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Advice from Jim Dulley
Q: Our neighbor has a kitchen water filter and her water tastes
better. I wonder what else is in our water that might harm my
children. What types of water filters are best for flavor and safety?
- Ann T.
A: Even if your water is from a public supply, it may still
contain contaminants that may be harmful, particularly to children and
the elderly. By the time water gets to your house, the chlorine level
may have often dropped to the point where it may have gotten
reinfected in route to your home. It may not be a bad idea to have
your water tested.
Although there are many specific models, brands and trade names of
water filters, the basic options can be broken down into distillation,
reverse osmosis (RO), ozone, ultraviolet light (UV) and carbon. Each
type has its advantages for improving various water problems.
Countertop electric distillers are effective for improving most common
water problems and removing most contaminants. Since the water boils
during the distillation process, it is also disinfected. The water
vapor condenses and drips into a gallon jug. Once the jug is filled,
slip it out and store it in your refrigerator.
I have used a small countertop distiller for years at my own home. It
has a replaceable carbon filter bag that fits into the water outlet
spout. This removes some volatile chemicals that vaporize and condense
with the water and improves the taste.
The only drawback that I ever found is that it takes about four hours
to produce one gallon of pure water. RO systems are also effective for
most common drinking water problems and they produce filtered water as
you use it. This eliminates the chances of recontamination when the
filtered water is stored. These units use an RO membrane that acts
like a super-sieve to filter out almost everything in the water. Most
units also have pre- and post-carbon filter cartridges to remove
chemicals.
Ozone generator units use a small corona discharge ozone generator. To
purify one gallon of water, it is recommended to run it for 15
minutes. At only 24 watts, this costs less than a penny per gallon.
Ultraviolet water purifiers also use only about 30 watts of
electricity. Many replacement carbon filter elements are priced in the
$20 range. If you are a biker or runner, there are now special
filtering water bottles to remove impurities, cysts, bad flavor, etc.
They fit most bottle holders.
Q: My answering machine, VCR, microwave, telephones, etc.,
don't seem to last very long even though I use plug-in voltage surge
arrestors. Would installing a powerful whole-house surge suppressor
help? - Mary G.
A: Today's homes have many devices and appliances that use
sensitive solid-state components. In addition to the common electronic
equipment you mentioned, most new major appliances (refrigerators,
dishwashers, clothes dryers, etc.) have electronics that can be
damaged by voltage surges.
Although you are not aware of it, there can be hundreds of very short
duration 1,000-plus-volt surges in a typical home's wiring everyday.
The frequency and intensity of the surges depend on your specific
location. Your utility company does everything it possibly can to
minimize these voltage surges, but it is impossible to eliminate them.
The source of the surges is not your utility company's generators.
Surges are usually caused by lightning or when electrical equipment,
often large motors in nearby commercial businesses, switches off. They
can even be generated inside your own home when your air conditioner
compressor stops or you are running your dishwasher or clothes washer.
Although small plug-in surge arrestors help, they do not provide the
best protection.
Even if the voltage surges are not strong enough to destroy the
electronic components, frequent smaller surges can slowly break down
wiring insulation. This can cause premature device failure or just
faulty operation.
Microwave ovens have been known to start on their own. Your computer
may get glitchy. Your telephone answering machine may miss messages. A
combination of a high-quality whole-house surge suppressor and small
plug-in units (on sensitive electronics) provides the best protection.
If you have a computer, VCR or any newer appliances, you should
install a whole-house unit. It uses practically no electricity itself.
Several companies include a free $10,000-damage warranty when you buy
their whole-house units. If any of your major electric appliances are
damaged by voltage surges, they will repair them for free up to a
$10,000 maximum.
There are three basic styles of whole-house surge suppressors that are
commonly used. One design mounts on the circuit breaker box with wires
(I use this type in my own home). Another design has the surge
suppressor built into a snap-in circuit breaker. The third design, and
often the most powerful, mounts directly under the electric meter.
To understand how they work, think of a large "electric sponge". When
a voltage surge hits, instead of burning out your equipment, the
sponge (usually an MOV material) absorbs the energy. Since the surge
is of very short duration, the sponge dries out and is ready for the
next surge. A bigger sponge can absorb a bigger surge without being
fried itself.
Be thorough when selecting a whole-house surge suppressor. There are
significant differences in the level of protection of the many surge
suppressor models available. You cannot judge its quality and level of
protection by just looking at it or weighing it.
The key factors to consider are the strength of the surge current that
it can dissipate without burning out itself, how fast it reacts, and
the clamping voltage at which it begins to block the surge.
Compare the following specifications. The maximum surge current
indicates the surge strength that it can withstand. A higher number is
better. A reaction time of one nanosecond or less is adequate. A lower
clamping voltage is better because it begins to block the surges while
they are still small. Some of the newest models also provide
protection for your telephone and TV cable lines.
Many computer and fax machine modems have been destroyed by surges
through the telephone lines from a distant lightning strike. The input
and output telephone and TV cable jacks are built into the unit.
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