In an earlier text, I stated the reasons why I decided on PVC carpentry. At the moment (more precisely, the year) of selection, due to the numerous advantages of PVC joinery compared to other types, this seemed to me to be the most correct decision. In the future, I assume, more natural materials will be used, but more on that later…
After the decision to install PVC carpentry, a slightly more difficult part followed, which was the selection of the manufacturer of PVC joinery , and thus the selection of the most optimal offer from the available carpentry market. After several weeks of research and compiling offers from various companies in the vicinity of about 30 km, I made a final decision, and I will write about it in detail in another text. Well, let’s start from the beginning…
At the very beginning, I must say that from my own research and experience, the choice of profile plays only a part in the overall quality of the installed joinery. Just as important as the profile are the fittings that are built into them. Furthermore, the glazing itself is also important , i.e. the glass company that produces glass and prepares it for installation on the joinery profiles. In addition to the selection of joinery components, it is also important which company (or joinery manufacturer ) welds and joins the profiles, and installs other components in the profiles. And finally, the quality of the carpentry installation is equally important , i.e. the craftsmen themselves who install the carpentry on the house.
However, let’s start from the beginning, which is the choice of profile, where most of us started when choosing PVC joinery.
PVC PROFILE CLASS
On our (and at the same time the EU market) there is a solid selection of good PVC joinery profiles from various manufacturers such as: Salamander, Gealan, Veka, Rehau, Schüco, Kömmerling, Aluplast, Alphacan, Roplasto, Thyssen, etc. Each domestic company mostly works with by one proven manufacturer of PVC profiles. I personally contacted a dozen companies from which I received offers of various prices and specifications. So let’s start with what you should pay attention to when choosing a PVC profile.
All the above-mentioned profiles belong to class A or class B PVC joinery , and thus meet the standards of EU norm PN-EN 12608:2004, with which the classes are defined as follows:
- Class A – outer wall thickness ≥2.8 mm, inner wall thickness ≥2.5 mm,
- Class B – outer wall thickness ≥2.5 mm, inner wall thickness ≥2.0 mm,
- Class C – everything else. There are no minimum requirements – defined by the manufacturer.
What exactly is meant by the thickness of the outer and inner walls , you can see in the picture below.
In other words, class A and class B profiles have defined wall thicknesses for which they have certificates from a third party. This makes these profiles a safer choice compared to class C, because we “know what we’re buying” with them. Class C is therefore not a reliable choice for new construction or energy renovation, so this class is hardly ever used in these circumstances. Class C windows and doors are possibly installed in some external auxiliary rooms, sheds, etc. that are not heated – if you want to save something on carpentry.
Also, in addition to the thickness of the plastic walls, steel reinforcements are also important . As far as I have seen, all class A and B profiles have steel reinforcements with galvanized steel 1.5-2 mm thick, so I was more confident about the durability of the profiles themselves. My recommendation is that you look at the section of the profile on each of the profiles of various manufacturers, where you can see the shapes of the steel reinforcements. Namely, each manufacturer adapts the shape of the steel reinforcement to the profile, so they differ quite a bit, and it is desirable that the reinforcement be as large as possible when viewed in cross-section (as, for example, in the picture above).
CHAMBER NUMBER and SEAL
Another thing you will come across when viewing the carpentry is the number of chambers . The number of chambers affects the energy efficiency, and in today’s class A and B profiles it is usually between 5 and 7 chambers. What is perhaps more important here is the installation depth (width) of the profile itself, because there are profiles with the same number of chambers, but different installation depths.
By studying the brochures of various profile manufacturers, I saw that profiles with the same number of chambers (e.g. 6 chambers) have different installation depths – for example, from 74 mm to 92 mm. So, if we look at energy efficiency, a larger number of chambers does not necessarily mean better, but the installation depth of the profile should also be considered.
As for seals , there are profile options with two seals – outer and inner, or with three seals – outer, central (central) and inner. If you pay attention to energy efficiency, the option with three seals is far better because it improves the air tightness of the window and prevents the penetration of water and moisture on the inside of the profile (during a gust of wind or the appearance of condensate) or, as the people say, the window seals better.
COLOR
As far as profile color is concerned, there is a very wide range of profile color choices, but there are also different ways to color the profile. So, for example, the manufacturer Gealan offers painted joinery, where the color is mixed with basic white, and the end product is the entire plastic profile in the desired color. On the other hand, there is the covering of the white joinery profile with foil in the desired color. As far as longevity is concerned, both are ok according to my research, so you should make your own decision here.
