It hit me yesterday evening: I just put some rough made fins inside the inlet and forgot they were there. That I think cause some problems like overheating and much less airflow. Like yesterday the panel outlet temp was 79 Celsius degrees. A day before it was "only" 66 C.
So I think I need to fill my trash bag again? Maybe it will fill within 15-20 seconds. Gonna do that test next weekend.
My panel surface is 3.2 squaremeters or 34.5 squarefeets. It is solar can heater made out of 340 beercans with double glasing. Inner is 2mm thick polycarbonate sheet and outer is 3mm acrylic sheet. Two layers for better performance in winter. Best regards jaskiainen[ Parent ]
With the beer cans, you should be getting a pretty even distribution of air through the collector as long as the manifold delivers air evenly to the can rows. You can do a rough check on this by temporary taking off the glazing. Let the collector stabilize in the sun with the fan on. Measure the surface temps of the cans with one the IR gun style thermometers. If you find fairly even temps that increase some for the intake end to the exit end, then the airflow in the cans is even and removing heat all over. If you find hot spots, those are areas that are not getting enough airflow. If you don't have the IR temperature gadget, you may be able to feel any hot spots just touching the surface with a finger.
How hard was it to measure the airflow with the plastic bag? Does the bag technique seem to work pretty well?
GaryGary gary@BuildItSolar.com www.BuildItSolar.com[ Parent ]
