Retrofitting electric window drives: tips and information
Controlled fresh air supply, optimised indoor climate, greater safety thanks to smoke and heat extraction systems: Retrofitting windows with automated window drives brings a wide range of benefits for the building, for building operation and for users. At the same time, retrofitting is comparatively simple and cost-effective.
GEZE ventilation expert Dominik Landerer explains the advantages of electric window drives and important considerations when retrofitting them.
Let’s start with a fundamental question: why should building operators retrofit automated window drives?
Existing buildings can be made fit for the future through building renovation and modernisation. © GEZE GmbH
If we look at the entire life cycle of a building, we realise that buildings are being used for longer and longer. There are economic reasons for this, but also environmental ones, as sustainability is becoming an increasingly important issue. To make existing buildings fit for the future, they need to be modernised or even renovated. The Climate Protection Act in particular, in addition to other legal measures such as the Energy Saving Act (EnEG) or the European Green Deal contain requirements for the energy quality of buildings and thus serve as the impetus for building renovations: buildings in Germany must be climate-neutral by 2045. Due to this requirement, much needs to be done in terms of energy efficiency. This doesn't always have to mean a complete renovation of the façade – in many cases, simple modernisations such as electric window drives can help significantly improve a building's energy balance.
Climate Protection Act
The Climate Protection Act stipulates that Germany must become climate-neutral by 2045 at the latest – and it applies to the building sector as well. Energy efficiency in new buildings, but above all the energy-efficient renovation of existing buildings, offers the greatest potential for achieving this goal. The savings potential is huge: building operations account for around 35 per cent of final energy consumption and around 30 per cent of CO2 emissions in Germany.
What are the arguments in favour of retrofitting with window drives?
There is one big plus in particular: the existing windows are retrofitted with electric window drives – no new windows are required. For this reason, retrofitting – i.e. extending functionality by retrofitting the windows – is also comparatively manageable in financial terms. Converting to power-operated windows is therefore an enormous advantage in terms of the construction work required, because it can be done cost-effectively. It also promotes the sustainable use of buildings and helps them meet legal requirements and targets. Automated windows also offer functional advantages.
Are there concrete, practical advantages for users and operators?
Absolutely. After all, if the window drives are retrofitted, this not only has an impact on the comfort and utilisation of the windows, but also on ecological and economic factors. This benefits building operators and building users alike:
- User comfort: Window areas that previously could not be opened or were rarely opened by the user can thus be integrated more easily into daily use and significantly boost well-being and comfort in the room.
- Improved indoor air quality: Automated ventilation systems enable precise monitoring of the room temperature, humidity and CO2 concentration. The indoor climate control system creates an optimised indoor climate in which pollutants, allergens and CO2 are efficiently reduced at the same time.
- Energy efficiency: Electric windows can be controlled by sensors to optimise the room temperature: Heat losses in winter can be minimised, while automatic ventilation helps control the building's climate during the cool night hours in summer. This conserves resources and reduces costs.
- Fire protection: Integrated or networked functions such as a smoke and heat extraction system increase safety for people and buildings. The windows not only supply fresh air, but also ensure smoke and heat extraction in the event of an emergency.
- Increasing the value of the property: Retrofitting automated windows increases comfort and improves the energy efficiency of the building. Both factors help increase property value.
Building users feel more comfortable overall when the indoor climate, air quality and temperature are right – and they don't have to adjust them manually.
To make these issues even more tangible: What does retrofitting look like in practice?
Slimchain chain drives for increased safety and energy efficiency. © Sigrid Rauchdobler // GEZE GmbH
Schools are a good example, as many people remember stuffy school buildings from their childhood that were in need of renovation. Instead of replacing the entire façade, retrofitting windows is more practical and cost-effective.
CO2 sensors monitor the indoor air and activate the natural ventilation system as required: Electric window drives open turn-and-tilt windows, allowing fresh air to flow in and be distributed throughout the room by means of a piston effect.
To ensure child safety, the closing edges are monitored using a laser scanner such as the GC 342+. The IQ box Safety safety module stops or reverses the movement of the window as soon as a foreign object is detected at the closing edges.
