How to choose the fixtures? What are the important characteristics that windows and doors must have? Complete guide to the functions of the windows in the relationship with the building.
Have you ever wondered what are the most important features that windows must have? This question is fundamental in the choice of fixtures. Here is the complete Windowo guide dedicated to the
role of windows and doors as a fundamental architectural element
within the building envelope .
The characteristics of the window: the relationship with the building in the choice of fixtures
The frame fulfills the very important role of
creating a contact between the internal and external environment of the building. The need to
create a passage for people, the facing, the ventilation of the interiors, and many other functions (which we will see in this guide) have made it essential the moving parts that can accommodate the total or partial opening of the window frame itself.
The characteristics of the window frames allow the user to control the passage of air, light, sounds, smells and the passage of people or animals. Furthermore, the window allows the maintenance of an optimal internal microclimate by limiting heat loss (in winter) and the contribution of heat (in summer). The behavior of a window or door depends on the context in which it is inserted and on the technologies with which it is made.
Watch the video to understand how to choose a frame
Here is the list of the important characteristics that every window or door should have.
Click on the links to directly choose the characteristic of the window.
- Visual well-being
- Aeration and cooling
- Thermal insulation
- Control of solar radiation
- Air tightness
- Water tightness
- Condensation control
- Natural air exchange
- Hearing well-being
- Noise and vibration non-generability
- Wind resistance
- Fall protection
- Fire resistant
- Resistance to intrusions
- Limitation of space inside the premises
- Maneuverability
- Integrability
- Cleanability
- Resistance to false and violent maneuvers
1. Visual well-being of windows: light control in the rooms
This type of requirement is linked to the
control of the luminous flux : the introduction of natural light should be adequate for carrying out the activities planned inside the rooms. It should also be possible to adjust the light according to the time of day (and in relation to the position of the sun).
The size of the window frame in proportion to the surface of the internal environment determines the amount of natural light that is introduced into the building. Furthermore, the height of the opening relative to the floor also affects the amount of light emitted. Another important factor is the height of the opening in relation to the height of the floor. Finally, the presence of darkening screens can regulate the introduction of light or the achievement of complete darkening.
2. Ventilation and cooling of windows: the role of windows in correct air circulation
By ventilation we mean the
formation of air currents inside the rooms. It is a phenomenon influenced by the context in which the building is inserted, by its confirmation, by the number / location / size of the windows.
To have a good air circulation, two openings are necessary positioned so that one constitutes the entrance and the other the exit of the air flow. The amount of air flow generated by a pair of windows corresponds to the difference in wind pressure at the inlet and outlet, together with the size of the openings. In the case of accommodations without more than one exterior view, ventilation is achieved by involving several rooms (therefore, the movement of fumes, vapors and odors between the reference rooms must also be taken into account).
3. Thermal insulation of doors and windows: how to limit heat losses
A house disperses about 30% of its energy through its windows: this is why it is important to evaluate this important aspect. By
thermal insulation we mean the ability to contain the heat losses that occur by radiation, by conduction and by air exchange between the internal environment and the outside.
All the parts that make up the window frame (glass, frame, hinges, gaskets), but also the conditions of the wall space and the presence of screens or any box, contribute to the more or less efficient thermal insulation of the house. To have a good result on this front it is therefore necessary to use the appropriate hardware, use the right elements for fastening to the shaft and use suitable insulating materials. Depending on the materials used, thermal bridges are physiologically created due to various factors (interpenetration of materials with different conductivity, variation in the thickness of the construction, difference in the surface air that disperses on the internal and external sides, etc.). In general, it is advisable to lay the window frame in such a way as to form a continuity with the insulating layer of the wall (in order to eliminate these thermal bridges). In any case, the part that connects the window to the wall must be filled with insulating material and hermetically sealed.
The variation in the thickness of the glass has almost no impact on the thermal resistance, but is determined only by the existence of a glass (in fact the thermal resistance of a glass is proportional to its thickness and varies in the ratio of 1 to 1000). To calculate how much energy a window or door disperses through the surface, the
coefficient of thermal transmittance is used: Uw . The lower
Uw, the greater the thermal insulation. To improve environmental comfort, it is possible to opt for low-emission glass or elements such as roller shutters and shutters (for the winter) that reduce heat dispersion, or for selective glass (for the summer) able to block the sunlight that heats.
4. Control of solar radiation of windows
The screen (such as roller shutters or shutters) is the element responsible for
controlling direct solar radiation . There are also reflective glass which also allows the window itself to limit its passage. The frame should also consist of elements that allow the user to adjust the irradiation, without unduly compromising visibility.
