The heat pump is 100% run by sustainable electricity from oekostrom, produces no on-site CO2, and supports both heating and cooling. The pump creates heat energy from the outside air that is fed into the central heating pipes to reduce pressure on the boiler. This technology also cools the floors of the rooftop apartments in the summer, which decreases the load on the air conditioning system and guarantees a comfortable indoor climate — indeed, much more comfortable than conventional air conditioning. The byproduct of this cooling mode is thermal energy, which is in turn used for the hot water heater and reduces the energy consumption of the gas boiler.