Because refrigerators generate large electric fields, they should be given a dedicated circuit and the wiring should be shielded with one of the recommended metal conduits in order to block the fields. In addition, the metal refrigerator cabinet should be bonded to the electrical ground. Since the compressor motor and defroster will still produce high magnetic fields, the home should be designed with the refrigerator at least 12 feet away from living and sleeping areas.
As discussed in the section on air barriers in Division 7, electrical boxes must be sealed in order to make an exterior wall airtight. You may have experienced the flow of air coming through an outlet on a cold day if the boxes are not installed in an airtight manner. It is necessary to prevent air from flowing into the living space from a wall cavity not only for the sake of energy efficiency but also to maintain optimal indoor air quality. The following gasketed electrical boxes are designed to create an airtight seal:
• Lessco Air Vapor Barrier Boxes
• Allied Moulded Vapor Seal Boxes
Residential lighting can also be a source of electromagnetic fields. Here are some pointers on residential lighting and EMFs:
• Transformers of low-voltage lighting produce a magnetic field. If you use low voltage lighting, choose remote transformers and locate them in closets at a distance from where you spend a lot of time.
• Fluorescent lighting with ballasts emits magnetic fields that may not be detectable on an inexpensive gaussmeter. Avoid fluorescent lighting with ballasts in areas where you spend a lot of time, and never locate it on a ceiling below a bedroom. It should also be noted that fluorescent light tubes and compact fluorescent lights contain mercury and should be properly recycled. Breaking the tubes may release the mercury. (For more information about proper disposal, see earth911.org.)
• If you are using recessed can lighting, specify insulation contact airtight (ICAT) cans. These cans save energy and prevent dust and attic gases from filtering into the cans.
• If wiring is run through a metal conduit, the metal housing of the fixture must be in electrical contact with the metal conduit in order to shield the occupied space from electric fields.
The two basic types of smoke detectors are ionizing and photoelectric. The ionizing type contains a radioactive substance called americium-241. Although the radioactive substance
is shielded, we cannot recommend this type because there is no safe place for disposal once the smoke detector is discarded. Smoke detectors are available for use with 9-volt batteries or for hardwiring into the 110-volt household wiring, with or without battery backup. We recommend a hardwired photoelectric system with battery backup, which can be purchased through BRK/First Alert and MCS Referral & Resources. If you are wiring so that your bedroom circuitry can be shut off, it is important to put the smoke detector on a separate circuit so that it will always remain active. If this circuit is run through a metal conduit, the electric field will be minimal.
All gas-burning appliances to which occupants are exposed, such as gas ranges and dryers, should be tested for carbon monoxide emissions prior to building occupancy. Hie installation of a simple monitoring device ensures that you will be alerted if a problem with carbon monoxide develops. The device should have battery backup and a digital readout. The following CO monitors meet these criteria:
• Aim S-450 is a portable pocket alarm CO detector unit with a digital readout.
• BRK/First Alert
• NightHawk Carbon Monoxide Detector contains a sensor that samples the air every 2У2 minutes and updates the digital readout.
Becker, Robert O. Cross Currents. J. R Tarcher, 1990. A timely and eloquent warning on the hazards of electronic pollution
Von Pohl, Gustav Freiherr. Earth Currents: Causative Factor of Cancer and Other Diseases. Freeh — Verlag, 1987.