Frigidaire FS4BI Series, R-410A Ultra High Efficiency iQ Drive Air Conditioner, 22 SEER. The iQ Drive Air Conditioning System features fully variable speed compressor technology and variable speed indoor and outdoor motors. The system provides variable cooling capacity as needed. It operates near the nominal rated capacity at the thermostat set point and modulates as temperature difference between set point and room temperature changes. The system may run at additional 18% capacity to provide rapid cooling. The system has a built-in humidity control that will activate humidifier equipment (if supplied), and reduces blower speed if indoor relative humidity is greater than set point (default set at 60%). iQ Drive - Inverter driven Panasonic rotary compressor which provides fully variable operation. R-410A Refrigerant - Environmentally friendly nonozone depleting refrigerant. Designed using galvanized steel - with a polyester urethane coat finish. The 950 hour salt spray finish resists corrosion 50% better than comparable units. Copper Tube / Aluminum Fin Coils - Both indoor and outdoor coils are designed to optimize heat transfer, minimize size and cost, and increase durability and reliability. Permanently Lubricated Motor - A heavy duty brushless motor for long lasting reliability and quiet operation. Requires no maintenance and is completely protected from rain and snow. Compressor Sound Blanket - Engineered to significantly reduce unwanted compressor noise. Swept-Wing Fan Blade - Engineered to provide quiet operation. The specific energy absorbing hub is designed to reduce noise while operating through various frequencies. Louvered Condenser Guard - Durable metal guard protects the coil from yard hazards and extreme weather. Removable Top Grille Assembly - Allows ease of service from the top without disconnecting fan motor leads. High Pressure Switch - Protects against abnormally high system pressures. Auto-reset feature prevents nuisance service visits. Low Pressure Switch - Protects against loss of system refrigerant charge. Liquid Line Filter Drier - Included with unit, field installed. One Piece Top/Orifice - Designed for maximum airflow and quiet operation. Easy Compressor and Control Access - Designed to make servicing easier for the contractor, access panels are provided to all controls and the compressor from the side of the unit. Highest Efficiency With The lowest Sound Levels - Up to 25.5 SEER with sound ratings of 59-72dB depending upon operating conditions.