Düsseldorf / Dortmund. About six weeks before the official presentation at ISH 2009 in Frankfurt (10 to 14 March 2009) the Dortmund-based pump manufacturer WILO SE organised an exclusive preview of its new decentralised pump system “Geniax” for the German trade press in Düsseldorf, Germany. The location was the VDI house in Düsseldorf’s Airport-City, inaugurated in autumn 2008, in which the new technology is already applied.

According to the manufacturer, “Geniax” is a real technical revolution in heating technology. Instead of temperature control valves, it relies on several miniature pumps at the heating surfaces or the heating circuits. The conventional “supply-oriented heating” with a central heating pump will thus be replaced by a “demand-oriented heating”. Pumping will only take place if heat is required. Another novelty is a central control intelligence for the entire heating system. It makes sure that the heating system operates in the hydraulic optimum at any time and makes it more precise, faster and more energy-efficient. The fields of application are new buildings, but it is also applied when it comes to retrofitting old buildings. The system can be installed in single-family houses as well as in multi-family houses, but also in commercial properties like administration buildings. The main advantage is, besides improvements in hydraulics and comfort, that heating energy demand is considerably reduced by approximately 20 %.

Consistently continuing the innovation chain
“Many important milestones of pump technology have their origin at Wilo in Dortmund”, emphasises Dr. Thomas Schweisfurth, chairman of the board at the beginning of the presentation. The company is considered to be the innovative leader in the pump sector and has already become famous with a large number of ground-breaking product developments like the first circulation accelerator (1928), the first fully electronic circulation pump (1988) and the first high-efficiency pump for heating, air-conditioning and cooling applications (2001). The latter allows power savings of up to 93 % compared to uncontrolled standard pumps. This was shown in a scientifically supported replacement project in the Maritim Airport Hotel in Hanover. From the technical point of view, no more savings are possible just by optimising the pump alone.

In this context the engineers at Wilo recognised that the right way to achieve more energy efficiency in pump technology is to optimise the heating system construction itself. A few years ago this was the starting point for the pioneering idea of a decentralised pump system. Since then the company has been working on this concept with very ambitious research effort and in close co-operation with scientific institutes to make the system ready for the market.

With “Geniax”, Wilo performs as a system supplier in the heating sector, Dr. Schweisfurth underlines. For this reason, various and even new interfaces to the rest of the installation were defined and adjusted. Furthermore, a completely new central control with intelligent control and particular requirements regarding the software was developed. Another very important step in technology is the development of very small, but still powerful and, above all, reliable miniature pumps which are not larger than a conventional thermostatic valve. For the first time, “Pumpen Intelligenz” is made visible in the living space. The decentralised pump system is topped off by an intuitive, easily learnable operating concept.

From the individual pump to the innovative overall system
Dr. Thorsten Kettner, the project manager responsible for the development and the market introduction of “Geniax” from the Research and Technology Center of WILO SE, gave a detailed technical description of the new decentralised pump system. Wilo relies on the power-saving EC motor technology for the miniature pumps which is known from the high-efficiency pumps. Dr. Kettner underlines that the new development of pumps for the living space was a special challenge because they did not only have to be of small construction size and be very sturdy, but they also had to be as quiet as possible.

He carried on explaining that in the raw installation phase only the pump adapters are installed; those are optionally available in the versions inline, H-block inline or H-block angle. The pumps themselves are only mounted as the final step of installation. The heating installation must not be drained. The third component is the pump electronics installed near the pumps which controls them via a cable connection. Design housings are available for pumps and pump electronics for a modern integration into the living or office ambience.

Furthermore, Dr. Kettner introduced the appropriate room user interfaces with different functions for single-family houses, multi-family houses and commercial properties. The user can set the temperature individually for each room and can program different setback periods in the daily and weekly routine in order to save even more energy. Moreover, a central user interface is provided.

“Geniax” server: central intelligence in the heating system
Another decisive component of the decentralised pump system is – besides the miniature pumps and their pump electronics – a central management unit with an interface to the heat generator, Dr. Kettner emphasised. The task of the “Geniax” server is the management of all components in the entire heating system in coordination with the heat requirement in the individual rooms and the specifications from the room user interface. The server sends control signals to the pump electronics which then regulate the pump’s speed, the pump’s mass flow and the heating power variably and accordingly to what is actually needed. Furthermore, the server controls the indications of the room user interfaces, it monitors all connected components, collects data for diagnosis and controls the heat generator via the 0-10 V interface. In addition, the system is open for the integration into building automation systems.