5. Air tightness of doors and windows: the rabbet surfaces and the gaskets
This characteristic essentially concerns
the "stop" between the opening parts of the window and the fixed parts . In fact, the window is one of the few building elements that makes movement its essential feature, hence the difficulty of maintaining the
tightness of the joints over time . In areas where the contact surfaces do not adhere perfectly, the gaskets are not compressed perfectly and therefore do not guarantee the seal itself.
6. Water tightness of windows and doors: the importance of the junctions between the sill and the lower crosspiece
Even for water tightness, the criticality is constituted by the openable joints. In this case, particular attention must be paid to the
junctions between inhomogeneous elements . Normally the windows today guarantee excellent performance on this front even in case of pouring rain. It is however necessary that the frame and the sill help the flow of water.
7. Control of window condensation through temperature control
It is essential to
avoid the formation of condensation on the windows . This is mainly for three reasons: one because the fogging of the glass is annoying, two because a wet frame is unpleasant to the touch, three because water can accelerate the deterioration of the window itself. The internal surfaces of a window frame are as cold as the insulating capacity of the elements that constitute it is lower. To block the formation of condensation, which occurs when the surface temperature of the perimeter walls is lower than the dew point, we recommend the use of double glazing and insulated materials.
8. Natural air exchange in high-performance windows
In the past, the air exchange was guaranteed by the poor air tightness of the fixtures and the inadequate sealing of the frame / wall joint. All characteristics that on the other hand led to the uncontrolled loss of heat, infiltration of dust and passage of noise. Today, high-performance air-tight windows eliminate these drawbacks but leave the burden of periodically opening the window to the user.
9. Hearing well-being of windows and doors and sound insulation from external noises
Normally a window or door offers less soundproofing guarantees than the masonry part. For this reason, it is necessary to act not only on the windows, but also on the sources of emissions of such noises and making appropriate design choices relating to the location of the building.
The
acoustic performance of a window is evaluated with reference to the
soundproofing power Rw . The window frames must have a certain
acoustic performance class in relation to the intended use of the rooms and the noise level of the placement area.
10. Blocking of noises and vibrations of the windows
Shutters or shutters, as a screen element, can give rise to noises if subject to the impact of rain or hail or to the flapping of the wind. To reduce these noises it is possible to use heavier type slats or slats filled with polyurethane foam which increases the mechanical resistance and soundproofing.
11. Wind resistance of windows
Vertical window frames must be able to resist the action of the wind in order to guarantee safety for users and guarantee functionality over time, and must also prevent the wind from generating too much noise, vibrations and flapping.
12. Protection against falls of windows
The "fall protection" feature is only important for openings in front of external slopes greater than one meter in height. If the height exceeds 0.9 m, provision should be made for the installation of complementary safety devices such as parapets or railings.
13. Fire resistance of windows
Fire resistance consists in the ability of the window to retain, in whole or in part, within a certain duration of time and despite the action of fire, the stability
R (from the French
Résistance ), the seal
E (
Etanchement ) and the insulation. thermal
I (
Isolement ). The symbols REI, RE and R followed by a measurement (in minutes) identify a construction element that maintains stability, tightness and insulation for a certain time.
14. Resistance to window intrusions
The location of the different openings of a building determines the greater or lesser importance attributed to this requirement. The components of a window frame that can affect the level of security are: the locking hardware with at least one anti-burglary locking point, the handle with a safety button or key, a shatterproof glass, the frame fixed with anchor screws, hinges suitable for weight of the window.
15. Limitation of space inside the premises
This characteristic depends on the size of the window and the position in the wall of the room. The type of opening determines the portion of the floor used for the maneuverability of the frame.
16. Simplicity in handling the doors and windows
It affects the moving and maneuvering organs of the moving parts of the fixtures.
17. Possibility of integration with roller shutters, shutters or other screens
This feature concerns windows with screens, which must allow mutual completion (without losing functional capacity or technical characteristics).
18. Cleaning of windows and doors: easy and safe
This is an important feature that a window or door must have, especially if you want to preserve the transparency of the corresponding glass surfaces.
19. Resistance to false or violent maneuvers of the windows
A window frame must guarantee sturdiness to cope with significant stresses acting on planes or directions other than those normally envisaged. This is because users can also perform incorrect maneuvers, especially in the case of operations that are not immediately understood.
Choose the fixtures: if you have any doubts contact us
We hope that this guide on the characteristics of windows will be useful for you to understand what characteristics each window should have. Do you have any doubts in choosing the fixtures? Contact us, Windowo staff is at your disposal.
