Solar yield too low; how to adjust three flat collectors

  • Erstellt am 2012-10-28 14:25:51

Bauexperte

2012-10-30 19:11:46
  • #1
Hello €uro,

This is not about the retrospective (it has been bad enough so far) - or what might have gone wrong beforehand, ... I myself have asked the user to speak up here in the forum. In the hope (perhaps naively or unfortunately without result - if things go really badly) to receive a response from the very well-known and heavily advertising heat generator manufacturer.

Some criticized suppliers express themselves here; they also take action - and often there is a mutually satisfactory solution.

I am not making any progress – do you have comparable cases from the past – any ideas? Possibly a starting point ...?

Kind regards
 

€uro

2012-10-31 09:25:09
  • #2
Hello construction expert,
At least an attempt!
However, one should differentiate clearly! Very quickly, mostly hastily, because it seems so easy, manufacturers are blamed when something "doesn't work." Often completely unjustly, but in individual cases quite justified. A manufacturer is neither a system planner nor an installer!!!! Most omissions or deficiencies are rooted here!
As a rule, the manufacturer is not the contracting party, but a general contractor/subcontractor or a heating or system builder. If something significant (planning/dimensioning/execution) was neglected here, it is not the manufacturer's fault. It would be their goodwill to react here, for which there is probably hardly any time! The contracting party has to assume warranty and guarantee for the "overall work," the manufacturer only afterwards in connection with the installer when it comes to actual device defects.
Anyone who cannot handle manufacturer information should think twice! General contractors/subcontractors are not entirely innocent here. X devices from manufacturer Y are ordered because they are so inexpensive and then pushed onto the naive builder, completely regardless of whether it is actually economically sensible for them or not! That is possible since energy efficiency or consumption costs are not part of the contract.
Anyone who needs information about what should be included in a general contractor/subcontractor contract in this regard can get in touch.
If in the present case the manufacturer requires an optimal flow of XY, the planner or executor must also ensure this; otherwise, it is a defect!!!
The statements of the original poster alone already reveal deficiencies here!
I only plan devices from manufacturers who provide me with all data, e.g. characteristic curves, technical data. Those dealing exclusively with marketing gimmicks, the usual suspects, are mostly found with general contractors/subcontractors.
See above!

Best regards,

NB: The best advice you can give builders is to take system technology out of the general contractor/subcontractor contract and assign it externally after prior planning/dimensioning! Alternatively, to "upgrade" the general contractor/subcontractor contract in such a way that no problems can arise!
 

Bauexperte

2012-10-31 12:15:03
  • #3
Hello €uro,


I fully agree with you! It was and is not my intention to blame the manufacturer – what I intend is for the gentlemen – whether master plumber or manufacturer representative – to make an effort to come together at one table and work out a solution in the interest of the builders.

Currently, it is obvious that the "error" cannot be found. According to the plumbing company, the measured values correspond with the installed system – nevertheless, the system does not "run" smoothly. Both the master plumber of the plumbing company and a technician from the manufacturer’s company were on site several times and searched for possible sources of error. Always without result, and unfortunately to this day, the builders are left alone with their defective system. In my opinion, this must not be the solution to the mystery!

So this is an attempt to create public awareness and through this way initiate a change in thinking. Who moves how and why, whether additional costs arise or not, is initially secondary – after all, on the one hand warranty applies, and on the other hand liability in case of faulty calculation; what is primarily important is that the builders can operate a functioning system in the end.

Against this background, it seems only logical to me that a solution lies in the interest of the manufacturer and that he will put his market presence on the line.

Best regards
 

€uro

2012-10-31 13:27:15
  • #4
Hello construction expert,
Here, the contractor assigned to the builder should primarily take responsibility!
What is a fault? What does it mean: the system does not run "smoothly"? By which parameters is this measured? The fact is that the optimal mass flow required by the manufacturer is not achieved. Period!!! If the installer of the system cannot guarantee this, it is his problem and his liability. The client should not be affected by this. On the contrary, he can claim financial loss against the contractor!
How blind can they actually be? The contractor has not even complained about the economic result, but merely about compliance with manufacturer specifications!!!!
Then they should turn to their contractual partner and put appropriate and lasting pressure on them!
Fudging the accounting of a solar thermal system not only affects an efficiency status defined on paper, but sustainably and permanently also the client’s wallet. Anyone who feels urged to hold back here does not know what he is giving away but has paid dearly.
Whoever is a sucker now must also pay the tuition fees in the long run!
What is a functioning system?

Best regards
 

Micha&Dany

2012-11-01 07:18:55
  • #5
Hello construction expert

I can't really assess the situation from a distance and I'm not very familiar with solar thermal systems, but I did have an idea (although it has probably already been checked):
Is the pump operated single-phase with 230V, or is it a three-phase 400V pump?
I once had a similar phenomenon where I had a far too low flow rate in my system and even increasing the speed didn't bring any improvement. Eventually, I noticed that although the pump was connected correctly, there was a left-hand rotating field in this lab. I changed the rotating field to the right - and, oh wonder - I had the expected flow rate.

@Euro: You are absolutely right with your explanations - but "would have," "should have," and "must have" don't help the builder! The builder may have (from your point of view) made a mistake (that happens to me sometimes with topics I'm not familiar with), and has probably understood that by now - but now it's about solving the situation as effectively as possible. So either you have a *helpful* idea based on your experience, then please share it with us poor ignorant ones, or just say that you don't have any ideas either...

Best regards Micha
 

€uro

2012-11-01 09:02:59
  • #6
The facility was not built/planned by the client, but someone made money with it and therefore has to deliver a flawless work!
Is the client now supposed to tinker with it himself based on the forum remote diagnosis?

Best regards.
 

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