Thursday, October 22, 2009

Plumbing and Phase Change Balls

Oct 21: I spent part of the morning laying pipes in the attic - 28mm copper pipes. I did much of the cutting to length and positioning, so they can be soldered another day.
Now that the panel positions are finalised (with flexibility provided by using rubber hose) I can now finalise the indoor plumbing and the location of 5 holes in the wall.
     Later, at the university, I was walking past a skip in our department and the technicians were wondering how to dispose of a large number of balls. They aren't allowed to put the balls in the skip as they are unsuitable for landfill. I offered to take ALL the balls as the balls are actually spheres of Phase Change Material, ie a special formulation of Salts or Wax that is suitable for use in buildings. They were left over from some lab research in 2008 into phase change materials.

 I had been wanting to have a thermal buffer in the attic to include in our experiment, but a water tank would be extremely inefficient and over bulky. A crate of PCM balls would be vastly better as their melting point is high, and they dont freeze. So the Heatpump can GET heat from the balls (which are at about 23ºC) and at other times the Solar panels can PUT heat into the balls (which remain at 23ºC). The balls will never heat to melting point because the panels are low temperature, and surplus heat will go down to the boreholes. They cant freeze as they are already solid. And I can get them through the loft hatch!
There are three dustbin sized containers of them, probably enough to fill a large wheelie bin. So a custom cubic container will have to be filled with the balls and ultrafine sand around them, with a zig zag of copper or plastic pipes going through them. This loop could be set with valves and thermo-couples to the input and output, so the performance can be measured, and the cube can be isolated if we need to do maintenance on it.

1 comment:

  1. Thanks for provide solar services, if we used solar charging technique then we save money.
    This is very informative like


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