uPVC Windows Guide

Double glazing your windows is one of the most successful ways of improving the energy efficiency of your windows and therefore your home.  You can get in professionals to do the work for you, or if you have some home imporvement talents, you can carry out DIY double glazing on your  windows.

In this article we will try to explain window glazing briefly and as un-scientifically as possible.  This can be a bit difficult when you start to talk about such things as ‘spacers’, ‘solar heat gain coefficients’, ‘low emissivity glass’ ‘secondary double glazing‘ and the many other terms that arise when we talk about double or triple glazed windows and doors.  However we will attempt to keep the terminology to a minimum and see if we can break down glazing for your windows into some basic and understandable points.

•    Multiple glazing is the assembly of various panes of glazing into one unit.  This could comprise two panes of glazing windows (double glazing), or three panes of window glass (triple glazing), and so on.  If we are talking about double glazing, then between the two sheets of glazing will be present a gas or a vacuum.  This gas or vacuum will be thermally efficient and will also have properties that assist in insulating your home against sound pollution.
•    The glass in a window unit is necessary, not surprisingly, in order to allow in light and allow the homeowner to see out of the property.  This may sound obvious, but in terms of insulating a building properly, it would actually make more sense to leave out windows altogether, because they are one of the highest contributors to heat loss in a building.  The thickness of each glazing sheet can range from a high of circa 10mm down to 3mm and are usually all of the same thickness.
•    Different and specialized types of glazing can be used when carrying out window glass replacement or installing new windows.  These can include low-emissivity glass, which has the ability to reflect radiation from the heat of the sun, tinted glass, which can help to reduce heat build up in the room and coated glass, which is a glass with a coating on it, which can improve the insulation of heat and noise in the home.
•    Spacers are the strip of metal or foam that you see between the panes of glass when you look at a double glazed window.  These spacers keep the panes of glazing apart and create a seal which traps the gas between the panes, or helps to seal and create the vacuum.  These spacers are used whether you are dealing with timber, aluminum or uPVC windows.
•    The manufacturers of double glazed house windows will most often carry a warranty for ten to about twenty years and this lifespan can be effected by various  factors, including whether the units are installed in the Northern or Southern Hemispheres. Typical reasons for homeowners changing window units or having to get them repaired would include seal failure and desiccant saturation. Desiccant is present in the spacers and its function is to remove the moisture from the sealed area that has formed during the manufacture of the window and also it stops moisture formation inside the gas or vacuum area.

These are some of the basic points that come to the fore when you are considering window glazing or replacement glass for your home.  Many homeowners face the choice of replacing their windows at some stage after they have exhausted the idea of carrying out window repairs to their existing window units.  Consider getting a double glazing quote for your home as double glazing windows are now the most popular choice with homeowners, as they provide excellent energy efficient units at a competitive price.

If you have decided to install double glazing in your home, then congratulations.  You have made a good decision and will most likely reap the benefits over the coming years.  However in order to make the most of your decision you have to first select quality window units and proper replacement glass for your home.  Then you have to find a window or glazing installer from the many double glazing installers that are out there looking for your business.

This is not necessarily the most difficult thing to do, once you take your time at the process and carry out plenty of research.  When it comes to selecting an installer that you would be happy to install your windows, it will certainly help if you have some basic knowledge of what double glazing windows are about and of the installation process also.

The reason that double glazing is so popular worldwide is that it helps a home to become energy efficient if double glazed windows are used in conjunction with other actions, such as attic insulating, etc.  double glazed uPVC windows are especially popular, as they allow you to improve the thermal capacity of the home at a fairly reasonable price.  A PVC window also helps to improve the security of a property and is reasonably maintenance free.  The fact that they are available in a very large selection of styles and colours makes them attractive to homeowners also.

When it comes to window glazing one of the most important things to understand when talking to installers is the ‘U-Factor’ of the window units.  This is a measure of the ability of the window to prevent heat loss and it is a measure of the entire window unit and not just the glazing.  Other terms to be aware of are the ‘Solar Heat Gain Coefficient’ which judges how well the window is able to prevent the suns heat from entering the home, ‘Air Leakage’, which tells you how much air can leak through particular windows and ‘Design Pressure’ which is a measurement of the ability of the windows to stand up to wind pressure.

These are all pretty technical terms and are explained very basically here.  However, even by knowing this amount of information, you will be able to make comparisons between the different window units and glazing that are on offer and also between the different double glazing installation services on offer.  If a double glazing installer is unwilling or unable to discuss the above measurements with you as they pertain to the windows he is selling, he either does not know his windows very well, or the windows are not very good.

It is probably wisest to purchase from a company that is in business for a lengthy period of time.  This may cut down your list quite a bit, as double glazing fitting companies go out of business quite regularly after only a few years, but this is precisely the reason you want an established company.  There is not much point in getting excellent guarantees with regard to maintenance and service if the company is not around to honour its commitments to you.

Getting quotations does not cost you anything and will help you to further narrow your list of potential double glazing fitters.  When you have narrowed down your list in this way you can go into more detail with the remaining companies on the list, visit their websites If they have one, look at the testimonials they have received and even contact homeowners in your area that have had work carried out by these companies.

Good double glazing installers may be difficult to find at first sight.  However the more enquiries that you make and research that you carry out, one or two names will keep cropping up as being honourable, trustworthy companies that are in business for the long haul and that homeowners have been satisfied to use.

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.

uPVC 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.