I am wondering if some of you have any feedback regarding HAT-System as an option for renovating existing floor heating systems. I got a quote from NAEF AG, they offer a guarantee of 20 years and costs are in the 25-30k CHF. I am considering it as an alternative to replacing existing underfloor heating pipes. Thank you!
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My pipes are 46 years old. They will cause trouble at some point in time, but if you can extend their life service for another 25-30 years (assuming extra 5-10 years above guarantee period - but might even be longer), seems a good deal to me. I got very different opinions about using the service, some really recommend it, other say it’s really not worth it, so I am asking around before forming an opinion. Replacing the whole system comes with much more work and triple costs so for me it does look interesting.
we had it installed about 10 years ago (system was about 30 years old then). No problems so far.
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I do not know the system, but Inthink the topic is interesting. my thoughts are:
Do you have any trouble yet with your pipes? Eg some issues related to oxygen in the Water / corrosion of some elements in the installation? How does your heating water look like?
Are there any informations available how thick the coating will be?
Any coating in the pipe will reduce diameter and by this increase flow resistance. This can be a problem, so I assume a very light coating. Which in turn leads me to the idea that the coating will not improve the mechanical stability but only makes it diffusion tight. It seems to me, that it protects more the quality if the heating water than the pipes. They still are exposed to thermal changes etc and will leak eventually.
Oxygen content is higher than normal limits, same as for Iron & total water hardness.
And this is how the coating looks like on the inside of the pipe, not too thick, not too narrow:
It’s basically a pipe within a pipe, some heat loss will happen but should be minimal as per vendor indications.
Classic way to extend the lifetime of a pipe, also used in other applications (municipal utility etc.)
You can find out the state of your pipe system by analysing the water. If you find a lot of particles, the conductivity is higher than expected, corrosion is happening somewhere. This seems to be the case in your analysis. However, it seems, that some of the values are out of range, because the filling water was already out of range (water hardness for instance). So someone saved some bucks and put normal water inside instead of demineralised water, and did not even took the oxygen out (using natrium bisulfite). Maybe just a water change could help ? (however iron is rather high still).
the main resistance to the heat transfer will the ground itself → the epoxy coating will just reduce reactivity a bit (the heat is still transferred, just a bit slower). The main thing is actually, that the pipe becomes slightly narrower, so the head loss will be higher, meaning you need more pumping energy, in the grand scheme of things, this is peanuts.
Without having it installed myself, I would say this is a valid way to extend the lifetime of your heat distribution system. You apprantly have issues in your system, so I would say go for it,
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