Solar Collector Fin Efficiency Calculator

The Calculator Inputs:

These are the numbers you need to enter to get an efficiency calculation:
 

Fin Material Thermal Conductivity -- This is the thermal conductivity of the material that the fin is made from.  You can input your own number, or choose one of the materials that the calculator provides.

Fin Net Width -- This is the width of the fin from one edge to the other.  For fins that connect to the opposite edges of the tube, subtract the outer diameter of the tube from the fin width -- that is, only count the width for the outer edge of the fin to the point where it connects with the tube.  For the kind of tube in a groove in the fin connection we commonly use, I would subtract one half of the tube diameter from the total fin width.

Fin Thickness -- This is the thickness of the fin material.  If you use one sheet under the tube and one over, as in this collector, I would use the total thickness of the two pieces.  If you use a narrower piece under the fin, as in this collector, then I would count half the thickness of the lower sheet.

Collector Loss Coefficient -- This is the total loss coefficient for the collector.  It includes all losses, but most of the loss will be out the front glazing.  xx.xx is typical for a single glazed collector, and yy,yy would the typical for a double glazed collector.

Ambient air temperature -- This is just the temperature of the air around the collector -- i.e. the outside air temperature.

The Calculator Outputs:

After filling in the inputs, click the "Calculate" button, and calculator will calculate the Fin Efficiency.  Anytime you change an input, you need to hit the Calculate button again.

Fin Efficiency -- This is the fin efficiency.  It is defined in such a way that a (say) 5% drop in fin efficiency will mean a 5% drop in collector output, so it is a powerful factor.

Please read this...

If you have any comments, corrections, or suggestions on the calculator, please email me: Gary