The charts to the right and below show the pressure drop test results of both the metal collector and
Sunreps Geotextile 307 collector. The size of the
holes in the respective collector surfaces determine how fast air can pass through. The smaller the
hole the lower the flow but the higher the
10 cfm per sq ft of air-flow through a collector is
scientifically noted as the optimum. The best
test results Sunreps has seen for a metal collector
is 7.6 cfm per sq ft. Sunreps' 307 collector has a
flow rate of 8.5. Overall this difference is rather
small but in the field of bragging rights, Sunreps
307 is the current winner.
Collector Test Results
Below is the test result for the Sunreps 307 collector fabric. To be used in the commercial building sector all surfaces of a duct need to be fire resistant to a specified level. The test
results shown below meet those requirements.
There is basically one test required to understand the capabilities of a transpired solar collector and that is how fast air will pass through the collector surface at a specific static pressure level. .10 inch H2O of pressure is the baseline for a collector.
At .10 inches or above the wind will not pull the heat off the collector surface.