HRV: AirPro Heating
http://airproheatingairconditio.supersites.ca/contact/
They've done several installations for Calgary Canreefers (me included, did an A/C at the same time). They know their stuff, they'll take a look at your square footage and air volume and how much turnover you need to keep moisture under control. I can't recommend these guys enough. I have them do all my heating/ducting work now.