Choose solar collectors: plans or vacuum tubes?

Solar thermal energy in all its forms: solar heating, hot water, choosing a solar collector, solar concentration, ovens and solar cookers, solar energy storage by heat buffer, solar pool, air conditioning and solar cold ..
Aid, counseling, fixtures and examples of achievements ...
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loop
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by loop » 29/03/08, 09:07

Hello

I recovered a transparent plastic tube, outside diameter 63 mm, lg 1700 (PC, PVC or PMMA?)
I will place a D16 copper tube, a half-cylinder of styrodur below and steel sheets on the side
The principle is the same as a flat sensor but very elongated and the outer envelope is waterproof
Advantage: you can size your own lengths according to the available roof (length of the tubes) and place as many tubes as you want in width
The only "delicate" part is the connection of the tubes to each other which must serve as a sealed collector / distributor and as a fastener at the same time. I can envision a machined part with O-rings.
ESE produces ready-made absorbers which would suit very well but they do not respond to emails :!:

Sensor manufacturers today are unable to take this approach with their "standard" hardware.

I take pictures and tests with my "proto" as soon as possible

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by gegyx » 29/03/08, 10:13

Don't loop
:D
We want to see your find
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by F.MYKIETA » 12/04/08, 08:57

Hello,
I discovered here, not long ago, your comments on the documents that I put online.
I am delighted that they serve to shed some light on the different types of equipment offered on the market and that finally, the terms "cabalistic" are within the reach of all, that the "we say" s' extinguish if they are unfounded, that the wind sellers are discouraged by an imbalance of skills to their disadvantage.
Thank you for the encouragement I receive every day.
Thank you also for all the questions, all these comments, all these remarks, which come to me directly or indirectly and which then serve to improve the presentations.

Best regards,
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by Christophe » 12/04/08, 09:14

Hi Frédéric and welcome here.

Yes, we try to defend the scientific and technological "truth" as well as possible long before, of course, commercial interests that we do not have anyway.

What do you think of defining a concept of COPA (annual COP) for solar?

As I said above: your tests are very interesting but they only reflect the performance of "laboratories". In fact, exactly as a heat pump builder defines his COP ... This is good but insufficient with installations that take years to pay for themselves (> 10 years excluding self-construction).

So what are you thinking of setting up fatigue tests and resistance over time (deliberately overheating the panels, exposing them to UV tubes for an extended period, exposing them to frost ... etc etc) and therefore estimating a COPA (technological and financial) over 20 years.

It is a colossal task but which could / should ultimately be taken care of by the Ademe or the UFC which to choose ... Obviously one could be based on the tests of the certification body but again they make instantaneous tests or are based on manufacturer data ...

What do you think?
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by Rabbit » 12/04/08, 11:32

we can consider providing the panel with a vacuum pump outlet.

Or fill the hydrogen panel.
Over time the hydrogen will desert the panel and suddenly
l a relatively satisfactory vacuum should be obtained.

The panel being under atmospheric pressure for the time of
taking joints (silicone or other) the montabe should not
poses insurmountable problems.
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by F.MYKIETA » 12/04/08, 19:19

Hello everybody
Hello Christophe.

To answer your first question about COPA (not to be confused with COPPA (excellent Italian sausage), you have to define what COP is.
And to define what COP is, it is essential to define what a return is.
Efficiency is the ratio between the energy returned and the energy absorbed.
We speak of an efficiency for an engine, for example because we provide energy to an engine, which, minus the losses by Joule effect, mechanical losses, slippage, etc., gives us this power in the form mechanical.

