QUESTION: Both my energy and water bills are increasing, so I plan to install low-flow showerheads. I tried them before, but my daughters hated them. Are they any better now, and how do I pick a good one?ANSWER: In 1992, all showerheads sold in the United States were limited to a maximum water flow rate of 2.5 gpm (gallons per minute) at a water pressure of 80 psi (pounds per square inch). Your showerhead now might be as high as 5 gpm. Many of the new low-flow showerheads provide very nice showers.I must have tested more than a dozen low-flow showerheads last year alone. There actually are significant differences in the showerhead sprays for ones with identical flow rates. The most efficient ones are as low as 1.5 gpm and the savings can pay back their cost in just a few months.Keep in mind, whether or not you like a specific shower spray pattern, and force is a personal matter. I personally prefer a more forceful spray to a slower one. On the other hand, if your daughters are trying to rinse long hair, they might prefer a slower, but fuller spray pattern.There are a number of factors that determine how much water and energy will be saved. The water savings are determined directly by the gpm rating for the showerhead. The energy saving is affected by the gpm rating and how much hot water has to be mixed with the cold for a comfortable shower. Showerheads that create larger water droplets feel warmer on your skin.Some needle-type low-flow showerheads create tiny water droplets. These tend to cool down before they reach your body. If this happens, you will set the faucet to a greater percentage of hot water, and you might actually end up using more hot water (energy) than before. Some showerheads also add air to the spray for more force, but this also cools the water spray.It is easy to distinguish a narrow needle-spray design because they are usually small. For a fuller spray, look for ones with many holes across a larger face. Some might appear to have a large face with many spray holes. If they have adjustable patterns, not all the holes are used simultaneously, so they actually might create a needle spray.There are two inexpensive add-on devices that can help reduce water usage on any showerhead. One is a tiny push/pull trickle valve that is mounted before the showerhead. While you are lathering, push the button to slow the water to a trickle without having to readjust the faucet each time.Another is a "Lady Bug" valve by ShowerSmart. You can turn on the shower and walk away. When the water temperature hits 95 degrees, the flow is slowed to trickle so very little is wasted down the drain. When you are ready to get into the shower, switch it and the warm shower starts.The following companies offer showerheads and systems: Alsons, 800-421-0001, www.alsons.com; Delta, 800-345-3358, www.deltafaucet.com; Price Pfister, 800-732-8238, www.pricepfister.com; ShowerStart, 480-496-2294, www.evolveshowerheads.com; and Speakman, 800-537-2107, www.speakmancompany.com.

QUESTION: I live in a two-story house with adequate attic insulation. I checked the run time, and my central air-conditioner seemed to run more when it was 75 degrees outdoors than when it was 90. Can you explain this?ANSWER: I have given this a lot of thought, and I cannot explain it. It seems to violate the laws of physics. When it is hotter outdoors, more heat transfers into your house so the air conditioner should run longer to remove it.Also, air conditioners become less efficient as the outdoor temperature increases making them run longer. Double check the run times again vs. the outdoor temperature. If this continues, have the system checked.

Send inquiries to James Dulley, Butler Eagle, 6906 Royalgreen Drive, Cincinnati, OH 45244 or visit www.dulley.com.James Dulley has a degree in mechanical engineering. His column is published in more than 400 newspapers.