finished solar hot water panels.. Condensation problems inside

[jondecker76]

I jus finished a 75 sqft solar hot water collector (based off of gary's $1000 solar water heater design on builditsolar.com)

My collector is glazed with single panes of tempered glass, and sealed water tight and pretty much air tight.
This is the first day watching it, but heavy condensation formed on the lower half of all the glass on the inside.
The condensation was actually heavy enough to form droplets and run down the inside of the glass.
There are absolutely no leaks, and the glazing was put on clean and dry in full sun.

Is this normal? Is there anything I can do about it? (The glazing is sealed on pretty much permanently)
I'll try to get pictures tomorrow if it doesn't rain

Thanks!

[jarrod9155]

My panels that I restored are factory built with vents . In the morning my panels start with a little condensation but quickly burns off ,maybe add some vents on the top and bottom create some air flow . Mine are also tempered glass.

[MattM]

Unless you use kiln dry wood the moisture is probably coming from your frame.  It will vaporize out in due time.

[jondecker76]

I didn't think about the moisture coming from the wood - I'll let it take on some sun for a week or two and see if it gets better - then if I have to I'll get a little more invasive with some vent holes


On a side note, I got the glazing on at about 2:00PM, and thought I would give it a test by connecting my garden hose to it - I cracked it in to what I guestimated at 1GPM, and the water was continuously coming out so hot you couldn't hold your hand in the exit stream at all - It was quite exciting!

[tomtank]

It is usual to have small drain holes(2) in the bottom of a collector. I would wait and see if the moisture evaporates through the cracks in the case.