Jake Kring. 02-04-25. I arrived for a new customer smell problem on the downstairs system. I spoke with the homeowner and they explained that the system on.y has a smell when the ac runs but not the heat. They showed me the location of the system and I found the home to be a tightly built home and its pray foamed. The system is a upflow in an upstairs closet. I checked the systems cleanliness and found the evaporator coil and blower housing to be pretty clean. I then checked the systems operation in cooling mode and found the systems static pressure to be running at 0.73 IWC and the manufacturer max static pressure is not to exceed or run close to 0.50 IWC. I cycled the system back off and explained that the system is running in cooling mode but the system may have what is called dirty sock syndrome. I explained that when a system is sized with ductwork that is to small the system can’t get rid of the air through the system fast enough and can cause the moisture in the air to stay in t