Certified passive house windows as energy savers
Insufficiently insulated windows often result in costly energy loss. Aluminium windows by heroal minimise this energy loss with thermally separated profiles, special fitting technology and an optimal profile geometry. Replacing old windows is not only an investment in more comfort, it also pays for itself in the long run through savings on energy costs. The modular structure makes it possible to individualise the planning of your windows with insulation classes ranging from highly insulated to passive-house certified.
What qualifies as a passive house?
A passive house has no active heating system and is heated only by passive energy sources. This allows for a reduction of up to 75% in heating energy. Passive house windows are an important component in achieving the passive house standard, as windows are one of the main sources of lost heat.
What’s so special about heroal passive house windows?
The U-value for passive house windows
The U-value (heat transfer coefficient) describes the efficiency of a window in terms of thermal insulation and heat transfer. Since the introduction of the German Energy Efficiency Directive (Energieeinspar-Verordnung, EnEV), this has replaced the k-value. This allows the measured values to be compared across Europe. The U-value indicates how much energy per m2of window area can escape from the inside to the outside. A lower heat transfer coefficient means that less heat can escape through the window, representing a higher level of energy efficiency. The thermal transmittance of the entire window (UW) is divided into a Uf and a Ug value, where the Uf value reflects the thermal transmittance of the window frame and the Ug value reflects the value of the glazing
- Uw(w = window): Heat transfer coefficient of the entire window
- Uf(f = frame): Heat transfer coefficient of the window frame
- Ug(g = glazing): Heat transfer coefficient of the glazing
The g-value for passive house windows
The g-value (solar energy transmittance factor) describes the total energy permeability of a transparent component such as window glass. The g-value consists of two components: the proportion of solar radiation that passes through the window and the heat emitted by the glass to the interior by solar radiation. A g-value of 1 represents a heat gain or an energy transmission of 100%, which represents a complete conversion of the incident solar energy. Windows normally achieve a g-value of 0.85. This means that 85% of solar energy can be converted directly into heat. A more energy-efficient triple glazing achieves a g-value of 0.55. This means that the interior is not heated as quickly by the solar energy. This is particularly advantageous in the summer, as the interior of the building stays cool longer.
Components of heroal passive house windows
There are many components that make the heroal passive house window a particularly effective energy saver. These include the factory profile compound, the heroal foaming process, a special thermal insulation glass, patented thermal break technology, an optimised isothermal curve and themodular insulation zone structure.

heroal's own profile composite - heroal is the only company producing thermally insulated aluminium-PVC-composite profiles under external monitoring (ift Rosenheim, testing institute).
Modular composition of sealing zones - Thanks to the modular composition of sealing zones, individual customer requirements become possible - from high thermal insulation to passive house suitability.
Optimised isothermal curves - Due to optimised isothermal curves, the thermal conductivity via the edges of the sealed glass pane is considerably reduced.
Low-E glass - To make sure that valuable thermal energy is not lost via the glass pane, our specialised partners will be pleased to give advice on the suitable insulating glass for your requirements. Depending on the required thermal insulation, coated Low-E glazing or triple glazing may be used.
heroal foam-filling process - In their modular insulation areas, heroal aluminium composite profiles are filled with PU-foams. The special process developed by heroal ensures that the insulation chambers are 100 % foam-filled, which leads to a better thermal insulation than other processes.
Patented insulating strip technology - heroal's innovative insulating strip technology combines high capacity with minimal loss of heat. The geometry of the insulating strips reduces the energy flow and thus also reduces heat conductivity significantly, exceeding the current requirements of EnEV, the German energy saving regulation, by far.
Requirements for passive house windows
Passive house certification by the Dr. Feist Passive House Institute
Assembly and installation of a passive house window
Passive house windows for existing houses and new construction projects
heroal passive house windows at a glance
Advantages of heroal passive house windows
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