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
Register Calendar Latest Topics
 
 
 


Reply
  Author   Comment   Page 1 of 4      1   2   3   4   Next
mclark999

Registered:
Posts: 182
Reply with quote  #1 
I've been kicking this idea around for awhile. I built a nice 44 sq foot double screen collector and placed it on the south side of my home three winters ago. It works great and starts adding substantial heat to the house around 10 a.m. each day. 

My southern facing wall that's it mounted to actually faces a little southwest, though, so the sun doesn't get to it as early in the morning as I would like. I've added reflectors on the ground that are a little to the east which help it pick up heat earlier in the morning. It works well enough that I am not considering changing it. It also works well enough that I've decided to build at least one more and maybe two more collectors for my home.

Given that I am going to build a new collector, I thought I'd place it so it gets the morning sun earlier. I have pretty bright sun on the east side of the house by about 7:30 even in mid-winter. I'm in Denver. 

My first thought was just to place a collector on the east side of the house but that would only provide heat for around 3 hours a day. So I started thinking of a sun tracking collector on the south side of the house that would rotate as the sun moves, starting in the morning facing east and ending in the evening facing west. 

What I'm imagining is a regular box type collector maybe 8 feet high by 5 or 6 feet wide. The collector would rotate on the vertical axis. To minimize duct work movement the inlet and outlets would need to be at the very center of the top and bottom. I could use one of the many sun tracking devices that are already available for PV solar. 

My biggest concern is just how it will look. It would need to be mounted far enough away from the wall that it can rotate 180 degrees, so if it was 6 feet wide, it would have to be at least 3 feet out from the wall. 

Then I'm also thinking of how I would adapt the ducts, (8" round metal) so they can rotate and stay together and be insulated. 


I'm open to what other people think about this and how they see it being put together.  

Here's a side view and 3/4 view to show a bit of what I'm trying to do.

20171214_113155.jpg  20171214_113201.jpg 




__________________
Denver, CO

Double screen hot air collector

stmbtwle

Avatar / Picture

Registered:
Posts: 2,686
Reply with quote  #2 
I don't doubt it would work, but I'm afraid it might be more cost and hassle than it's worth.

I've thought of two collectors arranged in a "vee" so that one would work in the morning, both at midday, the other in the afternoon. But there's still the cost and hassle. No I haven't tried it.

Another option might be a fixed collector with moveable reflectors.

__________________
Solar is like the wind. It may be free, but putting it to work isn't!
Willie, Tampa Bay
Bert

Avatar / Picture

Registered:
Posts: 490
Reply with quote  #3 
Here is a simple DIY tracker. It would have to be beefed up for a solar collector I think. Could use two for vertical and horizontal. The ducting would be a tough one.


I may give it a try on the solar oven I will be building soon.


__________________
Bert K.
Michigan

https://www.youtube.com/user/1thinkhealthy/playlists
gbwillson

Avatar / Picture

Registered:
Posts: 2,219
Reply with quote  #4 
Remember too, that you don't need to pivot 180˚ to capture more sunlight during a winter day. Even if you can pivot only 45˚ from either side of due south, you should still capture enough sun to keep the unit running far longer than a fixed collector. The sun is too low in the sky just after sunrise and just before sunset to capture much, if any, heat.

I find the biggest issue this time of year where I live is not only is it when the sun is lowest in the sky, but this is also the cloudiest time of year. Thankfully, January and February are frigid, but also quite sunny. 

And Willie has a good point about pivoting reflectors. They would be lighter, cheaper, and FAR less complicated. 

Greg in MN


mclark999

Registered:
Posts: 182
Reply with quote  #5 
A pivoting/movable reflector probably would be simpler. And I have a side fence close enough to use to anchor it to.

I may look into that. More physics involved in aiming a moving reflector than simply rotating a panel. 

And Greg, you make a good point that it wouldn't have to rotate 180 degrees. 45 in each direction would capture 90% of the daylight.

I've got about 10 months to think it through and decide on a design. I'll be aiming to have it functional by next Thanksgiving.

I did find 8 inch ball swivel ducts that were very expensive $350 each. I'd need 2 so that would be $700 just for swivels. My entire first build was only around $350 - $400.


__________________
Denver, CO

Double screen hot air collector
gbwillson

Avatar / Picture

Registered:
Posts: 2,219
Reply with quote  #6 
What about using ball joints, wheel bearings, or universal joints off a junker car or truck? Sure would be heavy duty and likely cheap or free.

Greg in MN
stmbtwle

Avatar / Picture

Registered:
Posts: 2,686
Reply with quote  #7 
I've tried making a "solar tracker" from those videos and couldn't. Note the wires go UNDER the board (to what?). There's more to it than they're letting on.

__________________
Solar is like the wind. It may be free, but putting it to work isn't!
Willie, Tampa Bay
gbwillson

Avatar / Picture

Registered:
Posts: 2,219
Reply with quote  #8 
If you were able to make the collector pivot, the ducting as shown in your drawing likely wouldn't work as the pivot would need to be hollow. Have the ducts enter the collector midline top and bottom as in your drawing, but entering from the back of the collector. The reason you would want oversized duct is that the ducts would need to be loose and free to move with the collector. You should only need a short section of loose flex duct for this to work. The ridges in the loose duct would be quite pronounced, and add quite a bit of resistance. By having oversized ducts you should still allow plenty of air to pass through without penalty.

Greg in MN
Bert

Avatar / Picture

Registered:
Posts: 490
Reply with quote  #9 
Willie

Here is his schematic


The panels are just wired in reverse to the motor. It's a fight. Whichever panel has the most light/power wins and moves the motor until they even out.
May need some diodes in there.



__________________
Bert K.
Michigan

https://www.youtube.com/user/1thinkhealthy/playlists
stmbtwle

Avatar / Picture

Registered:
Posts: 2,686
Reply with quote  #10 
Thanks. That's what I tried, but I couldn't get it to work. Maybe I didn't have enough panels. If my guess is correct those are 12v panels, so he's running 36v (or more) per side. Still, it looks like a short circuit as drawn.

Even though the panels are small, 12 of the little beasts would get expensive.

__________________
Solar is like the wind. It may be free, but putting it to work isn't!
Willie, Tampa Bay
Previous Topic | Next Topic
Print
Reply

Quick Navigation:

Easily create a Forum Website with Website Toolbox.

 

web statistics