Review
The Goodman 3.5-ton horizontal gas furnace and air conditioner system occupies a specific but important niche in residential HVAC. Designed primarily for horizontal installation in attics, crawl spaces, and other confined locations, this unit combines serious heating muscle with practical space-saving engineering. At under 48 pounds and measuring just 21 by 21 by 26 inches, it solves installation problems that plague contractors working in homes without dedicated mechanical rooms or utility closets.
Performance numbers tell a compelling heating story. The 96% AFUE rating and 80,000 BTU output from a two-stage burner deliver efficient, responsive warmth in most climates. Cooling capabilities are honest but secondary, with 42,000 BTU and 15 SEER ratings reflecting its single-stage condenser design. The variable-speed ECM blower motor adjusts from near silence at part load to full 1,600 CFM operation, adapting intelligently to demand and reducing runtime energy consumption. Energy Star certification confirms these efficiency claims.
Pros & Cons
Pros
- Exceptional 96% AFUE heating efficiency reduces natural gas bills significantly compared to 80-90% AFUE alternatives
- Variable-speed ECM blower motor automatically adjusts to home demand, improving comfort and reducing energy waste
- Compact horizontal design fits tight spaces, attics, and crawl spaces where traditional vertical units won't work
- Two-stage burner provides better temperature control and quieter operation during low-demand periods
- Energy Star certified with 10-year warranty when registered, protecting investment against premature failure
Cons
- Single-stage condenser limits cooling efficiency compared to two-stage units, capping cooling at 42,000 BTU despite 3.5-ton capacity
- 73 dB noise level is moderate but noticeable, particularly during heating cycles in quiet homes
- Requires plastic PVC exhaust flue, limiting installation flexibility in older homes with masonry chimneys
Who Should Buy
Best For
Contractors replacing furnaces in attics, crawl spaces, or tight mechanical rooms where standard vertical units are impossible to fit. Homeowners in moderate climates prioritizing heating efficiency over cooling capacity and willing to accept single-stage AC performance.
Consider Alternatives If
Buyers in hot climates needing maximum cooling output should look at two-stage condenser systems, and those without PVC exhaust infrastructure should explore alternatives compatible with masonry venting.
Installation
Installation hinges on your space constraints and existing infrastructure. The horizontal orientation and A-coil design fit readily into attics and crawl spaces where upflow furnaces cannot. You'll need proper ducting connections, 208/230V single-phase 60 Hz electrical service with 23.5 to 40 amp breaker sizing, and critically, a plastic PVC exhaust flue. Refrigerant lines come in standard 3/8 inch liquid and 1 1/8 inch suction sizes with recommended 1/2 inch insulation.
Warranty & Reliability
Goodman provides a substantial 10-year warranty when you register the unit online, covering parts and labor against manufacturing defects. This extended protection is valuable for horizontal installations where accessibility sometimes adds service costs. Registration takes minutes and directly impacts your coverage period and claim experience.
Specifications
| SKU | LS381183850 |
| Brand/Manufacturer | Online Supply |
| Cooling BTU | 42,000 |
| Heating BTU | 80,000 |
| Refrigerant | R410A or R22 |
| Electrical | 208 / 230 V. 1 Phase 60 Hz |
| Warranty | 10 Years with Online Registration |
| Decibel Level (dBA) | 73 |
| Weight (in lbs) | 48.000000 |
| Feature | Spec |
| 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 | 7368835 |
| Airflow Direction | Upflow/Horizontal |
| Exhaust Flue Requirement | Plastic / PVC |
| Furnace Efficiency / AFUE | 96% |
| Blower Motor | Variable Speed - ECM |
| Maximum CFM | 1600 |
| Configuration | Horizontal |
| Flue Location | Right |
| Energy Star | Yes |
| Burner Stages | Two |
| Fuel Type | Propane, Natural Gas |
| Height | 21" |
| Width | 21.125" |
| Depth | 26" |
| Resources | CHPF Installation Manual CHPF Specifications Sheet Goodman Evaporator Coil Warranty You will need Adobe® Acrobat® Reader to view PDF documents. |
| 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 | 3.5 Ton |
| 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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