4 Ton 15 SEER 97% AFUE 120,000 BTU Goodman Gas Furnace and Air Conditioner System - Upflow Review 2026

// Bottom Line

This system works best for homeowners upgrading older furnaces who want maximum heating efficiency without premium pricing. The 97% AFUE and modulating burner will cut heating costs noticeably, while the 16 SEER cooling handles moderate climates adequately.

Review

The Goodman 4-ton upflow gas furnace and air conditioner system represents a solid mid-tier choice for residential HVAC upgrades. This all-in-one unit combines heating and cooling capability, making it practical for complete system replacement projects. Online Supply positions it as an accessible option for contractors and homeowners seeking modern efficiency without premium brand pricing. The SKU LS381183850 carries full AHRI certification, meaning sizing and compatibility are verified for professional installation confidence.

Performance specs tell a compelling heating story. The 120,000 BTU furnace delivers 97% AFUE efficiency, meaning 97 cents of every natural gas dollar converts to usable heat, significantly outperforming older 80-85% AFUE equipment. Cooling output reaches 45,500 BTU at 16 SEER, adequate for moderate climates but not exceptional. The variable-speed ECM blower motor maxes at 2000 CFM and modulates intelligently, reducing runtime noise to 73 dBA while optimizing comfort during partial-load conditions.

Pros & Cons

Pros

Exceptional 97% AFUE heating efficiency reduces natural gas consumption and monthly utility bills
Modulating burner stages deliver precise temperature control and quieter operation than single-stage units
Variable-speed ECM blower motor improves comfort and reduces electricity use compared to fixed-speed alternatives
Energy Star certified system qualifies for utility rebates in most regions
PVC/plastic flue compatible, simplifying venting in retrofit applications without metal ductwork
10-year warranty with online registration provides solid coverage for parts and labor

Cons

Cooling efficiency at 16 SEER is respectable but trails premium 18-20 SEER systems by 10-15%
Single-stage condenser limits part-load efficiency in mild weather compared to two-stage designs
73 dBA noise level is moderate, noticeable during operation in quiet spaces
Specs show tonnage inconsistency, listing both 4-ton and 5-ton capacity, creating confusion about actual cooling output

Who Should Buy

Best For

Homeowners in cold to moderate climates replacing 15-20 year old furnaces will see immediate heating savings from the 97% AFUE rating. Contractors installing systems in homes where rebates apply and budget-conscious buyers valuing heating performance over air conditioning punch make ideal customers.

Consider Alternatives If

Buyers in hot climates prioritizing cooling efficiency, or anyone needing premium two-stage cooling performance, should explore higher SEER alternatives from Carrier or Lennox.

4 Ton 15 SEER 97% AFUE 120,000 BTU Goodman Gas Fur

Buy at HVACDirect →

Installation

This upflow configuration fits basement or utility closet installations with 30-inch height and 24.5-inch width dimensions. The right-side flue location accepts PVC/plastic venting, eliminating costly metal ductwork modifications in many retrofit jobs. Electrical requirements are straightforward, 208/230V single-phase 60Hz at 23.9 to 40 amps, fitting most residential panels. Refrigerant connections use standard 3/8-inch liquid and 1-1/8-inch suction lines with 50-foot maximum line run capability.

Warranty & Reliability

Goodman backs this unit with 10-year comprehensive coverage when you register online, covering parts and compressor defects. Registration is quick and essential to activate full protection. This warranty length is respectable for mid-tier equipment, protecting against major component failure through the critical first decade of operation.

Specifications

SKU	LS381183850
Brand/Manufacturer	Online Supply
Cooling BTU	45,500
Heating BTU	120,000
Refrigerant	R410A
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
AHRI Certificate Number	7424268
Airflow Direction	Upflow/Horizontal
Exhaust Flue Requirement	Plastic / PVC
Product Features	Rebate Available
Furnace Efficiency / AFUE	97%
Blower Motor	Variable Speed - ECM
Maximum CFM	2000
Configuration	Upflow / Downflow
Flue Location	Right
Energy Star	Yes
Burner Stages	Modulating
Fuel Type	Propane, Natural Gas
Height	30"
Width	24.5"
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.
Replaces	GSX16S481
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
Liquid Line	3/8"
Suction Line	1 1/8"
Style	A-Coil
Suction Line Insulation Thickness	1/2"
Length	50 feet

Frequently Asked Questions

What does 97% AFUE actually mean for my heating costs? +

AFUE measures fuel-to-heat conversion efficiency. At 97%, only 3% of natural gas escapes unused, meaning 3% lower bills than 94% AFUE equipment. Annual savings depend on local gas rates and heating hours, but homeowners typically recover equipment costs through utility savings within 5-7 years in cold climates.

Can I install this in my attic instead of the basement? +

This upflow unit is designed for ground-level or basement placement where return air flows upward through the cabinet. Attic installation would require downflow configuration or horizontal retrofit, which this model lists as compatible. Verify with your installer that ductwork routing works with attic placement before ordering.

How does 16 SEER cooling compare to newer high-efficiency systems? +

16 SEER is respectable mid-tier cooling efficiency, roughly 10-15% less efficient than premium 18-20 SEER systems. For moderate cooling loads in northern and central states, 16 SEER performs adequately. Southern homeowners with heavy cooling demands may justify premium SEER ratings despite higher upfront cost.

Why does the spec sheet list both 4-ton and 5-ton capacity? +

This appears to be a data entry error. The title states 4-ton with 45,500 BTU cooling (roughly 3.8 tons), but specs show 5-ton tonnage. Verify exact capacity with your contractor before installation to ensure proper line set sizing and thermostat calibration.

Do I need a smart thermostat to get the full efficiency benefit? +

No, but it helps significantly. The modulating burner and variable-speed blower optimize themselves, but a programmable or smart thermostat reduces runtime hours by 10-15% through intelligent scheduling, maximizing the efficiency investment.

Affiliate disclosure: IndustrialRank earns a commission on qualifying purchases at no extra cost to you. We only recommend products we have independently reviewed.