The new natural ventilation system optimizes the indoor climate, meaning teachers are no longer responsible for ensuring a regular supply of fresh air and the safety of children and staff is guaranteed.
Another advantage is that the window systems can be integrated into the building management system and thus can also be used for night-time cooling, letting in fresh air in the morning, or securely closing doors after operating hours, for example.
Natural ventilation using the Slimchain chain drive is a reliable alternative to manual window ventilation. It can also pay off compared to ventilation systems. © GEZE GmbH
How promising is such retrofitting for the future?
Extremely. Sustainable and resource-saving building operation is forward-looking. In addition, a certain degree of automation also makes a building more flexible: especially if it is possible that the way the building is used may change in future – for example, when flats are created in a former office building. The easier it is to convert a building, the more likely it is to be used for a longer period of time. Window drives are much easier to retrofit than a mechanical climate control system. The CO2 footprint is also much lower than when installing an air conditioner, especially when you consider its use over the entire life cycle – maintaining, converting and optimising it.
How does a building operator or planner know whether investing in automatic window drives is worth it?
Investing in automated natural ventilation with electric window drives usually pays off after just a few years of use – and doubly so when retrofitting the technology on existing windows. The return on investment (ROI) can even be used to calculate how quickly they pay for themselves and when the investment is considered worthwhile: This involves comparing the relatively affordable investment costs against the expected annual savings. Using this comparison, we can estimate relatively precisely in advance how quickly installing automated windows will pay for itself, depending on the application.
How are the window drives operated and controlled?
There’s no need to be worried about complicated processes. Generally, window drives can be controlled via local push buttons, remote controls, apps or even centralised building automation and control systems such as myGEZE Control. How the windows are operated and controlled in individual cases depends on several parameters:
- Are the windows controlled individually or in groups?
- Should the windows be controlled manually or autonomously via the building automation control system?
- Is the control automated according to time/temperature/weather/indoor climate?
- Is a particularly safe door closer required, for example in schools?
A major advantage of automated windows is that even hard-to-reach windows can be opened and closed with ease.
Can window drives be retrofitted everywhere?
It is important that building operators familiarise themselves with safety and with applicable regulations. Motorised windows are classified as machinery in accordance with the Machinery Directive 2006/42/EC and must be assessed and, if necessary, secured accordingly. The protection class of automated windows is calculated depending on the type of installation, room utilisation and activation, with protection class 0 requiring no further protective measures, while the top protection class 4 requires a high level of safety.
Learn more about protection classes and get tips on window safety systems
GEZE safety analysis
With the GEZE safety analysis, we provide support right from the planning stage with a risk assessment. Evaluate potential hazardous areas, find out the protection class required for your planned windows and receive a checklist of all the necessary protective measures.
In addition, of course, any building regulations and standards must be complied with. Especially in the case of listed buildings, this requires careful examination and approval by the responsible building authority. It is not uncommon for customised window solutions to be required, as in the Dresden Frauenkirche.
To the safety analysisHow do you determine which GEZE window drive is the right one?
Essentially, window drives consist of the drive, a power supply unit and the operating point. Depending on which additional functions are desired or required, the window drive can be extended: For example, additional protections and integrated sensors can ensure that no one gets their fingers trapped. Our specially developed GEZE WinCalc software takes care of selecting the right window drive. It performs all the complicated calculations involved in system design – whether for ventilation windows, smoke and heat extraction systems or NSHEVs. This ensures that the window drive is compatible with the respective window type and size.
Advising, assembly and maintenance – GEZE Services from a single source
In addition to comprehensive advising, our team also takes care of assembly and installation of the window drives. GEZE is also ready to assist with maintenance: after all, functionality and safety need to be checked regularly. Annual maintenance is also required by law for windows used as part of a smoke and heat extraction system. Annual maintenance is also recommended if the window drives are used exclusively for ventilation.
Our Service Contracts are a carefree option: customised to the needs of our partners and customers, we are available for regular safety checks and maintenance as well as to respond quickly in case of breakdowns – and all spare parts are included if needed.
