The reason why i'm asking is because i have a customer that would like to get an better air temp average around the house because he is saying that the top floor is always warmer in the summer. I know that this is due to improper duct sizing going to the top floor and also possibly a lack of vents. I would like to provide the customer with an option of installing a few more sensors to get a better average, he only has one sensor installed on the top floor. Another way to do it would be to install a vvt system in the home but that can get costly and i am just trying to do the best i can with the least amount of work cuz he does not want to get too crazy with all this. Basically i'm trying to fix the problem without doing alot of work even though i know it will not totally solve the problem.