GLASS
Glass makes up the largest area of the window, somewhere around 70%. It was interesting from my experience that all manufacturers talked about high-quality carpentry, thinking exclusively of profiles, while glass manufacturers/suppliers were not mentioned by anyone. Most likely because each company has its own glazier, so there is really no choice if you decide on a certain profile of a certain company. Be that as it may, there are several important options that you can still choose when choosing glasses.
The first thing is how many layers the glazing has, i.e. how many panes your window will have. Today, for the sake of energy efficiency, at least two-layer glass is regularly installed, and more often three-layer glass, while there are even four-layer glasses that are mostly installed on passive houses. More layers means higher energy efficiency, which in turn means lower heating and cooling costs. Also, multiple layers of glass enable better sound insulation. Choose two-layer, three-layer or even four-layer glass, and there are several parameters that can be changed.
The first parameter is the thickness of the glazing (the total thickness of the glass part of the joinery), which includes the thickness of all glasses and air gaps. So, if you see the marking, for example, 4-16-4, it is two glasses of 4 mm thickness with an air gap of 16 mm (see picture above).
The most common thicknesses you will encounter are:
- Double glass – d = 24 mm (eg 4-16-4)
- Triple glass – d = 40 – 50 mm (eg 4-16-4-16-4)
- Quadruple glass – d = 60 – 80 mm (eg 4-20-4-20-4-20-4)
It is important to note that all profiles allow the installation of various glazing thicknesses, where the number of panes can often be chosen. However, joinery manufacturers already have their standard glazing thicknesses that they regularly work with.
However, as far as glasses are concerned, there is an optimal choice, both for price and practicality. Namely, if we take a certain PVC joinery as an example, it has some limitations in terms of load capacity. The more layers of glass (and the thicker the glass), the greater the total mass of glazing, so for wide windows, PVC joinery need additional steel reinforcements. Also, looking at durability, lighter windows by some logic tend to be more durable.
As for additional glass options, there are IZO glasses , low-e coating and laminated glass .
IZO glasses (or more precisely IZO glazing) are filled with some noble gas, eg argon or krypton – here we mean the air space between the glasses. Since these gases are denser and heavier than air itself, they reduce the amount of heat transfer through the window glass. As for the gas filling, I’m not sure how much of this is useful and how much is a marketing gimmick.
First, I realized that there is really no way we can verify that the glasses are truly filled with gas. Second, the warranty on the glass itself is 2-5 years, and after that if the gas leaks out – nothing to anyone. So, the quality of IZO glass depends on the glaziers themselves, and as I have already mentioned, none of the carpentry manufacturers indicate from which company they supply glass. Therefore, there are no certificates and guarantees that the gas will last longer than X years. I believe that a quality company will ensure that this gas will last for a decade, however, who can guarantee that for sure!? Therefore, gas filling in my opinion does not play as important a role as the next item, which is the Low-e coating.
Low-e (low emissivity ) glass coating primarily blocks the infrared rays of the sun (heat rays of the sun that heat), but still lets sunlight through. The effectiveness of this coating, unlike gas filling, can also be checked by hand. Namely, when you put your hand on the low-e window from the inside during strong sunlight, the window will feel cold to the touch. This significantly increases energy efficiency and is definitely recommended.
There is also an option of laminated glass . This glass is intended for larger window surfaces (eg sliding walls) and for windows that are exposed to certain external influences that can potentially damage standard glass. Also, laminated glass has better sound insulation. Namely, this kind of glass consists of several layers of thinner glasses glued together with some kind of glue (eg PVB foil), which enables them to be more elastic, which enables greater noise protection as well as increased resistance to mechanical shocks. When breaking or shattering, laminated glass does not disperse, but remains stuck to the foil (like, for example, car windows).
IRONS
Fittings are mechanisms for opening and closing windows and are quite important in terms of the quality of the overall carpentry, because it depends on them how long the windows will last in terms of opening and closing, and therefore sealing. The choice of fittings includes various opening options: pivoting, on the statue in one or more positions, etc. Also, the level of anti-burglary is related to the fittings. The choice of fittings depends on the customer’s needs and wishes, which are defined with the joinery manufacturer.
Some of the quality manufacturers of fittings in our area are: GU, Roto, Aubi, Siegenia, Winkhaus, Schüco, Maco… All the fittings mentioned above are from the EU market (Germany) and are of top quality. The carpentry manufacturers themselves mostly work with one proven hardware, or else they offer a choice between several of them. Certain profile manufacturers also have their own hardware, so you can’t go wrong with it (eg Schüco). As far as I’ve been able to research, all of the above profiles have over 50,000 cycles (open-radiate-close), which is considered high quality fittings, so you can’t go wrong with any of them.
