buy

Best For

Contractors installing complete system replacements in residential homes with existing downflow ductwork will find this unit straightforward to configure. Homeowners in moderate climates seeking honest efficiency gains over 10-year-old units without spending on premium inverter technology will get reliable value.

Consider Alternatives If

Buyers in very hot climates needing aggressive cooling or homes where noise matters should explore two-stage condenser options instead.

3.5 Ton 15 SEER 96% AFUE 100,000 BTU Goodman Gas F
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Installation

Installation requires 115V single-phase power with breaker capacity between 23.5 and 40 amps, standard for most residential panels. Suction line comes pre-insulated with 1/2 inch foam and 50 feet of line set. Valve sizes (3/8 inch liquid, 7/8 inch suction) match common field copper fittings. PVC exhaust venting simplifies installation in homes without existing metal flue infrastructure. Total unit weight of 48 pounds requires minimal rigging.

Warranty & Reliability

Goodman provides 10 years of parts and labor coverage when registered online at activation. This covers compressor failure, heat exchanger cracks, and electrical component defects. Registration is straightforward and provides protection equal to units costing significantly more. Coverage does not include refrigerant, which is typical across the industry.

Specifications

SKULS381183850
Brand/ManufacturerOnline Supply
Cooling BTU42,000
Heating BTU100,000
RefrigerantR410A or R22
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

Does this unit come charged with refrigerant, or does it need field charging? +
The condenser arrives pre-charged with R410A or R22 refrigerant depending on your region. However, matching the refrigerant type to your furnace coil is critical during installation. Field technicians must verify compatibility and may add refrigerant if line set length exceeds factory allowances.
Can this downflow unit work in a basement or crawlspace installation? +
Yes. Downflow configuration means air exits from the bottom of the unit into ductwork below. Ensure adequate return air access and clearance around intake vents. Basement humidity control and condensate drainage become important in damp environments to prevent indoor coil icing.
How does 16 SEER1 compare to newer SEER2 ratings I see advertised? +
SEER1 and SEER2 use different testing protocols, making direct comparison difficult. SEER2 typically yields 15-20% lower numbers. This unit's 16 SEER1 roughly equals approximately 13 SEER2, still respectable but not premium-tier efficiency for new equipment.
Is the variable-speed blower motor really worth the upgrade over fixed-speed models? +
Yes. Variable-speed ECM motors ramp down during partial cooling or heating, cutting electricity draw during mild weather. Over 15 years, this translates to meaningful utility savings. It also improves humidity management and comfort consistency compared to on-off cycling.
What happens if I register the warranty late, and is online registration reliable? +
Registration must occur within a specified window after installation, typically 30-90 days. Goodman's online registration system is stable, but keep your receipt and AHRI certificate (7368844) as backup proof of purchase date and model authenticity.

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