Regarding the hydraulic planning Dr. Kettner underlined that “Geniax” does not differ from conventional systems. Planning can also be done in accordance with the established rules of laying and according to the known state of technology. Wilo provides a system set-up software for the building-specific configuration of the “Geniax” system by a HVAC craftsman company. The installation does not require special knowledge either. The pump adapters are installed just like the lower part of the thermostatic valve, e.g. in the raw installation phase. The pumps can be installed by means of a service adapter without any tools even when the heating system is filled. Upon commissioning, the decentralised pump system leads the installer step by step. Programming onsite is not necessary. Optionally Wilo also offers its support. “‘Geniax’” is not a mystery, it requires no more than the existing know-how which HVAC planners and crafts companies have anyway”, said the Wilo project manager in this context.

“Geniax” allows HVAC crafts companies to offer a convincing solution for more energy efficiency and convenience for heating. It offers a saving potential for heating energy of approximately 20 %. The additional costs for the installation of “Geniax” in a new construction with floor heating – amounting to approx. 1,600 euros for a single-family house with 150 square meters of living space – will pay off within approximately six years. Dr. Kettner shows the model calculation of the Deutsche Energieagentur (dena) [German energy office] for different restoration measures in an old building which pointed out that the pay-off period for the retrofitting of the decentralised pump system is clearly shorter than for any other energy saving measures like the replacement of the heat generator and solar system or the insulation of the façade. Dena calculated pay-off periods of eight or 15 years, whereas if the heating system is renovated, the additional costs of  “Geniax” compared to the conventional equipment already pay off after approximately five years, Dr. Kettner says. Furthermore, there is the considerable increase of comfort in room heating.

Extensive scientific support
One of the most important co-operation partners of the Dortmund-based pump expert in the development of the decentralised pump system, but also in the extensive field tests, is Technical University (TU) Dresden. Prof. Dr.-Ing. habil. Wolfgang Richter, professor for heating and ambient air technology at the local Institute of Power Engineering, presented the main points and central results of his work at the press conference. Since 2001, Wilo has been scientifically supported in three joint research projects of the pump manufacturer and TU Dresden. The significance of the new development is also reflected in the research support by the Federal Ministry of Economics which raised a total of 10 million euros to promote this innovation.

The focus of his institute’s research was the development and the testing of control strategies, comparative measurements with conventional control and to prove the achievable energy savings and improvements of comfort. For this, the decentralised pump system was subject to extensive field tests for several years. The example described by Prof. Richter is an empty experimental house in which realistic basic conditions of a single-family house were created and detailed tests were carried out. In the heating season 2003/04 a first result of saved heating energy could be confirmed with the measurements done in the building and this encouraged to go on. In this first field test with the decentralised pump system, heating energy savings of 20 % were reached compared to a conventional system construction with thermostatic valves. Since then the new system has been extensively tested in several single-family houses, multi-family houses and commercial properties with different insulation standards, with radiators and with floor heating. Parallel to this, TU Dresden established detailed building and system simulations in order to consolidate the measurement results.

Considerable reduction of heat losses in the heating system
“The energy-saving potential of the new systems is based on a clear reduction of heat losses in heat generation, heat distribution and in heat transfer”, the famous scientist emphasised. One of the reasons is a feed temperature which is controlled according to the demand, which also involves the reduction of the average system temperatures and therewith a considerably improved use of the calorific value compared to the conventional solution with differential pressure valves. In contrast to the control according to  atmospheric conditions, the decentralised pump system also considers that in many cases a lower feed temperature is sufficient for covering the heat load because there are always solar gains and inner loads, too. “This is how also the heat losses in the heat generator and the piping network are reduced”, Prof. Richter said.

He moreover explained that further savings are achieved when the heat is distributed into the room – thanks to a very precise control, an optimum use of heat gains by a fast reaction of the controller, an automatic heating interruption when a window is opened for airing, comfortable possibilities to specify heating periods as well as a self-learning heating-up and heating-end optimisation.

Furthermore, the decentralised pump system uses an automatic hydraulic balancing to make even higher energy savings possible. A system is hydraulically ideal when every heating surface is provided with the precisely required water quantity. Energy losses caused by hydraulic deficits can be avoided effectively.

As a final result, TU Dresden was able to detect heating energy saving potentials between 17 % (multi-family house, old building ) and 24 % (administration building, new building), depending on the type and the age of the building. The differences resulted – according to Prof. Richter – from the different thermal characteristics of the buildings and their use as well as the specific possibilities to reduce the feed temperature. On average, approximately 20 % of heating energy can be saved with the decentralised pump system.

Higher thermal comfort
In addition, a quick heating-up function ensures an improved thermal comfort. As the heat generator’s feed temperature can be directly influenced, the decentralised pump system reaches the desired room temperature faster than the usual system which is controlled by atmospheric conditions. This is achieved by a short-term increase of the feed temperature – if required also beyond the heating curve. A quick heating-up room by room is also possible.

