[Greenbuilding] low-mass sunspaces

[Gennaro Brooks-Church]

The magic of thermal heating is amazing. on one side you can use
thermal mass to heat and on the other you can use the lack of thermal
mass to also heat.

And you can even combine the two. For example you could have a low
mass sun room, with just glass for example, that is attached to the
house which has two large doors. During the day the low mass room
heats up quickly. Open the doors and let the warm air into the house.
But at the same time you let the sun shine through the two doors into
the house where there is a high mass floor, tiles for example. The
tiles don't heat up so fast but by the end of the day they are warm.
When the sun goes you close the doors because the sun room is going to
get cold and you want to keep that cold out. But at the same time you
are keeping the warmth from the tiles in the house.

This is the same general theory with Spanish style arched entrances.
The entrance patio crates an enclosure like the low mass sun room. In
the day you let the large front doors open to the main entrance room
that is usually tiles.

And the flip side is that during the summer when the sun is high in
the sky that very same entrance patio becomes a cool shaded space.

Gennaro Brooks-Church
Cell: 1 347 244 3016 USA
www.EcoBrooklyn.com




On Sat, Feb 21, 2009 at 3:53 PM, Nick Pine <nick at early.com> wrote:
> Rob Tom writes:
>
>> Perhaps someone would care to 'splain eet to me, the wisdom of making a
>> "low mass greenhouse" because quite frankly (and shirley too) I don't get
>> it.
>
> William A. Shurcliff 'splained the winsdom of a low mass sunspace:
>
>  It is hard to think of any other system that supplies so much heat
>  (to an existing house) at such low cost...
>
>  One could shorten the warm-up time of the enclosure and increase
>  the amount of heat delivered to the rooms by making the enclosure
>  virtually massless--by greatly reducing its dynamic thermal capacity.
>
>  This can be done by spreading a 2-inch-thick layer of lightweight
>  insulation on the floor and north wall of the enclosure and then
>  installing a thin black sheet over the insulation. Then, practically
>  no heat is delivered to the massive components of floor or wall;
>  practically all of the heat is promptly transferred to the air.
>
>  And since the thermal capacity of the 100 or 200 lb. of air in
>  the room is equal to that of one fourth as great a mass of water
>  (about 25 to 50 lb. of water), the air will heat up very rapidly.
>  I estimate that its temperature will rise about 40 F. degrees in about
>  two minutes, after the sun comes out from behind a heavy cloud cover.
>
>  At the end of the day, little heat will be "left on base" in the
>  collector floor or north wall and, accordingly, the enclosure will
>  cool off very rapidly.
>
>    New Inventions in Low Cost Solar Heating--
>    100 Daring Schemes Tried and Untried
>    Brick House Publishing, 1979
>
> This works well with airflow between the sunspace and living space during
> the day and no airflow at night.
>
> Nick
>
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