How should I decide between an HRV and ERV for a northern climate home?
I'm in the same situation. I think it depends on size of your home and number of people. If you've many people and do lots of cooking, shower, laundry etc and have smaller home then HRV is better because it will get rid of excess moisture. If you you've a large home, few people and air is very dry in winters then ERV is better. Also read ERV is better for old drafty homes (1960s old).
We opted for HRV because it is cheaper, we've a small house and we already have vented hood and exhaust in bathrooms.