Photos: Turning green into gold

Home Comfort Zone's MyTemp system uses balloons to regulate the amount of heat or air conditioning flowing into the rooms of a home. Someone spending all day in the den could shut off the heat to the rest of the house. Balloons inside the ductwork expand and deflate to cut off the flow of air. The system could be installed in any forced air heating and cooling systems, reducing monthly bills by half, according to the company. Currently, the system costs up to $8,000 to install, but the company wants to bring prices down.