That's a diverter. To prevent hot air recirculate

the purpose they doing this is to redirect the hot air to center compare original hot air through side

To prove working 100% or not maybe need to test on wind tunnel or smoke test to see surrounding temperature/airflow volume before and after but the results have not much different sebab....

See the picture already know that not the best spot for installing compressor but due to many reasons end up juga install di situ tldr user/installer/management problem 😂