In this sports hall reference project, Hoval collaborated with its Belgian partner EDERGEN to create a sustainable, climate-friendly heating system, including water heating, in a state-of-the-art sports facility in Emines – a district of the municipality La Bruyère. A sophisticated hybrid system takes care of heat generation in the sports and multi-purpose hall, which also boasts an attractive, compact architectural design in the form of three nested cubes.
The total heated area of the Hall Sportif de la Bruyère amounts to 2136 m2, with the heat diffused via water-based air heaters and radiators. In addition to heating the sports hall, the heating system also has to heat water for a total of 22 showers. The design temperature of the heat distribution system is 60°C. A minimum outdoor temperature of -9°C was taken as a basis for the system, resulting in a calculated heat load of 99 kW for the sports and multi-purpose hall.

The output required to heat the sports hall changes with seasonal temperature fluctuations – the heat of summer and the cold that winter brings. The advantages of this efficient heating and hot water system are clear: if cold winter temperatures mean that the Belaria fit air/water heat pump is no longer able to cover the required heat output, the UltraGas 2 gas condensing boiler steps in to help ensure the necessary room temperature.

With its two built-in compressors featuring inverter technology, the climate-friendly Belaria fit (53) heat pump is capable of optimising its output to meet the prevailing heat demand. Unwanted on/off cycling is effectively prevented, stopping the negative impact this has on compressor lifetime when any heat pump is operated over an extended period.

Using the Belaria fit in a hybrid system enables 83% of the annual energy consumption for the building complex to be covered by the energy-efficient Belaria fit with a heat load share of just 50% for the heat pump. This means that carbon emissions can be reduced with this hybrid system.

The Belaria fit heat pump heats the EnerVal buffer storage tank to the required setpoint temperature. Either the heating circuits or the CombiVal ER domestic water storage tank can now be supplied directly depending on the priority circuit.

The Belaria fit heat pump heats the EnerVal buffer storage tank but the required setpoint temperature is not achieved. The UltraGas 2 gas condensing boiler therefore steps in and heats the heating water to the required setpoint temperature of 60°C. Either the heating circuits or the CombiVal ER domestic water storage tank can now be supplied directly depending on the priority circuit.

The efficiency of any air/water heat pump will decrease at low outdoor temperatures. The bivalence point is the precise point at which it becomes advantageous – from the perspective of the overall heating system efficiency – to use a second heat generator in order to provide the total heat required. 
The bivalence range (area shown in blue in the diagram below) is the range in which the second heat generator must cover the required heat load of the building. The UltraGas 2, the second heat generator, is activated at the bivalence point – which always relates to an outdoor temperature.
A key advantage of a hybrid solution is that a lower heat pump output can be selected as a result. This reduces not only the investment costs but also the operating costs in comparison with a monovalent heat pump system. At temperatures above the bivalence point, the sports hall is supplied with renewable energy all year round. As the outdoor temperature increases, so too does the efficiency of the heat pump. Using this hybrid solution with a lower heat pump output also means that unwanted on/off cycling is prevented during the height of summer.
A further advantage is that having two heat generators increases the operational reliability of the system. If one heat generator fails, heat can still be supplied to the sports hall.

With the sustainable and ecologically efficient combination of the Belaria fit air/water heat pump and the UltraGas 2 gas condensing boiler taking care of its heating and hot water, the sports hall in La Bruyère benefits from a powerful, climate-friendly heating system with maximum supply security.