Room with a view, Oostende
In the centre of Ostend, on Belgium’s coast, a new building project is being completed. The Waves complex will be made up of four buildings, ‘Sea’, ‘Salt’, ‘Sand’ and ‘Sky’. In a special room on top of ‘Sea’, there is a hybrid air-gas heat source, which will provide heating and sanitary hot water for the 118 flats and commercial spaces below.
Lessons learned
- “By constantly injecting a minimum amount of hot water to each floor of the building, the system makes it possible to draw hot water out of the taps almost instantly.” (D. Vanlandeghem, Vermote)
- “The heat output of the heat source was calculated according to the needs of the fully occupied building. In this way, substantial savings can be made on the total installed power for the production of hot water.” (L. Depaepe, Vaillant)
Key facts
| Building | Heat Pump and Source | ||
| Location | Ostend, Belgium | Number of HP | 8 |
| Construction | ongoing as of 11.2023 | Installed power | 8 x 8,5 kW |
| Heat distribution | – | Operation mode | bivalent |
| Heated area | – m² | Heat source | air |
| No. of apartments | 118 + commercial spaces | Model | Vaillant aroTHERM plus VWL 125/6 A |
| level of insulation | very good | ||
| Heating sytem | Domestic Hot Water | ||
| Heat demand | – kWh / (m²a) | DHW demand | – kWh / (m²a) |
| Type of system | central | Type of system | central |
| Heating temperature | 75 °C | Max. temperature | 75 °C |
| Circulation system | yes | ||
| Other information | |||
| additional heating units | gas town’s heating network | COP | 5.4 |
| Capacity | 600kW with gas condensing boiler and 96 kW wirh air/water monobloc heat pumps | Refrigerant | R290 |
| Hot water storage | 1,500l + 2,000l | Costs | ~130.000€ |
Description of the technical concept
The room atop the 14-story building contains five Vaillant ecoTEC gas condensation boilers, an exhaust duct and two allSTOR plus reservoirs, of 1,500 and 2,000 litres. The large reservoir is connected to eight air-water aroTHERM plus heat pumps which sit on the roof, outside the building, while the smaller one is connected to the town’s heating network. This will allow it to use the waste heat from Ostend’s incinerator and industries.
Buffer tanks play an essential role in ensuring that heat pumps and gas boilers work together. The air-to-water heat pumps work at a lower temperature. The return water from the combined loop first passes through the heat pumps’ buffer tank. It then flows into the small buffer tank connected to the Vaillant ecoTEC plus wall-mounted gas condensing boilers, where it is heated further if necessary. Vaillant has calculated the size of the buffer tanks to ensure sufficiently long operating times for the heat pumps and boilers.
In addition, Vaillant has a fully modular control system that can be expanded as required. All this ensures that the different energy sources (gas boilers, heat pumps) work together smoothly.
BE001 Room with a view
- https://www.ehpa.org/news-and-resources/publications/heat-pumps-and-high-rise-homes-case-studies-from-across-europe/ ↩︎