[Alfisti]

I have obviously googled this as best i can but thought i would run it by the folks here who seem to know a thing or two about housing and construction issues.

House is 3200 sq feet plus basement, windows installed near 16 years ago during a major rebuild/reno, we bought the house 11 years ago. Windows are wood from a high end manufacturer in Toronto (Marvin Windows), double hung. They are not great windows though, if it wasn't $60K to replace them I would.

Now, the problem is getting progressively worse on really cold days. So say below 0 celcius, as the furnace kicks in, condensation begins to appear on the sills, being double hung there are two sills per window so it is a 20 minute job to remove the condensation each morning. if i do not remove it, i get mold.

Right now it is minus 12 celcius, furnace is set to 70 and condensation was enough to partially soak a bath towel once i was done.

We do have a humidifier, I set it as low as i can possibly set it, any lower and it is so dry in here that we zap each other.

My suspicion, as a guy who knows little about these things, is a) the windows are not great and are contributing to the problem, but i suspect there is also jut not enough airflow in the house either.

Any thoughts here? It is really chronic and needs to be addressed. Thanks in advance.