Unitized curtain wall is composed of large units that are pre-assembled and glazed in factory before shipping to building site for installation. With unitized curtain wall forming the core component of the external envelope of the building, thermal efficiency, sound transmission and fire safety becomes the key performance criteria of the system.
Unitised curtain wall can be installed either from the interior of the building using a beam on the floor above, or from the outside using a crane. The installation team must be safely connected to the structure via a harness.
Benefits of unitized curtain wall system:
Factory assembled, providing enhanced quality control
High performance systems (thermal, air, water, dynamics)
Adaptability to modern design concepts
Accelerated, year round field erection
Accommodation of multiple spandrel systems (glass, metal panels, stone, terra cotta, etc.)
Unit curtain wall classification characteristics
"Unitised curtain wall" can be divided into: "unitary curtain wall" and "semi-unitary curtain wall" also known as the strong unitary curtain wall, semi-unitary curtain wall can be divided into: vertical split-unit composite curtain wall, window wall unitary curtain wall.The above unit curtain wall classification is different, but its basic principle is exactly the same.
It and frame type curtain wall in the production principle design construction has the essential difference.Now the characteristics of the unit curtain wall are introduced as follows:
One, the unit type solution curtain wall leakage problem, adopted the "equal pressure principle".
Curtain wall produces leakage phenomenon, must have three conditions, the first is the presence of water, such as rain scrub curtain wall water.
Second, the path of water movement;Third, there are six dynamics of water motion: gravity, momentum, surface expansion, capillarity, airflow and pressure difference.Pressure difference is the main reason that causes most curtain wall juncture to leak, outside curtain wall moisture, no matter be rain or wash window water to enter indoor, besides must have breach or crack to exist, still must demand outdoor pressure is bigger than indoor pressure.
If the pressure inside is equal to or greater than the pressure outside, water will not enter the wall even if there are cracks or cracks.Generally, the traditional waterproof method is to try to reduce the possible openings in the long joints, such as with a variety of sealants, rubber tape on the contact joint seal plug.The new waterproof way into the room is to use the way of rainwater drainage, water into the isopressure chamber, and then water out of the wall.
In order to achieve isopressure, we keep some or all joints open, but isopressure cavity is not an aeration space, it must be limited to a certain range of aeration space, in order to effectively produce isopressure effect.In order to achieve a complete isobaric effect, the pressure in the "isobaric chamber" must at all times be greater than or equal to the outdoor pressure.
But we know that the surface pressure of a building, because the wind speed changes from time to time, will not be permanent, the higher the building, the greater the pressure difference.The positive wind pressure near the ground is smaller than that at the height, and the positive wind pressure at the center of the facade is larger than that at the corner. The same horizontal material may be subjected to positive pressure at one end and negative pressure at the other end, and the influence of other factors makes the design of the equal pressure effect more complex and difficult.
Therefore, high-tech solutions are required.Isobaric principle is the unique core of the unit curtain wall.
Ii. The unit height of the unit curtain wall is the floor height and the width is generally 1.2m to 1.5m.Therefore, the transmission of simple, can be directly hung on the floor embedded parts, easy to install.
Three, the unit is processed in the factory, glass, aluminum or other materials can be assembled in a unit in the processing plant, promoting the degree of industrialization of the building.
Four, because the unit parts in the processing plant the whole assembly, easy to inspect in the factory, is conducive to ensure the overall quality of the diversified, to ensure the curtain wall quality of the project.
Five, the unit curtain wall from the floor below the direction of the upper installation can be synchronized with the civil construction construction, greatly shorten the project cycle.
Vi. All works of the unit curtain wall can be completed in the floor, during the installation can save the tall scaffolding and crane ship.
7. Curtain wall element installation and connection interface structure design can absorb inter-layer displacement and element deformation, usually can withstand a large amount of building movement, especially for high-rise buildings and steel structure type buildings.
Viii. The unit curtain wall can be designed to achieve and maintain a double-layer sealing system.
Nine, after the installation of the unit curtain wall, between elements and elements, as a result of pin connection, can not be injected with silicone sealant (some can also be injected with glue, depending on the installation method is different)
The joints of the unit curtain wall frames are arranged in a straight line, which is easy to form an excellent image of the exterior wall.
Xi. The location and installation of the embedded parts of the unit curtain wall need high accuracy.
Twelve, the unit curtain wall needs to use the high-tech design principle, the contractor requires some advanced design personnel and equipment, has the strength of the curtain wall company, can be able to build the unit curtain wall.
Thirteen, unit curtain wall requirements of high-tech components, the shape of aluminum profile is more complex, with more aluminum profile.Its form is slightly higher than the frame curtain wall.(never more than frame curtain wall).
The advantages and disadvantages of unit curtain wall and frame curtain wall are shown in the following table.This is not absolute, to each kind of curtain wall comparison, want to depend on specific actual case and decide.
unitized curtain wall
unitized curtain wall system
Frame-type curtain wall
unitised curtain wall