Ceiling fan
A ceiling fan is a mechanical fan mounted on the ceiling of a room or space, usually electrically powered, suspended from the ceiling of a room, that uses hub-mounted rotating blades to circulate air. Ceiling fans typically rotate more slowly than other types of circulating fans, such as electric desk fans. They cool people effectively by introducing slow movement into the otherwise still, hot air of a room. Fans never actually cool air, unlike air-conditioning equipment, they in fact heat the air due to the waste heat from the motor and friction, but use significantly less power (cooling air is thermodynamically expensive). Conversely, a ceiling fan can also be used to reduce the stratification of warm air in a room by forcing it down to affect both occupants' sensations and thermostat readings, thereby improving climate control energy efficiency.
Federal roofing tax credit for energy efficiency
The 2009 roofing tax credit is part of a twofold plan rolled out by the US federal government. The first and most relevant of goals was intended to stimulate the economy by motivating Americans to replace their roofs with more energy efficient roofs, thereby creating jobs by increasing the demand for labor in the roofing, manufacturing, and construction industries. The other goal of the 2009 federal roofing tax credit was to reduce carbon emissions to the environment by requiring consumers to install Energy Star products on their homes in order to receive the tax credit; the installation of energy star roofing products in homes would reduce the consumption of electricity needed to maintain the desired temperature within the residence.