Vehicle air conditioning

A vehicle comprises a passenger cabin 103 and a reversible air conditioning system comprising a Peltier device. First and second optionally independently controllable blowers direct first and second airflows over respective first and second sides of the Peltier device. The first airflow discharges 428 to the cabin and the second airflow discharges outside the cabin, optionally via a door compartment 1011 via an optional non-return valve 501. Respective inlet ducts draw air from inside the vehicle optionally in the foot well region to take advantage of non-turbulent, filtered air with a lower temperature difference from a target temperature and further ducting returns heated/cooled air to the cabin. Exhaust air may leave the compartment from a vent 1016 at the bottom of the door and above a vehicle sill 1005 to protect the vent from water ingress and turbulent air and encourage drainage. The air conditioning system may be mounted in a space in the door separate from the compartment to protect it from external conditions with the source/sink side of the Peltier device facing outward to minimize thermal exchange with the cabin interior. Provided reduced NVH and improves efficiency