For heating, we will talk about a yield, but there, it is a little more complicated because comes a grafted concept hitherto not addressed, the PC or Calorific Power.
We will talk about efficiency as well if we make the relationship between the energy returned and the PCI as between the energy returned and the PCS.
PCI: lower PC
PCS: Superior PC.
Clearly, the PCI only takes into account the energy resulting from the simple combustion of the material without taking into account the water vapor contained in the material nor the energy necessary for its evaporation (PCS).
This is one of the reasons why some boilers now have yields greater than 100% ... No, but sometimes there is something to laugh about. And people dive ...
We will talk about yield on PCI or PCS for fuels such as Gas, Fuel oil, Wood.
The important thing is not the value of the yield but to know how to find one's bearings and determine whether the given figure for a given yield is established with the PCI or the PCS. Then we compare ...
But there we have a return properly speaking because we start from a primary energy and we transform it into heating energy, with more or less significant losses.
Today, a good return (on PCS) is around 80%, a very good return around 90%

The operation of a heat pump is really different from a conventional heating generator because we do not use fuel.
The COP, or COefficient of Performance, is the ratio between the energy absorbed and the energy returned.
Thus, we are essentially talking about a COP for a heat pump (heat pump) because unlike any other heat generator for which we will talk about efficiency, the heat pump does not intrinsically have efficiency.
What does a PAC do?
In fact, overall, it displaces an energy contained in a matter (air or water) towards another matter (air or water).
Thus, to move 2kWh of energy contained in the outdoor air and send it to indoor air, you generally need 1kWh of electricity.
We get a COP of 2. (Annual for an Air / Air heat pump).
If we now consider the entire energy production chain and start from fuel oil, for example, to produce electricity which will then produce heat via a heat pump, we have an approximate yield of ...
R1 = 50% to transform fuel oil into mechanical energy (overall the efficiency of a heat engine);
R2 = 80% to transform mechanical energy into electrical energy (including line losses, transformers, etc.) arriving at the home;
COP = 2 to restore electrical energy as displaced heat.
So we have our total return equal to:
Rt = 0,5x0,8x2 = 0,8
And yes, we have 80% yield!
Either overall a yield as good or as bad as for conventional energy.

For solar now.
Solar is a bit complicated because we have several elements combined:
Radiation;
Transport;
Electricity ;
To determine what at the beginning of the post we called “COPA” (Annual Coefficient of Performance), we must actually establish a relationship between the energy returned and the energy absorbed, all proportional to the withdrawal.
What some call… A GRS or Guarantee of Solar Result.
Today, no institutional aid is conditioned on any GRS for the individual.
For local authorities, any aid allowing the financing of solar installations is conditioned (not always it is true, but more and more often) to the installation of measurement instruments allowing the validation in time of the forecast GRS established during the project.
Some organizations (EDF for example) are validating the performance of solar thermal equipment to establish a performance label (Promotelec style) which, in the long term, will allow the spread of institutional aid according to the performance index of the equipment that the individual will consider installing.
Tomorrow, after tomorrow, or in a while, but we will get there.
And there, we will see a plethora of manufacturers scratching their heads to meet quality requirements. Unless, of course, some lobbies go through there and stifle history…
The fact remains that today there is a growing number of professionals who demand the systematic use of GRS before any quote is presented and thus allow users to avoid having them take their bladders for lanterns.
As an example, I was again visiting customers this morning with a person to whom a professional validated the installation of an SSC (Combined Solar System) at € 15k to install 10m² of solar panels tilted at 15 ° on an installation of high temperature radiators…

I will try to answer the second idea more quickly, namely that the tests that we have carried out are "laboratory tests".
Well no, these are not laboratory tests, but real tests, because our pilot installation delivers both in a low temperature heating floor and in a CESI of 500l.
We can, alternatively switch the panel field on one or the other of the receivers and thus operate our field with a DT sometimes low, sometimes high.
We are in a configuration allowing to recover a maximum of energy during the intermediate / cold season.
We wanted to test a certain number of material to have a clear idea of ​​the market offer and not to base ourselves on commercial speeches.
We have published a certain number of results, there are still tests to be carried out but overall, we can say that there is no significant difference in terms of results between the 2 sensor technologies.
And this, in a standard configuration for our usual applications.
It is obvious that to produce steam at high temperature, the best is not the flat collector ...

