Maybe the ISO 13790 can help you to decide.

"In "*In particular you have not to dived a space in more thermal zone if:

1. Set-point temperatures for heatingcooling of the spaces differ by no more than 4 K;

2. The spaces is serviced by the same heating systeme (if any) and the same cooling system (if any);

3. At least 80% of the floor area are serviced by the same ventilation system;

4. The ammount of ventilation (in cubic metre per square metre of floor area per second) differs by not more than a factor of 4 within 80% of the floor area."area.*"

Maybe the ISO 13790 can help you to decide.

"*In particular you have not to dived a space in more thermal zone if:if

1. Set-point temperatures for heatingcooling of the spaces differ by no more than 4 K;

2. The spaces is serviced by the same heating systeme (if any) and the same cooling system (if any);

3. At least 80% of the floor area are serviced by the same ventilation system;

4. The ammount of ventilation (in cubic metre per square metre of floor area per second) differs by not more than a factor of 4 within 80% of the floor area.*"

Maybe the ISO 13790 can help you to decide.

"*In decide. "In particular you have not to dived a space in more thermal zone if

1. if 1. Set-point temperatures for heatingcooling of the spaces differ by no more than 4 K;

2. K; 2. The spaces is serviced by the same heating systeme (if any) and the same cooling system (if any);

3. any); 3. At least 80% of the floor area are serviced by the same ventilation system;

4. system; 4. The ammount of ventilation (in cubic metre per square metre of floor area per second) differs by not more than a factor of 4 within 80% of the floor area.*"area."