Hello all, I am having air issues with a multi story hotel. I have a 5 ton split unit that controls the corridor is starving for air. My return air is very poor. I checked my coil and coil is not plugged. I traced my return air duct to the attic and found an air to air plate exchanger by american energy exchange which also has a Hoval patent. It is in series with the OSA and return. I located an access panel on the return riser in the attic catwalk and removed it, then the fan coil began to circulate the air much better. I continued tracing the return duct and found an air to air plate exchanger that is not connected but is in the air circuit. The set up I found has an OSA intake that is hooked up to one side of the exchanger and on the other side goes to a fan which exhaust the air out to the roof, the third connection to the plate exchanger goes to the return air from the fan coil. The return riser has four branches. One branch per floor. The OSA intake to the exchanger does not have any type filter, is it possible that the exchanger is restricted? Why does it have a fan exhausting the air from the return? can someone explaing the purpose of this set-up?
Thanks to all in advance