The modernization of the school in Suchy Dąb

The modernization project involved converting the oil boiler room in the Primary School building into a gas boiler room supported by a cascade of air heat pumps.

To accommodate the heat pumps, the connection capacity was increased by 85 kW. The maximum power consumption of one heat pump is 39.5 kW. The remaining capacity is necessary to power the equipment in the boiler room.

A cascade of two heat pumps was installed, supported by a 300 kW gas boiler. The boiler provides peak heat demand during the winter months when the efficiency of the heat pumps is at its lowest, and their operation is inefficient. A pellet boiler was kept as a backup heat source in case of failure or gas supply interruption.

The gas boiler was located in the existing oil boiler room. The central heating distributor, buffer tanks, and fittings were installed in the space previously occupied by the oil tanks. Due to the gas boiler’s capacity, it was necessary to install a magnetic shut-off valve, a gas detection system, and a boiler water loss sensor.

The heat pumps operate in an indirect system via a heat exchanger. This allows the heat pump system to be filled with glycol, which provides protection against freezing and prevents damage to the equipment and heat exchangers in the heat pump. The buffer for the heat pump system consists of two tanks, each with a capacity of 1,000 liters.

Domestic hot water is prepared in a storage water heater with a coil. The coil of the water heater is powered by the gas boiler.

The boiler room equipment and fittings were protected against contamination from the existing heating system. For this purpose, a magnetic dirt separator was installed. All separate systems—glycol, heating, and domestic hot water—were also protected against pressure increases.