With global temperatures rising and many facing rising energy costs, you may have noticed an increasing demand for buildings featuring passive cooling capabilities. What are some of the essential considerations and tips for creating them?
Understand the Effects of the Surrounding Environment
Experts know something as seemingly insignificant as a large tree limiting the sunlight that passes through a home’s window during the hottest part of the day can have noticeable effects. That’s why those designing buildings with natural temperature regulation capabilities should pay attention to the landscape and try to work with relevant features.
Designers took that approach when creating a modestly sized house in Argentina. They incorporated several sustainable features, such as a system that collects water and treats sewage affluents so occupants become more reliant on previously untapped fluid sources.
This one-bedroom home sits above mountain grasslands that naturally regulate the conditions. It also features unrestricted water drainage underneath, which maintains a continual supply of humid air that aids temperature management.
These examples show how energy-management decisions must begin by studying nature and its influence. Similarly, architects can take inspiration from how animals design their homes to cope with the typical temperatures.
Consider the Long-Term Benefits
Those experimenting with passive cooling options should evaluate which possibilities will bring the most enduring and positive effects for the building’s occupants. They can take an approach similar to how industrial decision-makers determine which changes to make in their facilities to meet specific goals.
In one example, a glass manufacturer began using a closed-loop free cooling system to reduce resource usage during its process. Doing so has significantly reduced water consumption while discharging virtually none. The selected solution lasts up to 15 years when well-maintained, which makes it a wise investment.
Building design professionals should review the short- and long-term benefits. Detailing them to clients helps those parties make informed decisions and know what to expect. Minimizing unnecessary consumption is a common goal for those interested in passive cooling, especially if they hope to save money on bills.
One thoughtfully created Kentucky residence serves as an enticing example of the possibilities. Those associated with an affordable housing nonprofit created it while relying on climate and daylight models to determine how to make the residence hold heat in the winter while reflecting it in the summer.
The design team even considered factors such as the height of an overhang. It will block the sunlight from coming into the home during the summer — when the sun is higher — but allow it to stream in and provide a heat source during the winter.
Estimates suggest these choices will save more than $3,000 per year in energy bills, making it easy to see the long-term payoffs. Designers noted they intentionally exceeded some building-code requirements when planning this home, but they recognized the additional related costs would become worth it over time.
Evaluate Opportunities to Use Porous Surfaces
Experts have begun using progressively more permeable surfaces in many urban design projects. This approach promotes better drainage, which can reduce the contaminants that end up in the area’s bodies of water. However, some recommend that architects and other professionals try to balance the ratio of impervious surfaces to porous ones.
For example, recommendations associated with parts of Western Australia stipulate that sites should have a minimum of 50% pervious surfaces, such as green roofs and permeable surfaces. Traditional pavements can absorb heat, trapping the warmth and making them uncomfortable to touch.
Elsewhere, researchers from Penn State University found that attaching plastic sheets to enclosed surfaces can significantly reduce the temperature. These thin, porous additions reflect visible and short-wave infrared light, making buildings cooler in the daytime. The team believed these innovations could provide simple but effective ways for people to cool their homes passively and supplement existing air conditioning systems.
Tests involved creating a box out of the porous sheets and monitoring the temperature changes within it. The results showed they could reduce temperatures by approximately 14 degrees Fahrenheit by reflecting an average of 96% visible and infrared light.
Additionally, when the researchers placed the box outside on a sunny day in 80-degree F heat, they found that the interior temperature was about 15 degrees F cooler than the surrounding environment. Although more work must occur to determine commercial viability, this example shows small improvements can bring substantial benefits.
Promising Potential for Passive Cooling
As these design strategies develop, architects, energy experts and others can achieve excellent results by remaining mindful of environmental characteristics and creating their structures accordingly. Then, the people using the structures will remain comfortable as operating costs decrease due to better energy efficiency. Let these examples inspire you to pursue innovations and think outside the box.
About the author: Ellie Gabel is a science writer specialising in astronomy and environmental science and is the Associate Editor of Revolutionized.
Energy in Demand - Sustainable Energy - Rod Janssen 