Wireless Access

I have a customer that has deployed 7 AP 175's in their outdoor facility and is experiencing some inconsistent coverage. The deployment is at a large sewer plant and there are very few obstructions "visibly" that should be blocking the signal.  With that said, there are some gases present in the air due to the process involved at the plant.  One of the gases that is present is Hydrogen Sulfide, there is some methane obviously but that is very controlled due to its explosiveness.  So my question is has anyone experienced any issues with these types of gases or a deployment at a sewer facility?

There is not enough information to answer your question.

You did not say:  

- How high the AP175s are mounted

- What external antennas are in use

- What clients are used for connectivity and what band.

Anything with metal conceivably could interfere with Wifi.  You might want to consult an expert to go over the specifics of that deployment.

The AP's are mounted at around 15 feet up and the antennas are ANT-2x2-2005 and the ANT-2x2-5005.  Devices connecting are IPads.

I don't think the gases are going to contribute in any major way to attenuating or causing severe RF issues. What kinds of distances are you needing the iPads to connect to the APs, or is there a distance that seems to be a major concern. Additionally, if you can output the results from 'show ap active | include 175' so we can see what channels and powers the APs are at, that might help. In some cases if the APs are up high and outdoors, and the clients are lower with more RF attenuating environment, if ARM is enabled the APs could be at a lower power than what you need, which can be fixed by either changing the Max/Min ARM values set for that AP group (be careful to keep the 175s within their own group if you change up the ARM Max/Min), or you can disable ARM and set a static channel and power.