Keeping windows closed in cold temperatures, and blinds drawn during warmer weather, are the most effective ways to save energy in the home, a study has found.

Kamiel Gabriel, professor of engineering at the University of Ontario, and Wei Yang and Yaolin Lin, associate professors at the Wuhan University of Technology, in China, developed a holistic and integrated model that considered the building enclosure, mechanical systems, external environment, the proportion of window opening and the shading factor based on data collected from 270 households, including single and multiple units, as well as different heating methods. All houses were located in the city of Oshawa, Ontario, located 55 km east of Toronto, Canada.

To calculate the building energy consumption, the researchers simulated the occupants' possible activities on different days for various types of housing while utilizing a number of heating and cooling methods. The activities included turning on lights, using electrical appliances and the continuous adjustment of the thermostat.

The results show that opening windows had the greatest impact on the energy consumption during times when the heater was used to warm the house, while using window shades had the greatest impact on reducing the energy consumed during warm weather.

The researchers recommend hanging appropriate window shades to help reduce energy costs. Image credit: Pixabay.The researchers recommend hanging appropriate window shades to help reduce energy costs. For an increased reduction in energy use, homeowners should keep their windows closed in winter, add solar panels to reduce the heating loads of their house, adjust the thermostat temperature only slightly during transitional seasons and turn off lights when not needed.

"The study is a first of its kind in that it related actual energy usage in typical households to the consumer's actual trends and habits in consuming energy," Gabriel says. "The latter was obtained through surveying the inhabitants of the homes we monitored."

To ensure a high level of reliability in future studies, factors such as climatic zones, occupants' attitudes, as well as financial, social and cultural behaviors will be integrated into the existing building performance simulation.

The researchers believe this model could be used for creating efficient building design and for retrofit analysis, as it takes into account factors such as building orientation, building envelope material, shading and control on heating and cooling. "Once we can accurately classify the type of consumers in terms of high, medium or low consumption, municipalities and governments can effectively develop programs targeting these segments," Gabriel says.