Rick (I'm guessing),

Unfortunately, no useable columns for the most part. I can mount sensors lower, at the dead end of each aisle, but the aisles are about 85 feet long & my past experiance with long aisles was not awe inspiring. I can probably do the same with the large open area.

I'm considering using Hubbell sensors that are both passive infra-red & ultrasonic.

Marc,

I'm going to be using T5 HO fixtures. Unfortunately, I will not be able to use the Ruud fixture since something else has been specified & I don't think I can get the owner to change their minds. I've used Ruud in the past & what impresses me about that company is how helpful they are when you encounter a problem.

Tom

Few things are harder to put up with than the annoyance of a good example.