Renewable energy could 'rape' nature

Been thinking about what you said about radiant heat barriers. In 1970 I stayed in a house in mexico that was almost perfect as to passive solar heating. Basically it was a high south, thick, adobe wall, shed roof to a north low wall, trapezoid east/west walls. That solar radiant heat kept the place warm until about 12PM/1AM.

So I’ve been thinking of a way to improve on that design with louvers on all 5 surfaces(incl roof), as suggested by you. It’s only a prelim idea of course but it might work for southern(warm/hot)climates. The only mech’l parts needed would be high torque/low speed electric motors and photocells for the louvers, plus add’l A/C system, mostly for fresh air in the house. Any mech’l engineer out there interested in hearing more about the idea?

Yes, I was thinking of springs as a return mechanism, but not just 2 positions(open and shut). My thought is louvers that turn 15 deg/hr, keeping the edges pointed at the sun. That way the rays shine full on the dark surface below and re-radiation sideways is bounced back to the surface off the silvered louver surface.

Thus the east wall opens to pointing east at 6AM, then swings 90 deg up until noon, following the sun edge-on. The south wall louvers swing 180 deg from east to west 6AM to 6PM. The west wall the reverse of the east wall. The north wall louvers open at 6-8AM to edge-on due north, then close again 4-6PM towards the end of the day. The north wall has the most windows. The roof louvers open to vertical from 6AM to 6PM and close down to the(say)2:12 roof slope from 6PM evening to morning at 6AM again.

Basically this is a “sunflower” idea wherein the louvers are edge on to the sun, sucking up max rays during the day(heating up the adobe and/or insulation); then buttoning up w/closed louver layers at night, forming radiation back-bouncers and closed convection cells outside the adobe/roof. The 2 man doors are in the east & west walls with a third possible thru north wall to garden to the north. It’s a shed roof of course from high south wall to low north wall.

If you’re into solar collectors, the dark south wall(primarily)would be your collecting surface. The roof I’d make just EPDM rubber roofing(black), about 45 mil. The wall color could be dark purple/dark blue instead of pure black(virtually the same albedo).

As to the louver material, shiny silver both sides, aluminum metal strips would probably be too expensive, maybe plastic mylar strips instead. 2’ o.c. support shelves up the wall, ie, too great a length for the plastic louvers and they’ll be constantly fluttering in the wind(or sagging on the roof). Swing an entire side w/high torque, low HP motors turning rods which in turn pull strings. Springs return all the 5 layers to their closed/pre-dawn positions at about 6-7PM(buttoned up for the night). As you get variable cloud cover, a timer would probably work better than a photocell for louver edge-on orientation.

So, there it is : a passive solar house that opens up to the sun during the day, then buttons up at night, letting that stored solar energy in the insulation ooze into the interior all night long(12-16 hr delay of heat-pulse). Would it be cost effective, practical? Donno, it’s only a prelim idea as an improvement over that ideal solar house in mexico that I stayed in for a couple of months(winter of 1970-71).

Of course if you had an exterior wall/roof material that turned black when heated by the sun, then white/silver when the sun is not shining on it, you wouldn’t need the 5 louver layers(as per blackbody radiation losses to a cold night sky). But that may be an unobtainium problem...

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