Welcome to the Solar Collector
Brainstorming and Development Page!


 

Home

Hot Air Collector

Hot Water Project 1

Hot Water & Space Heating

Solar Electric

Solar Construction 101

FAQs

Best Collectors

Simply Solar
Sign up Calendar Latest Topics
 
 
 


Reply
  Author   Comment   Page 1 of 3      1   2   3   Next
Scott Davis

Avatar / Picture

Super Moderator
Registered:
Posts: 697
Reply with quote  #1 

Yes, this solar collector is only about a foot high and 24 feet long. It sits on the ground, is well hidden and works great!



http://www.n3fjp.com/solar/solarhotair.htm

Also, these days, we really have the wind at out backs for neighborhood acceptance. Everyone is annoyed with their utility bills and Green is in!

If you are planning a solar project, first mention it to your neighbor, but use a little tact. Instead of mentioning your panel plans first thing, when you see your neighbor in the yard, ask him/her if they got their latest utility bill. After you've commiserated together for a few minutes about the cost and high rates, tell your neighbor you've just got to do something about it and work your plans into the conversation. By this point your neighbor might be ready to start on a solar project too! Of course, plan your project so that the end result is attractive as well as functional.


__________________
Take care, Scott MD

stmbtwle

Avatar / Picture

Registered:
Posts: 2,839
Reply with quote  #2 
Check your state laws.   Florida for instance has passed laws favorable to solar arrays & collectors, even solar clothes dryers (clotheslines) that preempt homeowners' association rules.  In other words you may be able to build it even if the association doesn't like it. 
__________________
Solar is like the wind. It may be free, but putting it to work isn't!
Willie, Tampa Bay
GaryBIS

Registered:
Posts: 243
Reply with quote  #3 

A fence and solar collector can be combined -- I think this could look very nice if done carefully.

Another way to make a nice looking solar collector is to add a low thermal mass sunspace to your house.  These can be just as efficient as dedicated solar collectors, and they also add some usable square footage to the house, and they can look great  -- see Mike's or William's sunspace in this section: http://www.builditsolar.com/Projects/Sunspace/sunspaces.htm#LowMassSS

A nice think about the low mass sunspaces is that if they are done well, they add value to the house on resale -- that is, everyone can see the value of both energy saving and a nice sunny space to hang out in.

Gary
Ky-Jeeper

Avatar / Picture

Registered:
Posts: 199
Reply with quote  #4 
Im considering a front porch railing with a solar air heater behind it.
stmbtwle

Avatar / Picture

Registered:
Posts: 2,839
Reply with quote  #5 
Actually that sounds like a neat idea.   You'd lose a little to shading, but as long as you allow for it why not.  Wouldn't be the first time we've had to compromise.
__________________
Solar is like the wind. It may be free, but putting it to work isn't!
Willie, Tampa Bay
Parkie

Registered:
Posts: 6
Reply with quote  #6 
Looking at the horizontal unit that Scott built, has me seriously considering that direction rather than 4 x 8. First and foremost, "she who must be obeyed", suggested a more cosmetic and pleasing look since it will be hanging on the south side of our home. 
My thoughts are on a 20 foot by 2 ft high unit. Couple of questions on construction:

1. Would you suggest double glazing using the tufftex or similar and if yes how far between each layer?

2. I like the idea of rounding the plenum to allow the air to flow more easily and larger ends rather than using the pipe in your picture.

3. I am thinking of a duct fan but not sure how one figures how to decide on 4" or 6" . Is it because of the volume of air or speed of the fan? Any suggestions?

 I want this full size one to have almost constant flow of over 80F coming in. Am I being within reason to expect that from that size?
solardan1959

Avatar / Picture

Registered:
Posts: 1,845
Reply with quote  #7 
Parkie,
   You broke the most common rule while posting your questions.  How can we answer your questions such as:
Quote:
I want this full size one to have almost constant flow of over 80F coming in. Am I being within reason to expect that from that size?

