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Designers research new ways to cool homes

As summer's heat and humidity start to make inroads in areas of southern Canada, building engineers might take note of two initiatives based in the southern U.S.


As summer’s heat and humidity start to make inroads in areas of southern Canada, building engineers might take note of two initiatives based in the southern U.S.

First, a Toronto-based company known as “sustainable.TO Architecture” has won top prize in an international competition to design a passive house for New Orleans. The firm, led by Paul Dowsett, designed a house for hot and humid New Orleans that uses key components of the Passive House Standard, which requires 80-90% energy savings over conventional construction and is part of President Obama’s Better Buildings Initiative.

Dowsett’s scheme for the winning “Low Cost, Low Energy House” was selected from 65 entries from around the world, including the U.S., Mexico, Egypt, France, Germany, the U.K., Hungary, Indonesia and Malaysia.

The design includes an airtight, super-insulated envelope that has no thermal bridges. The envelope provides passive shading in summer and solar heat gains in winter and highly-reflective galvalume wall and roof cladding. A concrete floor topping provides thermal mass, and the house has a balanced energy recovery ventilation system and split-zoned high-efficiency heating and cooling units. Hot water is supplied from an ultra high-efficiency on-demand unit.

In the post-Katrina era, houses in New Orleans have to be raised 7 feet above grade, which is for safety during flooding, but which also provides shaded parking, storage and outdoor living spaces.

Second, a student at Texas A&M University has won a grant from the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) to model a new energy saving strategy for low-income households n hot and humid climates. Simge Andolsun will model a new HVAC&R streategy that uses partial conditioning, or reuse of air. “Partial conditioning is based on using he remaining energy of the air returning from the occupied zones in unoccupied zones before it returns to the system or is exhausted from the system,” according to Andolsun.

The strategy is intended to provide over 50% reduction in the overall air conditioning energy consumption of residential buildings.

According to ASHRAE, statistics show that over 38 million low-income households need help paying for energy. ASHRAE notes that in the hot and humid summer months it is particularly difficult to reduce their energy consumption.