QUESTION: We are considering installing a heat pump or central air-conditioner. We currently have radiant heating. I have heard mini-duct systems are very comfortable and quiet. How do they work?ANSWER: Mini-duct systems are also sometimes called pressurized or high-velocity systems. They are ideal for installation in an existing home without a central duct system or in a new house instead of installing a standard central duct system.Although they are often used for air-conditioning, they are also equally effective for wintertime heating. The heating source can be an efficient standard heat pump, geothermal heat pump, electric furnace, etc. Since mini-duct systems are often installed in homes with radiant heating, hot water coils can be added to also provide supplemental forced air heat.Mini-duct systems use small ducts (two or three-inch diameter) instead of large metal ducts. The ducts are highly insulated and covered with foil. The complete insulated duct is small enough to run through an existing wall or ceiling made with stud framing.Instead of the main blower being located in a utility room or basement, it is usually located in the attic. A large main insulated trunk duct is run along through the attic. The many small insulated two-inch ducts run from this long trunk duct to the individual rooms. You may choose to heat or cool just several rooms, or perhaps an addition, with the mini-duct system.To get enough air flow through the small ducts, the blower operates at a higher pressure than a blower using standard large ducts.This is a distinct advantage when cooling in humid climates. With the high pressure, the heating/cooling coils can be dense and three times deeper than standard coils. This dramatically improves the dehumidification.Instead of floor registers, the heated or cooled air blows out two-inch diameter outlets in or near the room ceiling. There are several outlets per room. The air flows out at a high velocity, but it is very quiet.Its velocity creates an aspiration effect which mixes the heated or cooled air with the room air for more even (floor-to-ceiling) temperatures.The two-inch ducts have a five-inch diameter flange. They can be painted to match the wall color or are available in brass and natural wood. For outlets in bathrooms or kitchens, long narrow rectangular ones fit above or below cabinets.With the high pressure (and suction) of the mini-duct system blower, often only one return air duct is required. This can be located in a hallway where sound will not be annoying when your family is sleeping.Special sound-muffling sections can also be added near the end of the ducts by the outlets.The following companies offer mini-duct central systems: Comfortpro Systems, 800-968-8905, www.comfortprosystems.com; Energy Saving Products, 888-652-2219, www.hi-velocity.com; Mestek, 413-568-9571, www.spacepak.com; and Unico, 800-527-0896, www.unicosystem.com.

Send inquiries to James Dulley, Butler Eagle, 6906 Royalgreen Drive, Cincinnati, OH 45244 or visit www.dulley.com.QUESTION: I have to replace the kitchen faucet. I currently have a two-handle faucet, but I am considering installing a one-handle faucet. Is there any conservation advantage to either type of faucet?ANSWER: They both work equally well. A two-handle faucet has two valves, instead of one in a one-handle faucet, so there is a slightly greater chance it may leak over time. Also, a one-handle faucet is more convenient to use.If you have children, a two-handle faucet may be more efficient. When a child needs cold water from a one-handle faucet, he often moves the handle toward the center. This mixes in some hot water when only cold is needed.