I have just removed the airconditioner pod from the roof of my 21 foot van and will need to replace the air vent (the type with the 4 separate adjustable flaps) since they leak like crazy.
The aircond unit has left behind about 2 square foot hole in the roof and the vent about 4.
I have about 48 square foot comprising 3 solar panels.
I am tinkering with a solar hot water system using Suntuff sheeting. I havent tried this yet.
The idea is to fabricate an end channel for both ends and snip out every other internal wall to a depth of about 1 1/2 inches. I fill the chanel "manifold" with silicone 1/2 inch and push it over the ends of the panel so as to provide a serpentine path for water pumped up onto the roof. I will paint the panel black. There will be no airgap or other insulation but I will space the panel about an inch away from the outer skin of the van. Since there is a 8 foot head between the pump and the panel there will be no tendency to leak out / any seepage will be bubbles of air getting in which I can seal with thick paint.
ASIDE : Those with a more devious turn of mind will see the potential to make a smaller collector that can be lifted higher for cooking moonshine
The pumps / plumbing is completely sorted out since I did something similar in an off grid beach shack I built a few years ago. That time I used a 100 METRE long black PEX oil on the roof which worked perfectly - a collector like that is not going to be practical on a van.
Yesterday was about 30 degrees C and the van got up to 40 degrees inside. The idea will be to space the panels and the HWS with an airgap to keep the skin temperature down and to rehabilitate the 2 vents in the roof with (possibly) 12 volt computer fans to keep air circulating.
I will be tending to the warmer climes so cooling will be more of an issue than staying warm. I am quite comfortable in the heat and dont generaly require aircond. However no one can survive in an unventilated van with no shade.
I am debating if I might glue the solar water heating panels inside the solar panels or to incorporate them separately as extra shade. OTOH They are fairly robust so shouldnt require too much bracing to secure them to the roof as a separate assembly.
Any one tried anything like this before?
BTW I work with SI when I am doing science and imperial when working with my hands. Not trying to score any points here - horses for courses.
-- Edited by Muzzlehatch on Friday 11th of September 2015 03:30:27 PM
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And I somehow rather fancy that I'd like to change with Clancy ..
If you want my advice do NOT use that Suntuf twin wall expensive junk, and believe you me it is rubbish as it becomes extremely brittle when exposed to heat and sunlight causing it fracture anywhere where even light pressure is applied.
It also expands and contracts a huge amount between hot sun and cold at night making it almost impossible to make a waterproof seal.
Yes I'm talking from personal experience.
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I had a thought but it got run over as it crossed my mind.
I had done considerable reading on the suitability of that product for the application I had envisaged. Many knowledgeable proponents of Ecosustainability Good Intentions Paving Company, have only done the drawing board phase of the project. It is thing of loveliness when glimpsed from afar. If this product is as unstable as you have found it to be, it would be useless. The evaluations that came from said GIPC didn't pass the sniff test.
I move with a bunch of engineers but work as a technician.
"In theory there is no difference between theory and practice but in practice there is..."
Kind regards.
-- Edited by Muzzlehatch on Friday 11th of September 2015 06:56:14 PM
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And I somehow rather fancy that I'd like to change with Clancy ..
Polycarbonate roofing whether single sheet or twin wall has a UV protective coating on one side only. If it is used with wrong side up it will not last very long due to degradation of the plastic by sunlight. When used correctly should last at least 10 years.
