Passive Solar Collector - Link

[FrankG]

The link below is to a pair of passive solar collectors that I recently completed...

http://www.theworkshop.ca/energy/collector/collector.htm

[force9BOAT]

Frank,

I am really impressed with your heater.  There are so many simple things that can be done produce heat and power.  I wish these things were built into new houses as a matter of good construction to save energy.  Someday I hope to build a house from scratch and you have given me another idea I would like to use.

Rob

[GaryGary]

Hi,

Nice construction project -- like the pop cans.

Here is another alternative that also fits in a garage door.  I use it to heat my garage/workshop.  It keeps the old garage door to use as moveable insulation.

http://www.builditsolar.com/Projects/SpaceHeating/garcol.htm

As long as the sun is shinning, the workshop is warm, and I like the lighting (but, some might find it a bit bright).

Gary

www.BuildItSolar.com

[FrankG]

Gary,

Now that looks slick!!!

I surfed about on your site and noticed a reference to a "Data-Logger" but didn't get a chance to see if you have more details posted... Will check back later...

[Tom in NH]

Nice, Frank. I have some large window sash that I want to make into something similar. How did you apply the silicone to glue the cans together? Did you just put a spot on the ends of the cans and press them together? Or did you do it some other way? -tom

[Gordy]

Gary,

I read your site and think your right, those new doors do look better than regular garage doors IMHO.

For thermo mass, Have you thought of painting the floor black ? I don't know if that epoxy paint for garage floors comes in black, or you could use a dark oil based house stain. The stain thing I saw on "This Old House", to color a walkway made of concrete and one of those plastic forms to make it look like set rocks (each rock stained a differant color). They claimed it should last 5-7 years outside before needing restaining. This should heat the floor better, forcing the heat deeper into the concrete than the stock gary color.

A neighbor built a large sun room 7 or 8 years ago with a hinged door panel at the bottom of the windows on the out side, with foil faced foam insulation. The door panel was raised and lowered with a boat winch, which also let him ajust the panel so the foil would reflect more light into the windows. He loved it exept the night time temp drops. SO the next year he covered the floor with 16" sq x 1.5" thick dark red patio blocks, and 3' high of recycled bricks along the walls (heavy duty wains coating )

Gordy

[FrankG]

Tom,

The bottoms of the cans have a complete bead of silicone run-round it. It certainly seemed excessive as I was applying it but the result is a good seal through the whole stack and it adds to the mechanical strength of the tube.

Since the doors do get used a few times a day every day, the last thing I wanted was for the stacks to separate and have to remove the glass to fix it.

Though if I was to do this over again, and having seen Gary's "Poly-Cabonate" solar wall design, I may consider parting with the cash for the P-C panels, but try the pop cans as the collectors.

Since the doors were installed, All we've had up here is cloudy snowy days (except for a brief period when the first door was hung... I did install the second Digital Thermometer to monitor the outside temperature, and been checking the set-up occasionally.

Typically what I saw yesterday was -8C outside -3C inside and 0C to +2C out the top of the center stack... I assume that the ambient light and the reflective property of the snow is enough to raise the temp in the stack the 4 to 5C differential...

[GaryGary]

Hi Frank,

I have a couple of Onset Computer 4 channel data loggers that I like and use a lot.

The 4 channel unit is about the size of a match box, and you can plug up to 4 sensors into it.  The sensor cables can be long, so you can cover a wide area with one logger.  It will sit there and log for days (or months) on its own little battery without being hooked up to anything.  When you want the data, you just connect the logger to a PC via USB and read the values into the PC for plotting.  So far they have been very reliable -- even the one that sat in a puddle for several days :-)

If you do the site search on my site for "logger", several projects I used it on come up.

My only complaint about it is that its a bit on the pricy side:

     4 channel logger $90

     Temperature sensors $30 each  

     Software   $90

They make a bunch of other sensors for current, events, ...

I have one on order that does light intensity.

Gary

[GaryGary]

Hi Gordy,

"For thermo mass, Have you thought of painting the floor black ? I don't know if that epoxy paint for garage floors comes in black, or you could use a dark oil based house stain. The stain thing I saw on "This Old House", to color a walkway made of concrete and one of those plastic forms to make it look like set rocks (each rock stained a differant color). They claimed it should last 5-7 years outside before needing restaining. This should heat the floor better, forcing the heat deeper into the concrete than the stock gary color."

Sounds like a good idea. My only hesitation in trying to put more heat into the floor is that I don't know if there is any insulation under it.  It seems to cool off pretty fast once the sun is not on it. I guess another possibility would be to paint the floor white with the idea that it would reflect heat further back into the garage?

I might have a go at painting the West 8 ft near the door black, and take some temperature measurements for a few days.  I have one of those hammer drills, and could drill a small hole in the slab, and place a temperature sensor (say) 4 inches down -- see what it does with both black paint and white paint.  Hmmm.

"A neighbor built a large sun room 7 or 8 years ago with a hinged door panel at the bottom of the windows on the out side, with foil faced foam insulation. The door panel was raised and lowered with a boat winch, which also let him ajust the panel so the foil would reflect more light into the windows. He loved it exept the night time temp drops. SO the next year he covered the floor with 16" sq x 1.5" thick dark red patio blocks, and 3' high of recycled bricks along the walls (heavy duty wains coating )"

Sounds like a nice scheme -- you get insulation at night and reflector during the daytime.  A bit like the Zomeworks scheme.

My wife says that we WILL have a sunspace for next spring -- so I guess we will :-)

Gary

[FrankG]

Gary,

Thanks for reply... That doesn't sound bad at all (Pricewise)... I installed a 4 channel unit for a "Pallet Kiln" operation last year that was well over $1,000 Canadian before taxes...

Though it was using "K-Type" thermal-couplers. The high price was what got me thinking that such units were out of my price range.

I can see making an order for those this week.

[theTinker]

that was a great build, i am definitely gonna try it.

what would be the result of not having an opening to the outside?

like just a board with the black cans behind a window. i know it would basically just recycle the air in the room and heat it but would this work fine or am i missing sumthing?

[FrankG]

Tinker,

I think that my setup is what you're describing... the only opening is a 2 1/2" slit at the top that allows me to look outside, but it is still behind the glass... so the unit is simply re-circulating the air within the garage...

Gary,

I did an exhaustive search on data loggers, kits and even components for scratch built...

The onset does infact look like one of the best price-point per feature deals going for an assembled unit, though the further I looked I saw some attractive options in hte kit market.

http://www.hobbyengineering.com/H1255.html

The link above is for a 4 channel unit that logs directly to a PC but the price is hard to beat...

Though I think that I'm going to go the scratch built route using a Dallas Semiconductor DS1615 single chip solution... it may be a few weeks before it's done, but will post details as they become available.

[hotwired]

If weight is not a problem would thin wall al pipe filled with ethylene glycol work better it would retain heat after sun goes down,that is filling but leave space for expansion of liquid.

[GaryGary]

Hi,

I think that if you are going to add thermal storage to solar collection system that you want to add the storage inside.  I believe that if you filled the absorber cans full of liquid they would lose their heat very rapidly after sunset because the glazing layer has very low thermal resistance (R1), and radiation to the cold night sky would be very high.  Basically all the heat you store in these cans would end up being lost to the outside, and not heat the inside space at all?

Some water containers mounted inside, just over the collector exit vent  will store some heat.  

I experimented with hanging a few paint cans full of water just over the collector exit vent on my workshop collector.  As I recall, the temperature of the cans got up to around 110F by the end of the day.  But, you would probably need more that a few paint cans to make much difference.

Gary