Anyone who builds or repairs a home should sooner or later ask themselves this question:
Which entrance door should I choose? Exterior doors made of PVC, aluminum or possibly steel?
There are many stereotypical and widespread opinions about which material is better and which is worse suited for making entrance doors. Therefore, it is worth looking at the objective properties of individual materials without prejudice.
Let's focus on those that are especially important for the normal functioning of external doors.
HEAT INSULATION
Exterior doors should provide good protection against heat loss. The coefficient of thermal conductivity λ determines the thermal insulation properties of this material. The lower the coefficient λ, the lower the heat loss.
| Aluminum | λ = 155 |
| Steel | λ = 50 |
| XPS (door panel filler ) | λ = 0.35 |
| PVC (HPL sheet door panel ) | λ = 0.17 |
PVC is undoubtedly the best insulator in this comparison, while aluminum is the worst. Due to the high thermal conductivity, aluminum profiles must have a multi-chamber design and special thermal breaks are used. This significantly increases the cost of their production.
Steel frames do not provide for thermal breakage, as a result, steel doors do not meet current heat loss standards.
The larger the mounting width of the door profile/Leaf, the better the heat insulation.
TIGHTNESS AND DURABILITY
Leaky or blown doors lose all their insulation advantages because the temperature is freely exchanged due to leaks. The tightness of the door is determined by the rigidity of the door leaf. The stiffness is determined by the young's modulus. This is a parameter that allows you to determine the stresses at which this element will deform. The larger the young's modulus, the greater the force required to bend or dent a given material.
The table shows that bending, for example, a steel sheet requires three times more force than bending an aluminum sheet of the same thickness.
The above parameter also affects the durability of connecting threaded elements, such as hinges or screws.
| Steel | E = 210 GPa |
| Aluminum | E = 70 GPa |
| PVC | E = 2.8 GPa |
| HPL | E = 13 GPa |
The table shows that steel is three times harder than aluminum and seventy-five times harder than PVC.
As a result, PVC doors are reinforced with a steel profile that takes on all the rigidity of the structure.
Another very important advantage of Steel is its strength and hardness. Thanks to this, the elements screwed into the steel are attached stably and for a long time. Aluminum is a relatively soft material, which significantly increases the risk of "breaking" the thread.
The weight of the door leaf (double-glazed windows can weigh up to 100 kg) affects the durability of the door. A heavy door leaf puts a load on the hinges, which reduces their service life. Unstable fastening of the hinges causes the so-called sagging of the sash and, in the future, can damage the locks.
As a result, replacing heavy double-glazed windows with Masco door filling significantly improves the reliability of doors.
The use of internal opening doors also significantly affects the possible deformations of the sash and, as a result, the tightness of the door.
Linear expansion coefficient (α)
Doors (like all materials) expand and contract under the influence of temperature.
The surface of dark doors can be heated up to 80°C on a hot day. In winter, the temperature can drop to -25°C. It is safe to assume that the maximum annual temperature amplitude is 100°C.
Sometimes there are thermal shocks, for example, when a thunderstorm with hail occurs on a hot day. Most homes are equipped with air conditioning. On a hot day, the temperature difference on the door surface outside and inside is up to 50°C. outside, the material expands much more than inside, and the door leaf tends to bend into a so-called banana.
This leads to problems closing and opening the locks, can lead to final depressurization of the doors, and in extreme cases can make it impossible to open or close them.
The ΔL value determines how much the length of a 2-meter element will change with a temperature difference of 100°C.
| PVC | α = 52 | ΔL = 10.4 mm |
| Aluminum | α = 24 | ΔL = 4.8 mm |
| Steel | α = 12 | ΔL = 2.4 mm |
| HPL | α = 4 | ΔL = 0.8 mm |
The comparison shows that the most heat – resistant material is HPL, and the least-PVC.
The PVC frame and sash can deform by more than 10 cm throughout the year – that is why it is important to follow the recommendations for reinforcement with a steel profile of the appropriate cross-section, as well as protection and stabilization of the sash with a light door filling in the form with HPL (Masco overhead panel ).
Door filling folding method to minimize the transfer of thermal deformation of the outer sheet to the door leaf.
Making an internal opening door, not an external one!!!
This is due to the specific Thermal deformations of the internal opening doors ( Type Z ) compared to the external opening doors ( Type t ).
The aluminum frame and door leaf can deform by more than 4.8 cm in a year. For this reason, it is necessary to use technological procedures in aluminum doors aimed at limiting the impact of thermal expansion. Namely: a damping layer in the door panel or a sash with a panel expansion compensator.
It is also very important to use a suitable mounting gap that will allow the door to work freely. To reduce problems with the temperature expansion of doors, all manufacturers recommend protecting them from direct sunlight.
It is desirable that the doors have a suitable roof or are placed in a niche. This is especially true for dark doors.
Protecting the door surface from direct UV exposure will also extend its service life and protect it from fading ( in relation to steel or aluminum doors ).
WEATHER RESISTANCE
How to ensure that the door does not deform under the influence of temperature and moisture. They were resistant to UV radiation, heat and Frost, were not subject to corrosion, did not require burdensome and expensive maintenance and painting.
PVC doors, white or decorated with high-quality films, are quite strong and weather-resistant. A special coating with low adhesion makes it very easy to wash the door with the simplest means - water and dishwashing liquid.
Aluminum doors, subject to high-quality painting, are also quite strong and weather-resistant.
Steel doors and traditional decorative materials of the canvas, which are not durable to atmospheric conditions.
Burglary and noise protection
The MACKO offer includes a choice of door panels with burglar resistance classes RC2, RC3, as well as doors with a sound insulation coefficient of up to 38 DB. Few door manufacturers offer special doors with such a high level of protection.
PVC doors, provided that the panel with aluminum sheet and safe double-glazed windows is used, can achieve the RC2 burglar resistance class.
Aluminum doors can reach RC3 under certain structural conditions, as well as certain fire resistance classes.
Design
A wide range of colors, a variety of patterns, glazing and decorative finishes and accessories make the offers of PVC and aluminum doors meet the expectations of the most demanding and original customers.
Aluminum panels have much more options in surface decoration. After all, we can paint them in any RAL color or special decor, while forming a smooth ( the surface is delicate against possible damage or stains from external touches), matte or structural surface ( which is much more resistant to external damage ).
Also, on the aluminum surface of the panel, we can form arbitrary decors in the form of recesses ( grooves or grooves ).
FAVORABLE PRICE
PVC doors with easy and good HPL filling are the best offer for facade doors with standard dimensions.
Aluminum doors with filling-an offer for those customers who have high expectations of reliability and durability, as well as the desire for larger dimensions of the door leaf.