Attachment to existing radiators
KELIT COPTIMIZER - Innovate your radiator
Millions of buildings in Europe are still equipped with traditional radiators, designed for high flow temperatures. However, modern heating systems such as heat pumps or low-temperature district heating only work efficiently at low temperatures – this is where old radiators quickly reach their limitations. Rooms do not get warm enough or heating up takes too long. Replacing radiators with bigger ones is expensive, time consuming and therefore hardly feasible for many homeowners. This means that the necessary modernisation of existing buildings is becoming an obstacle to the energy transition.
With the KELIT COPTIMIZER, KE KELIT offers a simple and efficient retrofit solution: existing radiators can be upgraded in a mere 15 minutes – without any intervention in the heating circuit, without a power connection, dirt or construction work. Through targeted ventilation, the KELIT COPTIMIZER increases heating output by up to 40%, distributes heat more evenly and enables the efficient operation of modern heating systems with low flow temperatures. This saves energy, reduces operating costs and increases living comfort – immediately and sustainably.
The KELIT COPTIMIZER is an attachment for existing radiators and consists of an energy unit on top and a fan unit in the bottom part of the radiator. Both components can be easily installed using a plug-and-play system without any structural alterations. Unlike comparable systems, the device does not require a power connection. The KELIT COPTIMIZER is energy self-sufficient. Electrical energy is generated by the temperature difference between the hot side (radiator) and the cold side (heat sink), taking advantage of the Seebeck effect in thermoelectric generators, thus driving the fans.
The advantages at a glance
- Reduction in energy consumption and therefore heating costs
- Modernisation of existing radiator systems without full conversion – clean and quick
- Reduction in flow temperatures, increasing the efficiency of heat pumps
- Energy self-sufficient – no electrical connection required
- Easy retrofit: installation takes around 15 minutes per radiator
- Suitable for almost all standard panel radiators
- No chiselling work or painting required
- Even heat distribution throughout the room
- Extends the life cycle of existing radiators and therefore saves CO2
- Optional cooling function for greater comfort in summer
The advantages when connected to district heating
District heating is considered one of the most efficient forms of heat supply. However, its actual efficiency depends crucially on the return temperatures in the network.
This is exactly where the KELIT COPTIMIZER comes in play: it ensures lower return temperatures, thereby improving the efficiency of the entire system and creating stable, optimised operating conditions – for both energy suppliers and end customers.
Lowering return temperatures not only reduces hydraulic demand on the system, but also decreases heat losses in pipes.
The advantages when connected to a heat pump
Heat pumps achieve their highest efficiency at low flow temperatures. However, this is often a challenge in existing buildings, as the existing radiators are designed for higher flow. The KELIT COPTIMIZER solves precisely this problem: it increases the heat output of the existing radiators, reduces the required flow temperature and at the same time ensures an even temperature distribution in rooms.
This allows the heat pump to operate under optimal conditions – with a higher COP value, lower power consumption and a longer service life. The system continues to use the existing heating infrastructure efficiently without the need for major structural changes.
Perfect heat distribution in the room
Conventional radiators heat up air directly at their surface, causing it to rise and accumulate at the ceiling. This leads to an uneven heat distribution: too hot at the top and too cold at the bottom. Especially in large or tall rooms, this results in inefficient heating, as a higher flow temperature is often necessary to achieve a feeling of comfort – at the expense of energy consumption.
KELIT COPTIMIZER solves this problem with an integrated, self-powered fan unit that actively and evenly distributes the warm air throughout the room. This eliminates localised warm pockets, the room heats up faster, and the desired temperature can be achieved lower flow.
The system operates independently, quietly and automatically, without an external power source or manual operation. It not only improves living comfort and energy efficiency, but also allows for more flexible room design and extends the life cycle of the radiators. Overall, a conventional radiator is transformed into an intelligent and sustainable heating system that combines comfort, efficiency and value retention.
Radiators come in countless varieties: narrow, wide, low, high, etc. However, this is not an issue for the KELIT COPTIMIZER. Thanks to its intelligent, modular design, the system can be easily adapted to almost all panel radiators – regardless of size, width, height or connection type. The KELIT COPTIMIZER is a sophisticated modular system. Both the energy and fan units consist of individual segments that can be daisy chained to fit the width of the radiator. This allows precise adaptation to the respective radiator size – from particularly narrow to very wide models. This modular structure provides maximum flexibility, meaning that almost any radiator can be covered. The system is always attached to the front panel of the radiator. Different top cover variants allow flexible adaptation to different radiator depths. The position of the heating pipes is also irrelevant, which greatly simplifies planning and allows for flexible use in almost all types of buildings. It does not matter whether the radiator has a centre connection or a side connection – the KELIT COPTIMIZER works reliably in both cases.
No special tools are required to install the KELIT COPTIMIZER. In just a few simple steps, the energy unit is hooked onto the top of the radiator, the fan unit is clamped onto the bottom, and both are then connected to each other via cables. The system is then immediately ready for use. Upgrading a radiator takes on average no longer than a quarter of an hour. No further setup or adjustments are required after installation. The KELIT COPTIMIZER starts automatically as soon as the radiator gets warm. Apart from the on/off switch on the electronic box, the system requires no further control elements – it works inconspicuously and is only noticeable when rooms warm up faster and more evenly.
The performance of the KELIT COPTIMIZER was tested at the accredited Institute for Building Energetics, Thermotechnology and Energy Storage at the University of Stuttgart according to strict scientific criteria. Standardised tests were used for this purpose, which are also common in European radiator certification. Identical radiators were operated under the same conditions – one in their original condition and one retrofitted with KELIT COPTIMIZER.
The results were impressive: at a typical flow temperature of 55 °C, the radiator output was increased by around 27 percent. The effect was particularly noticeable at lower temperatures, such as those relevant in combination with heat pumps or low-temperature district heating. At a flow temperature of 45 °C, a performance increase of over 35 per cent was measured. The test results lead to a clear conclusion: KELIT COPTIMIZER significantly increases the heat output of existing radiators, especially in the low-temperature range, and provides reproducible, independently tested proof of its effectiveness.
Sustainability means much more than just saving energy in operation. It also means conserving existing resources, avoiding unnecessary waste and keeping products longer instead of throwing them away. This is exactly where the KELIT COPTIMIZER comes in: instead of replacing old radiators, they are upgraded and reused. This not only reduces costs, but also saves valuable materials and the energy required to manufacture and transport new heating systems, while at the same time avoiding the disposal of old components. The KELIT COPTIMIZER turns an existing radiator into a future-proof system. Radiators that are no longer state of the art are given a significantly longer life cycle through retrofitting, thus reducing CO2 emissions by conserving existing resources.
