Passive Solar Collector...
and some sort of garage door...
This project is
less than exciting, but one that I simply can not put off any longer. The
picture below is of the Foyer to theworkshop.ca and acts as a storage area for
my wood supply. You'll notice a garage door is installed but what is not obvious
is that it takes 2 people to open or close the door, as it has been hit, bent
and the rails mis-aligned.
Also
notice that there are 3 rows of wood 7ft tall, 18 ft long. This image was taken
in late November.
With the door
stuck open I see a noticeable increase in my wood consumption when ever the
mercury dips below -15C, after -25C so it's a lost cause trying to keep the shop
warm.
Typically we get a
couple of weeks of colder weather in late Dec, a bit of a thaw in early January
and then the bitter cold of -20C down to as low as -35C until the end of
February.
I had the best of
intentions back in the November of 2005, but somehow other things were more
important. But with this week my last chance to do this job in reasonable
weather (first week of the new year 06) it's finally underway.
This patio door is
one of a pair that we replaced almost 10 years ago and has occupied this spot
ever since then. I don't know what glass is worth, as I've saved every scrap
since we bought the farm and find that they come in handy.
Personally I view
the glass as the embedded energy that went into it's original manufacture, plus
the savings on the time and expense of hauling it to the dump, as well as the
time and expense to buy the glass that I would otherwise have had to do now if
this was not on hand.
The glass pane
actually turned out to be 2 (two) plates that were sealed together with an
aluminum spacer embed in a quarter inch of adhesive.
After trying
numerous methods of removing the adhesive unsuccessfully, I resorted to the Sawz-all.
Aside from some
rounding of the edge of one of glass panes it went super quick... easily under 5
minutes to completely separate the panes.
Again recycled
materials are used in the form of rough timber 2 X 4's and 1/2" wafer board
recovered from the renovation of the foundry last summer.
We've gotten at
least 1 1/2ft of snow since November and the temps have climbed to a balmy minus
5C.
The basic framing
was done quickly and test fitted to be sure that my measurements were close
enough that I could be assured that I wouldn't be smashing glass and throwing
tools out into the snow-bank later.
Initially I had
planned on using 2 (two) panes of glass per door, but revised that plan as the
doors were quickly gaining weight as they were under construction.
This is the lower
sill that will act as a manifold of sorts for the passive solar collector. The
holes being drilled are 3/4" in diameter and will line-up to an array of
collector tubes to be housed behind the glass.
The glass pane is
34" X 42"
What little I do
know from past experience is that rough framed structures tend to shift and may
lose square at the most inopportune time.
With that in mind,
I carefully squared the frame, laid the glass in place and tacked all four
corners to ensure that it held it's square.
This are just a
few if the boxes of Aluminum soda cans that we've been saving since Nov/05 for
this project.
In total 176 cans
were used.
The idea of using
pop-cans came to me via Email from a correspondent in Missouri a couple of years
ago (Thanks Again Jimmy!!!)
The theory is that
the very thin walled cans coupled with the heat transfer properties of Aluminum
would offer a cheap and effective collector medium.
The image to the
left is the typical pouring spout fully opened, while the image to the right is
a 3/4" hole that had to be drilled into the bottom of each can. The domed
bottom and the recessed top also provide a nice fit when the cans are stacked.
Of note though is
that the cans have to be held very securely by the top and bottom NOT the sides.
The very first can I tried was almost my last. As the drill bit into the bottom
of the can, my grip on the sides collapsed the can leaving a very sharp spinning
metal mess that I instinctively was trying to hold. I can see how this could
turn ugly real quick.
The cans are fixed
into stacks with Silicone sealant. In total I used 5 tubes (that would fit in a
caulking gun).
The cans are left
to set-up overnight in the makeshift crib to ensure that they are straight in
the morning.
Initially I had
tried "Hot-Glue" but found that due to the heat dissipating properties
of the aluminum cans that by the time I'd ran a bead of glue around the bottom
the point that I'd started at was already hard.
The other bonus
with the silicone beyond the longer "Working-Time" is that it is UV
resistant and supposedly rated to 350F and will retain it's pliability for 35
years.
The stacks are
painted flat black with a High Temperature paint typically used for wood stoves
and BBQ's. The Painted stacks are glued into place with the same Silicone adhesive within
the array.
Before the door
gets filled with insulation and sheeted on the face, I included this image to
help illustrate how I hope that this will work.
The slot on the
bottom of the array will draw cool air from within the garage. The sun will heat
the air inside the black cans under glass and exit out the top back into the
garage via convection.
One door is done
and has been tested with an indoor/outdoor digital thermometer today.
The cool air
entering the base was -7.3C and the air exiting the top was 34.9C under the weak
afternoon sunshine that broke the day around 2PM.
This is very
encouraging as the opening in question faces South-East and is bathed in sun
until about 11:30A.M. As well the coldest days tend to be very clear sunny
days.
Insulation is
installed on the left...
Glass and wafer
brd skin is installed on the right.
A quick coat of
paint and it is ready to hang.
The slot located
on the top of the array was left to allow a measure of light into the garage,
and allow me to look out to see outside when the dogs are barking.
This
is the view from the inside, around 4:30 in the afternoon.
There are a few
spots that I can see light coming in, but this has to be an improvement over the
gapping hole that was previously here.
The slit windows
let in just enough light to be able to get wood and allow a good view to the
outside world.
This device is an
indoor/outdoor thermometer with min/max memory. What I particularly like is the
dual display.
As you can see in
the late afternoon of a cloudy day, the ambient temp of the room is the same as
what is in the top can of the center stack.
I have a similar
unit that will be mounted to monitor the actual outdoor temperature in the near
future.
In the
"Wishful-Thinking" category I would love to find the enthusiasm to
build a 4 to 6 sensor Thermocouple that would log data samples and interface to
a PC for more detailed trend analysis. The key points to monitor would be
theworkshop.ca, the wood storage room, the top of the panel, the base of the
panel and lastly the outdoor temperatures.
The intent of
data-logging over a 24hr period would be to see the net gain during the day, but
also the inevitable reversal of the heating trend in the afternoon and evening
as cold air rolls out the bottom of the collector and heat in the room is lost
to the outside as it's drawn in through the top of the panel.
From the outside
this is the view...
I think
esthetically I could have made this considerably uglier.
Over the next few
weeks some misc hardware will be added, otherwise I'm glad to finally be done
with this project.
In total this has
spanned 6 days, including allowances for adhesives to cure, paint to dry and
numerous trips into town to get nails, adhesives, paint & the thermometer.
If I had this
project to do over again, I would have opted for much lighter construction
materials as each door is well over 100lbs. The issue of a cooling effect in low
to no sun conditions would have been addressed in the design... The short term
solution would be a simple 1-way baffle at both the top & bottom of the
collector made of light sheet plastic...