Preface. Renovation of the heating system and installation of a computer controlled energy efficient installation

Transcription

1 Renovation of the heating system and installation of a computer controlled energy efficient installation Apartamentos Goetten S.L., Playa de Aro Preface The company Goetten Apartamentos S.L. in Playa d Aro (Gerona) has as many as 103 guest apartments within his holiday resort, located in five different buildings. At the turning point of the years 2004/2005 the energy supplies of three centrally supplied buildings were completely renovated under the aspect of energy saving and efficiency of investment. 80 apartments, a indoor pool and a restaurant get their energy supply from the new system. It replaces an old oil-fired central heating with hot water supply consisting of two boilers and a conventionally controlled distributor and has hot water cylinders of l in volume and consists of two condensing boilers, one solar panel field, two fully automatic heat distributors with digital automation station as well as two hot water cylinders of 500 l each. The system was not only planned in order to save a considerable amount of primary energy need, but also in order to make a 24/24-surveillance possible by means of digital automation station, to ensure the heat supply of a sensitive business scope and guarantee short times for intervention in case of failure. The installation is part of a huge renovation process of the apartment complex, subdivided into several phases and with the goal of realising an extensive energy concept by combining anlagentechnik and architectural adaption within the frame set by the capacity of the building.

2 Presentation For forty years now Goetten Apartamentos has been of significant importance on the tourism market of Playa de Aro. With 103 apartments of various size located in different buildings the company is providing space for up to 300 tourists in completely furnished flats with central heating. To complement this offer the complex includes an indoor pool as well as a restaurant. Just like all other areas of everyday life, tourism is prone to a ongoing change and while package holidays are shifting more and more to non EUmember countries, the classic holiday destinations such as Playa d Aro are trying to find a new identity. This may be very easy for a region like this, if one takes a closer look at its history, its people, its food and its unspoilt countryside. There is a form of soft tourism developing in this part of Spain attracting tourists that are on the one hand ready to open their eyes to the beauty of the country but who on the other hand are more critical when it comes to accommodation especially with regards to ecological aspects - and Goetten Apartamentos is responding to this. Former renovation measures have already been considering this aspect. Especially convenience factors such as soundproof apartments, thermal insulation and floor heating are much appreciated by the guests. When finally the renewal of the energy supply got started, it was clear that these plans had to be implemented under ecological as well as economic aspects. However saving energy is not a priority when it comes to such apartment complexes, as investments are rather focused on the outward appearance. But if a large scale renovation like this is ahead, one cannot help but model oneself on state-of-the-art technology as a sign of readiness to adopt an innovative energy policy that makes it easier for the client to see responsibility reflected in the investor s action. It is for sure that the combination of Spain s attractiveness and the ecologically responsible action of people working in its tourist industry leads to a prosperous development of tourism in this region. The task to replace the existing unprofitable oil-fired heating, that had until then supplied the three houses Großes Barbara, Kleines Barbara and Carolina by a combined Gas-Solar-Heating system with a state-of-the-art control system featuring energy efficiency and user-friendliness, was a result of these facts.

3 Project Right from the beginning it has been decided that the existing oil boilers were to be substituted by gas condensing boilers in a first step and to want to install a thermal solar plant, which from a physical point of view is a more than practical thing in these regions. It was also clear that if a thermal solar plant was built, it necessarily had to support the heating system, as during an earlier renovation it was made sure that surface heating was used in order to reduce the temperature of the positives. The problems in connection with conventional solution of solar thermal accumulation, though, were wellknown, that is large supplies of warm water, little consumption during the summer months and in connection with all this a standstill of the complete system which would sooner or later lead to irrepairable damages. Another criterion - especially in a hotel-like complex was to realise short reaction times in case of a breakdown, which means not to wait until the client starts complaining, but to be informed beforehand in order to react adequately. any period of time, and in this case this is actually being done. During this process any data relevant for the system, such as temperatures of all circuit lines, streams of volume, outdoor temperatures and heat supply, are recorded. Something that is also very important, especially in wide spread circuit lines is the automatic refill of the circuit lines. Here, too, the volumes fed in are under surveillance, which makes it possible to find leaks at an early stage by means of a set treshold value. If components, e.g. putting devices, fail, there is still access to the system from whatever place outside by laptop with an GSM-modem and heat flow can still be diverted until the component has been exchanged in order to keep up the basic supply of the buildings. To make sure that in case of power failure there is no loss of programmes and data and that there is still access to the system from outside, the stations have an uninterruptable power supply (UPS). But also the management of surplus energy of the collectors during the summer months is dealt with correctly and adequately. As soon as the station realises that there is no more energy use/consumption, it increases the temperature of the positive of warm water or it switches to a narrow prevention cycle for legionellas in order to drain off energy via the circulation lines. The system that has been ultimately realised consists of the following items: two condensing boilers of 180 kw, one solar panel In order to collect data, the amount of energy consumed by the existing system was recorded in 2003 and served as a basis for the calculation of the new concept. Searching for new effective distribution systems, a newly developed distribution system created by Parabel GmbH was found, which allowed a significantly more efficient use of energy input on the basis of plate heat exchangers. Another advantage of the system is that it is delivered to the building site as a completely installed block, with all the changers, pumps, and putting devices necessary, that only needs to be connected to the proper circuit lines within the building. The control of the system, which is run by a Riedel digital automation station, equipped with a specially designed software, is convincing, because with a delay that can be set it transmits occurring faults directly to the project participants via an industrial modem, and in addition stores and transmits any system specific data, so that the efficiency of the system can be checked in terms of efficiency over field of 16 big surface panels and an absorber area of 128 m² and a maximum output of about 96 kw, three solar accumulation cylinders of l to assimilate surplus energy of the solar panel field, two hot water cylinders of 500 l each for the pre supplying hot water of the buildings, one SEC main distributor in the boiler room and a HAST distributor supplying the houses Kleines Barbara and Carolina, as well as two integrated Riedel digital automation stations, which are communicating with each other and provide the connection to the outside.

