Given the high price of fuel and the expectations that this mean-price is going to climb even higher over the coming months and years, it is important that we consider any and all ways to cut down fuel consumption in our homes. By installing uPVC windows, a homeowner has the opportunity to obtain an energy efficient uPVC double glazing window unit that will improve the thermal capacity of the home and cut down on fuel consumption. There is undoubtedly a double glazing cost that has to be taken into account and as there are many different types of these windows on the market, it is important to purchase a quality product as cheap uPVC windows do not neccessarily make the best windows for your home. In order to do that and t0 be able to decide which uPVC windows to purchase, it helps to understand what is meant by window insulation, what units are used to measure window efficiency and what symbols to look out for on quality windows.
With regard to materials in general, the resistance of that material to heat loss is called its R-value and this unit is suitable for measuring the insulation capacity of materials that make up walls and roofs for example. However because windows have to allow light through them, they interact very differently with the exterior environment than solid objects such as walls do. For this reason a better measurement of the energy efficiency of windows is what is called the U-factor, which measures the rate that heat is transferred through the window unit. A simple guide to help you remember the difference between the R-value of a material and the U-factor, is that the higher the R-value the better the energy efficiency of the material and the lower the U-factor, the better its insulation properties.
There are other terms that may be quoted when you are researching for a suitable type of PVC window for your home. These include:
• Solar Heat Gain Coefficient: This is the term used to describe the measurement of how capable a product is at blocking the sun’s heat. This value will be lower in a product that is good at blocking heat.
• Air Leakage: Most products allow a certain amount of air to be transmitted through them and with regard to windows and other objects that contain openings that need to be sealed when they are closed, this is certainly the case. The lower the air leakage value, the better the window is at blocking air from getting through. Presently there is no official requirement on manufacturers to display this measurement.
• Visible Transmittance: This calculates the ability of the product to let light through. The higher this value is, the better the window is at letting light in.
• Condensation Resistance: This value calculates how good the product is at deterring the production of condensation and the greater the value the better the product is in this field.
When you are considering any or all of the above terms and their values, you should remember that the value should be relevant to the entire uPVC window unit and not simply the glazing. Having uPVC or vinyl windows with excellent glazing is of little comfort if the frames and seals and other components are not up to the task.