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warm rooms vs dryers
6 feb 1998
birgit ferran writes:
>this summer while we were in norway we rented an apartment that had a
>clothes dryer that was the size and shape of a refrigerator. on the inside
>it had a set of prongs over which you had to hang your wet clothes. instead
>of wringing or spinning your clothes dry, what it did was to make hot air
>circulate through your clothes...
one hotel on the isle of harris, where it rains a lot, has a "warm room"
off the hall, a large 100 f (?) closet with pegs around the walls where
guests hang their damp raincoats and sweaters...
a 4'x4'x8' tall closet lined with 2" of styrofoam insulation has a heat
conductance of 160ft^2/r10 = 16 btu/h-f. keeping it 100 f in a 70 f home
should require about (100-70)x16 = 480 btu/h or 141 watts, eg a couple of
100 watt light bulbs, vs a 5 kw dryer, and the heat and moisture could
stay inside the home in the winter, slowly adding desirable humidity to
an air-leaky home in the winter. in an airtight home, the water vapor
might leave the closet and condense inside a 70 f container.
drying 20 pounds of clothes with 20% moisture means evaporating 4 pounds
of water with about 4,000 btu or 1.2 kwh over at least 1.2 kwh/200w = 6 h.
adding a 1500 watt ie 5100 btu/h heater with a little fan and thermostat
would raise the closet temperature to 70 + 5100/16 = 390 f in principle,
drying clothes faster and making the closet usable as a sauna...
>i was thinking that it might be possible to make a similar appliance
>using solar energy to heat the air. does anyone know if such an
>appliance exists?
sure. a sunspace with a clothesline, or a solar closet for 24-hour or
cloudy-day drying, eg an 8' cube mostly filled with sealed water drums
with insulation on every side, and a glazed solar air heater on the
south side, with air circulation during the day, and none at night.
nick
nicholson l. pine system design and consulting
pine associates, ltd. (610) 489-0545
821 collegeville road fax: (610) 489-7057
collegeville, pa 19426 email: nick@ece.vill.eedeeyou
computer simulation and modeling. high performance, low cost, solar heating and
cogeneration system design. bsee, msee. senior member, ieee. registered us
patent agent. solar closet paper: http://leia.ursinus.edu/~physics/solar.html
web site: http://www.ece.vill.edu/~nick
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