1.   The coils warm the air, and it is distributed by the duct system.

2.   A motor-driven blower forces the heated air throughout the house via a duct system.

3.   But Bruce McCormick, an inventor from Houston, has come up with a face mask that works like steam heat in a duct system.

4.   Does each AC system have its own duct system with each duct system serving only half the house?

5.   If you have ever inspected your duct system, you can appreciate how much dirt a cleaning project will get out.

6.   Q. I have a three-family house with three furnaces in the basement, with their own separate duct systems.

7.   She said two contractors were working in the terminal, one on the duct system and another on the fans and control panels.

8.   Still the homeowner should inspect as much of the duct system as possible.

9.   That way, it is hoped, the air from your unit will stay in your duct system.

10.   The best way to evaluate the efficiency of a heating duct system is to have a heating specialist run a flow hood or blower door test on the ductwork.