ROANOKE TIMES
Copyright (c) 1995, Roanoke Times
DATE: Sunday, December 17, 1995 TAG: 9512180024
SECTION: HOMES PAGE: D2 EDITION: METRO
COLUMN: Cut Your Utility Bill
SOURCE: JAMES DULLEY
Q: My house smells stuffy and my allergies are bad. Even though I have a central air cleaner, should I run a room air cleaner too? What types are best and do they cost much to run?
A: Many people, not just ones with allergies, suffer from "sick home syndrome." As homes and offices become more efficient and airtight, indoor air becomes a chemical and particle soup. Only about one-tenth of the particles floating in indoor air are large enough to be visible.
It does make sense to use room air cleaners in addition to a central furnace air cleaner. I use a quiet one in my bedroom at night. Most room size air cleaners use less electricity than a 100-watt light bulb.
Room air cleaners are especially effective for allergies. Whereas a central air cleaner runs only when the furnace is on, a room air cleaner works continuously. This removes particles and odors before they settle.
There are many effective designs of room air cleaners - HEPA (high efficiency particulate air), electronic precipitators, self-charging electrostatic, ionizers and ozone generators.
Each type of air cleaner is particularly effective for specific-size allergen particles, so don't just buy the cheapest one on sale. Select one with an activated charcoal final filter to remove odors, too. Heavier charcoal is more effective. Some have as much as 25 pounds per element.
HEPA and electrostatic precipitators are the most effective overall, especially for small smoke particles. A HEPA (very dense and finely-packed filter material) air cleaner is 99 percent efficient. Pleated media is a less efficient, loosely packed type of HEPA filter and is less expensive.
Electronic precipitators electrically charge allergen particles as they pass through the air cleaner. These charged particles then stick to collector plates with the opposite charge in the air cleaner.
Self-charging electrostatic filters use a material that develops a static charge as air moves through it to trap the particles. They are most effective for larger allergen particles like mold and pollen.
Ionizers produce negative ions that cause particles to drop out of the air. The particles collect on walls and tables so they can be easily vacuumed.
Ozone generators produce very mild ozone concentrations and use little electricity. Ozone (activated oxygen) chemically destroys odors, smoke, bacteria, etc. Ozone causes the fresh sweet smell after a lightning storm.
Q: I like a steamy shower in the morning, but I run out of hot water after the kid's showers. Setting the water heater thermostat higher is wasteful. Will an efficient tankless instant water heater help?
A: A gas, propane or electric whole-house tankless water heater can provide an endless supply of steamy hot water, enough for 10 consecutive showers. There are also mini point-of-use units available for a single bathroom.
Eliminating the need for a water heater tank saves the typical 15 percent standby energy losses and cuts your utility bills. The hot water temperature can be adjusted on the tankless heater or remotely in the bathroom.
Tankless water heaters offer several other advantages. With no tank to rust out, one will last a lifetime. The stainless steel parts, copper heat exchanger and solid state controls are easily replaced if they ever fail.
A tankless water heater (also called instantaneous) uses powerful built-in gas or electric heaters to heat cold water as it passes through the heat exchanger. Some heat exchanger designs force the water to make nine passes for the quickest and most efficient, low-cost water heating.
When a hot water faucet is first turned on, an automatic pressure differential sensor in the tankless water heater switches it on. Within seconds, precisely heated water is flowing to the bathroom or kitchen.
Automatic sensors and heat output controls are built into gas and electric models. If only a slow flow of hot water is needed, the burner operates on a low setting. As you need a greater hot water flow rate, the burners output automatically increases.
In electric models, the elements come on sequentially to achieve accurate hot water temperature control. Some newer designs use sophisticated electronic controls to vary the elements on-time for constant temperatures.
Tankless water heaters are small and lightweight enough to be mounted on a utility room or basement wall. This saves floor space.
Some gas and propane models have power vents to exhaust the flue gases outdoors through a horizontal flue. This simplifies converting from a costly electric water heater to an efficient gas or propane tankless model.
Point-of-use tankless water heaters are ideal for a single bathroom. One new electric model, Instant-Temp, has a digital temperature control mounted on the shower wall. You can instantly adjust the shower or bath water temperature. It maintains the temperature within one degree of the setting.
For a buyer's guide of 20 efficient room air-cleaner manufacturers, listing filtration methods, air flow rates, number of speeds, weights, prices and an allergen size chart, write to James Dulley, The Roanoke Times , 6906 Royalgreen Dr., Cincinnati, Ohio 45244. Ask for Update Bulletin No. 933.
For a buyer's guide of efficient whole-house and point-of-use gas, propane and electric tankless water heaters manufacturers, listing hot water output rates, specifications and prices, ask for Update Bulletin No. 929 Each bulletin costs $2. Enclosed a self-addressed, stamped envelope.
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