I am modeling a 15-story residential building. Each story has 4 apartment units. I have two problems.

Problem : Lighting energy consumption of 15th floor is higher than 14th floor.

Case A (See images): I modeled 4 thermal zones (each include 15 vertical apartment units). The result of lighting energy consumption of different floors: 1-Floor: 9895, 2-Floor: 9890, 7-Floor: 9560, 14-Floor: 9502, and 15-floor: 10068 kWh. There is big jump between 14th and 15th floor. Lighting energy consumption must decrease, not increase. After adding a 16th floor, I re-simulated the 15th floor, then the result dropped 9392 kWh. How it is possible that the lighting energy consumption of 15th floor is higher than 14th floor? How can I fix this problem?

Case B In order to solve this problem, I considered each apartment unit as a single zone and I created 60 zones in total. And re-simulated. Average ligthing floor consumption is 11819, Which is higher than all above. How it is possible?

Hi, I am modeling modelling a 15-story residential building. Each story has 4 apartment units. I have two problems.

Problem : Lighting energy consumption of 15th floor is higher than 14th floor.

Case A (See images): I modeled modelled 4 thermal zones (each include 15 vertical apartment units). The result of lighting energy consumption of different floors: 1-Floor: 9895, 2-Floor: 9890, 7-Floor: 9560, 14-Floor: 9502, and 15-floor: 10068 kWh. kwh. There is big jump between 14th and 15th floor. Lighting energy consumption must decrease, not increase. After adding a 16th floor, I re-simulated the 15th floor, then the result dropped 9392 kWh. kwh. How it is possible that the lighting energy consumption of 15th floor is higher than 14th floor? How can I fix this problem?

Case B In order to solve this problem, I considered each apartment unit as a single zone and I created 60 zones in total. And re-simulated. Average ligthing ligting floor consumption is 11819, Which is higher than all above. How it is possible?