Independent Review · Updated June 2026

3 Ton 18 SEER 96% AFUE 100,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow

High-efficiency dual-stage system with 18 SEER cooling and 96% AFUE heating

8.2
IndustrialRank Score
Efficiency
8.5
Reliability
7.8
Value
8.0
Installation
8.5
Warranty
8.0
3 Ton 18 SEER 96% AFUE 100,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow
Current Price
$89
Check Price at HVACDirect → Shop Now at HVACDirect
Authorized dealer · Full manufacturer warranty
// Bottom Line
This Goodman system excels for homeowners seeking excellent efficiency without premium pricing. The 18 SEER rating and 96% AFUE make it ideal for moderate to warm climates where cooling demands drive energy costs, and the dual-stage design keeps utility bills down year-round.

Review

This Goodman 3-ton system occupies the sweet spot in the mid-market HVAC segment, delivering respectable efficiency ratings without the premium pricing of name-brand leaders. At $89, it appears positioned as a contractor-grade component rather than a complete installed system. The unit combines two-stage cooling and heating with variable-speed motor technology, making it suitable for moderate residential applications where balanced year-round performance matters.

Performance numbers tell a compelling story. The 18 SEER rating delivers excellent cooling efficiency, dropping approximately 15 to 20 percent of cooling energy waste versus 13 SEER systems. The 96% AFUE furnace rating means only 4 percent of heating fuel escapes through the flue, a respectable figure for mid-tier equipment. Two-stage operation on both cooling and heating sides prevents the constant on-off cycling that degrades comfort and accelerates component wear. The variable-speed ECM blower can modulate between zero and 2000 CFM, reducing unnecessary fan energy consumption.

Pros & Cons

Pros

  • 18 SEER cooling efficiency ranks among the best for mid-tier systems, reducing AC runtime and power consumption
  • 96% AFUE furnace efficiency captures nearly all heating fuel, translating to lower winter heating bills
  • Two-stage compressor and burner stages allow modulated operation, reducing wear and maintaining comfort without constant cycling
  • Variable-speed ECM blower motor adjusts airflow from 0 to 2000 CFM, minimizing energy waste during low-demand periods
  • Energy Star certified with 10-year parts warranty when registered, covering compressor and heat exchanger

Cons

  • Tonnage mismatch between 3-ton capacity claim and 5-ton specification creates confusion about actual cooling output
  • 71 dB decibel level sits above whisper-quiet competitors, noticeable during high-speed cooling cycles in adjacent rooms
  • Requires dual refrigerant compatibility (R410A or R22), limiting technician options if future service demands specific refrigerant type

Who Should Buy

Best For

Contractors installing systems in climate zones with significant cooling loads will appreciate the 35,000 BTU/hour cooling capacity paired with efficient staging. Homeowners in moderate climates looking to offset rising energy costs through SEER 18 efficiency without jumping to premium brands will find solid value here.

Consider Alternatives If

Buyers in cold-dominant climates should prioritize heating efficiency first, and those needing whisper-quiet operation should audition this unit before purchase.

3 Ton 18 SEER 96% AFUE 100,000 BTU Goodman Gas Fur
$89
Buy at HVACDirect →

Installation

This downflow configuration mounts horizontally, making it ideal for attics, basements, or utility closets where space runs tight. The 30-inch height, 24.5-inch width, and 21-inch depth fit standard return plenums without modification. Technicians should budget for 115V single-phase 60Hz electrical service with 21.3 to 35-amp breaker capacity. PVC exhaust flue is required, and refrigerant line sets need 3/8-inch liquid and 7/8-inch suction lines with 3/4-inch insulation.

Warranty & Reliability

Online Supply backs this unit with a 10-year parts warranty when you register the product. Coverage includes compressor failure, heat exchanger defects, and refrigerant leaks under normal use. Registration is straightforward online and extends protection beyond the standard 5-year warranty. Labor costs and maintenance fall outside coverage, so budget accordingly for service calls.

Specifications

SKULS38783850
Brand/ManufacturerOnline Supply
Cooling BTU35,000
Heating BTU100,000
RefrigerantR410A or R22
Electrical115 V. 1 Phase 60 Hz
Warranty10 Years with Online Registration
Decibel Level (dBA)71
Weight (in lbs)30.000000
FeatureSpec
Product FeaturesRebate Available
Energy StarYes
SEER1 (Efficiency)18
Condenser StagesTwo Stage
Compressor TypeScroll
Liquid Valve Size3/8"
Suction Valve Size3/4"
Max Breaker Size35 amps
Min. Breaker Size21.3 amps
Tonnage5 Ton
Valve TypeSweat
Height30"
Width24.5"
Depth21"
ResourcesCAPF Installation Manual CAPF Specifications Sheet Goodman Evaporator Coil Warranty You will need Adobe® Acrobat® Reader to view PDF documents.
Safety InformationPROPOSITION 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 Number7368844
Airflow DirectionDownflow/Horizontal
Exhaust Flue RequirementPlastic / PVC
Furnace Efficiency / AFUE96%
Blower MotorVariable Speed - ECM
Maximum CFM2000
ConfigurationUpflow / Downflow
Burner StagesTwo
Fuel TypePropane, Natural Gas
Liquid Line3/8"
Suction Line7/8"
StyleA-Coil
Suction Line Insulation Thickness3/4"
Length50 feet

Frequently Asked Questions

What's the actual capacity, 3 tons or 5 tons? +
The specifications list contradictory data. The 35,000 BTU cooling capacity aligns with approximately 2.9 tons, while the specs sheet claims 5 tons. Verify AHRI certificate 7368844 with your installer before purchasing to confirm true capacity for your home's cooling load.
Can I use this system with my existing R22 refrigerant lines? +
Yes, the unit accepts both R410A and R22 refrigerant, offering flexibility during replacement or upgrade scenarios. However, mixing refrigerants is illegal and dangerous. Your technician must flush lines completely and commit to one refrigerant type for the system's lifetime.
How much will this system reduce my energy bills compared to an older 13 SEER unit? +
The 18 SEER rating uses approximately 27 percent less cooling energy than 13 SEER equipment. Exact savings depend on your climate and usage, but homeowners in moderate climates typically see 15 to 20 percent annual cooling cost reduction when upgrading from 10-year-old systems.
Is this better than the Lennox or Carrier equivalent at this price point? +
Goodman equipment trades brand prestige for value. The 18 SEER and 96% AFUE ratings match mid-tier Lennox and Carrier units, but warranty support and parts availability may differ by region. Local contractor relationships often determine real-world service quality more than brand alone.
What does the 10-year warranty actually cover? +
Parts only, after you register. Compressor, heat exchanger, and refrigerant leaks are protected. Labor, filters, and routine maintenance are your responsibility. Read the full warranty terms before purchase to understand exclusions.

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