Peter - I downloaded a copy of Solkane and it is very nice stuff, lots of respect for the authors.

When I put the numbers in that I use it came back with exactly the same answers so very pleased with that agreement.

So at this point I cant yet see where SH improves the COP and as MAD points out if you enter the wrong data into Coolpack it will give the wrong answer. It does not seem to check if what you are trying to do is reasonable. Solkane is also similar in it allows unrealistic SH to be added although the COP remains pretty constant. The basic reason seems to be neither consider the box temperature which in a real scenario is essential.

The main idea of this thread is to find out if SH ever increases COP and is not intended to show up Coolpack or Solkane but as a corrollary to the thread it does appear that care should be exercised in their use.

So my only intention is determine if SH ever improves COP and so far I have not seen any conclusive evidence.

Now there may be many reasons why SH is a good thing but that can be looked at later.