What is passive cooling?

Technologies or designs used to cool a space without power consumption. Examples of passive cooling include reducing the amount of heat that enters your home and removing heat with ventilation. The following are simple ideas for staying cool this summer. Because passive cooling requires little to no electricity, you can sit back and relax—you're guaranteed to see savings on your energy bills, and who doesn't enjoy a little fresh air?

1. Hot Air Out, Cool Air In

Illustration courtesy of Island Cooling Concepts

Whole-house fans are ideal for Hawaii’s climate, where average temperatures are in the 80s during the day and in the 70s at night. The fans are designed to “change” the air in your home by drawing in cooler, outside air and exhausting the warmer air inside (see diagram above). The cooling is quick and economical, reducing the temperature in your home faster than central air conditioning, at a fraction of the cost.

“For cost-effective cooling, they’re hard to beat,” says Ivan Whitworth, of Island Cooling Concepts. “They usually pay for themselves in a few short seasons.” The company offers Triangle Engineering brand’s patented, whisper-quiet, whole-house fan in three sizes.

Tamarack Whole House Coolers, from RMA Sales, are also easy to operate and virtually maintenance-free. Plus, they use about as much energy as two 60-watt light bulbs. "It’s technology that’s so smart, it’s simple,” according to Tamarack.

2. Open Up

Photo courtesy of Breezway

Maximize the flow of cool breezes with louver windows. Breezway Louvre Windows' Altair line opens twice as wide as regular windows to efficiently capture home-cooling trade winds. Next month, look out for the release of the Altair ios window systems, made on Oahu exclusively from corrosion-resistant materials for extra strength and durability.

Similar to louvers, awning windows are another popular option for increasing air flow, says Luis Larcina, of Custom Contractors Inc. In fact, awning windows allow for 95 percent more air flow than a traditional slider or single-hung window.

3. Let the Light In

Photo courtesy of Screens & Things

In areas where you do not need window treatments, you can still let the light in while keeping the heat out. Marvin low-E glass windows, from Screens & Things, provide three invisible silver layers of protection that prevent heat and UV rays from passing through the glass. Low-E windows are great for any island home and ideal for one with intense sun exposure.

4. Made in the Shade

Photo courtesy of Sunburst Shutters

Reducing heat transfer is a key part of passive cooling. By filtering the light that enters your home, you reduce the amount of heat that is transferred through windows. Sunburst Shutters’ woven wooden shades and blinds do just that, adding a rich, natural look to a room while keeping it cool. 

5. Preventative Measures

Photo courtesy of Aluminum Shake Roofing

“A cool roof is probably the single most important component of a building, in terms of achieving energy efficiency,” says Fred Rehm, of Aluminum Shake Roofing. An aluminum-shake roofing system, such as the company’s Country Manor roof system, can help reduce energy costs by keeping the heat where it belongs—outside. “Once heat enters a home, that’s when it gets costly to get rid of,” Rehm says. Country Manor aluminum shakes are made with 95 percent recycled content and even the dark colors offer total sun reflectivity.