The third idea discussed is that of depreciation.
I will try to be shorter and shorter.
DO NOT MAKE A SOLAR THERMAL INSTALLATION SO IT WILL BE AMORTIZED ONE DAY!
If you want to dampen a heater, buy a nightcap, socks and a hot water bottle. During the day, put on sweaters!
Clearly, if you opt for the choice of a solar thermal installation, do so with the sole concern of disconnecting from your dependence on your energy supplier.
And that must go hand in hand with a reduction in your overall consumption, your annual energy balance.
To be even clearer:
You consume 20.000 kWh / year of heating energy and you are 2/3 at home: it is too much, reduce.
You use 10.000kWh / year of heating energy and you are 4/5 at home: Impec, there you can start to worry about how it can be possible for you to "go solar".

The fourth idea developed is that of the life of the equipment installed.
Indeed we must take this into account. But again, no complicated reasoning:
UV resistance: it has been carried out for 30 or 40 years, it must be verified by the installer / client that the materials used for the manufacture of the panels envisaged to be purchased are compatible with outdoor use, by all the time…
It's a bit basic as an answer, but why do you think there is expensive equipment and cheaper equipment?
Why do you think some manufacturers have been making panels for 20 or 30 years and others have only been doing it recently?
Resistance to high temperatures = Resistance to stagnation: This is a sizing story. A technical study must be carried out for any installation. The turnkey sold by some cannot work for very long. It's cheaper, for sure, but it's especially not always suitable for use…
Resistance to frost: Same fight, it's a sizing story.
In general, don't trust the "yaka". It does not work, some have tried, they had problems,… that said, it is you who see…

The tests carried out by specialized organizations are real tests, with accelerated aging, tests in cold and hot periods, etc.
Look on the side of CSTB in France, on the side of the SPF in Switzerland, on the side of ITW in Germany.
These are very serious people who really take the time to perform relevant tests.
Reading, on the other hand, requires some learning that many, end customers, installers, salespeople, etc.) do not take the time to do.
Are you planning to go "solar"? Know that it is not a television or a camera, take the time to compare, read, understand and above all ... to find people who love their profession and not opportunistic salespeople who see in you only a bundle of cash to be moved.

Latest anecdote:
I was called recently by a salesperson from a solar equipment distribution company. Okay, don't worry, I'm a polite guy, I answer.
The salesperson wanted to know if I could be interested in his equipment.
I reply that I am still interested ...
So there, the guy, he talks to me about prices, deadlines, solar kits,…
I kindly ask him what is the nature of the selective glass of his panels.
I hear him stammering, reading his sales brochure and finally telling me that he can't find the information.
IT CANNOT FIND THE INFORMATION!
However, he has sold his equipment to professionals for several years and he has never had this question!
He finally tells me that he will search and that he will call me back ..
I'm still waiting for her answer, it's been 10 days now…

I hope I haven't been too long for a first message ...
Pk,
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by RV45 » 13/04/08, 12:58

loop wrote:Bonsoir

No news from ESE, I suspected a little :frown:

I do not know if this company deigns to work with individuals, nothing is stated on their website about it, and also no price!

Christophe, it's your turn, of course with diplomacy : Mrgreen:

For the comparison between plan and tube sensor technology (see link at the beginning of this topic), the test conditions are a little challenged by some forumheat-to-earth

But soon the vacuum level sensor :!: : Cheesy: to get everyone to agree

A+


for the vacuum planar collector and well just look at earth heat : Idea:

http://www.chaleurterre.com/modules/AMS/article.php?storyid=1

As for the actual tests what is interesting is not the performance in full sun with a temperature of 17 ° C which is important except for the campsites in the south of France :? But the performance there and when we are not overheated : Idea: but rather when the sun is scarce. :|

Watching its last weeks in my region and a few others we have a very cold cloudy weather with a very strong alernance of cloud light and rain.

The observation of members calling like earth heat is the same in some cases and I site Malogne in Belgium which has the two types of sensors or myself with the installation of my father and mine shows that inertia due to the temperature on the one hand but also to the volume of water and the insulation of the sensors that the tube sensors are more reactive and are able to start the circuit-breakers longer and more often than the flat sensors.
however effectively in high exposure the flat collectors have very good performance.

