3.5 Ton 15 SEER 96% AFUE 80,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow Review 2026

// Bottom Line

This Goodman system is ideal for homeowners upgrading from older furnaces who want significant energy savings without premium pricing. The 96% AFUE furnace combined with a 16 SEER1 air conditioner makes it an excellent choice for climates with both heating and cooling demands.

Review

Goodman's combined gas furnace and air conditioner system represents solid mid-tier performance for contractors working on budget-conscious residential replacements. This downflow-capable unit pairs an 80,000 BTU furnace with a 42,000 BTU condenser, sized for homes around 3,500 square feet. The system carries an AHRI certificate number 7368843 and qualifies for ENERGY STAR certification, signaling compliance with efficiency standards that matter to homeowners watching utility costs.

The 96% AFUE furnace rating puts this unit well above the federal minimum of 80% AFUE, translating to real savings during heating season. The air conditioner achieves 16 SEER1 efficiency, considerably above the current baseline. The variable-speed ECM blower motor handles up to 1,600 CFM and adjusts output automatically rather than running constantly at full speed. Two-stage burner modulation in heating mode provides comfort without energy waste, making this system particularly strong for homes with inconsistent temperature demands.

Pros & Cons

Pros

96% AFUE furnace efficiency means minimal fuel waste and lower winter heating bills
16 SEER1 air conditioner rating significantly exceeds federal minimums for cooling efficiency
Variable-speed ECM blower motor adjusts to comfort needs and reduces energy consumption
Two-stage burner provides modulating heat output for better temperature control
Scroll compressor design known for reliability and quiet operation at 73 dB

Cons

Single-stage cooling compressor cannot modulate capacity like more premium systems
Only 10-year warranty requires online registration and doesn't cover labor costs
Spec sheet shows conflicting tonnage ratings (product title says 3.5 ton, specs list 5 ton) causing confusion

Who Should Buy

Best For

Contractors and homeowners in mixed climates who need both strong heating and cooling performance at mid-market pricing. This system works well for homes with existing ductwork requiring upflow or downflow configuration.

Consider Alternatives If

Anyone needing variable-capacity cooling for maximum efficiency should consider two-stage compressor systems, and buyers in mild climates may overpay for heating capacity they won't use.

3.5 Ton 15 SEER 96% AFUE 80,000 BTU Goodman Gas Fu

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Installation

Installation requires 115V single-phase power with circuit breaker between 23.5 and 40 amps, standard for most residential panels. The downflow configuration works with existing ductwork in homes where supply air needs to flow downward. Plastic or PVC exhaust flue is required. Suction line insulation comes pre-installed at 1/2 inch thickness. The A-coil style fits standard indoor positions. Techs should verify existing refrigerant compatibility before connecting to R410A or R22 systems.

Warranty & Reliability

Coverage extends 10 years on parts when you register online, which is competitive for this price tier but shorter than some premium brands offering 15-year coverage. The warranty covers manufacturing defects but excludes labor, meaning repair costs depend on your service provider rates. Goodman also includes separate evaporator coil warranty protection. Registration is required to activate full coverage, so documentation matters.

Specifications

SKU	LS381183850
Brand/Manufacturer	Online Supply
Cooling BTU	42,000
Heating BTU	80,000
Refrigerant	R410A or R22
Electrical	115 V. 1 Phase 60 Hz
Warranty	10 Years 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	30"
Width	21"
Depth	21"
Resources	CAPF Installation Manual CAPF 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	7368843
Airflow Direction	Downflow/Horizontal
Exhaust Flue Requirement	Plastic / PVC
Product Features	Rebate Available
Furnace Efficiency / AFUE	96%
Blower Motor	Variable Speed - ECM
Maximum CFM	1600
Configuration	Upflow / Downflow
Burner Stages	Two
Fuel Type	Propane, Natural Gas
Liquid Line	3/8"
Suction Line	1 1/8"
Style	A-Coil
Suction Line Insulation Thickness	1/2"
Length	50 feet

Frequently Asked Questions

What's the actual tonnage of this system, 3.5 or 5 ton? +

Specs show 5 ton listing, but the product title claims 3.5 ton. We recommend contacting Online Supply directly for clarification. This matters because a 5-ton system handles larger homes than 3.5 tons. Verify against your existing system and home square footage before ordering.

Can this system work in an existing upflow or downflow setup? +

Yes, the configuration field specifies both upflow and downflow capability, making retrofit easier. However, verify your current ductwork dimensions match the 30-inch height, 21-inch width, and 21-inch depth. Improper fit reduces efficiency and increases installation costs.

How does 16 SEER1 compare to what I currently have? +

Most systems replaced today are 10-13 SEER units, so 16 SEER1 represents roughly 20-30% better cooling efficiency. On a typical AC-heavy cooling season, expect lower electric bills. SEER1 is the updated rating metric replacing older SEER ratings for accurate comparisons.

Is the single-stage compressor a limitation compared to variable-capacity systems? +

Single-stage compressors run at full capacity when active, cycling on and off rather than modulating output. Variable-stage compressors provide finer temperature control and marginally better efficiency in mild weather. For most residential use, single-stage performs adequately at a lower price point.

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

No, the warranty covers parts only. Labor and service calls are your responsibility. This is standard for mid-tier equipment but worth factoring into total cost of ownership when comparing quotes.

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