How to Cool a Space During Extreme Heat

Guidance for building operators and staff on cooling a space, which is one of the best ways to prevent heat-related illnesses.

Low-Cost Ways to Cool a Space

Cooling a space can be challenging, especially in buildings where neither passive cooling strategies nor mechanical cooling systems were incorporated. Here are some low-cost actions that building operators, staff, and tenants/clients can take to cool a space:

  • Close blinds or drapes during the day
  • Keep windows closed during the day and open at night when it is cooler
  • Use a fan at night to pull in cooler air if the temperature is below 35°C
  • Avoid using fans when the temperature is above 35°C as this may increase the temperature
  • Use a range hood when cooking to remove heat and humidity
  • Limit heat from appliances like stoves, ovens, dryers, and dishwashers

Mechanical Cooling Systems

When sized and used correctly, mechanical cooling systems like fans and air conditioners can help keep indoor temperatures comfortable. Using mechanical cooling building-wide, or in a designated “cooling room,” can help tenants/clients survive in extreme heat. Look at our Cooling Strategies sheet and our Air Conditioner Sizing Guide to see what mechanical cooling system is appropriate for your space.

New Construction

New buildings need to be designed using future climate data. The Overheating and Air Quality Design Guide Supplement helps builders create housing that is prepared for future extreme heat events. This document looks at risks and resilience, guidelines for future climate modelling, and design strategies for dealing with poor air quality and ensuring thermal comfort.

Building Overheating and Air Quality: Considerations in New Construction webinar covers topics as climate projections, how overheating affects a building’s Step Code targets, and what are active and passive building design strategies to mitigate and prevent overheating.