The study carried out is however of major interest and we all welcome it.

But the important thing is to equip yourself, whether in tubes or in plan. Each system has advantages and disadvantages 8)
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by Christophe » 13/04/08, 14:34

F.MYKIETA wrote:Thus, we are essentially talking about a COP for a heat pump (heat pump) because unlike any other heat generator for which we will talk about efficiency, the heat pump does not intrinsically have efficiency.
What does a PAC do?
(...)

Either overall a yield as good or as bad as for conventional energy.


Completely agree in terms of greenhouse effect and gross energy consumption: a heat pump with COP (A) average of 3 powered by a gas-fired thermal power plant generally does the same thing as a gas boiler ...

F.MYKIETA wrote:Transport;


Hu? What transport?

Apparently you have not gone to the end of the reasoning.

Do you have an idea of ​​the COPA of a "medium" flat solar panel and that of a vacuum?

It is precisely there that the vacuum could be advantageous (in theory at least ...) right?

F.MYKIETA wrote:Well no, these are not laboratory tests, but real tests, because our pilot installation delivers both in a low temperature heating floor and in a CESI of 500l.


We agree, it's better than pure lab but these tests have not been done over a long period to my knowledge ... and have not taken fatigue into account ...

F.MYKIETA wrote:We have published a certain number of results, there are still tests to be carried out but on the whole, we can say thatthere is no significant difference in terms of results between the 2 sensor technologies.

And this, in a standard configuration for our usual applications.


In terms of COP and performance ok ... but at COPA level?

F.MYKIETA wrote:DO NOT MAKE A SOLAR THERMAL INSTALLATION SO IT WILL BE AMORTIZED ONE DAY!
If you want to dampen a heater, buy a nightcap, socks and a hot water bottle. During the day, put on sweaters!
Clearly, if you opt for the choice of a solar thermal installation, do so with the sole concern of disconnecting from your dependence on your energy supplier.


Well, depreciation is still the number ONE argument of sellers and subsidy policy right?


F.MYKIETA wrote:In general, don't trust the "yaka". It does not work, some have tried, they had problems,… that said, it is you who see…


Can you be more specific? You mean you are not for self-construction for example?

F.MYKIETA wrote:Are you planning to go "solar"? Know that it is not a television or a camera, take the time to compare, read, understand and above all ... to find people who love their profession and not opportunistic salespeople who see in you only a bundle of cash to be moved.


Ah well concerning us it is already "done" (delivered with the house):

Image


F.MYKIETA wrote:Latest anecdote:
I was called recently by a salesperson from a solar equipment distribution company. Okay, don't worry, I'm a polite guy, I answer.
The salesperson wanted to know if I could be interested in his equipment.
I reply that I am still interested ...
So there, the guy, he talks to me about prices, deadlines, solar kits,…
I kindly ask him what is the nature of the selective glass of his panels.
I hear him stammering, reading his sales brochure and finally telling me that he can't find the information.
IT CANNOT FIND THE INFORMATION!
However, he has sold his equipment to professionals for several years and he has never had this question!
He finally tells me that he will search and that he will call me back ..
I'm still waiting for her answer, it's been 10 days now…


Yep, there are people who are not really passionate about their job and who do more than that by economic and financial oportunism ... FYI it was that it marks? :)

F.MYKIETA wrote:I hope I haven't been too long for a first message ...
Pk,


: Lol: No just the right length :)
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by F.MYKIETA » 30/04/08, 08:32

Hello everybody
Hello Christopher,

Unfortunately I do not have the material time to detail but,

Transport:
Transport = Heat transport = Losses.

Lab or non-lab tests:
I regret to tell you that the tests in the test laboratories are not as precise as one might expect at first. I will detail if I have 5 minutes a day.
It should mainly be said that the labs cannot (and do not want to, question of ethics) test sensors by comparison. They test in absolute and not in relative.
In addition, there is a whole series of "compensations" to integrate the behavior of the tested sensor according to the seasons, the outside temperature, ...
The tests that we have conducted are interesting because they allow us to work in relative terms and put a certain number of sensors under exactly the same test conditions.

fatigue:
Practical or aging conditions, it is indeed a test that is difficult to conduct but that we will do soon.
The best aging remains the state of stagnation with very strong radiation. We are well placed in the South of France to do this.

