3 Ton 15 SEER 96% AFUE 100,000 BTU Goodman Gas Furnace and Air Conditioner System - Horizontal Review 2026

// Bottom Line

This 3-ton Goodman system delivers excellent efficiency with a 96% AFUE furnace and 16 SEER1 cooling unit, making it ideal for homeowners in moderate climates seeking solid heating and cooling performance. It's particularly suited for horizontal installations in crawlspaces or attics where space constraints demand a compact footprint.

Review

The Goodman 3-ton system combines a gas furnace and air conditioner in one package, offering broad appeal to budget-conscious homeowners and contractors. This horizontal configuration serves the specific market segment needing compact equipment for tight spaces. Goodman holds significant market share in mid-tier HVAC equipment, balancing reliability with affordability. The system ships with comprehensive documentation including installation, service, and parts manuals, supporting both DIY-inclined homeowners and professional installers.

Performance specs show a 100,000 BTU heating output with two burner stages and 34,800 BTU cooling capacity delivered through a scroll compressor. The 96% AFUE rating exceeds current minimums and the 16 SEER1 efficiency outperforms the advertised 15 SEER designation. Electrical requirements remain modest at 115V single-phase with breaker sizing between 18.7 and 30 amps. The variable-speed ECM blower motor, rated for 2000 CFM maximum, intelligently matches airflow to actual conditioning needs rather than running constant.

Pros & Cons

Pros

96% AFUE furnace efficiency reduces heating fuel costs significantly compared to older systems
16 SEER1 cooling rating exceeds the title's 15 SEER specification, offering strong AC performance
Variable-speed ECM blower motor adjusts to actual heating/cooling demand, improving comfort and reducing waste
Two-stage burner provides modulating heat output for more consistent temperatures and lower short-cycling
Energy Star certified with potential rebates available through utility programs
10-year parts warranty with online registration gives reasonable peace of mind

Cons

73.5 dB noise level during operation is moderately loud for residential settings, especially in quiet homes
Single-stage compressor lacks variable capacity, so cooling doesn't modulate like higher-end units
Requires 115V/60Hz single-phase power with 18.7 to 30 amp breaker sizing, limiting some older home compatibility

Who Should Buy

Best For

Homeowners replacing older furnace-only or basic AC systems who want good efficiency gains without premium pricing. Contractors installing systems in homes with horizontal configuration requirements, particularly crawlspaces or attic applications where the 34.5 inch height fits existing plenums.

Consider Alternatives If

Buyers seeking ultra-quiet operation or variable-capacity cooling should look at two-stage compressor units, and homes with undersized electrical panels may need upgrades before installation.

3 Ton 15 SEER 96% AFUE 100,000 BTU Goodman Gas Fur

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Installation

Horizontal downflow configuration suits crawlspaces, attics, and basements with limited vertical clearance. Dimensions of 34.5 inches tall, 21 inches wide, and 28.75 inches deep fit standard plenums. Requires 3/8 inch liquid and 7/8 inch suction lines with 3/4 inch insulation thickness on the suction line. Plastic or PVC exhaust flue capability supports modern venting codes. Professional installation recommended for proper refrigerant charge and airflow verification.

Warranty & Reliability

Goodman includes a 10-year parts warranty upon online registration, covering manufacturer defects in components. This extended coverage is stronger than typical five-year policies, reducing out-of-pocket risk during the system's early service years. Labor and refrigerant are typically not covered under standard warranty terms, so clarify with your installer before purchase.

Specifications

SKU	LS38783850
Brand/Manufacturer	Online Supply
Cooling BTU	34,800
Heating BTU	100,000
Refrigerant	R410A or R22
Electrical	115 V. 1 Phase 60 Hz
Warranty	10 Years with Online Registration
Decibel Level (dBA)	73.5
Weight (in lbs)	30.000000
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	30 amps
Min. Breaker Size	18.7 amps
Tonnage	3.5 Ton
Height	34.5"
Width	21"
Depth	28.75"
Resources	Goodman Brochure Goodman Installation Instructions Goodman Parts Manual Goodman Service Manual Goodman Specifications Goodman Technical Information Goodman User Information Goodman Warranty 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.
Configuration	Downflow/Horizontal
Liquid Line	3/8"
Suction Line	7/8"
Style	A-Coil
AHRI Certificate Number	7368844
Airflow Direction	Downflow/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	3/4"
Length	50 feet

Frequently Asked Questions

How does this system compare to the advertised 15 SEER rating? +

The spec sheet lists 16 SEER1 efficiency, which exceeds the title specification. SEER1 represents updated testing standards and is slightly more conservative than older SEER metrics. You're getting better cooling efficiency than the headline suggests, making this a solid value proposition.

Can I install this in a standard attic space? +

Yes, the horizontal A-coil configuration specifically supports downflow attic installations. At 34.5 inches tall and 21 inches wide, verify your attic clearance and ensure proper return air ductwork. Plastic exhaust venting through the roof is straightforward with modern PVC materials.

Will the two-stage heating really save energy? +

Two-stage burners modulate heat output, running at lower capacity on mild days and reducing short-cycling losses. Combined with the variable-speed blower, you avoid the constant on-off cycling of single-stage units, resulting in tangible utility bill reductions, especially in spring and fall shoulder seasons.

How does this compare to higher-SEER units with variable compressors? +

This unit's single-stage compressor runs fully loaded whenever cooling demand exists, using more energy than two-stage or variable systems during part-load conditions. Premium units reach 18-20 SEER but cost significantly more. This represents the sweet spot for mid-budget retrofits seeking real efficiency gains without premium investment.

What's covered under the 10-year warranty? +

Parts only, with online registration required. Labor and refrigerant fall outside coverage. Always hire a certified technician and keep service records to protect your warranty claim eligibility.

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