Air curtains to prevent flies and other flying insects from entering a premise, also called "fly fans" where they can find a source of food and safe shelter.
An air curtain supplying a high velocity air stream across an opening will avoid flies and other flying insects from entering a building.
The presence of these insects in drink and food production plans, restaurants, community kitchens, supermarkets, hospitals and other food service premises, can cause food contamination and accordingly imperiling public health.
If besides the requirement of climate control at building doors, there is need for insects' control, not all the air curtain models are appropriate:
- The air stream must be between 5-12 cm wide, a minimum speed of 8 m/s of air 1 meter above the floor. It is recommended to install a more powerful air curtain that the one required when just taking into account the height of the entrance.
- It is required an air curtain with an adjustable blade that can angle the air stream away from the area to be protected. An angle of about 20° from the vertical is usually optimal.
- It is very important to cover the entire doorway and even slightly surpass it so that there are no gaps for the insects to enter.
The Insect Control air curtains or fly fans can be mounted on the inside or outside of the doorway. When the building contains odours that are attractive to flying insects it is recommended that the air curtain be mounted on the outside so that odourless air is used to create the barrier.
As well as flying insects, air curtains can also discourage rodents from entering a building. Research has shown that rats, mice and other furry intruders do not like the sensation an air curtain creates on their fur and will avoid it.