When you think about saving energy at home, you probably think of things like turning down the thermostat, purchasing energy-efficient appliances, adding insulation, and upgrading your home. In fact, there are some simpler ways to save energy at home. One of these ways is opening and closing window blinds according to the time of day and the season.
When to Close Your Blinds
Closing window blinds at the right times can reduce the energy used at home. On hot summer days, when the sun's light shines into some of your windows it's heating the interior, causing you to turn up the air conditioning and use more energy. By closing the blinds, you keep direct sunlight out of your home and reduce unwanted solar heat gain. Closing window blinds can also save energy in the winter. During cold nights, heat is lost through windows. Closing the blinds adds some insulation to the windows, reducing heat loss. Some blinds also reflect heat back into the room.
When to Open Your Blinds
Opening your blinds at the right time also saves energy. On sunny winter days, sunlight allowed to shine through windows helps to heat the inside space. This is called passive solar heating, and is an effective design strategy to lower energy consumption in buildings. To increase passive solar heat gain, include thermal mass in your interior design. An example of solar mass is tile floors.
Although most people like to keep their blinds closed at night, opening them a little during the hot summer months can allow heat to escape to the cool night air, reducing cooling costs.
Interior or Exterior
Most blinds are on the interior. The advantages to interior blinds are that they are convenient to operate, install and replace, but they are also less effective at controlling solar heat gain. Exterior blinds are usually designed specifically for solar control. They have either manual or remote control operation. Common materials for exterior blinds are wood, vinyl, aluminum or steel. The advantages of exterior blinds is that they provide better solar control than interior blinds because they are sturdier, have fewer gaps, and they block the sunlight before it passes through the window glass.
All window blinds provide shade for windows and can add to the window's insulation value, reducing heat transfer through windows. However, reflective blinds perform better because they reflect light and heat. This is beneficial in summer to keep homes cool, and in winter to reflect interior heat back inside. Some reflective blinds are reversible, with one side highly reflective and the other highly absorptive. The reflective side should always face the heat. In the summer, the reflective side faces out, and in the winter it faces in.