Improve Your Home’s Energy Efficiency.
One of the most effective ways to improve your home’s energy efficiency is by installing thermally enhanced uPVC windows. At Window Advice Centre, we provide impartial expert advice to Scottish homeowners looking to enhance their properties with energy-efficient solutions. In this article, we’ll explore some of the aspects that make uPVC windows so energy-efficient, including their specific design and material properties, glazing options, and frame construction. We’ll also look at Window Energy Ratings (WERs) and U-values to help you make an informed decision.
The Importance of Energy Efficiency in uPVC Windows
As a consequence of the substantial increase in energy costs Energy efficiency has become an important consideration for more homeowners than ever before, especially in Scotland’s variable climate.
Thermally efficient windows can significantly reduce your energy bills, lower your carbon footprint, and increase the overall comfort of your home.
uPVC (unplasticized polyvinyl chloride) windows can deliver excellent long term levels of energy efficiency as long as they manufactured to conform with British Standards BS14351, BS 12608 & BS7414 and glazed with thermally enhanced glazing as opposed to traditional double glazing that has three times the rate of heat loss.
Design and Material Properties of uPVC Windows
uPVC is a highly durable and low-maintenance material that can provide excellent insulation when extruded into hollow multi chamber window frames. However due to the materials relative flexibility and very high co-efficient of thermal expansion PVCu frames require to have steel or similar reinforcement inside the frames to provide a strong foundation for the ironmongery (hinges and locking gear) and to give the rigidity necessary to ensure the frames do not warp and start to allow drafts and leaks due to the significant temperature variations that can result across the seasons between direct summer sun and cold winters night.
Properly manufactured PVCu frames can maintain their energy-efficient properties over many years with no additional maintenance costs post installation.
Multi-Chambered Design
One of the key reasons for uPVC Window and Door energy efficiency is its multi-chambered design. These chambers are a barrier to conductive heat loss significantly reducing heat transfer. This helps to keeps your home warm during the winter and cool during the summer maintaining a comfortable indoor temperature year-round.
Frame Construction and Seals
Proper fabrication of uPVC frames is essential to ensure long term energy efficiency.
The frames are designed to have internal reinforcement that provides the rigidity to allow the integral weather seals to prevent cold drafts and moisture ingress. Quality manufactured product with reinforcement and high-quality seals around the window openings coupled with accurate fabrication standards with hinges and locking mechanisms secured to the internal reinforcement will deliver long term air tight windows without gaps developing between the opening sashes and the fixed frames through which large volumes of cold air can pass causing significant heat loss.
Energy Efficient Glazing Options
uPVC windows can deliver significantly different levels of thermal efficiency and cost effectiveness depending upon the glazing:
- Double Glazing: This involves two panes of glass separated by a spacer bar. The energy efficiency of double glazing ranges widely depending upon the type of glass and the sealed units construction. On a cold frosty day thermally efficient double glazing will lose circa 20 watts per square meter compared to 60 watts with traditional double glazing.
- Triple Glazing: Similar to double glazing, but with three panes of glass and two layers of insulating gas. Triple glazing provides some benefits but a proper cost benefit analysis is needed to determine the break-even time span needed to recover the additional expenditure.
- Secondary Glazing: This involves the installation of an additional line of glazing generally on the inside of a window and can be an extremely cost efficient way to enhance energy efficiency and noise reduction particularly where thermally enhanced double glazing is installed.
Understanding Window Energy Ratings and U-Values
Window Energy Ratings and U-values are established metrics for assessing the efficiency of windows.
- Window Energy Ratings (WERs): Windows are rated from A++ (most efficient) to G (least efficient) based on their overall energy performance. These ratings take into account the rate of energy transfer (heat loss) through the window, the amount of solar gain, and air leakage. It is important to recognise that solar gain is not a factor at night time, when it is cloudy and overcast or where the windows are north facing. In these circumstances the actual rate of heat loss can be exactly the same in products with different Window Energy Ratings. Windows ability to resist air leakage is measured by a series of tests under BS 6375. In the broadest of terms windows can be rated as Severe, Moderate or Sheltered exposure rated. This corresponds with the volume of air that can pass through a window at different wind pressures. When high winds flow over and around a building it can create low pressure on the lea-ward side of the building in addition to creating high pressure on the side of the building facing into the wind. To remain draft free the pressure that the window has to be capable of resisting is the pressure difference between the low pressure side and the high pressure side. The shape of a building, its orientation, elevation, the topology of the landscape and proximity to other structures can either exacerbate or reduce the design wind pressure affecting windows. Place a window with a low rating in an exposed location and it will leak large volumes of cold air from the day it is installed.
- U-Values: This measures the rate of energy transfer per square meter per second. The lower the U-value, the better the window’s insulation properties. A U-value of 1.0 W/m²K indicates a rate of energy transfer of 1Joule of energy/per second/ per square meter for each one degree Kelvin (Celcius) temperature difference between the inside and the outside. The cost difference between a low energy efficient window and an energy efficient window can pay for itself very quickly and can be recouped many times over across the life of the window making the more energy efficient windows the least expensive option over time and best value for money even though the initial purchase cost may be slightly more at the outset.
Investing in energy-efficient uPVC windows is a smart choice for any homeowner. Not only do they reduce energy bills and enhance comfort, but they make the property more attractive to potential purchasers potentially attracting higher bids at the point of sale offsetting a fair proportion of the investment while contributing to a more sustainable future.
For expert, impartial advice on the best options for your home, contact Window Advice Centre today. Understanding the specific design and material properties that make uPVC windows highly energy-efficient, you can make an informed decision that will benefit you and your home for years to come.
Why Choose Window Advice Centre?
Without charge or obligation, the independent Chartered Architectural Technologists and Replacement Window & Door experts at Window Advice Centre are available to help you.
By contacting Window Advice Centre you can access impartial expert advice to help you identify the best energy-efficient solutions tailored to your needs, preferences, and budget. You can then be provided with itemised directly comparable costs from a range of approved reliable Replacement Window & Double Glazing companies who have all been the subject of constant appraisal over hundreds of installations over many years, ensuring you receive only the best quality and service.
Energy Efficiency: Find Out More and Get In Touch
For more detailed information from Window Advice Centre on thermally-efficient high performance windows, and optimum energy-efficient solutions in Glasgow, Edinburgh, Perth, Stirling, Dundee, Fife, Lanarkshire, Ayrshire, or elsewhere across Central Scotland please Contact Us by telephone on 0141 332 7878 or 0131 225 7999 or 01382 200 345 or arrange your FREE no-obligation Survey and expert advice by clicking this Book a FREE Survey link or the button below.