Animal Welfare Professionals

We are a small, rural animals shelter (3,500 sq ft - 25 dogs).  Our shelter was built in 2021. At that time, we installed a Trane commercial HVAC system and just recently learned the evaporator coils are rapidly deteriorating even tho we did the recommended routine maintenance.  Apparently bleach, urine and humidity can cause this.  However, since this is standard in any animal shelter, we are wondering what we should do differently so we don't have to replace our system every 5 years.  Or maybe 5 years is as long as we should expect? Has anyone else had this problem? 

Just clarifying. 
Its urine and bleach getting on the outside unit correct?
Many years ago, I bought a brand new house. We had to replace the outside portion of the AC after 2y.  Seems the dogs hiking their leg on it isn't great. The acid in their pee dissolves the copper tubing.

If this is along the lines of what you have going on, it would mean relocating the unit to a place where the dogs and cleaners aren't going to get on it. I've seen people put it on the roof or on a platform. If you did a platform thats about 3' tall, it would be above hike level haha.
We rented a building that was a former house. We were there for 4y without any issues like both outdoor components were away from the areas that would be sanitized and we didn't allow the dogs to hike on them.

We are a small, rural animals shelter (3,500 sq ft - 25 dogs).  Our shelter was built in 2021. At that time, we installed a Trane commercial HVAC system and just recently learned the evaporator coils are rapidly deteriorating even tho we did the recommended routine maintenance.  Apparently bleach, urine and humidity can cause this.  However, since this is standard in any animal shelter, we are wondering what we should do differently so we don't have to replace our system every 5 years.  Or maybe 5 years is as long as we should expect? Has anyone else had this problem?