I came accross HealthandEnergy.com while looking for examples of Heat Recovery Ventilation duct work installations. It is a very good site for forward thinking ways of looking at energy and how it relates to health
The site covers many things more general than how to run the duct work for an ERV, but if you want to know how to run ERV duct work, man do they do a great job explaining it.
Running duct work in an old and space cramped Brooklyn brownstone is no easy feat. So this was a good site.