HEAT TRANSFER COEFFICIENTS
When talking about energy efficiency, it is important to define several important terms in this regard. The most important term is the window heat transfer coefficient U w , which you will see on every offer you receive, as well as on every profile manufacturer’s prospectus, as well as PVC joinery manufacturers. This coefficient consists of the coefficient of heat passing through the profile/frame U f and the coefficient of heat passing through the glass U w :
- In w – heat transfer coefficient of the entire window,
- U f – heat transfer coefficient through the profile/frame,
- U g – heat transfer coefficient through the glass,
- U d – heat transfer coefficient through the door.
Heat transfer coefficients tell how much energy you will lose through your woodwork. The unit of measurement is W/m 2 K, which translates to how much power you lose per square meter of surface at a temperature difference of 1 K (or 1°C). If we multiply this by the area of the observed window [(W/m 2 K)*m 2 ], we will get the unit W/K, that is, how much power we lose at a difference between the outside and inside temperature of 1K (or 1 °C) or, how much energy in We lose J (Joules) every second through the window at a difference between outside and inside temperature of about 1 K (or 1 °C).
You can calculate the approximate total heat transfer coefficient through the window (or door) using the formula:
U w =U g *A g +U f *A f /(A g +A f )
where: A g and A f are glazing surfaces and profiles. We can apply the same formula for doors where only U w is replaced by U d . On the Internet, I came across a table that perhaps speaks more clearly about energy savings regarding different windows with different heat transfer coefficients:
| Item | Window (100×100 cm) | Heat transfer coefficient U w | Annual consumption of fuel oil for heating (l/m 2 ) |
| 1. | Old windows with one glass | 4,6 | 50 |
| 2. | Old windows with two panes | 2.8 | 30 |
| 3. | PVC joinery with double-layer IZO glass and 3 chambers | 1.9 | 20 |
| 4. | PVC joinery with double-layer IZO Low-E glass (5 or 6 chambers) | 1,2 | 13 |
| 5. | PVC joinery with three-layer IZO Low-E glass (6 chambers) | 0.7 | 7 |
Table taken from https://www.abs.hr
As the above table shows, joinery greatly affects the total consumption of energy for heating. This is not surprising, since windows and doors occupy a certain area of the house, and also have the highest heat transfer coefficient of all other parts (floor, ceiling, walls). If we apply the table for a house of 150 m2 , the annual energy consumption from item 4 will be around 1900 liters, and item 5 will be slightly under 1000 liters . In other words, on a multi-year basis, investing in quality carpentry is definitely profitable, especially due to the increasing prices of energy sources.
BLINDS
As far as blinds are concerned, there are several options regarding installation, color and the actual lifting. As far as installation is concerned, there are over- window blinds , front -window blinds and front- window blinds. In the case of new construction or replacement of windows, over- window blinds are regularly installed that come above the profile, but with which you must take into account that they reduce the height of the window itself, i.e. the glazing. Here, the blind box is not visible due to the facade covering, and also, these blinds cannot be installed suddenly after installing the joinery.
You can install pre-window plaster blinds after installing the window (but before installing the facade), but you have to remove part of the wall above the window so that the blinds can be installed (if you want the fully raised blind not to cover part of the window). This type of blind can also be an option in new construction, where you can get a higher height of the window itself (the height of the window can be increased compared to over-window blinds by the height of the blind box itself).
And finally, front window blinds are installed if you do not currently have blinds, and you have decided to install them. Here the blind box is visible, where also this type of blind reduces the height of the window (as well as overhead blinds). Which blind option you install in a new building depends solely on you. Also, there is an option of anti-burglary blinds .
MOSQUITO NETS
When it comes to mosquito nets, there are several options of different mosquito net technologies. The simplest (and also the longest-lasting) mosquito net is a fixed mosquito net, which can be removed and placed on the outside of the window at will. Also, there are roller mosquito nets that can be in the profile, or out of the profile afterwards. Furthermore, there are also ” plisse ” or accordion mosquito nets. These mosquito nets are suitable for wider windows.
There are also sliding mosquito nets, which are the only option in addition to accordion mosquito nets for glass walls. Here I would like to mention once again that some profile manufacturers have the option of integrated mosquito nets in the profiles themselves. What mosquito nets you will choose depends mostly on your taste in appearance, and which ones I chose and why, you can read here.
As far as the dimensions of the mosquito nets are concerned, you can choose options that cover the entire window or only a part of the window, which is both a more affordable and a more practical option because, after all, we don’t use them throughout the year.
FINAL SELECTION
Personally, I made the final choice after several weeks of detailed research about the carpentry, primarily regarding the quality of profiles and fittings, and also the selection of the type of glazing. Returning to the table above, the choice of energy-efficient (but also quality) carpentry can pay off the difference in price between two different classes of windows within a decade (if we go by the heat transfer coefficient, which is also the main indicator of energy efficiency).
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