The Great Simply Solar Hot Air Collector Absorber Challenge!

This contest is presented as a framework to encourage useful solar hot air collector absorber testing, that will reveal designs that will help us all to build even better performing collectors in the future.

This is an informal "competition", there is no monetary award and it is really all about experimentation, encouraging new thoughts and ideas. We are a club, working together and encouraging each other in a fun way to learn, experiment and move the DIY hobby, art, science of solar forward. When one of us wins, we all do!

Good, accurate testing and data collection is strongly encouraged, however, everyone should understand that these are DIY experiments from folks at all skill levels, that unless duplicated, can't be verified. The submissions we see here will not necessarily be the "definitive" answer. The intent is to bring promising ideas and designs to light for further review.


Testing Concept:

The key to accurate performance comparisons of hot air collectors is side by side testing of the collector under test to a reference standard, using identical airflow. With everyone using an identically designed reference standard, we can make useful comparisons all over the world in widely varying conditions.

We want to open this contest to as many folks as possible, whether building specifically with testing in mind, or building a permanent collector with two or more bays to test alternative heat absorbers. Those builders may want to use glazings other than Suntuf.

We also want to collect the most meaningful data that we can. To do that, the reference standard we all use should be identical, including the glazing. We have decided to try to accommodate both goals by utilizing two award categories - Verified and Unverified.


Contest Objective:

To design a hot air collector absorber that will outperform the reference standard, double layer screen collector (with screens separated). Examples of the double layer screen design are here:

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

Please note that in the design above the screens are not separated, but Gary adds "For the collector used in the comparison testing with Scott, the screens were separated, and this seems sensible to me."

Or here:

http://groups.yahoo.com/group/SimplySolar/photos/album/1082811597/pic/list?mode=tn&order=ordinal&start=1&dir=asc

and:

- The depth and dimensions of collector under test is at the builder's discretion, provided the total square feet of glazing area are equal to the reference standard.


Requirements for Verified Category:

- The reference collector must be built to the specs we've laid out and glazed with either Suntuf or Tuftex glazing (readily and inexpensively available at Lowes and Home Depot). Identical reference standards will provide the most useful comparisons, regardless of location.

- The collector under test must also be glazed identically with Suntuf or Tuftex.

- The collector under test must have identical width and height dimensions to the reference standard. Depth dimension can be different, but an explanation for the different depth should be included.

- Width and height dimensions must be at a 1 X 2 ratio (minimum 2 feet wide X 4 feet high)

- Airflow should aim for 3 CFM per cubic foot of collector.

- All submission will initially be placed in the unverified category. A submission will be considered verified on a case by case basis, either by the overall assessment of the quality of the submission (reference standard collector design construction conformity, confidence in air flow test measurements, etc.) or verified by an independent duplication of results by another member.


Submittal:

Submit your entry to the group via e-mail with the following information and attachments:

- The date and time of the test.

- The output temperature of both collectors.

- The input temperature of both collectors.

- Your estimated airflow in each collector at the time the measurements are taken (estimates based on timing the filling of a trash bag will be accepted).

- The ambient outdoor temperature (or environment indoors if a sun simulator is used)

Also please provide:

- A written description, picture or video demonstrating how you balanced the airflow.

- A picture or drawing that clearly shows your absorber design. Enough detail should be provided so that others can accurately duplicate your design and ultimately your results.

- A picture of your test setup.

- A picture of the sky conditions during the test.

- A picture of the fan(s) or blower(s) used.


Awards & Rewards:

- The winner will receive lots of great recognition, a certificate award, suitable for framing, our effusive thanks and of course, bragging rights.

- All participants will receive the fun, satisfaction and educational benefit this contest will bring, not to mention the warm inner glow of knowing we all are helping to move the hobby / art / science of DIY solar forward, saving money and benefiting the environment.

- Free heat!