Or this job I performed a evaluation. Upon arrival homeowner stated that they feel like the system has not been cooling as efficiently since last visit but they aren't sure if it's because it's been hotter or is missing refrigerant. During inspection I did not see any significant abnormalities what refrigerant or Delta levels one checked. I use the thermal camera to check the supply and return plenums and could see that there was cold air leaking out of them. I recommended properly sealing the plenums to help air not leak out. The homeowner mentioned that their wife has severe allergies, I briefly spoke about the best option for people with allergies installing a upgraded filter system and a UV system. Lead set for IAQ specialist, to look at system and give estimates.