COP, yield and COPA:
There, we must also integrate gray energy, whether the sensors come from China, Turkey or elsewhere.
It is obvious that a French sensor (made in France and not assembled) would undoubtedly be, for the French market, the sensor with the least gray energy.
But to interest self-builders, this sensor must also not be "too expensive" compared to Chinese or Turkish sensors.

Amortization and subsidy policy:
The rapid amortization of a solar installation remains to be proven.
Saving money today cannot be justified on a solar installation, no offense to those you call "sellers".
For these salespeople paid for the sale, the most easily understandable argument (for them, and therefore allowing them to deploy a sales argument) remains the "saving in the medium term".
For many artisans, their customers and many self-builders, the objective is elsewhere: The important thing is to gradually disconnect the homes of energy suppliers.
Government grants are there to "facilitate" the installation of alternative systems to meet the quotas imposed by Brussels. It's a shortcut that I admit to being quick but the bottom line is there.
When the quotas are reached, the subsidies will go elsewhere.
A lot of "alternative" equipment is subsidized.
Among these, 2 make me bristle the little hair I have left:
PACs and Photovoltaics:
If photovoltaics is generally a good thing (gray energy removed ...), heat pumps are really wounds.
No time to detail here, but PAC = powder in the eyes, for the better.
The PV remains:
Question: Who installs Photovoltaics in France?
Answer: Basically, those with cash. And if there are people who have no money but who still equip themselves, the money comes from the banks.
And the PV is subsidized at least 50% by government institutions. (sometimes more, in certain departments, certain regions).
And it is true that 50% subsidized, a PV installation is a very good investment of money. Overall, today, an installation "costs" its owner around 15.000 euros and "earns" 40.000 euros over 20 years ...
Better than booklet A, it is on.
But there is something that bothers me:
In fact, the "very good placement rate", as your "sellers" say, is only ensured by taxpayers' taxes ...
That is to say you, you, we in fact.
Which amounts to saying that "we" pay so that some, who already have circles, have even more.
And we find that normal.

Yaka and self-construction:
It has nothing to do.
Many self-builders realize that carrying out the installation of a complicated process is not easy. Self-builders do not embark on an operation of this type without taking some "technical" insurance.
But I wasn't talking about them but rather your "salespeople" and gullible customers.
My point was to say that you should be wary of salespeople and advisers who argue in "yaka", that's all.

Go solar:
I understand that your house was equipped with an out-of-service installation during the purchase and that you patiently restored it. It is a good thing and I congratulate you on your involvement.
But, you shouldn't have bought this installation. She was HS therefore "given" with the house.
Have you costed the cost of such equipment as a whole?
Objectively, if you had had to buy functional equipment, would you have taken the step?
If you had the rounds, how would you have chosen your installer?
On the Forum Apper, there is another one who came to complain that he bought a solar installation to aid central heating from a heating specialist who installed 10m² of solar collectors to heat 160m² on radiators ...

Brand :
No brand, it annoys.
And since I'm not for people to get angry ...

I had promised to be fast, it is still missed!

Pk,
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by Christophe » 30/04/08, 11:39

Hi Fred,

F.MYKIETA wrote:Practical or aging conditions, it is indeed a test that is difficult to conduct but that we will do soon. The best aging remains the state of stagnation with very strong radiation. We are well placed in the South of France to do this.


You are the pro but here are 2 suggestions: iradier with UV and "simulate" more or less violent rams ...

F.MYKIETA wrote:It is obvious that a French sensor (made in France and not assembled) would undoubtedly be, for the French market, the sensor with the least gray energy.


It all depends on how we calculate the gray energy, because if we take into account the work-dodo work of French workers for example, the gray energy can rise very quickly compared to a Chinese worker who goes to the factory by bicycle or on foot ... And if we take into account the leisure or holidays of the French worker? In short, making the gray energy balance is complex ...

