Gone with the wind

The claim:
To repel mosquitoes,use a house fan
The facts:
The battle against mosquitoes is often fought with chemical repellents.
For those who prefer a chemical-free repellant,a plain and simple house fan just might do the trick.

Studies have found that wind is an effective method against mosquitoes and other airborne pests. The reason seems obvious: it prevents them from circling and landing on you,like a windstorm keeping a plane from its descent. But that is not entirely the case.
A fan dilutes and disperses the carbon dioxide you exhale. Carbon dioxide is one of the major chemicals that attract mosquitoes. The wind from a fan also cools you off. Sweat,lactic acid and body heat attract mosquitoes — factors that a fan can help minimise.

In one study in 2003,entomologists at Michigan State University used traps set up in a wetland to attract mosquitoes. Releasing carbon dioxide attracted more pests to the trap,and the more carbon dioxide,the more mosquitoes.
Using fan-generated wind of various speeds helped keep them away. But there was no link between wind “velocity” and “mosquito body mass.”

“We recommend that fan-generated wind should be pursued as a practical means of protecting humans or pets from mosquitoes in the backyard setting,” they wrote.
For an indoor setting,a fan on medium or high speed should do the job.
The bottom line:
Using a fan can ward off mosquitoes.
_NYT