wrong energy balance in chimney
 

Hello, I have checked whole the forum and I havent found anything.

My problem is about chimney effect (Fluent). Energy summary says, that the energy is taken from the system by two ways: PRESSURE-OUTLET 250W (it is OK) and PRESSURE-INLET 40W - and it is probably nonsense right? This answer mean that something is wrong? (energy to the system is from wall, and it is 290W)

Do you have any experinces, PLEASE?