Independent Review · Updated June 2026

3 Ton 17 SEER 96% AFUE 100,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow

High-efficiency two-stage system with 96% AFUE heating and strong cooling performance.

8.2
IndustrialRank Score
Efficiency
8.5
Reliability
7.8
Value
8.0
Installation
8.5
Warranty
8.0
3 Ton 17 SEER 96% AFUE 100,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow
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// Bottom Line
This Goodman system excels for homeowners upgrading older furnaces who prioritize heating efficiency and want Energy Star certification. The 96% AFUE and two-stage burner design make it ideal for cold climates, though the tonnage mismatch between furnace and condenser requires careful system balancing.

Review

Goodman's 3-ton downflow system targets the replacement furnace market with solid two-stage technology across heating and cooling. This packaged unit delivers 100,000 BTU heating capacity with 35,000 BTU cooling output, positioning itself as a heating-focused solution for contractors and homeowners upgrading from older single-stage equipment. The Energy Star certification adds market appeal, though real-world performance depends heavily on proper installation and system balancing.

The 96% AFUE rating exceeds current minimum efficiency standards and translates to measurable heating cost savings, while the 18 SEER cooling efficiency provides decent air conditioning performance. Two-stage operation on both furnace and condenser allows modulated output rather than on-off cycling, improving comfort and reducing energy waste. The variable-speed ECM blower motor adjusts airflow from 0 to 2000 CFM based on demand, a key feature for maintaining efficiency across diverse operating conditions.

Pros & Cons

Pros

  • 96% AFUE furnace efficiency with two-stage burner for modulated heating output
  • 18 SEER cooling with two-stage scroll compressor and R410A refrigerant
  • Variable-speed ECM blower motor optimizes airflow across all operating conditions
  • PVC exhaust flue compatibility simplifies venting in modern construction
  • 10-year warranty with online registration provides solid long-term protection

Cons

  • Tonnage mismatch: 100,000 BTU furnace is rated for 5 tons but condenser delivers only 3 tons cooling capacity
  • 71 dB noise level is moderately loud for a two-stage system, noticeable during operation
  • SKU LS38783850 appears to be a package deal that may create compatibility questions

Who Should Buy

Best For

Homeowners in cold climates replacing 15+ year old furnaces will appreciate the 96% AFUE heating efficiency and modest cooling capability. This system works well for houses with existing ductwork suitable for downflow installation and standard 208/230V single-phase power.

Consider Alternatives If

Skip this if you need balanced heating and cooling capacities, live in hot climates requiring maximum cooling, or prefer single-stage simplicity over two-stage complexity.

3 Ton 17 SEER 96% AFUE 100,000 BTU Goodman Gas Fur
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Installation

This downflow configuration requires adequate clearance above the unit, minimum 30 inches height with 24.5 inches width and 21 inches depth. PVC exhaust flue simplifies venting compared to older metal flue systems. Two-stage systems need proper refrigerant charge accuracy and accurate furnace calibration to function correctly. A qualified HVAC tech should verify ductwork sizing matches the 2000 CFM maximum output.

Warranty & Reliability

Ten-year coverage on parts requires online registration and protects against manufacturing defects. The evaporator coil carries separate extended coverage under Goodman's coil warranty. This covers genuine defects but excludes damage from improper installation, refrigerant contamination, or lack of maintenance. Registration is straightforward and highly recommended.

Specifications

SKULS38783850
Brand/ManufacturerOnline Supply
Cooling BTU35,000
Heating BTU100,000
RefrigerantR410A
Electrical208 / 230 V. 1 Phase 60 Hz
Warranty10 Years with Online Registration
Decibel Level (dBA)71
Weight (in lbs)30.000000
FeatureSpec
AHRI Certificate Number7368844
Airflow DirectionDownflow/Horizontal
Exhaust Flue RequirementPlastic / PVC
Product FeaturesTwo Stage Condenser
Furnace Efficiency / AFUE96%
Blower MotorVariable Speed - ECM
Maximum CFM2000
ConfigurationUpflow / Downflow
Energy StarYes
Burner StagesTwo
Fuel TypePropane, Natural Gas
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.
SEER1 (Efficiency)18
Condenser StagesTwo Stage
Compressor TypeScroll
Liquid Valve Size3/8"
Suction Valve Size3/4"
Max Breaker Size35 amps
Min. Breaker Size21.3 amps
Tonnage5 Ton
Valve TypeSweat
Liquid Line3/8"
Suction Line7/8"
StyleA-Coil
Suction Line Insulation Thickness3/4"
Length50 feet

Frequently Asked Questions

Why does a 100,000 BTU furnace pair with only 35,000 BTU cooling capacity? +
This reflects regional climate assumptions, where heating demand exceeds cooling demand. The 3-ton condenser suits mixed climates. However, you'll lose efficiency benefits if your home needs balanced heating and cooling. Confirm this sizing matches your local climate with your installer before purchase.
Can I install this in an upflow orientation instead of downflow? +
Yes, the specs show configuration supports both upflow and downflow, though this unit ships configured for downflow. An HVAC professional must verify your ductwork and return air plenum support the alternative orientation. Improper conversion reduces efficiency and may void warranty coverage.
How much will this system reduce my heating bills compared to an 80% AFUE furnace? +
Upgrading from 80% to 96% AFUE provides roughly 20% heating energy reduction. On a 4,000 heating degree day climate with $1,200 annual heating costs, expect savings around $240 yearly. Results vary based on thermostat use, insulation, and weather patterns.
Is 18 SEER cooling competitive with newer systems on the market? +
18 SEER falls into the efficient category but newer 20+ SEER options exist. This represents solid performance without premium pricing. For mild to moderate cooling climates, 18 SEER performs adequately. Hot climate buyers should compare higher-SEER alternatives.
Do I need a specific electrical upgrade for 208/230V operation? +
Check your home's main panel voltage before ordering. The system requires 208 or 230V single-phase 60 Hz power with 21.3 to 35 amp breaker capacity. Most homes have 230V available, but older properties may need electrician evaluation.

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