Richard,
I just dragged out Type 539, connected it to a TMY-3 weather file and ran it for a month. The results from the model exactly match the results from the Qu=Mdot*Cp*(Tout-Tin) equation to the 12th decimal. Check to make sure you have the same specific heat in both, have the correct connections etc. If you are still running into issues then send the project to your distributor for a closer look.
Jeff
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Jeff Thornton
President - TESS LLC
22 N. Carroll Street, Madison WI USA 53703
Office: (608) 274-2577 Fax: (608) 278-1475
www.tess-inc.com
E-Mail: thornton@tess-inc.com
On 07/31/2012 8:33 am, Richard Thygesen wrote:
I have a question about type 539 solar collector.
When I compare the output useful energy gain with my own calculation it doesen’t match.
Why is that and shouldn’t the useful energy gain be the same as my calculation?
I have used the following q=massflow*Cp*(Tout-Tin) to calculate the useful energy.
Best regards
Richard Thygesen