Block of flats in the HUN street
Topic of the practice
Renovation of a ten-storey panel building in Budapest by utilizing geothermal energy via heat pumps
Good Practice Information
This practice concerns a ten-storey panel building in Budapest consisting of 256 flats and approximately 1 000 occupants. Before the investment the building had been connected to the local district heating system. First of all the building envelope had been insulated, new energy efficient windows, and controllable heating (by occupants) were installed. After this investment it was worth to think about a renewable investment. A groundwater heat pumps system was installed. This system utilizes four wells and six injection wells. The wells are 14 meter deep. Three heat pumps were installed, with 434 kW nominal capacities for heating, 245 kW for domestic hot water supply. In Hungary approximately 20% of the building stock in 2005 was built by this industrialized technology. According to the Hungarian statistics, roughly 2 million people (it’s about one fifth of the population) live in panel-houses in Hungary today. Because water is returned to the ground, the underground water supply is not depleted by the heat pump’s operation. In Hungary the block of flats haven’t got their own land, so the wells were drilled in public places.Therefore first of all it was needed to amend the local legislation such as: National City Planning and Building Requirements was amended in September 2008: so the renewable energy based projects parts in all construction zone can be installed. Budapest Urban Planning and Construction Framework have been adjusted, so the district's rules of city planning had changed: the wells can be placed in public places. In Hungary there was no precedent for such an investment before. Since most of the panel buildings were built in the 70's and 80's a mass failure of these systems is expected in the near future, which is going to cause a huge maintenance cost. Therefore panel renovation is a very important technical, economical and social task in Hungary.
Evidence of success
Indicators of success is that these energy efficiency measures the energy consumption of the building fell by over 70%. Additionally, the maximum supply temperature (for dimensioning) could be reduced to 62°C, a crucial measure regarding the efficient operation of the heat pump system. The 62°C supply temperature is obviously only necessary on the coldest days/hours of the year (when the outdoor temperature is -15°C) while in the rest of the season the heat pump uses a lower temperature. As a result the SPF (Seasonal Performance Factor) of the heat pump system in the 2010-2011 heating season was 3,2. Because water is returned to the ground, the underground water supply is not depleted by the heat pump’s operation so the geothermal energy exploitation is sustainable at long term.
Contact details to obtain further information on the practice
Hungarian Energy Center
Annex completed on: 03-24-2011