I am a property manager and I have a building that is 1 story, with about 20ft of space from the drop ceiling to the roof. I have two exterior doors that when opened, cause a major draft of air blowing in from the outside. This causes comfort issues in the summer and winter and then also causes issues during the fall when leaves continuously blow in. Another note that may be helpful is the interior temperature is balanced when the HVAC system or fan is running, but if the system is cut off for any extended period of time (2-3) hours we have 8-15 degree differences within the HVAC zones. Would anyone have any ideas to help me fix these issues?