|
| Back to Contents Page |
Home Energy Index |
About Home Energy |
| Home Energy Home Page | Back Issues of Home Energy |
Home Energy Magazine Online September/October 1993
CONSERVATION CLIPS
Conservation Clips is compiled by Cathlene Casebolt of the
National Center for Appropriate Technology, a non-profit organization working
in sustainable energy, agriculture, affordable housing, and environmental
protection. Conservation Clips contains brief summaries of useful
research reports and articles in related magazines, and other publications
collected by the NCAT staff. Contact NCAT, P.O. Box 4000, Butte, MT 59702. Tel:
(800) 428-2525; Fax: (406)494-2905.
Puget Power's Conservation Reductions. Puget Power and Light will no
longer fund residential heat pumps, retrofit thermostats, or insulated doors,
as a result of its new total resource cost (TRC) test. The test, effective
April 1, 1993, determines a measure's cost-effectiveness by taking all
associated costs into account (including customer expense and utility payments)
and weighing them against the measure's total benefits (including electricity
savings and Puget's "avoided cost"). If total costs outweigh total benifits,
the utility won't fund it. Prior to implementing the TRC, cost-effectiveness
was based only on Puget's cost. In addition to eliminating those measures, the
utility will decrease funding for several other measures as a result of the
TRC. Changes are also expected in the commercial and industrial sector. Puget
is allowing a grace period for customers to install measures soon to be
discontinued. Conservation Monitor, (April/May 1993), News Data
Corporation, Box 900928, Queen Anne Station, Seattle, WA 98109.
Tel: (206)285-4848; Fax: (206)281-8035.
Electric Water Penalties in California. Title 24 of California's
building code requires new buildings to meet an "energy budget" through
measures such as energy-efficient appliances, insulation, and fenestration
products. Measures that reduce energy consumption are assigned positive points,
and those that increase it are assigned negative points. Trade-offs between
measures are allowed, but the total points (taking all measures into
consideration) must not fall below 0 in order to comply with the code. In
revisions to the code, electric water heaters create a "substantial point
deficit," (about -20 for a 1,600 ft2 home), which is difficult to
offset in other areas of the building's design.
More practical options are gas- and propane-fired water heaters and heat pump
water heaters which, in a 1,600ft2 home, have a point value of +1.
Woodstove boilers constitute another option. Heat pump water heaters,
considered the most energy-efficient systems, are about three times as
efficient as electric resistance systems. In addition, these systems supply
"free" cooling, which means reduced air conditioning costs in summer (though in
winter, the heat comes from the heating system). Heat pump water heaters are
not widely used in California, largely because customers aren't aware of their
advantages. Electric Water Heating News, Winter (1992-1993), EPRI, P.O.
Box 10412, Palo Alto, CA 94303. Tel: (415)855-8950; Fax: (415)855-2954.
Ozone and Indoor Pollutants. Through a study led by Charles J. Weschler,
scientists have discovered that smog ozone promotes volatile organic compound
emissions in nylon carpets. The study revealed that ozone can infiltrate
buildings--in some cases, nearly equaling outdoor levels--and then interact
with indoor materials such as nylon carpets and backings. In the four
experiments conducted for the study, a stainless steel reaction chamber was
carpeted. A ventilation system changed the air inside the chamber once each
hour. Scientists measured VOCs for a week and then introduced ozone to the
chamber. When the ozone had stabilized (28-44 parts per billion), air samples
were taken again. The results showed that emissions of formaldehyde and
acetaldehyde (both suspected carcinogens) were three and 20 times greater,
respectively, when ozone was present. Ozone also stimulated other aldehydes by
reacting with the carpet's nylon pile. Worth noting, though, is that the ozone
reduced several other VOCs from carpet adhesives and backing, including the one
causing "new carpet" odor. Science News, (December 19 and 26, 1992),
11719 N St. NW, Washington, DC 20036. Tel: (202)785-2255.
Indoor Air Quality Sensor. Ventilation unquestionably ensures good
indoor air quality in tight homes. Fresh air can help dilute pollutants, but it
may not be enough. To help solve more serious indoor air quality problems,
Gaztech International of Goleta, California, has developed a new ventilation
controller that introduces more fresh air when it senses an excess of certain
pollutants such as carbon dioxide and carbon monoxide as well as a rise in
indoor humidity. The system--the Venostat 2001 Series--is based on "Non
Dispersive Infrared Technology," which has been used in medical and gas-sensing
products for more than 40 years. Through infrared radiation, the sensor can
identify gases with polyatomic molecules, which diffuse through a membrane into
a "sampling chamber" in the product. When too many of such molecules are
present, a microprocessor calls for more fresh air. Popular Science
(February 1993), 2 Park Ave., New York, NY 10016. Tel: (212)779-5000; Fax:
(212)779-9468.
Exhaust Appliances and Backdrafting. While powerful exhaust appliances
in tight homes can help remove indoor pollutants, they can also cause indoor
air quality problems. A case in point: After becoming ill at the beginning of
two heating seasons, a homeowner in Vermont suspected that his new house was
causing his illness. He began operating his 500-cubic-foot-per-minute range
downdraft fan to help remove the pollutants. However, an investigation by
Central Vermont Public Service Corporation revealed that the range fan was
actually to blame--it depressurized the house, which ultimately caused the oil
furnace to backdraft.
One way to solve such problems is to eliminate chimneys and natural draft
combustion appliances altogether. Builders in British Columbia, however, are
trying a different approach--installing fresh air supply fans to offset
depressurization caused by exhaust fans. In fact, building codes there require
this design feature in new homes with chimneys. The same thing is required of
consumers participating in BC Hydro's new construction and retrofit energy
programs. Energy Design Update, (March 1993), Cutter Information
Corporation, 37 Broadway, Arlington, MA 02174. Tel: (617)648-8700; Fax:
(617)648-8707.
Heat Recovery Not Cost-Effective. Heat recovery ventilators can provide
mechanical ventilation in tight homes and, at the same time, retain 50%-90% of
the heat in the exhaust air. However, two studies, one conducted by the
Northwest Power Planning Council for the Super Good Cents Program, and the
other by the State of South Dakota, found that heat recovery ventilators are
not cost-effective in milder climates. Some of the reasons cited are high
installed cost, low system efficiency (about 55%-75%), and higher infiltration
levels in homes. To determine whether a heat recovery ventilator is
appropriate, factors such as ventilation rate, energy costs (including
electricity costs of defrosting the heat recovery ventilator in a cold
climate), and heating system efficiency must be taken into account.
For example, a 2,500ft2 home in an annual 7,000 heating degree-day
climate, with a 95% efficient propane furnace (and with fuel cost as low as
65cents per therm) and with an hourly air change rate as low as .25, would pay
only about $90 in annual ventilation energy costs. A $3,000 heat recovery
ventilator system would take 32 years to pay for itself--not a very
cost-effective investment. On the other hand, in colder climates, such as
Saskatchewan with 12,000 annual degree-days, heat recovery ventilators offer
considerable energy savings. Indoor Air Review, (October 1992), IAQ
Publications, Incorporated, 4520 East-West Highway, Suite 610, Bethesda, MD
20814. Tel: (301)913-1005; Fax: (301)913-0119.
| Back to Contents Page |
Home Energy Index |
About Home Energy |
| Home Energy Home Page | Back Issues of Home Energy |
Home Energy can be reached at: contact@homeenergy.org
Home Energy magazine -- Please read our Copyright Notice
|
