dpb wrote:

... the air that leaves is simply a small fraction of the same air that's
already there.

Heating the window from 70 to 100 F at constant pressure increases the air
volume by (460+100)/(460+70) = 1.057, ie 5.7% no? How many times must we
heat the window to lower the cavity air dew point to 0 F, if it starts at
50% RH and we replace the air that leaves the hole with dry air?

Nick