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