3 Ton 18 SEER 80% AFUE 80,000 BTU Goodman Gas Furnace and Air Conditioner System - Horizontal Review 2026

// Bottom Line

This Goodman system works best for homeowners upgrading from older single-stage equipment who want meaningful efficiency gains without premium pricing. The 18 SEER cooling and 80% AFUE heating deliver solid annual savings, especially in mixed climates where both heating and cooling see regular use.

Review

This Goodman gas furnace and air conditioner combination targets the mid-market residential replacement segment where contractors and homeowners balance efficiency improvements against installation budgets. At $2,142, the system delivers Energy Star certification and positions itself as a step up from aging 13 SEER equipment without the premium pricing of top-tier manufacturers. The horizontal configuration addresses a real installation challenge for homes with space constraints.

Performance specs show an 18 SEER cooling rating paired with 80% AFUE heating and 80,000 BTU capacity. The two-stage scroll compressor and variable-speed blower operate at 71 dBA, roughly equivalent to background conversation noise. Dual-stage operation means the system runs at partial capacity during mild weather, reducing cycling and energy consumption. The 35,000 BTU cooling output with R410A refrigerant handles moderate cooling loads efficiently, though matching with properly sized indoor coils remains critical.

Pros & Cons

Pros

18 SEER rating qualifies for Energy Star certification and delivers approximately 30% better cooling efficiency than 13 SEER baseline units
Two-stage compressor and burner design reduces runtime and noise to 71 dBA, lowering utility costs during partial-load conditions
Variable-speed blower motor with 2000 CFM maximum airflow improves dehumidification and comfort consistency
80,000 BTU heating output with 80% AFUE handles most residential heating demands without oversizing
Scroll compressor technology is proven reliable with fewer moving parts than reciprocating designs
Horizontal configuration fits tight attic or closet installations where standard upflow units won't fit

Cons

80% AFUE is outdated by current standards, missing out on 90%+ efficiency available in modern furnaces
5-ton condenser paired with description claiming 3-ton system creates specification confusion that needs clarification before purchase
35,000 BTU cooling capacity seems undersized relative to 5-ton rating, suggesting potential matching issues with indoor coil

Who Should Buy

Best For

Homeowners in mixed climates with attic or horizontal ductwork constraints who prioritize upfront cost savings over long-term efficiency. Contractors installing replacement systems for budget-conscious customers seeking Energy Star compliance without high-end pricing.

Consider Alternatives If

Buyers in heating-dominant climates should investigate 90%+ AFUE furnaces, and those seeking maximum efficiency should compare 20+ SEER condenser units.

3 Ton 18 SEER 80% AFUE 80,000 BTU Goodman Gas Furn

$2142

Buy at HVACDirect →

Installation

Installation requires 120V single-phase 60Hz power with breaker sizing between 21.3 and 35 amps. Refrigerant line sets are sized at 3/8 inch liquid and 7/8 inch suction with 3/4 inch insulation thickness rated for 50 feet maximum. Metal flue exhaust piping is mandatory. Sweat-type valve connections demand soldering skills or professional technician installation. Horizontal positioning simplifies attic placement.

Warranty & Reliability

Goodman provides 10-year parts coverage with online registration, standard for this brand tier. This protects against compressor failure and major component defects but excludes labor costs and refrigerant. Registration is mandatory to activate coverage. Compare this against manufacturer warranties from premium brands, which sometimes extend to 12 years or offer enhanced labor coverage.

Specifications

SKU	LS38783850
Brand/Manufacturer	Online Supply
Cooling BTU	35,000
Heating BTU	80,000
Refrigerant	R410A or R22
Electrical	120 V. 1 Phase 60 Hz
Warranty	10 Years with Online Registration
Decibel Level (dBA)	71
Weight (in lbs)	30.000000
Feature	Spec
Product Features	Two Stage Condenser
Energy Star	Yes
SEER1 (Efficiency)	18
Condenser Stages	Two Stage
Compressor Type	Scroll
Liquid Valve Size	3/8"
Suction Valve Size	3/4"
Max Breaker Size	35 amps
Min. Breaker Size	21.3 amps
Tonnage	5 Ton
Valve Type	Sweat
Height	24.5"
Width	26"
Depth	21.125"
Resources	CHPF Installation Manual CHPF 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.
AHRI Certificate Number	204633302
Airflow Direction	Upflow/Horizontal
Exhaust Flue Requirement	Metal
Furnace Efficiency / AFUE	80%
Blower Motor	Variable Speed
Maximum CFM	2000
Configuration	Horizontal
Burner Stages	Two
Fuel Type	Propane, Natural Gas
Liquid Line	3/8"
Suction Line	7/8"
Style	A-Coil
Suction Line Insulation Thickness	3/4"
Length	50 feet

Frequently Asked Questions

How much will this system save on cooling costs compared to my old 13 SEER unit? +

The 18 SEER rating delivers roughly 38% better efficiency than 13 SEER equipment. In a typical 2,000 square foot home running cooling 1,200 hours annually, expect $200 to $400 annual savings depending on local electricity rates and thermostat setpoints. Savings compound over 15 to 20 year system life.

Can this unit work in an attic with limited vertical space? +

Yes, the horizontal configuration is specifically designed for this application. Dimensions are 24.5 inches tall, 26 inches wide, and 21.125 inches deep, fitting tight horizontal plenums and attic cavities where vertical furnaces fail. Verify clearance before purchase for service access.

Is 80% AFUE adequate for my heating needs? +

80% AFUE is functional but dated. Modern furnaces reach 90 to 98% AFUE, cutting heating costs significantly in cold climates. If heating represents 60%+ of annual energy use, investigating higher AFUE options may deliver faster payback despite higher upfront cost.

What's the difference between this and a 16 SEER system at lower price? +

The 18 SEER rating means 12.5% greater cooling efficiency than 16 SEER units, translating to lower summer electric bills. The two-stage compressor also reduces noise and improves part-load performance. This adds $150 to $300 to system cost but recovers via 3 to 5 years of utility savings.

Does online registration really matter for the warranty? +

Yes, registration is required to activate the 10-year coverage. Without it, warranty defaults to one year. Registration is free and typically completed online within minutes after installation.

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