4 Ton 15 SEER 80% AFUE 100,000 BTU Goodman Gas Furnace and Air Conditioner System - Upflow Review 2026

// Bottom Line

This Goodman system works well for homeowners replacing older units who want moderate efficiency gains without premium pricing. The 80% AFUE furnace and 16 SEER2 condenser represent a practical middle ground for mid-range budgets, though it won't match higher-tier systems on comfort or long-term energy savings.

Review

Goodman's 4-ton combination system delivers straightforward heating and cooling without cutting-edge technology or premium pricing. The unit pairs an 80% AFUE furnace handling 100,000 BTU with a 16 SEER2 air conditioner rated at 45,500 cooling BTU. This is a replacement for the popular GSX16S481 model, indicating Goodman's incremental equipment updates rather than revolutionary changes. The system targets contractors and homeowners seeking mid-market performance for residential applications.

Performance metrics show competent but not aggressive efficiency. The furnace operates at 80% AFUE, meaning 20% of heating energy exits the flue, which is acceptable for non-condensing designs but trails modern 95%+ AFUE condensing furnaces. Cooling efficiency at 16 SEER2 meets current federal minimums with Energy Star certification. The two-stage burner and variable-speed blower motor improve comfort by reducing on-off cycling. At 73 dB output, noise levels remain reasonable for basement or utility closet installation.

Pros & Cons

Pros

16 SEER2 condenser delivers modern cooling efficiency at competitive price point
Two-stage burner and variable-speed blower provide better comfort than single-stage alternatives
100,000 BTU heating capacity handles most residential applications, including larger homes
Compact 21 by 21 inch footprint fits standard basement or closet installations
Energy Star certified cooling helps offset operating costs over system lifetime

Cons

80% AFUE furnace lags behind 95%+ AFUE condensing models, meaning higher heating bills in cold climates
Single-stage condenser cycling limits humidity control compared to variable or two-stage units
Metal exhaust flue requirement adds installation complexity for some applications

Who Should Buy

Best For

This system suits homeowners in moderate climates replacing 15-20 year old equipment who prioritize upfront savings over maximum efficiency. It's also appropriate for rental properties or secondary residences where operating costs matter less than initial investment.

Consider Alternatives If

Skip this if you're in a cold climate where heating dominates utility bills, live in a humid region requiring advanced dehumidification, or want maximum efficiency for a 30-year payback calculation.

4 Ton 15 SEER 80% AFUE 100,000 BTU Goodman Gas Fur

Buy at HVACDirect →

Installation

Installation requires standard sheet metal ductwork connections and proper refrigerant line sizing. The 3/8 inch liquid line and 7/8 inch suction line connect to external condensing units, with 50 feet of insulated suction line available. Metal exhaust flue installation is mandatory, requiring proper venting to exterior. The 120V single-phase 60Hz electrical requirement with 23.9-40 amp breaker sizing fits standard home panels. Upflow configuration suits basement or closet mounting.

Warranty & Reliability

Goodman provides a 10-year parts warranty with online registration, covering manufacturing defects on compressor, condenser, and furnace components. Registration is straightforward and extends protection beyond the standard limited warranty. However, labor coverage is typically excluded, meaning installation costs for repairs fall on homeowners after the first year in many regional agreements.

Specifications

SKU	LS381183850
Brand/Manufacturer	Online Supply
Cooling BTU	45,500
Heating BTU	100,000
Refrigerant	R410A
Electrical	120 V. 1 Phase 60 Hz
Warranty	10 Years with Online Registration
Decibel Level (dBA)	73
Weight (in lbs)	48.000000
Feature	Spec
Replaces	GSX16S481
Energy Star	Yes
SEER1 (Efficiency)	16
Condenser Stages	Single Stage
Compressor Type	Scroll
Liquid Valve Size	3/8"
Suction Valve Size	7/8"
Max Breaker Size	40 amps
Min. Breaker Size	23.9 amps
Tonnage	5 Ton
Height	30"
Width	21"
Depth	21"
Resources	CAPT Installation Manual CAPT Specifications Sheet Goodman Evaporator Coil Warranty You will need Adobe® Acrobat® Reader to view PDF documents.
Safety Information	PROPOSITION 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.
Airflow Direction	Upflow/Horizontal
Exhaust Flue Requirement	Metal
Furnace Efficiency / AFUE	80%
Blower Motor	Variable Speed
Maximum CFM	2000
Configuration	Upflow / Downflow
Burner Stages	Two
Fuel Type	Propane, Natural Gas
Liquid Line	3/8"
Suction Line	1 1/8"
Style	A-Coil
Suction Line Insulation Thickness	1/2"
Length	50 feet

Frequently Asked Questions

How does the 16 SEER2 rating compare to older air conditioning systems? +

A system from 2010 typically rated 10-12 SEER, so this 16 SEER2 unit delivers roughly 30-40% better cooling efficiency. This translates to measurable electric bill reduction, especially in warm climates where cooling runs 6-8 months annually. The actual savings depend on local electricity rates and your cooling season duration.

Will the 80% AFUE furnace work in my climate? +

Yes, but with caveats. In mild climates (South, Southwest), heating costs remain manageable. In cold regions (Midwest, Northeast), the 20% flue loss becomes expensive over winters. Consider upgrading to a 95% AFUE condensing model if heating season lasts over four months in your area or natural gas prices exceed $1 per therm.

Can I pair this condenser with a different furnace brand? +

Technically possible, but not recommended without engineering review. HVAC systems require matched refrigerant charge, blower speed, and control board compatibility. Mismatched equipment voids warranties and often underperforms. Stick with Goodman furnaces for this condenser or consult a licensed technician about cross-brand applications.

Is this system quieter than my old unit? +

At 73 dB, this runs quieter than most 15+ year old systems but similar to competitors in this efficiency tier. Single-stage compressors cycle fully on and off, creating noise spikes. Variable or two-stage condensers would reduce cycling noise, but those cost more and aren't included here.

What happens after the 10-year warranty expires? +

You're responsible for repair or replacement costs. Compressor failures typically run $800-2000 parts plus labor. Goodman systems generally last 15-20 years with maintenance, but older units become uneconomical to repair once warranties expire.

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