Energy efficiency - next to aesthetics, durability and, of course, price - is the most important issue taken into account by investors when choosing window joinery. It's hardly surprising - heating costs are constantly rising, technical requirements for insulation are still being tightened, and everyone dreams of a comfortable, warm and safe home. In light of this, how to choose windows that will really protect against heat escape?
The answer to the question - "what to pay attention to when looking for warm windows?" seems to be simple - theUw heat transfer coefficient. According to current requirements,Uw for vertical windows cannot be higher than 1.1 W/m²K. But starting in January 2021, this value will be lowered to 0.9 W/m²K.
These requirements are not technologically difficult to achieve. In fact, MS more than OKNA products already calmly fall "within the parameters" and guarantee a Uw heat transfer coefficient much lower than the required 0.9 W/m²K. - explains Artur Głuszcz, production director of MS więcej niż OKNA. - For example, reference windows from the ALU LOOK, WOOD LOOK, MSLine+ MD and MS evolution [82] lines with MS warm frame offer: Uw=0.79 W/m²K, and with a plastic frame even Uw=0.71 W/m²K. All our windows also feature good wind load resistance (up to class C3/B3) and waterproofing up to 1050PA.
However, there is a "but"
We must remember that windows from one line, manufactured with exactly the same technology, using exactly the same materials, but having different sizes will have a Uw of a completely different value.
The requirement for higher insulation must be met by EVERY window, regardless of dimensions, not just the reference ones. In large windows, achieving this parameter is not difficult, because the ratio of the area of the glass to the area of the entire window is favorable, and - as is well known - the glass is characterized by almost twice the U-value of the frame material. (Double-glazed windows, so-called triple-glazed, are characterized byUg=0.5-0.6 W/m²K). However, it is more difficult to achieve the required parameter with small windows. The smaller the window, the richer its equipment will have to be (better insulated profile system, warmer glass, plastic interglazing frame). That's why we must carefully check the relevant parameters of each window with the distributor each time. - explains Artur Głuszcz.
Not only the parameters of the window count
If we care about woodwork that will indeed effectively protect against the cold, as much attention as we pay to the choice of windows must be paid to... installation. With improperly carried out mounting, even the best and warmest windows will not meet our expectations. Therefore, when choosing a construction team, let's make sure of its qualifications, or rely on specialists recommended by the window manufacturers themselves.
The most important principles and stages of warm installation
- Embedding windows in the insulation layer.
- Proper mechanical fastening of windows in carefully prepared openings with dowels, anchors or screws (with prior stabilization with wedges).
- Careful placement of all layers of insulation in the correct order. From the outside, we use vapor-permeable insulation - so that moisture can evaporate; in the middle part - thermal insulation, most often it is an expanding foam; from the inside of the window - vapor-proof insulation so that moisture from the room does not penetrate the insulation zone. You can also use three-function tapes instead of three different products.
- Careful sealing of the lower element of the window, which is usually a sensitive point. This task is facilitated, for example, by warm XPS under-sill profiles.
- Final processing of the window and adjustment of the sashes only after the foam has set.
For more information, visit MS more than OKNA on our website.
