Welcome to European Tribune. It's gone a bit quiet around here these days, but it's still going.
Great experience...!
While I understand the photovoltaic and the solar heating part, I'm not sure about what is called the "canadian well" (pipes underground using thermal mass equilibrium). This process needs quite a lot of those pipes as: Either the section is too important and it won't work, or they are small enough but you end very quickly to heat the ground around it, loosing most of it's effect...!
There is today some questioning on the biological part of having water staying still for some time in contact with air in pipes (what material? As PVC is usually banned). If the water flows regularly the linear length  of the pipes combo needed is then to big and not so interesting!

Some filters might be needed if you use that solar heated water for body use (shower, etc.) as it generates the perfect temperature for Legionella bacteria to evolve quickly !

Have you thought of a Stirling engine ? As if you have windy conditions, you can generate a mechanical movement that will get you either heat or cold... On the other side, with a solar dish focused on the head of the cylinder you can generate cold while still having a mechanical movement that could reload your batteries with a dynamo !

One point you haven't described is the change rate of air in the well insulated house ?
Most use now an air heat exchange system with the outgoing heated air loading in temperature the incoming air. The English call it the "thermal flywheel", as it is a double maze of thin steel sheets, quite easy to build or to get done. Filters are here also needed for particles, incoming as outgoing...

Some basic sketches might be interesting with the progress of your work :-)

"What can I do, What can I write, Against the fall of Night". A.E. Housman

by margouillat (hemidactylus(dot)frenatus(at)wanadoo(dot)fr) on Mon Nov 26th, 2007 at 05:50:10 AM EST
Long time no read.  Very enjoyable to find you posting again, margouillat!

Don't fight forces, use them R. Buckminster Fuller.
by rg (leopold dot lepster at google mail dot com) on Mon Nov 26th, 2007 at 10:08:30 AM EST
[ Parent ]
Ssssh... I'm trying to re-enter walking on tip toes...!

"What can I do, What can I write, Against the fall of Night". A.E. Housman
by margouillat (hemidactylus(dot)frenatus(at)wanadoo(dot)fr) on Mon Nov 26th, 2007 at 05:50:20 PM EST
[ Parent ]
in future reports.

To some of your questions:
Pipe material is typically polyurethane or PEX (cross-linked polyethylene);
Water will not be considered potable - will not be used for showers, etc.
The main drawback for the 'geothermal' approach is the length of pipe required - order of magnitude is 500 meters. Even with looping, trenching is extensive, plus the authorities require a certain displacement between the trenches - I think about two meters. So - it takes a fair amount of "yard" to accomodate. In new construction, though, the trenches could be cut under driveways or even foundations, but best not spring a leak.
As to the usefulness or effectiveness of this approach - it is proven by many installations to be one of the most energy-efficient systems for space heating in terms of energy used to run the system.

Sven notes below the 'trombe' approach. Definitely a good way to go. In fact my "pads" may need something equivalent to glazing to work well in my environment. Only possible advantages that I can see for the water-based system is the relative energy-density of water vs. air; the light weight and low cost of the "pads"; and the relative precision and ease of control of a heat pump via thermostatic switch. As I say, though, this is an experiment. Only one way to find out what works in my opinion.

As to Stirling engines - I have a sketch and some ideas on a related device. I intend to work on it concretely after retirement.

As to air exchange - I hadn't really thought much about it in the terms that you mention. Currently, there is some warm-air leakage via two bathroom vents, a fireplace chimney, and the clothes dryer vent. The heat exchanger for the heat pump is set in the middle of a finished basement. If I go to a heat-exchange mode of outside-air intake, I will have to construct some kind of pipe system. Sounds like a good idea, though.

paul spencer

by paul spencer (spencerinthegorge AT yahoo DOT com) on Mon Nov 26th, 2007 at 11:28:28 AM EST
[ Parent ]
 I completely agree,  the "canadian well" (we call it here the "Provencal well" from Provence, South of France) works. The latest "Zenith" ( covered spectacle show theatre about 10 000 public when full) in Dijon by Philippe Chaix uses that technique. I believe it's the biggest volume to use it!

But then it's only for a few hours a day (and not every days) and uses air and not water for refreshing or pre-heating the volume.

When is your retirement ? :-) That related device sounds great !

Here (in France) we have regulations for air exchanges. Meaning getting new air in at about 200 m3/h (cubic meters per hour) for a 85 square meter flat (T4- about 212 m3), so it's the full volume of the housing per hour at peak time (kitchen while preparing food and shower and toilets times).-, half of it at night...
In fact, few flats achieve that, even less house ! The electrical fans that pulls air fro toilets and kitchens are often undersized, make too much noise and break down after a few years ad are seldom replaced!!!

In cities like Paris, we believe that air is more polluted inside the flats the outside in the traffic...! Most glues used in buildings or furniture can be formaldehyde based, plus several other household products can have drastic effects on our biology, specially nowadays when there are many more young with deep allergies. So the general idea is to get air moving... Without loosing the kW's :-)

"What can I do, What can I write, Against the fall of Night". A.E. Housman

by margouillat (hemidactylus(dot)frenatus(at)wanadoo(dot)fr) on Mon Nov 26th, 2007 at 06:17:20 PM EST
[ Parent ]


Occasional Series