Ancient Cooling, Heating Practices Coming Back Around in Sustainable Building Design

Fresh ideas about improving apartment living and operations through sustainable building design have been circulating throughout multifamily energy discussions in recent years.

Apartment designs are always changing to improve operational efficiency while blending the latest styles with building techniques that speak out from the curb. Inside, smooth lines and curves along with warm colors may set a relaxed mood but quickly fade into bold accents as tastes change.

Building engineers go through similar swings and don’t always rely on new, cutting edge designs to reach their ultimate quest of operational efficiency. They sometimes look back in the closet for inspiration.

One thing for certain: What goes around comes around.            

One of the latest is passive heating and cooling which, simply, is taking advantage of sun exposure to maintain comfortable building temperatures. 

For centuries, homes and other buildings have been heated and cooled by what nature provides, rather than relying on machines. Many ancient cities depended on constructing structures and positioning them to take advantage of sunlight, darkness, wind patterns and other weather-related factors to maintain temperature control.

Well before HVAC systems, homes were designed to capture winds to cool in the summer and warm through fireplaces placed to obtain the best possible draft.

Similar passive heating and cooling designs are being incorporated in building sustainability designs in multifamily as operators look to achieve maximum building efficiency to reduce the load on energy-powered HVAC systems.

Bioclimatic design re-emerging to lower operation costs

Peter Chan, who is Fairfield Residential’s Director of Ancillary Services, has seen a resurgence of interest among multifamily sustainability practitioners in such older architectural practices. Bioclimatic design – which uses ventilation, air flow and natural patterns of the sun to regulate temperature – is seen as a green way to lower costs in sustainable building design.

“This technology has been in application in various ways as long as people have lived inside buildings,” Chan said. “I’m seeing renewed interest in this architectural technique specifically because of sustainability and higher energy costs. It’s architecture looking for ways to achieve the same results or supplement the efforts to at least reduce building loads.”

As buildings burn energy to heat and cool they contribute 40 percent of carbon dioxide emissions in the U.S., according to the Environmental and Energy Study Institute. Bioclimatic design uses sustainable techniques that collect warm and cool air and push it up, down, around and through buildings to lessen the need for electric generation to heat and cool spaces.

Utilizing what the earth gives

Passive heating and cooling traces to the Middle East and North Africa, where dense populations coped with hot climates through combinations of shade, ventilation by wind, thick walls, courtyards and domed roofs.

Building design adapts to the location and cooling works on the theory of convection, evaporative, radiant and earth cooling. Well-insulated buildings use natural ventilation and night flushing, using cooler evening air to push out warm air that collects inside during the day.

Openings – either through windows or ceiling vents – enable air to be evacuated. In some climates, plants and water are positioned to catch wind sweeping through courtyards to lower air temperature.

Architecture varies by region and climate and requires modeling the effects of heat gains over several months, a year or longer. The angles in which sun hits the building, shade points and other factors play into the equation. Opening sizes at the top and ground floor are also factors.

In some applications, metal “solar chimneys,” which resemble smokestacks, automatically open to release hot air. The height and metal composition of the chimneys, along with the sun, warm internal air, which is exhausted. In the process, warm air from inside the building is released and replaced by cooler air below.

“It’s basically a black chimney that gets hot, and hot air goes out the top and creates a suction behind it pushing air through the building,” Chan said. “It’s very old technology but you are starting to see it crop up more.”

Office buildings naturally heating, cooling spaces

Three office buildings in Germany, England and Portugal are among the latest structures to employ the bioclimatic design technology. Each are naturally heated and cooled and considered near zero-energy buildings.

At one building, buried pre-cooling systems, which consist of a network of underground pipes, and heat towers help cool and heat the interior.

In the U.S., New York’s Cooper Union’s 41 Cooper Square received a U.S. Green Building Council Leadership in Energy and Environmental Design (LEED) Platinum Certification for incorporating passive heating and cooling into operations.

The structure’s building management system recognizes when temperatures are right for using natural ventilation to heat or cool. A central system controls individual building sub-components that include centrifugal water chillers and window panels to adjust air flows and achieve desired temperatures. 

In addition, the nine-story building’s exterior is double-skinned to reduce heat gains during summer months and increase insulation during the winter. Cooper Union’s 41 also features many eco-friendly features that reduce energy consumption, like a green roof terrace, rain water harvesting, day lighting and radiant ceiling panels.

Circling back through sustainable building design

Biophilic design, which can mask as an amenity or aesthetic improvements but betters building operation efficiencies, is becoming more prevalent in today’s designs. The technique maximizes available light, vegetation, water and other natural sources to control temperature and air quality.

Examples of biophilic design are located throughout buildings and sometimes disguised as amenities. The steady, calming effect of running water in a fountain can draw residents into an atrium for relaxation. But in reality, the fixture is a part of an evaporative cooling system that brings comfort on a warm day.

It’s just another example of thinking inside the box to create the sustainable apartment building, Chan says.

“Like fashion, it comes back eventually.”

The virtual RealPage Energy Summit 2021 Feb. 24-25 will feature panel discussions on innovations impacting heating and cooling, as well as the newest strategies around energy and water usage. Register here.