Before we had air conditioning, homebuilders employed a number of intuitive strategies to keep homes cool naturally. Natural ventilation, hefty thermal mass and evaporative cooling are all ancient techniques that are now considered an “alternative” known as passive cooling. It’s a fast-growing trend that’s not likely to go away soon. “People want to be able to work and live at home, without air conditioning,” says Steve Badanes, an architecture professor at the University of Washington in Seattle.
Over the years, I’ve been in enough naturally cooled homes—in brutally hot and humid climates—to know that passive cooling works. Check out these homes in North Carolina, Florida and South Carolina to see how it’s done. (I visited each of these during peak summer months and never broke a sweat.)
Architect Giles Blunden chose to build his 800-square-foot solar-powered cohousing unit in Carrboro, North Carolina, as a middle unit so that the attached homes on either side would provide valuable insulation for his un-air conditioned home. To keep his home cool, Giles used old-fashioned tricks that have been keeping Southern homes cool for centuries: a tin roof, roof eaves, vertical windows, tall ceilings, cross-ventilation and ceiling fans. On the home’s lower level, the bedroom and bathroom nestle into a berm on the north end and open up to take in southern sun and breezes. Cool air chimneys up from garden doors on the lower bedroom level, through an attic door that stays open all summer and out through a cupola above the attic. Ever conscious of mildew, Giles installed a tiny computer fan on a timer that exhausts air out of the bathroom, and the couple always hangs towels outside to dry.
Warm air is sucked up and out of the house through a cupola above the attic. Photo by Seth Tice-Lewis
Large French doors in the lower level bedroom welcome breezes. The closet doors are louvered to keep air circulating and prevent mildew. Photo by Seth Tice-Lewis
On warm days, Giles and Ginger open the large double doors in the living room to allow cross breezes and access to the covered front porch where they often enjoy dinner or a glass of wine in the evening. Photo by Seth Tice-Lewis
In the kitchen, cabinet frames built from recycled factory timbers have brushed steel fronts with holes reminiscent of old pie safes. These provide air circulation that helps cut down on mold and mildew.
New York ceramists Beth Kaminstein and Ron Levy’s oceanfront home in Islamorada on Florida’s Upper Matecumbe Key captures prevailing coastal winds instead of using air conditioning. “We wanted to make this a Florida house, more open than closed up,” says Ron. “We wanted to enjoy the sense of being here.”
Architecture firm Jersey Devil designed an addition to the Red Cross hurricane cottage, already on the property, to accommodate the family of four and Beth and Ron’s studios. An open-air, two-story breezeway and bridge connects the small cottage to the two-story building, which has three rolling garage doors that allow breezes to move from the sea, through the house and into a native hardwood and tropical forest. To further capitalize on ocean breezes, the new wing is lifted off the ground and into the treetops, and windows make up the oceanside wall of each bedroom.
Passive cooling is achieved through 70 strategically placed windows, roof overhangs, 14 indoor fans, sliding doors, and roof and wall vents. Closet doors are vented with louvers and grills to prevent moisture accumulation, mildew growth and musty odors. Concrete walls and floor help keep temperatures cool. The roof is constructed of reflective Galvalume steel over a radiant foil barrier and fiberglass insulation, and a ridge vent expels heat trapped beneath the roof surface.
The tower’s two lower stories are constructed of cool, sturdy concrete (mixed with some potash) to keep the home cool. Corrugated steel covers the exterior, providing protection from rain and airborne salt; it also reflects heat and sun. Photo by Bill Sanders
The staircase in enclosed in a “lipstick” column (so-called for its color) with “bicycle chain” vents made from 6-inch aluminum pipe sections between wood 2-by-12s, which let light and air penetrate. Photo by Bill Sanders
In the original cottage, bright yellow shutters form the outermost layer of hurricane protection for the living/dining room. The panels slide to the sides along with the glass doors, opening wide to expose the living room almost completely to the outdoors. A stained concrete floor helps keep the house cool. Photo by Bill Sanders
Custom-decorated vents help keep cool breezes flowing through the house, cutting down on moisture accumulation and humidity problems. Photo by Bill Sanders
Every bedroom has plentiful oceanside windows and sliding glass doors to decks. The windows are hinged at the top and flip open to protect from incoming rain. A long, broad overhang keeps solar heat from penetrating the home through the windows. Photo by Bill Sanders
“House of 8 Porches”
Rives and Wally Yost’s “proper beach house” on Dewees Island in South Carolina is a protest of sorts against the constant drone of air conditioners that can be heard throughout so many beach communities. Charleston-based architect Whitney Powers took inspiration from an ancient cleft dune that runs through the property to design a 2,700-square-foot house composed of two halves shifted slightly away from each other and joined by a transparent stair hall. The house is covered with cedar shingles and topped with a standing-seam Galvalume metal roof that reflects the sky.
With high ceilings, ceiling fans, and plentiful French doors and sash windows that are usually thrown open, there is no need for air conditioning. “We didn’t come all the way from Pittsburgh to close the windows and doors,” says Rives. A natural ventilation system pulls air in through windows on the lower floors and up through the house to windows located beneath the gables. Reflective window coatings deflect the sun and reduce solar heat gain.
Eight screened porches open off the living room, the open-plan kitchen, the multi-use dining room and home office area, all four bedrooms and the laundry room (as a dedicated place to hang laundry). “It’s nice to have a screened porch where I can hang the laundry without being bitten by mosquitoes,” says Rives, who once got into trouble for hanging towels out to dry in a beach resort that banned outdoor clotheslines. Old-fashioned sleeping porches provide naturally cool places to rest.
The Yost house is designed for indoor/outdoor living, with porches on the front, back, and corners of the house that provide outdoor living space and permit windows and doors to be left open for constant access to island breezes and the sound of birds, rustling trees, and crashing waves. Photo by Michael Shopenn
Lounge chairs double as outdoor beds on the screened porches that open off the bedrooms. These multi-use porches and furnishings were inspired by traditional sleeping porches popular in southern beach houses before air conditioning. Photo by Michael Shopenn
The Yost’s dining room has its own porch that serves as a plein-air dining room on pleasant days. The table is made of two matching pieces that can be pushed together for large gatherings or divided between the dining room and porch. Photo by Michael Shopenn