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  • This topic has 7 replies, 5 voices, and was last updated 15 years ago by Anonymous.
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    • #31029
      A-tec Design
      Participant

        I'm looking at solar water heating systems, and I've been told that the Solfex TZ system is about the best on the market.

        Does anybody have any experience of these, and are they any good. Is there any other systems that are better efficiency, or value for money.

        I'd appreciate comments please.

      • #35685
        Anonymous

          To find out more about the performance of a wide range of collectors on the market you’ll need to obtain independent test data reports to a suitable standard like EN 12975. Other than straight from the manufacturer/supplier, many of these can be found here: http://www.estif.org/solarkeymark

          You ask about comparing systems, but your reference may have been just the collector. Comparing collector performance alone is unenviable task at the best of times but comparing systems is even more difficult requiring hourly computer simulations to get reasonable accuracy. Efficiency is only part of the story since it is affected by temperature, so collector U-value is also important and sometimes under-rated.

          There are many other qualities about collectors that are worth considering such as appearance, county of manufacture, recyclability, pressure drop, corrosion resistance etc. . Some factors are explained on the above website.

          A nice free publication found here tells you more about optimising the whole system:
          http://www.greenspec.co.uk/documents/energy/EST-solarWaterHeating.pdf

        • #35686
          A-tec Design
          Participant

            Thank you for the information.

          • #35687
            Eco Design
            Participant

              Daren

              Solflex is based near Preston. I've just visited them with a mind to installing their gear. It's an Austrian manufacturer & very similar to the Austrian Gasokol panel. I was impressed with the units, flashings etc. and Solflex are competitive on all they sell & quality appears good. Will be in better position to say when we've fitted a few.

            • #35688
              Eco Design
              Participant

                Apologies Daren but the TZ series are the evacuated tubes, which I believe are Chinese not Austrian. It is their flat plate collectors that are Austrian. Solflex supply the TZ series only to meet customers demands. Have a look at the flat plate they collectors they sell (ORC & IRC ranges).

              • #35689
                Anonymous

                  For an independently written and interesting primer on Legionella and conventional solar compared to Solartwin (a technology which I declare an interest in producing) please read:

                  http://www.solartwin.com/index.php?page=96

                  This says of conventional solar twin coil cylinders “from a legionella proliferation point of view to have such a large volume of water sitting below the secondary heating coil has to be seen as a serious flaw in design, as on days where the solar gain is limited, this volume of water is unlikely to achieve the L8 recommended temperature of 60°C and thus may pose a threat of legionella proliferation.”

                  It is interesting that to get grants UK solar installers must apparently violate L8, something which we are not prepared to do. So Solartwin customers do not get grants – at the behest of the majority of the solar water heating industry.

                  If readers are buying solar heating (or if they alreday have them installed) it might be interesting to ask their suppliers “How does this installation comply with HSE Guidance L8 on Legionella?”

                  Regarding the discussion on best practice in solar there are a wider diversity of valid perspectives than industry lobbyists might have us us believe. This document (below) may give a refreshing alternative to some of the more old fashioned approaches contained in some documents which have been circulated – under what I think are surprisingly prestigious banners.

                  http://www.solartwin.com/PDF/Best_practice.pdf

                  Hope this stimulates debate!

                  Regards, Barry

                • #35690
                  Tom Foster
                  Participant

                    You've got my attention Barry

                  • #35691
                    Anonymous

                      Oh dear. I tried and failed to start up two new topics today.

                      One was abput the Solar Trade Associatioon.
                      The other was about the BPEC solar installers manual which they produce.

                      Unfortunately both got censored into oblivion after just a few hours. So I won't pass any opinion here on either STA or BPEC in case this posting gets deleted too.

                      Regards, Barry

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