4 To summarise let us highlight the main feature of the installation again: Any shift in energies leads to volume of the solar cylinders, too, is drastically reduced in comparison to conventional systems, without provoking standstills within the system, a fact that also makes lack of space less of a problem especially in already existing buildings. The most important fact, though, is that in combination with the computer controlled distributor and the condensing boiler, which it also controls, the overall output of the boiler could be reduced from to 360 kw. By now the system is supplying an average 180 persons as well as the bar and the indoor swimming pool with warm water in the summer, in winter the system will supply 80 apartments with heating and an average 80 persons with warm water, including bar and indoor swimming pool. loss of energy and therefore carrying energy directly to the consumer the most efficient form of energy management. This new distributor makes good use of that very fact by carrying the energy flow whether solar, gas, oil or biomass - directly to plate heat exchangers which are the connection to the building, be it to the heating, the water heater or to the cooling system. Thus the volume of hot water cylinders for example could be reduced from l to l in this project, a fact that already implies energy saving. By carrying the solar heat directly to the consumer the In 2003 the planning or the system had started, in the summer of 2005 after evaluation of the results it was finished. In November and December of 2004 the heating system was renovated and the new distributors were installed. As official approval was required the solar panel could not be installed until March The setting of parameters of the system was carried out in April 2005, so that we say the complete system has been in normal operation since May 2005.

5 Results In the analysis of the year 2003 an overall energy consumption of about kwh for the entire apartment complex was found out. Following these calculations the goal was to reduce this consumption to about kwh. 10 % were assumed to be realised by the use of new Picture 7: Comparison of total prime energy consumption about 38 % after all. This means a reduction of the necessary oil supply from about l or a CO2- equivalent of 85,5 t. After the system had been put into operation in may 2005, the first estimates on real savings could be made, with the results not adjusted to the average temperatures, degree-day numbers and the overnight stays per month so far. In the first four months of operation it was to established that depending on the number of apartments booked the amounts forecast are actually reached. Because of the results achieved it can even be assumed that by adjusting the parameter settings of the computers in the year to come savings in primary energy can be increased to 40 % and more. The remote surveillance, too, shows an important success. Failures of the boilers and of power supply for example could be detected at an early stage and could therefore be responded to swiftly without the users suffering any shortages. For the time being the remote surveillance is recording the condition the system is in, as well as the actual consumption. As was expected there were no standstills even as the solar components were operating at maximum value in this summer. Picture 8: Solar Cover to Energy consumption in 2003 condensation boilers and another 15 % by the use of the SEC. For the solar panel field an gain of energy of kwh was calculated, so that the primary energy need was likely to reduce to kwh, which would result in an energy saving rate of Because of is wide-spread structure of three buildings and the more complicated distributor technique necessary resulting from this, the installation is not really the ideal project to show the economicalness of the system. But even under these circumstances, which are anything but perfect it is perceived as very positive. Considering the possible subsidies and reckoming with an internationally accepted increase of energy prices by 7,5% per year to be expected, the break-even point of the system is going to be reched in the seventh year of its

6 Picture 9: Economicalness of the system operation. Assuming an operation period of about 20 years the system will yield a profit of about ,00. For compact buildings or compact building complexes these figures are even likely to improve.

7 Participants: Design, Supervision and Monitoring: arqsol+ Producer SEC and HAST: Parabel GmbH Producer Digital Stations: Riedel Automatisierungs GmbH Installation: Instal.laciones Perfall Picture 10: View to the solar plant from the court Project data: Project: Renovation of the heating system and installation of a computer controlled energy efficient installation Use: warm water consumption and heating of an apartment building with swimming hall Client: Goetten Apartamentos S.L. Place: Playa de Aro (Gerona) Boilers: 2 condensing gas boilers with each 180 kw Distribution: SEC und HAST with two automatic stations Riedel Number of collectors: 16 Aperture surface of the collectors : 128,6 m² Volume of the solar cylinders: l. Solar input: kwh Energy savings condensing gas boilers: kwh Energy savings automatic stations: kwh Solar gains: kwh Total energy savings: kwh Reduction of CO2-Emission: 85,5 t Total cost: ,00 Partial cost of solar plant and distributors: ,00