You know, the ergonomics of these kind of suck. If you are elderly, how do you reach up to adjust the air flow? It requires some detail hand work and these things never work very well--it is difficult to get the right flow of air aimed in the right place. Especially since you have to change your position to adjust the air, then when you sit down you have to test to see whether it is hitting the right spot on you or not, often requiring more adjustment, etc.
