re: construct a radiant barrier 'wall' to keep rv cool at 'home base'?
4 apr 1998
brent geery wrote:
>i have been trying to think of good methods of cooling my future bus
>conversion by passive means... for those times i'm at my 'home base'
>in the ca high desert about 75 miles north east of 29 palms, ca. (swamp
>coolers will be used on the road).
can you use the swamp coolers more passively at home, if you have a
source of cooled water, eg a shallow pond to the north of the bus?
>i would simply build a east/west running wall the length of the bus to
>provide shading to the south. the wall will be just to the roof line...
sounds good. i guess you won't need much heat in the winter.
>the bus will have 16 83 watt solar panels on the roof the will tilt to aim
>toward the sun, this will help shade a good part of the roof.
how about trickling some water over some of their faces
to make hot water for showers?
>the bus will also have a 5 foot c-band satellite dish that will also
>shade a bit more of the roof. total roof shaded will ba around 60%-70%.
why not shade more of the roof by covering it with foil,
or your insulated gravity-feed hot water storage?
>to the ends of the wall i will mount doors equal to the width of the bus
>allowing shading to the east and west (no shading is really needed in the
>north of course).
sounds pretty shady :-) maybe some sort of plants could do this...
>2. if double sided, do a allow for air to circulate from the bottom of the
>wall and create a chimney effect, or build to the ground and thereby more or
>less making it air tight.
i don't think it matters much how airtight the wall is, as long as it
blocks most of the sun, although less airtight probably means less
wall material and a little more cooling airflow through the wall.
>4. use one of the aluminum radiant heat barrier products in an effort to
>increase the effectiveness even further. (this stuff is already planned for
>the bus conversion).
i wouldn't waste that extra effort on the wall.
daggett, ca, has an average daytime temp of 88.9 in july, 74 at night
and 103.9 during the day. the average humidity ratio is 0.0071 pounds
of water per pound of dry air, corresponding to a dewpoint of 48 f.
you might cool water with a small shaded pond on the roof or to the
north of the bus. the max sun elevation at noon on 6/21 at your 35 f
latitude would be 90-35+23.5 = 78.5 degrees, so a 10' high bus, pvs etc,
would only provide about 2' of shade to the north. you might like an
awning on that side...