Friday, November 26, 2010

Phase Change Materials

25 Nov 2010: I am awakening my interest in Phase Change Materials.
I had a parcel given to me in the School office, but it was mis directed. When I opened it, it turned out to be a package for a Mr Ciu in the research labs (only a minor misspelling there!) and it contained some cuboids that contain phase change material that has a change at 26 degrees C.
This is very interesting! The 480 balls that I have in my loft have an unknown phase change and are also difficult to stack - they would need to be buried in a water tank.  So I still don't know what to do with them.

These cuboids have circular holes through them, so you can thread plumbing through them, and stack them tightly, avoiding the need for liquid or even for a tank! Or just allow liquid to permeate though those holes.

I shall send them to the correct recipient, but will contact the supplier.

Phase changing at 26 degs is exactly what we could use for underfloor heating using solar panels! 26ยบ is low enough to be right for solar panels to stack heat into them, and yet high enough to operate as an under floor heating source in a well insulated house (backed up by a few radiators to top up air temperature).

The other purpose of the PCM could be to be a buffer against overheating - if we used evacuated tubes in a future experimental installation, there is a danger that if the system was static for a while and then turned on, we might be getting glycol landing into the ground loop at 100 degs C - far far too hot! If the liquid runs through a Water tank, this might also get too hot. If it is run through a large crate containing PCM blocks, it would cool the liquid to a safe level but not lose any of the heat, it would simply delay it until later when the sun was not shining.

1 comment:

  1. if you choose our underfloor heating packs then you'll also need to factor in the cost of insulation board, screed and heating controls, as well as an electrician's call out and labour charge - our tradespeople costs guide has some typical jobs and charges to use as a benchmark for underfloor heating packs.


Comments will be moderated before showing. Please make them relevant to the subject of the posting. Comments which advertise commercial products will usually be deleted.

Popular Posts