Find out what makes IFB ACs Heavy Duty and Fastcool. IFB Fastcool ACs can turn any area into a cool haven.Even in situations where the outside temperature approaches 58°C, the IFB AC's Variable Velocity Twin Rotary Heavy Duty Compressor performs flawlessly. The IFB AC's AI evaluates the room's temperature as well as the outside air and adjusts the cooling to compensate.