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

// Bottom Line

This Goodman packaged system works best for contractors and homeowners replacing older 2-ton or 3-ton units in modest homes where upflow installation fits the existing layout. The dual-fuel capability, variable-speed blower, and Energy Star certification make it a practical mid-range choice for moderate climates where 80% AFUE meets code requirements.

Review

The Goodman 3.5-ton packaged system combines furnace and air conditioner into one weathertight cabinet, simplifying installation for retrofit projects and new builds. Rated at 100,000 BTU heating and 42,000 BTU cooling capacity, this upflow A-coil configuration fits standard attic or basement installations. Goodman positions this mid-tier system as a replacement for aging 10 to 15-year-old units, targeting contractors who value straightforward service and homeowners seeking reliable comfort without cutting-edge efficiency.

Cooling performance delivers 16 SEER efficiency, exceeding the advertised 15 SEER specification, while the furnace achieves 80% AFUE with two-stage burner control. The variable-speed blower motor ramps between partial and full load, reaching 2,000 CFM maximum while keeping noise at 73 decibels. Energy Star certification confirms reduced operating costs compared to non-certified competitors. Scroll compressor technology and R410A refrigerant are industry-standard choices balancing reliability with environmental compliance.

Pros & Cons

Pros

16 SEER cooling efficiency exceeds the 15 SEER rating, delivering better summer performance than advertised
Two-stage burner with 100,000 BTU heating output handles cold snaps without oversizing for mild winters
Variable-speed blower motor adjusts to 2,000 CFM maximum, reducing noise (73 dB) and improving comfort during partial-load operation
Energy Star certified with dual-fuel capability for natural gas or propane, increasing installation flexibility
10-year warranty with online registration provides solid peace-of-mind coverage at this price point

Cons

80% AFUE is adequate but not class-leading, trailing high-efficiency units rated 95%+ AFUE by 15 percentage points
Single-stage condenser cannot modulate cooling capacity, cycling on and off rather than ramping efficiency in mild weather
Requires 208/230V single-phase power and 23.5 to 40-amp breaker, limiting options in older homes with undersized electrical service

Who Should Buy

Best For

Contractors stocking reliable packaged units for residential retrofit jobs and homeowners in moderate climates looking for a dependable workhorse system without premium pricing. This unit suits properties with existing upflow ductwork and adequate electrical infrastructure.

Consider Alternatives If

Buyers in very cold climates needing maximum heating efficiency or homeowners in hot, humid regions where single-stage cooling and 73 dB noise levels become problematic during peak demand.

3.5 Ton 15 SEER 80% AFUE 100,000 BTU Goodman Gas F

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Installation

Upflow orientation fits attic or basement placement with horizontal duct takeoff options. The unit weighs 48 pounds and measures 36.25 inches tall by 35.5 inches wide and deep, fitting most framed openings without structural modifications. Metal exhaust flue requirement demands proper venting to code, and the 208/230V single-phase power connection requires a dedicated 40-amp breaker circuit. Liquid and suction line sizes (3/8-inch and 7/8-inch respectively) match standard residential refrigerant piping.

Warranty & Reliability

Goodman backs this system with a 10-year parts warranty activated through online registration, covering compressor, coil, and furnace components. This warranty is competitive for mid-range systems but trails premium brands offering 10 to 12-year extended coverage. Registration is mandatory to activate coverage, so buyers must complete paperwork promptly after installation.

Specifications

SKU	LS381183850
Brand/Manufacturer	Online Supply
Cooling BTU	42,000
Heating BTU	100,000
Refrigerant	R410A
Electrical	208 / 230 V. 1 Phase 60 Hz
Warranty	10 Years with Online Registration
Decibel Level (dBA)	73
Weight (in lbs)	48.000000
Feature	Spec
Configuration	Upflow/Horizontal
Liquid Line	3/8"
Suction Line	1 1/8"
Tonnage	3.5 Ton
Style	A-Coil
Height	36.25"
Width	35.5"
Depth	35.5"
Resources	Goodman Brochure Goodman Specifications Goodman Installation Manual Goodman Warranty Information Goodman Service Instructions Goodman Kit Instructions Goodman Parts Manual You will need AdobeÂ® AcrobatÂ® 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
Burner Stages	Two
Fuel Type	Propane, Natural Gas
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	23.5 amps
Suction Line Insulation Thickness	1/2"
Length	50 feet

Frequently Asked Questions

Does this system actually deliver 15 SEER, or will real-world performance be lower? +

Spec data shows 16 SEER efficiency, which exceeds the advertised 15 SEER rating. Real-world cooling output typically runs 1 to 2 SEER points lower than rated due to ductwork losses and installation variables, placing actual performance near 14 to 15 SEER in typical homes.

Can I install this in a crawl space instead of upflow orientation? +

This unit is configured for upflow operation only, meaning horizontal ducts exit the top or side. Downflow or horizontal-only installations would require a different Goodman model. Verify your space orientation before ordering to avoid costly returns.

How does 80% AFUE compare to high-efficiency furnaces I've heard about? +

80% AFUE means 80 cents of every heating dollar converts to home warmth, with 20% lost through exhaust. Modulating 95%+ AFUE units extract additional heat from flue gases. For homeowners in moderate climates, 80% AFUE meets current code and saves 15 to 20 percent on heating versus 70% units.

Should I choose this dual-fuel system or a single-fuel gas-only unit? +

Dual-fuel capability adds minimal cost and provides flexibility if natural gas becomes unavailable or expensive in your region. Propane operation works identically to natural gas without modifications. For most buyers, dual-fuel is worth the small premium for installation options and future adaptability.

What happens if I don't register the warranty online? +

The 10-year warranty requires online registration to activate coverage. Without registration, you lose warranty protection entirely. Contractors and homeowners should complete registration within 30 days of installation to protect the investment.

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