All water used for the needs of employees in the offices is heated by the sun. The solar systems perfectly perform a task of providing us with hot water. Geothermal heat pumps located on the ground floor are the heart of our microclimate system. There are 4 of them. The energy of earth comes from 53 wells located on the site. Those wells are 70 m deep on average.
The thermal power of each pump is 40 kW, while its power consumption is about 8 kWh. If we were using electric heating, we would need about 100-140 kWh of electrical power. But thanks to heat pumps, we spend only 25-30 kWh on this purpose. We can confirm from our own experience – heat pumps are more than four times more efficient than electric heating.
The heating and air conditioning system in our office is implemented with heat pumps that heat or chill water, with fan coil units located in each room. Such combination allows the system to work at its best all year long: indeed, in the cold season, we heat air, while in the hot season, we can chill it. A technical solution of heating and cooling in each room plays a significant role in the comfort of the office workers, as the fan coil units allow to control microclimate for each room individually rather than centrally for the whole office.
Not at the first try: learning from our mistakes
Initially, a two-pipe system of heating and air conditioning was implemented in the administrative office. This solution had a flaw that the system could work only in one mode at a time: either heating or air conditioning. However, during the off-season, a need emerged to use both those regimes simultaneously. Since the building is constructed using modern energy-saving technologies with sufficiently high efficiency, some rooms needed cooling even at the sub-zero temperatures outdoors. After consultations with design and installation companies, we decided to upgrade the system from two-pipe to four-pipe. The latter would allow supplying both hot and cold water at the same time to each fan coil unit, and the users could always choose what they needed at the moment: cooling or heating. From the very beginning and until start-up works, the workgroup responsible for the upgrade faced various challenges: from the technical solution of some units to the start-up works as such.
Indeed, the modifications had to be implemented in the existing system located in the working office premises. The first obstacle faced by the team was the integration of the existing fan coil units designed for the two-pipe system into the four-pipe system. The ready-made solutions available on the market at that moment could not meet our technical specifications; that is why we had to design our own solution that would meet the specifications. The next stage was the installation works. In order not impede the work of the office workers, a significant portion of installation works had to be done during weekends and off work hours.