3.5 Ton 13 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 and contractors seeking a dependable, efficient heating and cooling combo at a mid-range price point. The 96% AFUE furnace and 13 SEER air conditioner deliver strong performance for moderate climates where both heating and cooling demands are significant.

Review

The Goodman 3.5-ton combined gas furnace and air conditioning system represents a practical middle-ground choice in the residential HVAC market. This downflow-configured unit pairs an 80,000 BTU furnace with 42,000 BTU cooling capacity, making it suitable for 1,500 to 2,000 square-foot homes. Online Supply positions this as a reliable workhorse system that balances performance, efficiency, and installation simplicity for contractors and homeowners who need both heating and cooling without paying premium prices.

The furnace delivers 96% AFUE efficiency, which ranks well above outdated 80% models and translates to noticeably lower winter heating bills. On the cooling side, the 13 SEER rating meets current DOE standards, though it sits at the baseline rather than premium tier. The single-stage compressor and burner design means the system runs at full capacity during operation rather than modulating down during mild weather, which moderately reduces part-load efficiency. The multi-speed blower motor does help compensate by allowing reduced airflow during lighter demand periods, improving comfort and lowering runtime costs.

Pros & Cons

Pros

96% AFUE efficiency rating significantly reduces heating fuel costs compared to standard 80-85% units
13 SEER cooling efficiency meets current federal minimums and qualifies for some utility rebates
80,000 BTU heating capacity handles medium homes without oversizing issues
Multi-speed blower motor allows better temperature control and quieter operation at part load
10-year warranty with online registration provides solid peace of mind coverage
PVC exhaust flue accepts modern plastic venting, reducing installation complexity and cost

Cons

Single-stage compressor and burner lack modulation, reducing efficiency during mild weather operation
13 SEER rating is baseline efficient, not premium, so electricity savings won't match higher-tier units
75 dB noise level is moderately loud for residential applications, especially in quiet neighborhoods
No Energy Star certification despite respectable efficiency numbers
Reciprocating compressor design is older technology with higher vibration than scroll compressors

Who Should Buy

Best For

Homeowners in mixed climates needing both heating and cooling who prioritize upfront affordability over premium efficiency gains. Contractors building spec homes or handling mid-range renovation projects will appreciate the straightforward installation and proven Goodman reliability.

Consider Alternatives If

Buyers in mild climates where AC dominates should seek higher SEER units, and those in cold climates might prefer higher AFUE ratings paired with superior modulation technology.

3.5 Ton 13 SEER 96% AFUE 80,000 BTU Goodman Gas Fu

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Installation

This unit requires standard 115V, single-phase 60 Hz electrical service with 23.9 to 40-amp breaker sizing, making it compatible with most residential panels. The PVC plastic exhaust flue eliminates costly metal venting, reducing labor time. Liquid and suction line sizes are standard at 3/8 and 7/8 inches respectively, fitting typical existing ductwork and refrigerant lines. Downflow configuration suits basements and crawl spaces. Most experienced HVAC technicians can complete installation in one day.

Warranty & Reliability

Goodman provides a 10-year comprehensive warranty when you register the unit online after purchase. This covers parts and defects across both the furnace and air conditioning sections. The registration process is straightforward and well-documented. While not the industry-leading warranty available, 10 years offers solid protection against premature compressor or heat exchanger failure, which are the most expensive components.

Specifications

SKU	LS38783830
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)	75
Weight (in lbs)	30.000000
Feature	Spec
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	5 Ton
Valve Type	Sweat
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.
Airflow Direction	Downflow/Horizontal
Exhaust Flue Requirement	Plastic / PVC
Furnace Efficiency / AFUE	96%
Blower Motor	Multi Speed
Maximum CFM	1600
Configuration	Upflow / Downflow
Flue Location	Right
Burner Stages	Single
Fuel Type	Gas
Style	A-Coil
Suction Line Insulation Thickness	3/8"
Length	30 feet

Frequently Asked Questions

How much will this furnace save on heating costs compared to an 80% AFUE unit? +

The 96% AFUE rating means 16 percentage points more fuel converts to heat. On a typical 80,000 BTU heating season running 1,000 hours, you'll save roughly 15-20% on gas bills annually. Exact savings depend on local gas rates and your climate zone, but most homeowners see 150 to 300 dollars in yearly savings.

Can this unit work with my existing R22 air conditioning lines? +

Yes, this system accepts both R410A and R22 refrigerant according to specifications. However, mixing refrigerants isn't recommended. If converting from R22 to this unit, flush and clean all existing lines thoroughly. Consult an EPA-certified technician for proper conversion procedures.

What does 13 SEER actually mean for my summer cooling bills? +

SEER 13 means your system removes 13 BTU of heat for every watt of electricity consumed. It's efficient by current standards but baseline, not premium. Modern homes see 10-15% lower cooling costs versus older 10 SEER units. High-efficiency 16-18 SEER systems save 20-30% more but carry higher upfront costs.

How does this single-stage system compare to a modulating two-stage unit? +

Single-stage runs full blast or off, consuming more energy during mild weather. Two-stage units modulate down to 60-70% capacity during partial load, improving efficiency by 5-10% annually. You'll pay 800 to 1,500 dollars more upfront for two-stage technology, so payback takes 8-12 years in moderate climates.

Is the 10-year warranty transferable if I sell my home? +

Most Goodman warranties are transferable to subsequent owners with proper documentation and registration. Verify specific transfer terms with Online Supply at purchase. Transferability adds resale value appeal for homes with newer HVAC systems.

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