However, in humid climates much energy is required to remove excess moisture from ventilation air.

Infiltration is separate from ventilation, but is often used to provide ventilation air.

In certain applications, such as submarines, pressurized aircraft, and spacecraft, ventilation air is also needed to provide oxygen, and to dilute carbon dioxide for survival.

A slight murmur of ventilation air was enough to blanket most of the noise of soft conversations elsewhere.

It had several mesh-covered openings to allow access to the engine and improve ventilation drawing air in through the commander's hatch.

This suggests that ozone should be removed from ventilation air, especially in areas where outdoor ozone levels are frequently high.

In many smaller buildings, 'forced' or 'mechanical' ventilation is not used to introduce ventilation air.

Ducts also deliver, most commonly as part of the supply air, ventilation air.

Small furnaces are not very expensive and some ductwork to every room is almost always required to provide ventilation air in any case.

In temperate climates ventilation air may need to be heated during winter months.