3.5 Ton 13 SEER 80% AFUE 100,000 BTU Goodman Gas Furnace and Air Conditioner System - Horizontal Review 2026

// Bottom Line

This 3.5-ton system works well for homeowners in moderate climates who need dependable heating and cooling without premium pricing. The 80% AFUE furnace and 13 SEER air conditioner deliver balanced performance for homes ranging from 1,200 to 1,800 square feet.

Review

The Goodman 3.5-ton horizontal gas furnace and air conditioner system lands solidly in the mainstream HVAC market, targeting cost-conscious homeowners and contractors who value proven engineering over premium features. Goodman's reputation for durability and service support makes this unit a practical choice for homes ranging from 1,200 to 1,800 square feet. The horizontal A-coil design fits tight spaces, while the two-component approach lets homeowners mix and match heating and cooling independently if needed.

Performance specs reflect a balanced mid-market offering. The furnace delivers 100,000 BTU with two-stage burner capability and 80% AFUE efficiency, heating responsively without excessive energy waste. The air conditioner provides 42,000 BTU cooling at 13 SEER with a single-stage reciprocating compressor, handling moderate loads effectively. The variable-speed blower runs up to 2,000 CFM, distributing conditioned air consistently throughout the home without excessive noise for its class.

Pros & Cons

Pros

Two-stage burner delivers responsive heating with 100,000 BTU output and reduced short-cycling
13 SEER cooling efficiency provides decent comfort without stretching electrical capacity on standard 208/230V service
Variable-speed blower motor optimizes airflow at 2,000 CFM maximum and improves distribution consistency
Horizontal A-coil configuration suits tight attic or crawlspace installations with compact 36.25" height
10-year warranty with online registration covers both heating and cooling components

Cons

80% AFUE is mid-range by today's standards, meaning higher heating costs than 90+ AFUE systems over time
Single-stage condenser cycles on and off rather than modulating, reducing part-load efficiency in mild weather
75 dB noise level runs louder than some competitor units, noticeable during operation
No ENERGY STAR certification indicates it doesn't meet current top-efficiency benchmarks

Who Should Buy

Best For

Homeowners in zones 4-6 with moderate heating and cooling demands who prioritize upfront affordability and simplicity over premium efficiency. Contractors installing systems in rental properties or spec homes where balanced cost and reliability matter more than cutting-edge SEER ratings.

Consider Alternatives If

Anyone in extremely cold climates needing high-efficiency heating, or homes on tight electrical budgets, should compare 90+ AFUE models or dual-stage cooling systems instead.

3.5 Ton 13 SEER 80% AFUE 100,000 BTU Goodman Gas F

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Installation

Installation favors experienced technicians familiar with Goodman systems. The horizontal orientation requires proper ductwork alignment and return-air clearance above the unit. Electrical needs are straightforward on 208/230V single-phase service with 23.9 to 40-amp breaker sizing. The included 30-foot suction line with 3/8-inch insulation and sweat fittings requires careful refrigerant line routing and pressure testing. Metal exhaust flue is mandatory for gas furnace codes.

Warranty & Reliability

Goodman backs this system with a 10-year parts warranty upon online registration, covering both furnace heat exchanger and air conditioning components. This mid-range coverage protects against defects but doesn't include labor or refrigerant, which are owner responsibility. Registration is essential, so confirm the dealer completes it during installation to activate full protection.

Specifications

SKU	LS38783830
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)	75
Weight (in lbs)	30.000000
Feature	Spec
Configuration	Upflow/Horizontal
Liquid Line	3/8"
Suction Line	7/8"
Tonnage	3.5 Ton
Style	A-Coil
Height	36.25"
Width	29"
Depth	29"
Resources	Goodman Installation Manual Goodman Specifications Goodman Technical Manual Goodman Warranty Information Goodman Brochure 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	No
SEER1 (Efficiency)	13
Condenser Stages	Single Stage
Compressor Type	Reciprocating
Liquid Valve Size	3/8"
Max Breaker Size	40 amps
Min. Breaker Size	23.9 amps
Valve Type	Sweat
Suction Line Insulation Thickness	3/8"
Length	30 feet

Frequently Asked Questions

Will this 3.5-ton system handle my 2,000-square-foot home? +

Generally yes for moderate climates in zones 4-6. However, proper load calculation by a licensed technician is essential. If your home has poor insulation or extreme weather exposure, you may need 4-ton capacity instead. The 42,000 BTU cooling output works well for homes with reasonable humidity control.

Can I install this myself or does it require a licensed HVAC contractor? +

Installation requires a licensed HVAC contractor in most jurisdictions. Gas furnaces demand proper venting and combustion safety testing, and refrigerant handling requires EPA certification. DIY installation voids the warranty and violates building codes. Professional installation costs $1,500 to $2,500 depending on ductwork complexity.

How does 80% AFUE compare to newer high-efficiency furnaces? +

80% AFUE is middle-of-the-road. Modern systems reach 95% AFUE, reducing annual heating costs 15 to 20 percent. Over 15 years, the upgrade to high-efficiency pays dividends in cold climates, but in moderate zones the payback stretches to 10 plus years. This unit suits budget-conscious buyers accepting higher utility bills.

Should I buy this or a variable-capacity cooling system with higher SEER? +

Single-stage cooling at 13 SEER cycles on and off, less efficient in mild weather than modulating systems at 16+ SEER. Choose 13 SEER if cooling demand is moderate and upfront cost matters. Pick variable-stage systems if you value longer equipment lifespan and lower summer electricity bills despite higher initial price.

Does the 10-year warranty cover labor if something breaks? +

No. The warranty covers parts only. Labor, refrigerant, and service calls are your responsibility. Service agreements or extended labor plans are available separately. Always register online within 30 days of installation to activate full warranty coverage on both furnace and air conditioner.

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