Review
The Goodman 4 ton downflow furnace and air conditioner combination represents a solid mid-tier offering for homeowners seeking proven reliability with modern efficiency features. This system pairs a high-efficiency furnace with a standard cooling coil, delivering adequate performance for most residential applications. The downflow configuration suits installations in attics or upper-level mechanical closets where ductwork routes downward through the home. Goodman maintains strong contractor support and parts availability across North America.
The furnace achieves 97% AFUE with modulating burners that continuously adjust heat output from 20% to 100% of the 80,000 BTU capacity, eliminating the efficiency losses from on-off cycling found in older systems. The cooling side delivers 45,500 BTU at 16 SEER1 with a scroll compressor running at single-stage capacity. The variable-speed ECM blower motor runs quietly at 73 dB and delivers up to 1,600 CFM, adjusting speed to match heating and cooling demand rather than running at maximum settings constantly.
Pros & Cons
Pros
- 97% AFUE furnace efficiency reduces heating costs significantly compared to standard 80-85% AFUE units
- Modulating burners adjust output continuously rather than cycling on/off, improving comfort and reducing temperature swings
- Variable-speed ECM blower motor runs efficiently at multiple speeds instead of full-blast operation
- Energy Star certified system qualifies for utility rebates in many regions
- Plastic PVC exhaust flue allows easier venting through exterior walls versus metal chimneys
- 10-year warranty with online registration provides solid coverage for major components
Cons
- Product listing shows conflicting tonnage specs: title says 4 ton but specs list 5 ton, creating confusion about actual cooling capacity
- SEER1 rating of 16 is good but not top-tier compared to premium units reaching 18-20 SEER2
- Single-stage compressor means air conditioner runs at full capacity or off rather than modulating like the furnace does
Who Should Buy
Best For
Homeowners in moderate climates replacing 15-20 year old furnaces who prioritize heating efficiency and want modulating comfort control. Properties using natural gas or propane where lower utility bills justify slightly higher upfront equipment cost.
Consider Alternatives If
Buyers needing variable-capacity cooling should look for two-stage or inverter-driven compressor systems. Those in very hot climates relying heavily on AC cooling may find the single-stage compressor less efficient than modulating alternatives.
Installation
This downflow system requires vertical stacking space of 30 inches height with 21-inch width and depth. The plastic PVC exhaust flue can terminate through an exterior wall, simplifying installation compared to metal flue pipes. Electrical requirements are 115V single-phase 60Hz with 23.9 to 40 amp breaker sizing. Suction line insulation at 1/2 inch thickness prevents condensation and maintains cooling efficiency. HVAC contractors typically complete installation in 4-6 hours after ductwork verification.
Warranty & Reliability
Online Supply provides a 10-year parts warranty upon online registration, covering compressor, heat exchanger, and major components. This extended coverage aligns with industry standard for mid-tier equipment. Registration is mandatory to activate the full term, and customers should retain proof of purchase and documentation. Coverage typically excludes normal wear, refrigerant loss from leaks, and improper installation.
Specifications
| SKU | LS381183850 |
| Brand/Manufacturer | Online Supply |
| Cooling BTU | 45,500 |
| Heating BTU | 80,000 |
| Refrigerant | R410A |
| Electrical | 115 V. 1 Phase 60 Hz |
| Warranty | 10 Years with Online Registration |
| Decibel Level (dBA) | 73 |
| Weight (in lbs) | 48.000000 |
| Feature | Spec |
| Replaces | GSX16S481 |
| 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 | 23.9 amps |
| Tonnage | 5 Ton |
| Height | 30" |
| Width | 21" |
| Depth | 21" |
| Resources | CAPT Installation Manual CAPT 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 | 7424271 |
| Airflow Direction | Downflow/Horizontal |
| Exhaust Flue Requirement | Plastic / PVC |
| Product Features | Rebate Available |
| Furnace Efficiency / AFUE | 97% |
| Blower Motor | Variable Speed - ECM |
| Maximum CFM | 1600 |
| Configuration | Upflow / Downflow |
| Flue Location | Right |
| Burner Stages | Modulating |
| 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
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