Gregory's Server|
23 comments
 The vacuum tubes are designed to keep the heat in, we have also a reflector that concentrates the sun rays. Some people put these little sun dials that works like a bull's eye to indicate if the reflectors are all angled.  I translate the name of the website, because "Sun in our dishes" is a great idea.  @ddlyh we're not going to share the specific brand but I'm sure you can find similar models based on the handle design. We found ours at a local hardware store. @neauoire That's so cool! 🤩 Which curve is the reflector? Parabolic? Or is it the elusive compound parabolic concentrator? @clh3 it's a piece of bent stainless that curves to follow the shape of the tube. I'm not sure what its name is @neauoire Ooh🤔 that sounds like an involute curve, the first curve segment of a compound parabolic concentrator. @neauoire One word of caution 🚧 : I've heard of tubes freezing and breaking if they're exposed to clear night sky -- but this event occurred with vacuum tubes with interior metal tubes filled with water. The research group at UC Merced had to cover their vacuum tube + reflector experiment at night due to hazardous radiative cooling. @clh3 ours are different, we use the household type that is normally installed on rooftops.   @nina_kali_nina @rek When you boil water, do you pour water directly in, or do you have a long skinny pot that you can slip inside?
[DATA EXPUNGED]
 @NicholasLaney @slew @rek it's not pressurized I think. The vacuum part is the double-walled glass tube.  @42GB @neauoire Ppl in France group-buy the vacuum tubes so you can build something similar, might be a good route: https://www.dusoleildansnosassiettes.com/boutique |
For more DIY projects to do with the vacuum tubes, there's this really cool workshop website.
https://www.dusoleildansnosassiettes.com/tube-de-sterilisation-solaire