Microwaves for You

["Pickett, Bruce D" <Bruce.Pickett@PSS.boeing.com>]

The following article appears in the Home Technology section of the
April 1997 issue of Popular Science magazine, published by Time Mirror
Magazines.

bruce d. pickett
Boeing Radiation Health Protection
bruce.d.pickett@boeing.com
(206) 393-3098

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Microwaves for You

MICROWAVES MAY BE great at warming up leftovers, but what about warming
people?

Using microwaves to directly heat occupants of a room would allow
significant lowering of a home's thermostat, saving much of the energy
wasted by heating walls and furnishings. And despite popular notions
about microwaves, this technique would be safe, according to Charles R.
Buffler of the Microwave Research Center in Marlborough, New Hampshire.
Low-power microwaves barely penetrate the skin (low-power microwave
penetration in a ham is approximately 0.2 inches, for example) and with
no adverse effects.

To test the concept, Buffler and a colleague subjected themselves to
microwaves in a special room using a standard 500-watt, 2,450 MHz
magnetron. They recorded measurements correlating microwave exposure to
the response time for the subjective feeling of warmth. They found that
a person will start to feel warmth at about 20 milliwatts per square
centimeter (mw./sq. cm.); a satisfactory sensation of warmth occurs
between 35 and 50 mw./sq. cm. By comparison, a person standing in
noonday summer sun feels the equivalent of 85 mw./sq. cm. And a frozen
burrito in your microwave oven receives about 1,000 mw./sq. cm.

In houses of the future, each room could be equipped with its own
magnetron, says Buffler. When you stepped into the living room, for
example, a motion detector would activate the magnetron, filling the
room with low-power radiation. In the same way that a microwave oven
heats up a hamburger, but not the plate it's on, you would feel the
warmth from the radiation without changing the temperature of your
coffee table. (You could, however, make your favorite easy chair even
more comfy by treating it with a radiation-absorbing chemical.)

While it might be some time before homeowners are comfortable enough
with the idea to install whole-body microwave heaters in houses, Buffler
says microwaves may appeal to livestock farmers. Lambs that are born
outdoors in winter, for example, are frequently lost to hypothermia.
Microwaves could warm the lambs safely and quickly.  - Richard Babyak