PET bottle pipes

Something I came across, accidentally, online – and thought there might be other examples.  There might even be examples already in the forums.

What is the best way to make pipework out of PET bottles? I’m sure it can be done better than in the example below.  Can the bottles be heat-welded together?

Plastic Bottle Rainwater Down Pipe With Filter

0

PET bottle solar collectors?

@frogfall

I was thinking more along these lines, but the added UV-exposure sure would not hurt:

@donald

Yeah, if the sun is entering the room, and hitting walls/furniture, then the overall heating benefit should be the same. You just won’t have a concentrated stream of warm air out of a can stack.

And yes, if PET doesn’t block UV, then I guess it might be possible to use such a bottle array to kill bacteria in tropical sunshine.  I would think that you would need narrower bottles, though, so the UV can fully penetrate.

@frogfall

I agree on the glue, this would only make sense outside of a frame.

 

The PoC test i did was in front of my window (inside) with simple stacks of opened cans and I did get a hot air flow, but I also liked having the sunlight in my room, so I tore it down again 😉

 

Don’t know why they use water in the shown setup, but I could see it working as a desalinator/grey water purification system…

@donald – from a hot-surface-to-air heat transfer perspective, all that gluing of the cans is probably a waste of time, effort, and glue.  If the whole glazed frame is sealed front and back, then you might as well scrunch all the cans, spray them black, and randomly fill up the framework with them.

That way, the surface area for heat transfer will be increased, as the air perculates (or is blown) up around the cans – and it will also create more turbulence.  n.b. Surface to air heat exchangers are some of the most difficult to design well.

It looks like the plastic bottle ones are water filled – which might keep plastic surface temperatures down to manageable levels – if the flow is high enough. However, stopping all those bottle-to-bottle joints from leaking won’t be easy. And if the water temperature does get too hot, then the bottles will distort and shrink – which will definitely split the joints. 😉

@frogfall
Cans have a similar problem and are mostly glued and framed.

I did some tests once, and cans can stand the heat for solarcollection, but solar heating plastic is a bad idea, unless you use the collector to feed an heat exchanger.

There’s also the UV-degradation, but that’s solved by spraypainting them black.

there was a another open story in this regard; how to weld sliced up PET patches from bottles together. remained unanswered. if you can ‘weld’ those patches together somehow, you could develop a ring roller like device which set or fix the diameter and transports the bottles along a heated cylinder to the counter role which also welds it together. i would consider this a pretty difficult task; otherwise, the patching idea could be enough to make whatever you like beyond this state; just guessing.

That is something really innovative. Processign PET is really hard if you dont have the right tools.