It is necessary to inquire a lot, because the vacuum collectors are better for a high final temperature but a little less good in yield for low temperatures and
you have to look and read everything that has been written on econology and elsewhere, yield curves and other details, by checking how it is calculated because the cylindrical vacuum sensors occupy only part of the surface due to their spacing.
http://www.apper-solaire.org/?Capteurs
In addition, the vacuum may not be preserved forever, and then the yield will decrease over time.
All is
depending on the quality of often Chinese sensors, which you have to be wary of sometimes.
One possibility is to have a nice surface of flat collectors which preheat and the vacuum collectors finish heating for DHW ??
For DHW or heating the floor to different T the optimums are not the same and therefore the sensors can be different.
It is worth seeing the yield curves per m2 occupied by the possible collectors, in general the simple plan is better for less than 40 ° C of difference and the vacuum better above.
In summer a pipe under plastic sheet will heat well, while in winter nothing at all.
see the curves in the middle of the page:
http://www.apper-solaire.org/?Capteurs
A project quite similar to yours in addition:
http://www.apper-solaire.org/Pages/Capt ... _Plans.pdf
Considering the input surfaces of the 2 sensor fields, it was expected that the performance
of the field of vacuum tube collectors would be greater than that of flat collectors and this all
especially during cold periods.
But during the winter season, it was found that the plane collector field produced at least
as far as the field of vacuum tube collectors.
This is all the more surprising given the theoretical and nominal performances displayed by
vacuum tube collectors.
It depends if you often have frost or not?
The ECS has a lot of practical experience in econology and elsewhere with traps to avoid.
Floor heating requires much more collector area at lower temperatures and is less common, therefore with less practical experience. It takes a maximum of floor area to be able to heat with water at the minimum T coming from solar collectors whose surface is fixed by their performance (a little better than under vacuum), the power required and the actual insolation in winter of your corner (different depending on the top or bottom of the mountain, or valley bottom too foggy, of your orientation of sensors, preferably south, and your optimum sensor is different). In addition, the orientation for winter is not the same as in summer (if you want to change it following the sun?).
The sensor with cylindrical parabolic concentrator or Fresnel lens is good, if in a fairly continental climate, in winter you have beautiful periods of clear and clear sun which is then concentrated and heats well for the DHW (by orienting the sensors well to follow the sun), but if you too often have a pale sun through a valley bottom fog that the sun never drives away in winter, it is better to have flat sensors which better capture the diffuse light to heat the floor heating a little.
In the fairly mountainous Limousin, I have the impression that the local climate is quite variable in winter depending on the locations.
Also to study the problem of adjustable flow to keep the optimal T which seems essential but neglected:
http://kheops.champs.cstb.fr/dddsm/Docu ... rI0097.pdf
Document yourself thoroughly by reading everything you can, because we are not going to rewrite everything that is written on econology and on the internet !!
Look at all the coherent projects documented on econology and on the internet.
read thoroughly and assimilate the whole site, entirely everything:
http://www.apper-solaire.org/
For example, this remarkable solar achievement uses flat collectors and is interesting to look at to know the characteristics of a coherent whole:
http://www.dlsc.ca/solar_collect.htm
http://www.dlsc.ca/how.htm
their solar collectors with 15m2 per house, insufficient in winter (much colder in Canada at 1050m altitude more north than Limousin)
http://www.enerworks.com/
http://www.enerworks.com/Pdf/New_Market ... ks_low.pdf
is a complete functional example similar to yours (if we forget underground storage)
Right now on A2 sent special traps and traps of solar and heating !!
In particular photovoltaics with a little shade of pine trees reduced to zero !!! (functioning too rudimentary)
Or leaks in the recessed roof !!
or wind turbine that explodes or costs more to maintain than the electricity produced.
And if we take a pro, interest in guessing well if it will not go bankrupt during installation, what happened to one of my sons and who with the help of his defense and recourse home insurance was able to recover his payments.
So for your house take good insurance, defense and recourse and that damage compulsory work.
) where sometimes we had -19 ° / -20 °.
which is required in any installation anyway! Your "thermal balloon" is then de facto in the depths ...