Transfer solar heat into your house without electricity

[Bamboo]

If you have big windows to the south, you already know you are saving a lot on heating costs on sunny winter days, IMO. With this simple DIY system you can harvest the heat that doesn't come through your windows, but normally gets reflected/inefficiently absorbed by your walls:

On the Bottom there are holes drilled through the walls, same at the top of that "window frame covering the outside wall". The wall absorbs the heat (maybe use black stones - more efficient), the air inside heats up and goes up. Warm air is flowing into the house at the top part of the construction, colder air from inside is coming in from the bottom. The upper part with the open windows is for "warm enough now"-situations. If the sun keeps shining, it continously heats your house.

JM .02$

 

[Hillhater]

If you have big windows to the south, you already know you are saving a lot on heating costs on sunny winter days, I
JM .02$

Good info & suggestions, but please remember this is a Global forum, such that for some of us , the sun doesn't go to the south !! :wink: :wink:

 

[tedcs]

This type of collector is known as a "Trombe Wall."
... coming to a hemisphere near you.

 

[spinningmagnets]

The best site for this kind of info is http://www.builditsolar.com, If you like this post, you will like that website.

 

[Bamboo]

...please remember this is a Global forum, such that for some of us , the sun doesn't go to the south !! :wink: :wink:

You're probably sure I make this up now, but I definitely had a line after "south" in there like "(unless you live in Oz, SA or Brazil)", but I deleted it before posting Didn't mean to be ignorant


Thanks, Ted, here is a schematic of a trombe wall:

Thanks for the link, spinningmagnets, proves everyone should learn english, the quality and abundance of info is so much better.

P.S. & OT: "Location: on holiday, in Cambodia" Ted, don't miss Ta Phrom at Angkor, the sunset on the hill temple near Angkor is also a must IMHO (stay until the average tourist has left and it's totally dark, unreal athmosphere), in Pnom Penh the little guesthouses at the lake facing sunset are simple, but really worth it if you don't need 5* IMO. Does the road from Siem Reap to Thailand still have potholes so big you could park a small truck in them (in 2000, regular buses were using the fields next to the road instead of the road itself)?

 

[tedcs]

... Didn't mean to be ignorant ...
Thanks for the link, spinningmagnets, proves everyone should learn english, the quality and abundance of info is so much better.
P.S. & OT: "Location: on holiday, in Cambodia" Ted, don't miss Ta Phrom at Angkor ...

OT & more OT:
Not to worry! Ignorance is good, everyone should have some.
The problem lies in not knowing how much one has.

I agree with spinningmagnets — http://www.builditsolar.com is a cool site.
It can be instructive, thought provoking, and entertaining.

With respect to Pnom Penh: Actually, I've never been within 8000 km of Cambodia.
see http://en.wikipedia.org/wiki/Holiday_in_Cambodia
(In addition, I don't know anything about the Dead Kennedys)

 

[dnmun]

why not just cut a hole in the wall and mount a window of that size? lotta work for little gain. you guys don't do this stuff so you have no idea how hard it is to cut a small hole in a masonry wall and seal it all the way through. just silly work imo. go for total passive solar and leave this stuff for magazines.

tear out the entire wall and rebuild it in glass. break out the floor and pour a hydronic heating slab over 6" of urethane foam. use a paloma pack or bosch boiler for heating the water in the floor for backup heat.

insulate, insulate, insulate and seal all the air leaks through the perimeter of the structure.

 

[dogman dan]

Sure, no doubt he will when you send him the $$ all that would cost. Not knocking the insulate, just saying that a good bit of heat will come into the house with this design. IT DOES WORK.

The best way to improve it is the way I did. Perfectly placed trees shade my solar gain walls in summer, but the sun shines around or under the canopy in winter. In spring and fall, I never get too much heat. Just when I'm about to convert to summer mode, the trees start to shade the glass more and more.

But the flaw in this, is it becomes a cooler at night, unless you cover the holes at night. That's what I do with mine. Since I scavenged two sliding glass door panels, my total costs were well under $100, and I save at least that montly in winter.

Here is the thread on mine, which become passive warm air pumps rather than trombe walls. Why that way? Because all night I retain my wall insulation! I open the vents only when hot air is going to flow out the top. So it does take some time, and you have to be there. Not an earthship, but cheap and it definitely works in my climate. http://endless-sphere.com/forums/viewtopic.php?f=41&t=34056

What would I do if funds were unlimited? I'd pull the whole wall apart, and put in 16" of double glass SGD's. Then 3' into the house, erect a masonary wall 4'6" tall, and more glass above. Sun would shine mostly on the masonary, but you'd still have the mountains view above. You could still vent a lot of heat to the living room with active fan circulation. But also have the trombe wall effect overnight. The whole 3' x 16' space would also be a good winter greenhouse.

 

[spinningmagnets]

I would like to point out that the Trombe wall in the top picture is in "house fan" mode. Air that is trapped between the wall and glass is heated and rises. If the glass windows at top were shut, the cold air drawn into the bottom holes would be circulated back into the house through the wall-holes.

Because of the top windows being open, the rising warmed air flows outside, and as such it pulls air from the house out (creating a draft). Opening a window on the other side of the house would create a steady flow of fresh air through the house. This is a variation of a solar chimney. Great option to add to a Trombe wall at a minimal effort / cost.

 

[Samd]

I've been studying the beer can version for 18 months, and saving up my beer cans accordingly (Honey - I need to drink more beer so I can save energy!).

I recently stumbled upon the aluminium fly wire design however - it appears to be even simpler to make than a backpass or downpipe design, and nearly twice as efficient as just a clear trombe.

Good comparison at build it solar:
http://www.builditsolar.com/Experimental/AirColTesting/Index.htm

 

[dnmun]

my point is that it is so hard and so extremely expensive to cut masonry walls that the project is not feasible when you do it to a masonry wall that already is built.

for my concrete cutting chainsaw with the diamond chain cutters i use $1/inch*2 for cost of the chain when cutting concrete. then you have to cut the framed wall inside the masonry also, and it has to be cut separately from the masonry.

it is just not practical to attempt such a procedure imo. it is easier and cheaper to start over from scratch imo. and yes i have built a passive solar system. i just don't believe trombe walls are as effective as a passive solar floor for a collector.

 

[Punx0r]

Core drill?

It's an everyday task to cut a 3" or 4" hole through 12" of brick to install a ventilation fan in a bathroom.

 

[dnmun]

all diamond tipped concrete cutting tools wear down rapidly especially without sufficient water for cooling. i use the $1/in*2 rule for the chainsaw blades because the chains cost about $300 each.

but like the man said, not everybody is up to knocking out walls and breaking out an uninsulated concrete floor to replace it with a window wall and an insulated slab for solar heat storage. with natural gas so cheap the economics are not there yet.

even for someone like me who does this sorta stuff, this would be a huge job. but i feel that the effort to build a trombe wall out of a finished exterior wall is equally not worth the investment when it is so expensive to be cutting the concrete or masonry in this case.

you can ask the guys who do this how much they charge. my neighbor paid almost $2k to install two basement windows. i got my ICS concrete cutting chainsaw on ebay for $400 and the bosch 1365 with a 14" diamond blade for $300. all for one $25 window in the basement wall. everybody is different, i like the openness of full window walls myself, the full length windows let in the outside, and my system really does work to keep the house comfortable and even hot in winter at 8k feet in the colorado mountains.

 

[Punx0r]

I'm not sure what kind of concrete you're cutting, but regular 12" abrasive diss cut concrete paving slabs and hard brick fine IME. Very dusty, though.