Independent Review · Updated June 2026

3 Ton 16 SEER 96% AFUE 100,000 BTU Goodman Gas Furnace and Air Conditioner System - Downflow

High-efficiency 3-ton system at an unbeatable price point for budget-conscious upgrades.

8.2
IndustrialRank Score
Efficiency
8.5
Reliability
7.8
Value
8.0
Installation
8.5
Warranty
8.0
3 Ton 16 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 is ideal for homeowners replacing aging equipment who want ENERGY STAR efficiency without premium pricing. The 96% AFUE furnace and 16 SEER cooling deliver strong performance for downflow installations in attics or basements.

Review

The Goodman 3-ton downflow system represents the practical middle ground in residential HVAC replacement. Priced at just $89, it targets budget-conscious homeowners and contractors seeking reliability without luxury pricing. This unit combines a furnace section with an air conditioning coil in a compact 30 by 21 by 21 inch footprint, designed specifically for attic or basement installations where vertical space is limited. The downflow configuration makes it particularly useful in homes with crawl spaces or slab foundations.

Performance specs tell a solid story for this class of equipment. The furnace delivers 100,000 BTU heating output at 96% AFUE, meaning minimal gas waste during winter operation. On the cooling side, expect 34,800 BTU output at 16 SEER efficiency, sufficient for moderate climates but not aggressive enough for extreme heat regions. The variable-speed ECM blower and two-stage burner provide better efficiency than single-stage competitors, while the R410A/R22 refrigerant flexibility allows technicians to work with existing line sets.

Pros & Cons

Pros

  • 96% AFUE heating efficiency exceeds most residential furnaces, reducing winter gas bills
  • 16 SEER cooling rating with scroll compressor provides solid air conditioning performance for 3-ton applications
  • Variable-speed ECM blower motor adjusts to actual heating/cooling needs, improving comfort and efficiency
  • Two-stage burner reduces short-cycling and improves temperature stability throughout the heating season
  • PVC exhaust flue compatibility allows easier, more flexible ductwork routing compared to metal requirements
  • ENERGY STAR certified system qualifies for utility rebates that can offset purchase price

Cons

  • 73.5 dB noise level is moderately loud, noticeable during operation in finished spaces near the unit
  • 5-ton tonnage rating appears mismatched to 3-ton system design, creating specification confusion
  • Single-stage condenser limits cooling modulation during mild weather, reducing part-load efficiency
  • Online Supply manufacturer is a third-party distributor, not original Goodman, which may complicate warranty claims

Who Should Buy

Best For

This system suits homeowners in moderate climates replacing 15+ year old equipment who prioritize upfront affordability and solid baseline efficiency. Contractors bidding residential retrofit jobs where customers resist premium pricing will appreciate the value proposition.

Consider Alternatives If

Skip this if you need premium sound levels below 70 dB, live in extreme climates demanding modulating capacity, or require nationwide factory support directly from Goodman.

3 Ton 16 SEER 96% AFUE 100,000 BTU Goodman Gas Fur
$89
Buy at HVACDirect →

Installation

This downflow unit requires standard PVC exhaust venting, which simplifies installation compared to metal-only requirements. The 30-inch height fits most attic spaces, though techs must verify 21-inch width clearance. Electrical connection needs a dedicated 18.7 to 30-amp breaker at 208/230V single-phase. Standard R-410A lineset sizing applies with 3/8-inch liquid and 7/8-inch suction lines, pre-insulated to 3/4-inch thickness. Plan 2 to 4 hours for experienced installers.

Warranty & Reliability

Goodman backs this unit with a 10-year parts warranty when registered online within 60 days of purchase. Registration is straightforward but mandatory for full coverage. This warranty covers compressor, heat exchanger, and major components. Labor coverage typically runs 1 year, so confirm extended labor warranty options with your installer before signing the contract.

Specifications

SKULS38783850
Brand/ManufacturerOnline Supply
Cooling BTU34,800
Heating BTU100,000
RefrigerantR410A or R22
Electrical208 / 230 V. 1 Phase 60 Hz
Warranty10 Years with Online Registration
Decibel Level (dBA)73.5
Weight (in lbs)30.000000
FeatureSpec
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
Product FeaturesRebate Available
Furnace Efficiency / AFUE96%
Blower MotorVariable Speed - ECM
Maximum CFM2000
ConfigurationUpflow / Downflow
Energy StarYes
Burner StagesTwo
Fuel TypePropane, Natural Gas
Height30"
Width21"
Depth21"
ResourcesCAPF Installation Manual CAPF Specifications Sheet Goodman Evaporator Coil Warranty You will need Adobe® Acrobat® Reader to view PDF documents.
SEER1 (Efficiency)16
Condenser StagesSingle Stage
Compressor TypeScroll
Liquid Valve Size3/8"
Suction Valve Size7/8"
Max Breaker Size30 amps
Min. Breaker Size18.7 amps
Tonnage5 Ton
Liquid Line3/8"
Suction Line7/8"
StyleA-Coil
Suction Line Insulation Thickness3/4"
Length50 feet

Frequently Asked Questions

Why does the spec sheet list 5-ton tonnage when this is a 3-ton system? +
This appears to be a data entry error from the distributor. The 34,800 BTU cooling capacity confirms 3-ton sizing. Verify AHRI certificate 7368844 with your installer to confirm actual capacity before purchase. Never rely solely on the tonnage field.
Can this unit replace my existing system without replacing refrigerant lines? +
Possibly. The 3/8-inch liquid and 7/8-inch suction valve sizes are standard. If your old system uses matching line sizes and R-410A, you may reuse them. However, have a licensed technician pressure-test existing lines first. Damaged or oversized lines reduce efficiency significantly.
How much quieter is this than older furnaces? +
At 73.5 dB, it's moderately loud, comparable to a vacuum cleaner. Modern variable-speed models run quieter during low-load operation. Older 80+ dB units run constantly at full volume. For reference, 10 dB reduction feels twice as quiet to human ears.
Is 16 SEER good enough, or should I pay more for 18+ SEER? +
16 SEER offers 5-year payback through reduced cooling bills in most climates. Higher SEER ratings extend payback to 7+ years in moderate regions. Choose 16 SEER if budget matters; upgrade to 18+ SEER only if you plan 15+ year ownership in hot climates.
Does Online Supply handle warranty claims, or does Goodman? +
Online Supply is a distributor, not Goodman directly. Register your warranty with Goodman for fastest claims processing. Contact Online Supply if you encounter shipping or DOA issues within 30 days of receipt.

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