Anyone know any places that supply solar selective paints and coatings. I'm specifically looking for info on low emmisivity (sp?) coatings.
Thanks in advance guys.
What's the application? It's tricky to do this locost for coatings and paints are not so effective. I presume you want to capture solar
radiation? Locost way is blackboard paint to adsorb short wave radiation and a glazing cover to reduce long wave emissions.
A pucca multilayer coating for a one off would be v dear!!
Cheers!
So black paint inside a glazed unit is pretty good would you say.
Just building some improvised solar collectors for a bit of fun really. Going to do a couple of evaporative tube and a passive system too.
If I can actually get them to work all the better.
I had th look evaporated tube up! 
Is that DIY able? There are loads of flat plate collectors around and they are so simple and cheap the lack of high efficiency does not matter unless
you are severely limited in the roof area department.
However the heat pipe is interesting I had always assumed it was too difficult to build.
I'm swithering between making and buying a flat plate connector with cost and reliability the deciding factors. Will be good to hear how you get
on.
I have had a go at making DIY solar hot water heaters using polycarbonate roofing sheets. If I remember correctly I got about 200 W from a metre
squared. Without a vacuum a fair amount of the heat is lost through conduction even with double glazing and good insulation on the panel back. I used
matt black paint because I couldn't find any low emmisivity coatings a couple of years ago. My interest was sparked by
http://www.acktar.com/category/products/lights-absorbing-foils but I couldn't obtain any.
I don't think that flat plates are the way to go unless they are really cheap. I also found it difficult to make them leak proof. Vacuum tubes
are available at http://www.eco-nomical.co.uk/SolarWaterProduct.htm. I don't know what they are like though.
Would silver window tint work, applied to the inside to reflect excess light back to the blackboard paint / tubes and add more heat?
Apparently very easy to make with copper pipe and acetone. I will post details when i get round to it 
quote:
Originally posted by v8kid
I had th look evaporated tube up!
Is that DIY able?
However the heat pipe is interesting I had always assumed it was too difficult to build.