Abstract: A system for heating air in an enclosed air duct or wind tunnel which comprises a series of wind producing devices which are powered by conventional electrical power sources and a series of wind collecting devices which collect the previously generated wind to generate electricity which electricity is transmitted to a series of heat exchangers. Additionally, wind collecting apparatuses, e.g., a windmill, are provided outside of the air duct to collect wind on the outside of the air duct to drive a generator which provides additional electricity which is also transmitted to the heat exchanger. The heat producing elements could include fans and/or squirrel cage devices which are driven by electrical power sources. The wind collecting devices could include squirrel cage devices and/or fan devices which are each connected to generators for producing electricity which is then transmitted to the heat exchangers. A system may be comprised of multiple units of each of these devices.