Michael:

How many airplanes are you going to build?  If your like me, my answer was just one......so after considering the few extra $$$$ and time (relatively), the answer was pretty clear;  especially since my copilot doesnt do heat very well.  Also John Durham, one of the original Lancair engineers convinced me that even with the 3rd intercooler, the pressurization air would be 110% that of ambient.  Since its pretty cool here on the west coast (most of the time), I normally only use the A/C for ground operation.  I use a single pole-double throw switch on an either/or circuit to control the A/C and Pressurization although nothing says that you cant use it in flight.

I have my plane apart for its 3rd annual.  I can take some photos if you like.  I also have some drawings around here someplace.  Be happy to look for them if your interested.  What do you need?

Regards, Bill Hogarty