  When we have no idea of where you at or the conditions you face?  Not picking on you it happens all the time.  My 3X20 horizontal panel that was a screen but is currently a downspout has been running since about 9.  It is now 3:30 and running strong pushing out 98 degrees at about 200 cfm.  Earlier, closer to noon it was putting out 118 at the same flow, the outside air has been about 20 degrees, the input to the collector has been about 60 degrees.  It would not surprise me if you got close to that or better with screen in a down and back configuration with a 2X20 panel. 
Here is one example of the first long horizontal I was going to build.
[image] 
here are some more ideas:
[image]
I am in no way trying to talk you out of downspouts but giving you other cheaper options.  Downspouts could be done in the same configuration using about three downspouts in each 1 foot section.   I later modified my screen collector to a downspout here and feel your adding a curved piece at the bend would definitely improve the flow.  Here is my current long horizontal downspout collector:
[image] 
the one channel on the left and the two channels on the right are cold air traps to keep the cold air out of my lower vents in addition to backdraft protection.  The finished product is here:
[image] 

I used twin wall ploy which is much easier than trying to use two layers of suntuf spaced slightly apart.  From what I have seen I would focus a lot more on backdraft prevention as even with twin wall my panel gets very cold inside of it.  I would just use one layer of suntuf if that's what you want to do and seal it up real well then do everything you can to prevent the air from getting into the house when the collector is cold.
backdraft preventers: http://www.homedepot.com/p/t/202907125?productId=202907125&storeId=10051&langId=-1&catalogId=10053&MERCH=REC%2d%5f%2dproduct%2d1%2d%5f%2d202907128%2d%5f%2d202907125%2d%5f%2dN

You never said how thick you were planning but with a 4 inch deep x 12 for the channel = 48 inches in each channel. A four inch pipe only has a volume of 12 inches where a 6 inch has 27 inches of volume.  You could get away with a four inch pipe and a blower like this http://www.htgsupply.com/Product-GrowBright-%208in-High-Velocity-Inline-Fan#
which will provide all the flow you need , I tend to like bigger like a 6 inch vent.  But there 6 inch is kind of overkill (420 cfm) so it would have to be slowed down with some type of fan control.
You could even use 8 inches with a much lower flowing fan such as a cheap duct fan.  These tend to slow down if resistance is felt but they are cheap and a higher rated one should provide you with the 120 cfm you need.

Hope I covered it all and provided some options for you.

Oh and "she who must be obeyed",  how do you know my wife?   (must be another Bortz fan)

Dan

mocars2

Registered:
Posts: 173
Reply with quote  #8 
Dan - what do you have under the downspouts? How did you attach them? And now that you went from screen to DS - any changes you do if you had the time? Your screen wasn't a down and back travel was it? And you changed that because of cold air back into the room - is that right?
thanks
solardan1959

Avatar / Picture

Registered:
Posts: 1,845
Reply with quote  #9 
mocars2,
  Yes the change was driven by the want of a cold air trap inside of the collector.
  No the screen was not a down and back, I was talked out of that before I built the original design because a straight through may be more efficient.  I changed it to try and build more heat during cooler periods.  I have seen 138 inside the collector at 20 degrees so they may have been right but it seemed to be a little better in the -10 temp range. (probably just my imagination or wishful thinking)
  The original design had metal panels like roofing material on the back in front of the polyiso because I thought that that would better trap any left over heat that got through a screen.  I was also acting like a back pass allowing air to collect heat from both sides of it.  I screwed the downspouts directly to this metal sheet, just a screw at each end.
  Changes: Well I would not add the metal plate unless I decided that would be the only absorber.  Curved pieces like Parkie suggested may be an addition (also like in the "zen of solar passive heating").  I would also try and cut down a little on the turn around area between downspout sections.  The curve would help that transition.  I also am not crazy about being able to clearly see the downspout layout.  Screen or something else may look a little better.

Dan
mocars2

Registered:
Posts: 173
Reply with quote  #10 
thanks Dan - So does the DS help with the cold drafts? And since it's the same housing (sort of) which is better - DS or Screen?
Previous Topic | Next Topic
Print
Reply

Quick Navigation:

Easily create a Forum Website with Website Toolbox.

 

web statistics