While portable ACs can be vented through a door, wall, or ceiling, they are most frequently vented through windows. Although it isn't unsafe to run your portable AC without venting, it is counterproductive.

Yes. The water is accumulated in an internal drain pan. This water is evaporated and sent out the exhaust hose in the form of water vapor. Occassionally, the unit will need to be drained in humid environments.

If we just take the sample of an 8,000 BTU (250 square feet of cooling power) portable unit with a standard EER, we can expect the unit to consume between 900 and 1100 watts. That's like a microwave running 24-7! Needless to say the energy consumption is massive, and you can expect bills to absolutely skyrocket.

Is a portable air conditioner worth it? If you can install a different type of air conditioning system in your home, such as a window AC unit, it's preferable to a portable air conditioner. If you have no other options, portable AC units cool down a room more effectively than a fan, particularly in humid climates.