Windows not only add aesthetic looks and often a very important aspect of a home, but also a very significant component of home heating and cooling costs. Windows lose more heat per square foot of area in winter and gain more heat in summer than any other surface in the home.
When you consider that a single pane of glass can lose almost ten times as much heat as the same area of insulated wall, it is worth taking some simple steps to reduce heat loss through your windows to make your home more comfortable and reduce your heating costs.
The main areas where heat escapes are the loft, walls, windows, doors and floors. In fact, in older properties, original windows can be a dual offender with draughty timber frames and single glazing causing heat loss in your home.
How is heat lost through windows? Around 18% of the total heat within a house is lost through the windows. This heat loss through windows is caused by radiation through glazing, convection and conducted through the window frame.
About 30% of a home's heating energy is lost through windows.
R-value measures resistance to heat gain or loss. A typical insulated wall has an R-value anywhere from 12 to 19, while a double-pane window has an R-value of about 2. By using movable insulation within the window frame, the R-value nearly doubles. This will help reduce a home's overall heating and cooling load.
About 35% of the heat will escape through the walls and through gaps, in and around windows and doors, and about 10% of heat will disappear through the floor. Taking action to make sure your home is energy efficient has many benefits.
Around 10 per cent of the heat in our homes is lost through the window with that figure rising if you have single panes. It may not sound like that much but when you add up losses through doors, floors, walls and the roof every bit counts.
Dr Lindsay Browning, psychologist and sleep expert at bed retailer And So To Bed agrees that it's best to keep windows closed where you can. “Generally, when it is really hot outside it is a good idea to keep windows closed during the daytime, as you don't want the hot external air to come into the house warming it up.
Visual gaps around outlets and fixtures
Gaps and holes in your home provide entryways for outside air to enter. These gaps can be spotted quickly… look for gaps where walls and floors meet (especially on exterior walls), around electrical outlets, and where fans and recessed lighting connect to the ceiling.
Forty-eight percent of thermal gain comes through windows. To prevent radiation intrusion, block sunlight by planting trees and installing awnings and screens. Inside the home, add shutters, blinds and curtains, or add tinted film. About 19 percent of thermal gain intrudes through windows, doors and ceilings.
Heat gain occurs when heat enters your home either by radiating in through materials such as glass or by being conducted in through surfaces such as the walls and roof. Windows are responsible for around 48 percent of your home's heat gain, but you can reduce this by hanging drapes or heat-reflective blinds.
Your southern exposure windows are the hottest in your home, although east- and west-facing windows can bring in heat during early mornings and late afternoons. The cause for this comes from the southern part of your home facing toward the sun in the Northern Hemisphere.
We most often think that it's always better to open the windows when it's hot, but it's not. Sometimes, the air outside your home can even be warmer than the air inside your home. Opening the windows simply lets cool air escape and hot air to enter, resulting in hotter interiors.
Windows – Typically, windows lose the most heat in the winter and the most cold in the summer. If a room has a lot of windows in it, then summer heat and winter cold is going to be making its way in.
Drafts from your windows can let in cold air, raise your electric bill, and make an all-around colder home. Drafts can also let in cold-weather moisture, leading to issues like water damage and bugs. To find out if your windows are at the heart of your interior temperature problems, check for drafts.
"It might seem counterintuitive, but if the air outside is hotter than the air in your home, keeping your windows closed could help your home stay a little cooler," he explained. You can also keep your blinds and curtains closed during the day to help allow to keep your home cool.
The rule you should go by is whether it is hotter outside than inside. If the temperature is higher outside than it is inside, you should keep your windows and curtains closed. This will shut the heat out, and help to keep your home cool.
For those living in areas with high humidity or pollution, it may be better to keep windows closed and rely on air conditioning to maintain a comfortable indoor environment. In hot and humid areas, opening windows can increase humidity levels and make homes feel even warmer.
Absolutely. Curtains reduce the amount of air exchange between a cold window and the rest of the room. For keeping heat inside the home, high-quality curtains can reduce heat loss by around 40%, particularly if they are floor length and close to the wall and window panes.
Yes, blinds are good insulation for windows, regardless of the type of blind you use. This is because the closed blind forms a barrier (that is permeable to various extents depending on the blind), which helps to keep heat in, cold out, and to take the edge off draughts from rattly windows.
The average home will stay warm for 8-12 hours after the power goes out. After the first 8-12 hours, most homes will experience a gradual cooling over the course of the next couple of days.
Wall insulation
To reduce heat loss from walls, cavity wall insulation can be installed. This involves blowing insulating material into the gap between the brick and the inside wall. Care should be taken to ensure that no gaps are left in the insulation.