I would think the best way to know would be to just set up a glass tank with a UTH and measure with an accurate hygrometer. AC's and heaters tend to dry out the air of a house, so the ambient humidity inside is often much lower than it is outside. That may have some effect on what it is in the tank. However, if you know the humidity in your home stays relatively high, you might not have nearly as much trouble as someone who lives in say....Tucson.