Benefits of Polyamide Thermal Insulating Strips
In recent years, thermal efficiency has become one of the most important aspects of residential and industrial construction. Climate change and the ever-increasing costs of energy have resulted in special attention being given to a building’s thermal efficiency, which is to say, how good a structure is at preventing heat from crossing from the inside to the outside or from the outside in.
Window frames made of aluminum are extremely popular in construction: they are relatively cheap, easy to fabricate, strong, and visually appealing. However, aluminum is a highly efficient heat conductor. This is an excellent characteristic for components such as heat sinks, but it creates a problem when you want heat insulation in your product.
This article will introduce you to the concept of thermal bridges in aluminum window frames, which are often a significant source of thermal inefficiencies and can result in substantial costs dedicated to keeping away extreme temperatures from the outside. It will also introduce you to one solution to this problem: polyamide thermal breaks ( polyamide thermal insulating strips )
Essentially, a polyamide insulating strips in an energy-efficient aluminium window frame creates a thermal break in the structure which can be used to meet the modern needs of building physics. When seeking a cost-effective solution for the improvement of thermal values of a structure, aluminium casement windows have long been considered as one of the best options, for example when compared to uPVC. Moreover, with the addition of polyamide insulating bars to create thermal breaks, their thermal insulation properties can be improved no end.
What are Thermal Bridges and Thermal Breaks?
Thermal breaks and thermal bridges are concepts that go hand-in-hand. A thermal bridge works as a thermal connection, or bridge, that allows easy transfer of heat.
Regular aluminum window frames are a perfect example of thermal bridges. If you touch the aluminum frame of a window from inside your house when it’s freezing outside, you’ll probably find that the frame is also very cold.
The cold sensation in your hand indicates that your window frames are conducting, or transporting, heat to the outside of your house. Your wall is supposed to act as an insulator, but it becomes much less effective when the window frames act as a thermal bridge.
On the other hand, a thermal break is any sort of barrier that prevents this leakage, or transfer, of heat.
Regular aluminum window frames are made of a single, continuous piece of aluminum that thermally connects the inside and outside of the building. But a thermally broken window frame will have a different material that insulates the inside and outside parts of a frame, dramatically reducing heat transfer across the barrier.
How Do Polyamide Thermal Breaks Work?
In a thermally broken window frame, the parts of the frame inside and outside the building have to be separated so they cannot directly conduct heat. The aluminum window frame parts must be manufactured as two distinct pieces with another material in between.
The material used as the structural connection between these two aluminum pieces has to be a thermal insulator, which doesn’t conduct heat effectively. This just so happens to be an area where window manufacturers can use polyamides to achieve exceptional results.
Polyamides, such as nylon, are polymers with excellent thermal insulation properties that are a great option to connect the outside and inside parts of the window frames. By separating the inner and outer segments of the aluminum frame, heat cannot be efficiently conducted across the barrier. This effectively ‘breaks’ the thermal bridge that would otherwise exist if the frame was made as a single, solid piece.
Advantages of reinforcing aluminium window frames with polyamide insulating strips
When a thermally insulated aluminium window frame is reinforced with polyamide bars, these components are actually inserted between the interior and exterior profiles of the product. They can be fitted to aluminium window frames as well as high-end aluminium doors and high-end aluminium façades during the manufacturing process and have huge benefits compared to similar products which lack them.
For example, a polyamide insulating bar inside a frame prevents the transfer of heat from either the inside to the outside or vice versa. This means they are ideal in both winter and summer, depending on the environmental conditions they face. In common with other insulation systems, they prevent the frames from feeling cold when it is icy outside as well as preventing heat loss from the inside to the outside. Equally, when it is hot outside, they help to prevent the interior of a structure from warming up excessively.
Improving Uf values with polyamide insulating strips
When used with thermally efficient glazing, polyamide strips in the frames of aluminium windows will provide better Uf values. Where the commonly expressed U value of a window relates to the thermal insulation rating of its glazing, usually given in Watts per m2K, the Uf rating also includes the rating of the frame. For building designers who are seeking an overall building physics that is as thermally insulated as possible, then measuring the windows by their Uf rating - not just the glazing element - makes a great deal of sense. However, that is not all. The addition polyamide insertions also reduces noise from being transmitted into a building from the exterior, thanks to the break they create inside.
"A high-performance window must have low heat loss and air leakage, but high solar transmission."
The low profiles of aluminium frames are often excellent at allowing light to flood in as well as preventing unwanted airflow, but without polyamide strips are not so strong with thermal retention. Compared to some other frame materials commonly used, such as timber, aluminium alone can produce inferior results with thermal transmittance. It is only the addition of a thermal break consisting of a material of low thermal conductivity that will guarantee performance to be strong.