By Grey Lee
Buildings are designed to shelter us from the harshness of nature, but the most comfortable and energy-efficient indoor environments are those that use the free resources of the outdoors for heating and cooling. For many architects, using the outdoors to create more comfortable indoor environments means using operable windows for natural ventilation. To the mechanical engineers, bringing the outside in means using an airside or waterside economizer. However, these simplified versions of climate responsive building designs ignore other possibilities for harvesting outdoor thermal resources to maintain indoor comfort.
Although opening windows and using economizers have their benefits, they can also create new problems such as indoor pollution through the introduction of outdoor particulates. These deficiencies can be overcome by smart design strategies that make better use of the exterior thermal resource. Strategies that enable the design team to minimize building energy consumption without compromising occupant comfort include:
- Dividing free cooling into two components – humidity control and sensible cooling. This way free sensible cooling can be provided, even when energy-consuming indoor dehumidification is required.
- Achieving thermal comfort not only by convective heat exchange between the human body and the air, but also by radiant exchange with building surfaces. Use free natural resources to cool interior surfaces to maintain comfort.
- Recognize that the outdoor thermal resource also has three components: sensible, evaporative and radiant. Create systems that can use each of these components as they are available and are not dependent on their simultaneous availability.
- Recognize that outdoor thermal resources may not be available coincidentally with indoor thermal requirements. Add controllable capacitance (thermal storage) to the system to harvest outdoor thermal resources when available for later delivery for indoor comfort maintenance.
Attend this great educational session on Thursday October 2nd – “Bring the Outside Inside: Using the Outdoors to Create Indoor Comfort” with Thornton Tomasetti’s Gunnar Hubbard Principal and Syska Henessy's Daniel Nall, vice president and regional director of high performance solutions, who will talk about how to make better use of available environmental resources to increase indoor comfort.