So each clothes dryer appliance has an exit port. You connect a hose to it to vent the damp air to the outside.
I want all dryers to have an intake port so that I can use cold air from the outside for drying. This will keep me from using (expensive) warm air from the inside of my house.
I suspect this will also make the dryer more efficient because the cold incoming air could contain less humidity.
This is effectively what my parents do, with a dehumidifier in the basement where they hang their laundry.
They pre-spin them in in the gas drier for 10min to shake out wrinkles and heat the water in the clothes, then hang dry in the basement beside the dehumidifier.
A dehumidifier extracts the heat of condensation from water vapour, which is much greater than the amount of energy you would get by simply pumping heat from the outdoor air. That heat warms the basement which helps heat the house as well as dry the clothes further.
They live in a rainy climate so line drying is unfeasible and the basement needs dehumidification anyways, so it’s a win-win.