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  
matlocc

Registered:
Posts: 61
Reply with quote  #1 
I have been reading about the trouble with air contacting the glazing.  Could you put your screen inside and then stretch a screen across the top and staple it tight and then place your glazing on with say a 1/4 inch gap between it and the top screen. Actually you would have 3 layers of screen.  It would be glazing, 1/4 inch down screen, then the inside of the box with your two layer screen and frame.

gbwillson

Avatar / Picture

Registered:
Posts: 2,128
Reply with quote  #2 
I'm not sure what you mean about trouble with air contacting glazing. I've never heard of this.

Greg confused in MN
SolarInterested

Avatar / Picture

Spam Stomper
Registered:
Posts: 1,001
Reply with quote  #3 
Greg I believe it's about heat loss through the glazing when hot air is allowed to flow along the glazing.

Matlocc no sure exactly what you have in mind, a drawing would help. You could have a look at the 'zero pass' collector where most of the air flows between two layers of screen.

__________________
Both temperature rise and airflow are integral to comparing hot air collectors
matlocc

Registered:
Posts: 61
Reply with quote  #4 
It is about heat loss through the glazing. I was thinking more about this and instead of screen the window plastic may be a better idea.  It is like making the glazing a double pane window. Glazing, airspace then the clear plastic.  then the interior of the box. I will try to draw something and post a pic. I am not sure how to do the drawing stuff!!!!
SolarInterested

Avatar / Picture

Spam Stomper
Registered:
Posts: 1,001
Reply with quote  #5 
Quote:
Originally Posted by matlocc
It is about heat loss through the glazing. I was thinking more about this and instead of screen the window plastic may be a better idea.  It is like making the glazing a double pane window. Glazing, airspace then the clear plastic.  then the interior of the box.
I've thought about that too. The window plastic would be protected by the outer glazing but the interior airflow might cause it to bulge toward the glazing and also weaken over time. It would be an interesting experiment.

__________________
Both temperature rise and airflow are integral to comparing hot air collectors
gbwillson

Avatar / Picture

Registered:
Posts: 2,128
Reply with quote  #6 
Sounds like you want to replace the top-most screen layer with clear plastic. I would think screen would do a far better job of transferring heat to the air. 

There are plenty of drawing programs available for free or very cheap online. If you can sketch it on paper you can take a pic with your phone. In either case, simply save as a JPEG to post the same as a photo.

Greg in MN
matlocc

Registered:
Posts: 61
Reply with quote  #7 
let's see if this works

Attached Images
jpeg 20171117_111447.jpg (160.20 KB, 49 views)

SolarInterested

Avatar / Picture

Spam Stomper
Registered:
Posts: 1,001
Reply with quote  #8 
As far as the screens go it looks like the original double screen collector. The window plastic would add an extra 'pane' to the glazing and even if it bulged and partially touched the outer glazing it should still provide some benefit.


Screen collector examples:



http://www.builditsolar.com/Experimental/AirColTesting/ScreenCollector/Building.htm



__________________
Both temperature rise and airflow are integral to comparing hot air collectors
stmbtwle

Avatar / Picture

Registered:
Posts: 2,547
Reply with quote  #9 
The window plastic should do a better job of keeping the air off the glazing, but it would add another reflective surface, too. Whether it would be a net gain or loss is a matter for testing.

Same for the film vs the screen.

__________________
Willie, Tampa Bay
gbwillson

Avatar / Picture

Registered:
Posts: 2,128
Reply with quote  #10 
A single layer of glazing is fine in all but the coldest climates.  Designs such as the downspout, backpass, and ZP, keep the air passing through a collector away from the glazing better than others.

Make sure the output air temps are moderate and not too hot. Higher volumes of airflow will reduce the time air is exposed to the cold, minimize conduction though the glazing, allowing a collector to operate at maximum efficiency.

Greg in MN
Previous Topic | Next Topic
Print
Reply

Quick Navigation:

Easily create a Forum Website with Website Toolbox.

 

web statistics