3.5 Ton 13 SEER 80% AFUE 80,000 BTU Goodman Gas Furnace and Air Conditioner System - Horizontal Review 2026

// Bottom Line

This 3.5-ton Goodman system works best for homeowners in moderate climates who want dependable heating and cooling without premium pricing. The 13 SEER rating and 80% AFUE efficiency are solid for older homes or budget-conscious buyers upgrading from aging equipment.

Review

This Goodman 3.5-ton split system sits firmly in the mid-market segment, offering conventional cooling and heating without cutting-edge efficiency features. The horizontal configuration makes it practical for attic installations where vertical clearance is limited. Goodman has built reputation on no-frills reliability, and this unit reflects that philosophy. At 3.5 tons, it matches homes in the 1,400 to 1,800 square foot range operating in moderate climates.

The furnace delivers 80,000 BTU heating output at 80% AFUE, a baseline efficiency rating that recovers 80 cents of every energy dollar burned. Cooling capacity reaches 42,000 BTU at 13 SEER, which translates to reasonable summer performance without premium efficiency costs. The two-stage burner and variable-speed blower motor help prevent the rapid cycling common in single-stage units. Maximum airflow hits 2,000 CFM, sufficient for the system tonnage without excessive noise at 75 dBA.

Pros & Cons

Pros

80% AFUE furnace with 80,000 BTU output handles heating in most climates without oversizing
13 SEER cooling efficiency is respectable for a baseline unit, delivering 42,000 BTU capacity
Two-stage burner and high-efficiency multi-speed blower reduce short cycling and wear
Horizontal configuration works in tight attic or basement spaces with only 21 inches height
10-year warranty with online registration provides solid protection on major components

Cons

80% AFUE is below modern standards, 90+ AFUE units are increasingly common and more economical long-term
13 SEER lacks Energy Star certification, newer systems reach 15+ SEER more affordably
Single-stage condenser is less efficient than two-stage cooling in variable load conditions

Who Should Buy

Best For

Homeowners in zones 4-6 replacing 15+ year old systems who prioritize upfront affordability over premium efficiency. Contractors installing rentals or base-model packages where the budget cannot stretch to higher SEER or AFUE ratings.

Consider Alternatives If

Buyers in hot climates needing maximum cooling efficiency or cold regions requiring higher furnace output should explore higher SEER/AFUE alternatives.

3.5 Ton 13 SEER 80% AFUE 80,000 BTU Goodman Gas Fu

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Installation

This horizontal unit requires metal flue exhaust ducting and standard 208/230V single-phase electrical service between 23.9 and 40 amps. The A-coil evaporator uses sweat valve connections with 3/8 inch liquid and 7/8 inch suction lines. Dimensions of 21 by 21.125 by 26 inches fit most attic and crawlspace applications. Installers should budget the supplied 30-foot refrigerant line and 3/8 inch insulation thickness.

Warranty & Reliability

Goodman backs this system with a 10-year parts warranty upon online registration. Coverage extends to the compressor, heating exchanger, and evaporator coil. This warranty period is competitive at this price point, though some premium brands offer 12-year coverage. Registration is required, so buyers must complete paperwork to activate full protection.

Specifications

SKU	LS38783830
Brand/Manufacturer	Online Supply
Cooling BTU	42,000
Heating BTU	80,000
Refrigerant	R410A or R22
Electrical	208 / 230 V. 1 Phase 60 Hz
Warranty	10 Years with Online Registration
Decibel Level (dBA)	75
Weight (in lbs)	30.000000
Feature	Spec
Airflow Direction	Upflow/Horizontal
Exhaust Flue Requirement	Metal
Furnace Efficiency / AFUE	80%
Blower Motor	High Efficiency Multi-Speed
Maximum CFM	2000
Configuration	Horizontal
Burner Stages	Two
Fuel Type	Gas
Height	21"
Width	21.125"
Depth	26"
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.
Energy Star	No
SEER1 (Efficiency)	13
Condenser Stages	Single Stage
Compressor Type	Reciprocating
Liquid Line	3/8"
Suction Line	7/8"
Liquid Valve Size	3/8"
Max Breaker Size	40 amps
Min. Breaker Size	23.9 amps
Tonnage	3.5 Ton
Valve Type	Sweat
Style	A-Coil
Suction Line Insulation Thickness	3/8"
Length	30 feet

Frequently Asked Questions

Is 13 SEER adequate cooling efficiency for my home? +

Yes, 13 SEER works well for homes with moderate cooling loads in zones 4-6. However, homes in hot climates (zones 8-9) benefit from 15-18 SEER systems that reduce electricity costs faster. Compare your utility bills. High cooling season costs favor upgrading to 16+ SEER.

Can I install this in a tight attic space? +

The 21-inch height is excellent for horizontal attic mounting. You need roughly 26 inches of depth and 21 inches of width clearance. Ensure adequate airflow around the unit and metal flue ducting rated for furnace exhaust. Improper clearance reduces efficiency and voids warranty.

How does 80% AFUE compare to modern furnaces? +

80% AFUE is standard baseline efficiency. Modern 90% and 95% AFUE units recover more heat, reducing gas consumption by 10-15 percent annually. Payback on upgraded efficiency takes 5-8 years depending on local gas prices and usage patterns.

Should I choose this over a higher SEER unit? +

If budget is tight and you live in moderate climates, this 13 SEER unit saves money upfront. In hot climates or for long-term ownership, 16-18 SEER systems recover their cost premium within seven years through lower electric bills and better comfort.

What does the 10-year warranty cover exactly? +

Compressor, heat exchanger, evaporator coil, and refrigerant charge are covered. Parts and labor are excluded. Online registration is mandatory. Some brands offer longer warranties at similar prices, so verify coverage terms before purchase.

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