Canadian Research Council releases window blinds guidelines

Canada's National Research Council Institute for Research in Construction (NRC-IRC) has issued guidelines for the selection and operation of residential window blinds that reduce overheating in summer and heat losses in winter. The NRC-IRC used computer simulations and field energy performance data from houses at the Canadian Centre for Housing Technology.

All types of windows were tested, including older windows and high-performance panes, as were all types of shades, such as typical interior blinds and highly reflective metal blinds.

According to its findings, windows with high solar heat gains and low insulating properties were found to provide higher annual total energy savings for all types of houses in cold climates.

In addition, proper window treatments may also help reduce energy bills. "Typical interior blinds can reduce the house cooling energy use and the on-peak cooling power demand by up to 12 percent, compared to un-shaded windows," the study reports. The NRC-IRC hopes that their research will help homeowners select energy-efficient, cost-effective window treatments.

Homeowners looking to limit the amount their cooling systems are used may want to install energy-efficient blinds. Energy Star reports that an air conditioning's cooling capacity can be reduced by 10 percent in a room that is heavily shaded.