Quote Originally Posted by Rtic View Post
In cooling mode, on a MHI split system (where the metering device is at the condenser), both the delivery line to the evaporator is the suction, and the return to the condenser is also the suction. Phase change has occurred in the evaporator (ideally at the end; but with a 8-metre heat exchanger perhaps earlier .
If I understand you correctly the flow into an evaporator from the expansion device is a suction pipe? From my comprehension the suction line is the pipe from the evaporator to the compressor no more. I don’t think anyone here will agree with you on this.

However phase change starts from the expansion device therefore this pipe is below liquid line pressure and temperature but not yet at suction line pressure or temperature. Would you agree with this?


All you keep doing is replying about "actual evidence", but I'm not the installer of the original system, nor do I have access to the site. I have put my thought on this subject and have provided in detail why I think that insulating both lines will indeed have a "big effect".
Err no you haven’t all you’ve said it ‘big effect’ you haven’t actually provided any information let alone detailed to back this up in any way shape or form.

I asked you what temperature you think the pipes would be as this is fundamental to your assumption and you have failed to even consider what they might be..

You have said "at least 2 others have made sweeping statements about loss of performance but failed to back it up with any actual evidence", but that's because when on a refrigeration forum, after the OP question has been answered using what is basic knowledge that most refrigeration engineers should know, there is little more to add. However, you seem to want us to either go to the site to take accurate measurements or set up a test rig to prove what is already known

Sigh... so go on then give me your standard "actual evidence" reply.
Heat transfer relies on a temperature difference. I ask again what temperature difference would you expect between a suction pipe and a phase change pipe on any split let alone this one?

No one apart from Chemi has considered that the two pipes are nearly identical in temperature coupled with the potential that they would only be touching sporadically along the 8m length which may negate any real heat exchange effect. In fact there is a possibility that the suction pipe is colder than the phase change pipe which may turn your argument on it’s head.

The reason I ask for ‘actual evidence’ is that there is an assumption that it has a detrimental effect yet no one can provide any actual evidence to back this up.