Here is a "generic" calculation method based on the selling price which I like a lot and which strangely did not motivate the crowds, maybe you will be won over by it?
https://www.econologie.com/forums/methode-de ... t4897.html

F.MYKIETA wrote:But to interest self-builders, this sensor must also not be "too expensive" compared to Chinese or Turkish sensors.


Yes, but the auto construction market is biased by subsidies ...

F.MYKIETA wrote:Government grants are there to "facilitate" the installation of alternative systems to meet the quotas imposed by Brussels. It's a shortcut that I admit to being quick but the bottom line is there.
When the quotas are reached, the subsidies will go elsewhere.
A lot of "alternative" equipment is subsidized.


Precisely, I think it is the opposite ... the subsidies are pipetting the market just as the housing subsidies have contributed to the speculation of the rents ...

F.MYKIETA wrote:Among these, 2 make me bristle the little hair I have left: PACs and Photovoltaics


Toutafé ...

F.MYKIETA wrote:Better than booklet A, it is on.


Well not ...converts to an annual% on investment, in Belgium SolWatt (bought back around 0.8 € per kwhe !!) is equivalent to a 2.2% investment over 20 years ... Livert A in France is currently 3.5, right?

We have talked a lot about it, calculation supported, here: https://www.econologie.com/belgique-solw ... -3617.html

The most "profitable" "clean energy" investment is currently: insulation... yet it is the least subsidized and for good reason ...

F.MYKIETA wrote:But there is something that bothers me:
In fact, the "very good placement rate", as your "sellers" say, is only ensured by taxpayers' taxes ...
That is to say you, you, we in fact.


Still agree (decidedly), the sellers who talk about good placement have never made the calculation that we bothered to do, in short they are liars or incompetent.

PV to make land mass production is a scam ... when the panels come from an oil tanker it's even more laughable ...

F.MYKIETA wrote:Which amounts to saying that "we" pay so that some, who already have circles, have even more.
And we find that normal.


Well yes it is your neighbor who pays for your solar installation in fact ... it can obviously no longer work if everyone installs it ...

F.MYKIETA wrote:Go solar:
I understand that your house was equipped with an out-of-service installation during the purchase and that you patiently restored it. It is a good thing and I congratulate you on your involvement.
But, you shouldn't have bought this installation. She was HS therefore "given" with the house.


Yes, basically that's it. The agency had no certainty about how the solar works but the repair was not so terrible: it was simply the solar pump and the filling of the thermal buffer. After there was some small optimization: of the buffer before winter and last week of glazing.

I don't think we got it "free" but in any case we got it with a hell of a discount ... and so much the better because otherwise we probably wouldn't have been able to buy it.

F.MYKIETA wrote:Have you costed the cost of such equipment as a whole? Objectively, if you had had to buy functional equipment, would you have taken the step?


I would say between 30 and 40 € for the whole (000m² of panel, tank of 65 m70 and various).

For the purchase no I do not think that I will have made such a surface except maybe in new construction and again I will have I think privileged the insulation and the air conditioning (which is already the case in fact of this house) ... but the solar installation was a criterion for choosing the purchase of this house! Without this installation I don't think we would have bought. And this despite the risk that it does not work anymore ...

F.MYKIETA wrote:If you had the rounds, how would you have chosen your installer?


Well, this kind of thing is self-construction or nothing ...

F.MYKIETA wrote:a heating engineer who installed 10m² of solar collectors to heat 160m² on radiators ...


Against incompetence there are remedies, right?

F.MYKIETA wrote:And since I'm not for people to get angry ...


I wonder if solar incompetents are not put into nature by "who you know" just to disgust certain people ...At the time, electric heating installers did receive a "bonus" from EdF for each convector installed then ...

F.MYKIETA wrote:I had promised to be fast, it is still missed!

Pk,


No matter, it's always exciting your messages :)
By the way the brand of our sensors (just the absorber part) I finally have it: these are Hebco... have you heard of it?
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