Greenward Ridge Vent Turns Your Entire Roof Into a Solar Collector

Very, very clever <drool, dribble>.

Hey! Get in line! ("Join the queue!")

That's one that makes you slap your forehead with your palm and exclaim: Why didn't I think of that!?

Combine this development with "the Perfect Coffee Cup" (also in CR4's news today) and we've finally shattered the low-cost tepid beverage barrier that has so long plagued mankind!

It's the dawning of a true golden age!

My first thought is, "Wow, how many BTU's per hour can they extract with this system?" Probably not enough to make it worth your while.

Interesting idea, but a flat plate collector (aka Del's project) makes a lot more sense. You throw away a lot heat on the re-radiation off of the roof surface itself. The "cooler" air rising from the backside of the roof will dilute the hotter air from the front side. I'd love to see the data that shows the volume of air moved through the ridge vent, and then the Δt of the air after it passes by a plastic tube. Or how about some data showing the volume of water multiplied by its Δt?

Oh, if it's green, it's got to be good, right? In fact it does remind me of Mr. Haney on Green Acres.

Hot air flows from inside the attic through a ridge vent system whether or not you install an extractor such as this. From the times I've spent in attics I haven't noticed much, if any, dilution from the "cool" side. The heat mostly seems well distributed. Caveat: I haven't taken thermometers with me, just sweated prodigiously.

If you can pay for the tube system in a year or two by saving conventional water heating costs, who cares what "makes a lot more sense"?

And, install the flat plate system too.

Hooker

I won't disagree that it gets hot in the attic. Mine sure does. I don't go in mine during the day in the summer months. But again, I'd like to see the data that supports payback in one or two years.

Does that just account for the purchase price of the tube system? Or does that include the cost to install as well? Assume if you will you are replacing the whole roof anyways and the installation cost may be reduced considerably because it's incorporated into the roof replacement. But you still will need (at least in my nanny government neck of the woods) a licensed plumber to pull a permit to install it. Does it use a pre-heat storage tank? Circulating pumps? Drain-back system or closed loop? Closed loop systems (polyprop glycol based) need a double-barrier heat exchanger to meet most plumbing codes. During the winter months there will be almost zero benefit. Flat plat collectors work much better and if you don't mind the expense, the evacuated tube collectors are said to be much better than even the flat plate collectors.

One of the companies that operates a number of apartment buildings (blocks of flats) in the Glen Burnie, Maryland area is experimenting with both flat plate and evacuated collectors to see which type gives the best return in investment. I will be very interested to learn how that works out.

http://www.hometownannapolis.com/news/bus/2009/10/25-47/Testing-the-solar-waters.html

Caveat: I have no financial/emotional/intellectual interest in any of the following companies. These are just some of the places I've been researching possibilities for heating domestic hot water (and perhaps some space heating as well) in my domicile.

http://www.solarpanelsplus.com/

http://www.sunearthinc.com/

http://www.dawnsolar.com/downloads/DSBrochure.pdf

http://www.thermomax.com/

http://www.kingsolar.com/ (site under revision)

Cheers!!

Yeah, I agree that an ROI based on hard data would be helpful, but I'm just at the "tinkering in my mind" stage, so it's not mandatory. One or two year payback was just an off the top of my head comment.

I'm pondering whether it's possible to make a glycol closed loop system completely passive; ie, no energy eating pumps. And, as a pre-heat to take the chill off incoming water or to feed in line heating. That way you could install and virtually "forget" the system except for a regular look-see to be sure the ridge vent isn't blocked and that fluid is circulating.

I would disagree about almost zero benefit in the winter months. I lived in New Hampshire for 11 years and was surprised at the attic temperatures on sunny sub-freezing winter days. Again, no hard data, just personal observation.

Lastly, I don't need no steenkin' permits. (said semi-jokingly)

Oh, and thanks for the links.

Hooker