Is it okay to mount a 5800PIR-RES at 7 feet?

It would be safer to mount the 5800PIR-RES at 7.5 to 8 feet off the floor.

The reason for this is because the 5800PIR-RES was designed specifically to be mounted at that height. Choosing to mount it at a lower height could render the detector less effective by somewhat limiting the total range of the sensor. Typically, the sensor can detect movement up to 30 feet away at a 90 degree angle. To figure out what the new range of the sensor would be at a height of 7 feet, you would need to perform a walk test. Pair the sensor with your Honeywell control panel, then hold the sensor at its desired 7-foot mounting location. Then ask someone to walk at different distances away from the sensor to see how the sensor's range has diminished.