Prof. Richter resumed that for a large number of problems in heating systems – like the hydraulic balance, the reduction of room temperature fluctuations or the improvement of the intermittent operation – individual solutions existed already. “However, with the decentralised pump system the first and only overall solution is available which completely eliminates the hydraulic and thermal weak points of existing heating systems”, the scientist said.

From optimised hydraulics to energy savings
Prof. Dr.-Ing. Rainer Hirschberg, professor for technical development and resource-friendly construction at the faculty of architecture of the University of Applied Sciences Aachen and member of the executive committee of VDI until December 2008, described the new decentralised pump system as the “revolutionary idea for optimum system hydraulics, maximum heating comfort and reduced consumption of heating energy”.

He underlined the most important hydraulic differences between the standard system where the heating water is provided from one central place, and the new decentralised pump system where the heating water is only provided when it is actually needed. Whereas in  conventional system constructions the mass flow is controlled by means of throttle valves – involving energy losses –, the decentralised pump system works exclusively via the speed control according to actual demands of the individual radiator. There is also a decisive difference when it comes to the pump’s running times. Whereas the central pump must run for every single room, regardless of the heat required in these rooms, the miniature pumps of the decentralised pump system only run as long  as the respective radiator requires heat.

Manual hydraulic balancing omitted
Prof. Hirschberg also mentioned the manual hydraulic balancing to be a central key to more heating comfort and energy efficiency – because this will not be necessary anymore: „Conventional heating systems are often not hydraulically balanced. Hydraulic deficits in heating installations, however, means, especially in multi-storey buildings, an uneven heat distribution which plays a role in 70 % of the legal disputes between lessor and lessee”, the expert says. In practice, it is often tried to compensate this unbalance by installing overdimensioned pumps or by increasing the feed temperature. However, both methods involve excess energy consumption.

In the case of the decentralised pump system, the hydraulic balancing is already done with the planning of the heating installation. Just like in the conventional system, a heat requirement calculation determines the mass flow for the heating surfaces and the pressure losses. On this basis the appropriate and sufficient speed is determined so that the system always runs at a hydraulically ideal stage. These specifications are then automatically realised by the system. Thus every heating surface is provided precisely and energy-efficiently with the required water quantity for optimum comfort.

Prof. Hirschberg evaluated the energy saving potentials of the decentralised pump system compared to conventional heating systems. He presented an extensive energetic evaluation, which he drew up according to EN 15316 (heating installations in buildings – processes for the calculation of energy demand and efficiency of the installations – the applied process corresponds to DIN 18599) for the detection of heating energy and power requirements. In this step he compared one standard heating system with a high-efficiency pump and the decentralised pump system, both for different types of buildings. The result was that with the decentralised pump system a saving of thermal energy of approximately 18 % can be expected. However, the calculation process according to EN 15316 does not consider the feed temperature which is set according to actual demands of the decentralised pump system, through which further savings can be achieved. To sum it up, Professor Hirschberg was able to confirm by means of a conventional energetic evaluation that there is indeed the energy saving potential of approximately 20 % which TU Dresden stated to be possible in field tests and simulations.

Another focus of Prof. Hirschberg’s presentation was the configuration of the decentralised pump system in the VDI house, inaugurated in 2008, in which he took part. During the implementation phase, the radiators on the 5th floor were the first to be equipped with “Geniax” pumps. Furthermore the decentralised system is integrated into building automation via the server. Also the radiators in the other buildings have been set up for “Geniax”. It is planned to equip the entire VDI house with the decentralised pump system.

Start into a new era
Finally, Wilo’s chairman of the board, Dr. Thomas Schweisfurth, pointed out the importance of the decentralised pump system “Geniax” not only for his company, but for the entire heating sector. “’Geniax’ stands for the start into a new era of heating systems”, says Dr. Schweisfurth. Wilo proved the high significance of the project in the last few years by investing more than a quarter of its total expenditure for research and development into the decentralised pump system. “Also our sales partners benefit sustainably from our consistent innovation policy.”

Dr. Schweisfurth compared the introduction of “Geniax” with the market launch of the first high-efficiency pump for heating and air-conditioning in 2001. Back then, high costs for research and development and a long time to market process were also accepted in order to make an important step towards energy efficiency through pump technology. Today, products like “Wilo-Stratos” and the smaller variant introduced in 2005, the “Wilo-Stratos ECO”, are well established in the market. The use of high-efficiency pumps is recommended by many approved institutions like the Germany’s Consumers’ Association “Stiftung Warentest” or other consumers’ associations to be an energetically worthwile measure to reduce power consumption.

The Wilo chairman of the executive board announced that the market introduction of “Geniax” will be in the focus of this year’s ISH trade fair in Frankfurt. In parallel, Wilo starts with the support of planners and specialised craftsmen with trainings and product support.

Wilo at ISH in Frankfurt 2009: hall 9.1, stand B 46 to D 46