Furnaces dry out the air. Human activity can contribute moisture to the air. But the net effect is usually to leave the interior air dryer than the exterior air. Depending greatly on your lavatory ventilation.
Where I live, allowing outside air in greatly increases the inside humidity. And I would guess this is true for most people given the widespread complaints of dry winter skin and bloody noses. Which is the product of increased furnace operation.
Where I live, allowing outside air in greatly increases the inside humidity. And I would guess this is true for most people given the widespread complaints of dry winter skin and bloody noses. Which is the product of increased furnace operation.