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development document

Passive Solar Design

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goal

The goal of this development document is to create an efficient passive solar design for a house—with and without an attached greenhouse.

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Rob Stout

Aperture: receiver of sun (angle), 2 ft height + 45 degree angle (avoid perpendicular to summer sun) - avoids heat loss in winter and heat in summer - minimize heat loss area.

Make end walls (east and west) insulated

32 x 16 - make it the entire length of house, narrower (closer to the house wall) - larger greenhouse = larger collection area, minimize depth

sink it 18” minimum

Tank - make it linear, closer to the house, stop it before end walls (heat loss there)

Glazing -

Extend house overhang 4 ft

Send Rob a sketch

Ventilation: low row of operable vents

Air motion: direct PV fan ($20) - 12V (air movement 15 ft away) - attached to a small solar panel - angled so that they circulate air - at the top of the roof corner - pointed diagonally down.

Pond - direct gain on to surface of pond is not major heat source (should not influence the shape of the pond)

Floor - crusher pines (crushed gravel, compactable) - make it out of gravel

Northern 3rd of greenhouse roof insulated. Quad polycarbonate.

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Rob Stout

Solar thermal system: Rob has a patent

We can buy them used - $100 - installed almost vertical - 12V 20W + PV panel mounted vertical - panels with potable antifreeze - when vertical PV panel (90 degrees, 3 ft tall) gets sun - $60 circulates antifreeze from solar panels - and earth beds. Significantly increases freeze protection. High limit switch - wall thermostat - turns the system off at a given temperature.

Common wall - just mass (the more, the better) - smaller windows (3 ft high, wider than taller) - the higher the top of the window is, the deeper the light penetrates into room

Active trombe wall - it’s like a 4” greenhouse

Greenhouse needs carbon dioxide

Thermal gain from greenhouse not huge - good, but not a lot.

R80 for roof as min, R50 walls min - Windows (Alpen - R7)

20” of space for blown cellulose - R75

Cellulose performs better in lower temperatures - at 10 below, the R value of fiberglass drops to about 1/2