I currently don't have a Hrv. I'll have to research what model to get etc...
In the mean time I might try what George suggested and bring in fresh air directly to the cold air return with a damper.
As a side note my windows are made by Lincoln. Wood dual pane with no argon, casements (very cheap builder grade). I'm going to replace two bedroom windows this spring just because they have some rot already since they face southwest. The sun beats the crap out them and they will take paint three times a year if I had the time do to paint them that many times.