BobVila.com

Bob catches up with Mike Donaghey from American Standard behind the barn to learn more about the compressors. The units are part of the barn's air-conditioning system. They dissipate the heat from inside. The units have a powder paint finish and ceramic-coated screws to prevent rusting for safety as well as aesthetic reasons. Inside the lid is a little motor and a fan and on the interior walls is spined fin - a patented heat transfer agent that's essentially the copper pipe through which the refrigerant flows. Mike takes the sound jacket off to show Bob the scroll compressor which is nestled deep inside the unit. Scroll compressors have now replaced reciprocating compressors because they are more efficient. This a a 12-SEER unit (SEER in an acronym for Seasonal Energy Efficient Rating). The government has mandated that in five years this will be the minimum rating allowed. The compressor and coil both have 10-year warranties but can last much longer depending on the part of country. Rusting out of the casing -- especially with exposure to salt air -- is one big issue with life expectancy but aluminum to aluminum helps as does the powder coating.

The plumber Steve Bowton shows Bob how to sweat a joint in copper plumbing. First he cleans the pipes with an emery cloth. Then he explains that plumbers no longer use lead solder and instead use a tin and antimony mixture to protect homeowners from lead poisoning. Then he puts flux on the pipes and the fittings. Places the fixture on the pipes and levels it, then solders the joints. The flux helps draw the solder into the space.

Robert Kirkpatrick from Rinnai joins Bob to explain the tankless hot-water system being installed in the Manhattan Brownstone. Kirkpatrick explains that there are three key advantages to the tankless system. There's a huge space savings since the unit mounts on a wall, sparing the 12 to 16 square feet of floor space typically dedicated to the water tank. These tankless systems are also 70 percent more efficient than electric hot-water tanks. Most impressive of all, they provide an endless supply of hot water since the water is heated on demand rather than kept in storage. Kirkpatrick shows Bob the flow sensors that receive the water, generate the demand for heat, and gauge the amount of energy necessary to heat it to the desired temperature. The water is heated as it passes through the copper heat exchanger at the top of the unit. A double-wall pipe serves as the combustion air intake and the exhaust for the system, with a vent chamber up the middle surrounded by air intake along the perimeter of the pipe. This system is cost efficient as well, with payback of the initial investment in two to four years.

Here s another great tip from BobVila.com. If your pipes are whistling, banging or knocking when you turn the water on or off, there are things you can do to quiet them. Water hammer is a common cause of banging pipes. In plumbing where water pressure is high, shutting off the tap can cause the pressure to back up and jolt the pipe, a little like slamming on the brakes in your car. The jolt can be especially violent when a solenoid-controlled appliance like a washer or dishwasher shuts the tap since the shutoff happens instantaneously. Many homes come already equipped with water hammer arresters, which are small air chambers attached above the water line to absorb the pressure of the water as it s shut off. Spiral-shaped water hammer arresters were also used years ago and you may still find them in older homes. Plumbing that s not properly anchored to the framing can rub or bang on whatever is nearby and cause a racket. All this banging and jolting can strain pipes and copper fittings and you can eventually wind up with a leak. It s best to deal with the cause of the noise wherever you have access to the plumbing. Plastic or nylon pipe inserts work well to cushion pipes running through framing members, but they need to be installed when you do the plumbing. For retrofitting, try pipe hangers. These plastic hooks hold the pipe off the framing and have a felt or rubber cushion to absorb any movement and prevent noise. Whistling sounds are also common where a shutoff valve hasn t been opened all the way or where pressure is high. If your water pressure is excessively high, installing a pressure-reducing valve near the water meter will get rid of the noise and lower your water bill. But consult a plumber first to be sure it won t take too much pressure away from any upper story plumbing. Find out more at BobVila.com: the ultimate home improvement web site! 2008 BobVila.com

Freeze-proof outdoor faucets are the best replacement option in areas prone to freezing and low temperatures. The project requires drilling and soldering, so be sure you are confident taking on the project.

A corroded shutoff valve can start to leak. Consider replacing the valve to save water and prevent water damage.

Bob gets some tips about how to hook up an automatic ice maker from plumber Ed Mann. Ed demonstrates how to connect the ice maker with the water supply in the house. One-quarter-inch soft copper tubing is used and an extra five feet of slack is left on the line in order to move the refrigerator in and out without removing the line. Ed likes to use a copper tee and compression valve instead of the saddle valve because the earlier method will result in many years of service whereas saddles have a tendency to leak. A compression fitting is used to make up the copper tubing to the solenoid valve on the refrigerator.