Here is a video of a recently installed HRV system, yes I know it isn't finished, I made the video at this point in the installation to show the piping without insulation on it so its easier to trace. This HRV is installed in a "slightly" conditioned mechanical room.

http://www.youtube.com/user/skyheati.../7/2fp-JpuBrpM

I have a few more videos coming up of XL20i systems!