In this study, internet-controlled heating ventilating and air-conditioning (HVAC) system has been proposed with programmable sleeping time and automatic operation mode, three steps fan speed unit, adjustable fan angle, a remote control device with an LCD and a wed based control unit. A low cost microcontroller (MC) to control HVAC system and a PC as an Internet server are used. The system has three different control units (remote control by a hand-device, keypad control mounted on HVAC, and web based control). Each control units has same menu options for users. A data acquisition board provides communication between server and MC. A webcam is used to monitor HVAC parameters and room environment remotely over the Internet. The system uses HTTP protocol to control devices. Proposed web based control method remotely works for long distance. As HVAC systems have high voltage, driver circuits with opto-couplers have been used for safety of the system.