Product Lines
High Efficiency Comfort Systems

The 4SCU23LX Pro Series variable-capacity air conditioner delivers up to 21.5 SEER2 efficiency' making it one of the most efficient cooling systems available. Its inverter-driven compressor adjusts speed in small' precise increments to hold temperatures exactly where you want them while using significantly less energy than a standard air conditioner.

Pair this model with a Pro Series™ variable speed furnace and a Comfort Sync® A3 thermostat for optimum performance. With the Pro Series' you're in control of every aspect of your home's climate' as well as your energy costs.

• Up to 21.5 SEER2 Efficiency Meets ENERGY STAR® and CEE Tier 1/2 qualifications. This highly efficient cooling system can deliver significant energy savings compared to a conventional single-stage air conditioner.
• True Variable-Capacity Cooling The inverter-driven compressor changes its speed in small' precise increments and adjusts cooling up and down like a dimmer switch. Temperatures are held exactly where you want them' even in extremely hot weather.
• Comfort Sync® A3 Thermostat Compatible The ultra-smart thermostat unlocks total control over your home's ideal environment from anywhere. The system continuously monitors internal components for optimum performance and alerts you when maintenance is needed.
• Enhanced Dehumidification Lower speed operation removes more moisture from the air' providing consistent comfort throughout your home.
• Omniguard® Total Corrosion Protection Advanced corrosion protection extends the life of the unit and maintains peak efficiency over time.
• MHT™ Technology Armstrong Air's proprietary heat transfer system features rifled tubing to enhance refrigerant flow' while lanced coil fins increase surface contact between metal and air for maximum heat transfer and efficiency.
• Incredibly Quiet Operation Approximately 50% lower noise levels compared to a 14 SEER single-stage unit. Swept-wing fan blades and a heavy-duty compressor blanket further reduce sound levels.
• Integrated Compressor Protection The combination of both high and low pressure switches gives additional reliability' protecting the compressor from unsafe refrigerant pressures.