howzit work? | answered here with pictures
Passive solar heating
Design a new house for minimum heating billls
solar water heat collectors
insulated
window
shades block
heat loss
at night
By SETH MASIA
Seth masia is deputy
editor of SOLAR TODA Y.
contact him at smasia@
solartoday.org.
In most parts of the United States, the largest part of a home’s energy budget goes to winter heating. A typical snow-belt home with an oil-burning furnace or
electric heat can spend more than $2,000 over the winter.
(Natural gas is considerably cheaper, but the price bounces
up and down.)
Passive solar design sharply reduces heating costs by
gathering and storing the sun’s heat during the day and
gradually releasing it to the living space after dark. The term
“passive” implies that no outside energy or active mechanisms are used to move the sun’s heat through the house.
A passive house may rely on some moving parts: windows
and vents that need to be opened and closed to regulate
temperature on sunny days and insulated drapes, blinds or
shutters that can be closed to seal in heat at night.
The principles: Build the house with large windows facing the sun. (In North America, that’s south, of course.)
Use insulated glass that lets heat energy pass in and then
holds it inside. Use floors and interior walls of masonry or
concrete to soak up and store heat during the day and thick,
roof windows
vent warm air
in summer
thermal-mass
back wall stores
the sun’s heat
solar hot water storage tank
radiant-heated thermal-
mass floor stores heat
during sunlight hours
kurt struVe
Copyright © 2010 by the American Solar Energy Society Inc. All rights reserved.
airtight insulation in outer walls to seal in heat overnight.
Additional insulating windows on the other three walls, not
shown here, provide daylighting.
The simple home shown here uses wide eaves to shade
the solar-gain windows from summer sun, and windows
under the roof peak can be opened to create a chimney
effect to vent summer heat. But the house is optimized for
winter heat gain. The north wall is well-insulated against
cold north winds and is faced with thermal-mass masonry
to store the sun’s heat. These techniques don’t add much
to the cost of building a new home and can save 30 to 70
percent of the heating bill, depending on the local climate.
In this example, a radiant-floor heating system provides the
balance of needed heat.
This house uses two active systems: The insulated curtains are closed on winter nights, and the ceiling fan keeps
warm air moving in winter and helps to exhaust it in summer. Another potential active system would be a fan-driven
heat-exchanging ventilator to bring in fresh outside air with
minimal loss of internal heat. ST
