This is usually accomplished by using a hood that allows air ventilation.

They were equipped with forced air ventilation and downward opening windows.

Forced air ventilation is required to remove odours and allergens.

Using packed mud against the entire wood structure, the home was kept cool by natural air ventilation and water sprinkled on the dirt ground inside.

The second approach - outdoor air ventilation - is also effective and commonly employed.

Five stories tall, it had such wonders of the times as electric elevators and central forced air ventilation.

To alleviate these issues the air ventilation in the building needs to be improved.

Allergens such as pollen can be an issue when windows are used for fresh air ventilation.

The rest of the bore is used for forced air ventilation and water drainage systems.

They are very hard to find air ventilation as they are the deepest.