[Greenbuilding] Temporary Sunspace ?

[LarenCorie]

From: Lynelle Hamilton <lynelle at kos.net>

> Has anyone had experience with a removable "sunspace"? 

Hi Lynelle;

  I wrote an article about them (called "Instant Sunspaces"
IIRC) using the example of a Michigan Great Lakes climate,
very similar to your own, in ESSN in early 2005. The article
is available (free) at the link in my signature, below.

> I have a 7 x 14 foot sliding door on the south wall of
> the house.  The overhangs are such that I get no direct
> sun in summer, but do get a considerable amount in winter.
>  I use the door in the winter, as it's the shortest path to the
> woodpile and I am lazy. I am on Lake Ontario, near
> Kingston. My location means that I don't get a huge
> number of sun days in the winter, and the single slider
> (itself triple-glazed glass) means that there is no airlock
> when I load wood, let the dog out, etc.
> 
> I am thinking of constructing a sunspace that would only
> be installed in October/removed in April.  I am thinking
> that this would allow the collection of warm air, even in
> winter, helping to warm the house and offer a buffer for
> the cold. 

> Overall size is about 14 x 10 feet.

It should also greatly increase you effective collector area.
While your sliding door might have 75sqft of triple glazing,
The sunspace might have 130+sqft in single glazing, which
would transmit a lot more light. What you need to be careful
about is that your instant sunspace is sealed well, and that
you also keep the sunlight and warmth from being absorbed
by mass in the sunspace, and also down into the ground,
which would prevent it from ever getting into the house.
Carpeting, rolled out over the slab, and even over brick
veneer, can go a long way to accomplish this.

Here are  a couple of pictures of a crude temporary polyethylene
sunspace that I built to only be in place for a few months, one
Winter, while I was remodeling a house.

< http://web.axilar.net/LarenCorie/TempSunspace2.htm >

< http://web.axilar.net/LarenCorie/ssi1.jpg >
Notice the carpeting, to shade the uninsulated slab.
The uninsulated flexduct brings warm sunspace air
down, into the house through an old small milk
chute so that it could heat the locked house. 

> The south is my view of the water, so for the heat and
> the view, I don't want to have a structure out there in the 
> summer.  

   If you wish to maintain your Winter view, you will need to
avoid polyethylene, and multiwall or corrugated polycarbonate
glazings. There is a very clear, light weight material, available
from Warp Bros.

> I'm wanting something that would have, at most a 18" kneewall 
> on the perimeter, with the rest removable. 

I recommend having the whole South wall as glazing, and removable.

However, you might be better off, simply building this new wall
with more sliding glass doors, that you could look through to the
lake. Then depending on the conditions, open or close inside or
outside doors, to optimize performance.  That avoids having to
mess with twice annual sunspace building or tearing down, and
storage projects. And it might also provide you with expanded
Summer nighttime living space, for dining, sleeping, parties, etc.

> From: "Kathy Cochran" <kathys_old_house at goldrush.com>

> if you did this you would be able to grow winter
> veggies in pots that would get warmth thru the glass!  


Hi Kathy;

  Yes.  But it will depend on multiple factors. The pots might
be moved indoors at night, or have insulating covers. In Fall
and Spring, nighttime temperatures might not be too cold for
plants. And, of course, it will also depend on the kind of plants.
Since the house will be receiving heat from the sunspace, and
also sheltering the sunspace on its North side, it can also give
some heat back to the sunspace at night, for plants. However,
heating a sunspace drastically reduces the net heat gained that
it can supply to the house. 

-Laren Corie-
 Natural Solar Building Design and
 Solar Heating/Natural Cooling/Energy
 Efficiency Consultation Since 1975
 www.ThermalAttic.com  (many new
 photos and pages, coming soon)

Read my Solar house design articles in:
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www.essnmag.com

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