3.5 Ton 15 SEER 96% AFUE 120,000 BTU Goodman Gas Furnace and Air Conditioner System - Upflow Review 2026

// Bottom Line

This Goodman system excels for homeowners prioritizing heating efficiency and flexibility with its 96% AFUE rating and dual-fuel capability. It's particularly strong for cold climates where natural gas or propane furnaces deliver consistent, cost-effective warmth alongside reliable summer cooling.

Review

Goodman's 3.5 Ton gas furnace and air conditioner system represents solid mid-market equipment for contractors seeking reliable performance without premium pricing. The upflow A-coil configuration fits typical residential installations, and the dual-fuel design, accepting natural gas or propane, provides genuine installation flexibility. Online Supply positions this system as an accessible option for homeowners upgrading from aging equipment, particularly those concerned with heating season efficiency.

The furnace delivers impressive 96% AFUE efficiency with two-stage burners, meaning nearly every energy dollar converts to heat rather than exhaust loss. Cooling performance reaches 16 SEER1 with a 42,000 BTU capacity via a scroll compressor, supported by Energy Star certification. The variable-speed ECM blower motor optimizes airflow across both heating and cooling cycles, while 73 dBA noise output remains acceptable for typical residential outdoor placement, though not whisper-quiet.

Pros & Cons

Pros

96% AFUE furnace efficiency means minimal heating energy waste, translating to lower winter bills
16 SEER1 cooling rating significantly exceeds the 15 SEER standard, with Energy Star certification
Dual fuel compatibility, natural gas and propane, offers installation flexibility for various home setups
Variable-speed ECM blower motor delivers quieter operation and better humidity control than fixed-speed alternatives
Lifetime heat exchanger warranty provides long-term peace of mind on the most critical component

Cons

Single-stage cooling compressor cannot modulate capacity, reducing efficiency during partial-load conditions versus two-stage systems
73 dBA noise level is moderately loud for outdoor operation, noticeable in close residential settings
A-coil configuration requires upflow orientation, limiting placement options for some home layouts

Who Should Buy

Best For

Contractors and homeowners in moderate-to-cold climates seeking dependable year-round performance with strong heating efficiency will appreciate this system. It's ideal for homes where dual-fuel capability matters and budget allows for quality but not premium-tier equipment.

Consider Alternatives If

Buyers in hot climates prioritizing maximum cooling efficiency should explore two-stage or variable-capacity systems, as the single-stage compressor limits part-load cooling performance.

3.5 Ton 15 SEER 96% AFUE 120,000 BTU Goodman Gas F

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Installation

Installation requires standard refrigerant lines, 3/8 inch liquid and 1 1/8 inch suction with 1/2 inch insulation up to 50 feet. Electrical demands run 115V single-phase 60Hz with 23.5 to 40 amp breaker sizing. Upflow configuration mandates proper ductwork clearance above and below the unit, standing 34.5 inches tall. PVC exhaust flue compatibility simplifies venting compared to older systems.

Warranty & Reliability

Goodman backs the heat exchanger with lifetime coverage, a meaningful assurance given furnace longevity. Additional parts carry 10-year protection upon online registration. This tiered approach balances component protection with reasonable manufacturer risk, though registration requirements can trip up inattentive buyers.

Specifications

SKU	LS381183850
Brand/Manufacturer	Online Supply
Cooling BTU	42,000
Heating BTU	120,000
Refrigerant	R410A
Electrical	115 V. 1 Phase 60 Hz
Warranty	Lifetime Heat Exchanger and 10 Years Parts with Online Registration
Decibel Level (dBA)	73
Weight (in lbs)	48.000000
Feature	Spec
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
Tonnage	5 Ton
Height	34.5"
Width	24.5"
Depth	28.75"
Resources	Goodman Brochure Goodman Install 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 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.
Configuration	Upflow/Horizontal
Liquid Line	3/8"
Suction Line	1 1/8"
Style	A-Coil
AHRI Certificate Number	7368842
Airflow Direction	Upflow/Horizontal
Exhaust Flue Requirement	Plastic / PVC
Product Features	Rebate Available
Furnace Efficiency / AFUE	96%
Blower Motor	Variable Speed - ECM
Maximum CFM	2000
Burner Stages	Two
Fuel Type	Propane, Natural Gas
Suction Line Insulation Thickness	1/2"
Length	50 feet

Frequently Asked Questions

How does 16 SEER1 cooling efficiency impact summer operating costs? +

SEER1 ratings measure seasonal cooling efficiency; 16 SEER1 performs approximately 6 percent better than the 15 SEER minimum standard. For a typical homeowner running cooling 500 hours annually, this translates to noticeable but modest electric savings, roughly 3 to 5 percent of cooling costs depending on local electricity rates.

Does this system work with existing ductwork? +

Yes, provided your ductwork accommodates 2000 CFM maximum airflow and follows the upflow configuration. However, older systems may have undersized ducts. A contractor should verify duct sizing to avoid reduced efficiency and comfort. AHRI certificate 7368842 documents matched performance.

Why choose single-stage cooling over two-stage? +

Single-stage compressors run at full capacity or off, reducing efficiency during mild-weather days when partial output suffices. Two-stage systems modulate better but cost more. This Goodman suits moderate climates with moderate cooling loads where the efficiency penalty remains acceptable.

Can I use this system in very cold climates? +

Yes, the 96% AFUE furnace performs exceptionally well in cold regions. However, verify with a contractor that outdoor air intake and exhaust routing handle your area's winter conditions. Propane option provides flexibility where natural gas lines are unavailable.

What does lifetime heat exchanger warranty actually cover? +

Lifetime coverage protects against manufacturing defects and premature failure of the heat exchanger, the furnace's core component. It does not cover normal wear, maintenance neglect, or improper installation, so professional setup and annual service remain essential.

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