MonkeyClaw
Pre-takeoff checklist
The AC in the Columbias is very effective and VERY nice to have! I live in Northern AZ (4500') and use it quite a bit. The design of the plane allows a lot of sun into the cabin. You can block it with tints or shades, but it's SOOO NICE sitting on the ramp with the AC kicking and seeing everyone else with their doors hanging open while trying to do a runup or waiting for clearance. I don't recall the weight penalty off hand (~50 lbs sounds about right), but you won't notice the power difference at all.