daestrom wrote:

Condensation can be seen as two possible problems. Either there is too much
moisture in the air so the dew point is pretty high, or the inside surfaces
of the glass/frame are so cold that they are below the dew point for even
relatively dry air.

With no moisture source in the house, indoor and outdoor air would have
the same dew point. Minimal moisture from human activities (about 2 gal
per day for a family of 4) wouldn't change this much, for an average US
(224 cfm) air-leaky house.

Nick