On the way to Gas-free 2030 with a heat pump
In the series gas-free 2030, the 5 steps in making the switch to gas-free cost-effectively have now been discussed. One of the most important options for going gas-free is the use of heat pumps. In recent years, more and more houses and buildings have been built with heat pumps. The experiences most often highlighted in the press have been negative. But there are also positive experiences with heat pumps that have been functioning for several seasons. What experiences are there in de design stage and in the use stage? Read more about this in part 5 in the series gas-free 2030.
Practical example for shops
Most shops are renovated or redesigned every 5 to 10 years, and this is a natural moment to take a closer look at the heating and/or cooling of the shop. Traditionally, shops often have a boiler with a radiator in the back room area, ceiling units for heating in the shop area, and a heated air curtain above the door. In addition, shops also require cooling in summer in the form of a split unit. Modern split units can cool and heat, which basically makes them air-to-air heat pumps.
Air-to-air heat pump
An air-to-air heat pump draws heat from the outside air and gives it off inside, also via the air. An air-to-air heat pump with multiple indoor units (air heaters in the ceiling) can be used as an air curtain. This means a boiler and radiators are no longer required and the shop can be made gas-free. The gas connection can be turned off and there are no longer fixed and variable costs for gas. In addition, by choosing a heat pump, the energy label can be upgraded.
Analysis of all-electric shops and shops with gas and electric shows that the costs for all-electric are approximately 500 euros per year lower. Practical experience in shops has shown that sequential control of the air curtain and other units must be set up correctly and that staff must also receive clear operating instructions.
Practical example for offices to be renovated
In 2016, the Z-building in Leeuwarden required extensive renovation to have it serve as an office. This was the moment for owner Evert-Jan Hofstra to choose a more radical renovation and to work towards an energy-efficient and gas-free building. In hindsight, the choice worked out very well for the owner and the tenants, but from their experience points of attention can be identified when transforming a building to gas-free.
Going gas-free with a view to the future
The old Water Company building, built in 1964, had energy label F and was heated using a conventional boiler. The walls and floors had not been insulated after construction and some windows were single glazed. The building is listed, which limited the options for addressing the building envelope and made them costly. Nevertheless, the choice was made to pursue gas-free and label A. According to Hofstra, this was the natural moment to press ahead and make the building as energy efficient as possible. Reports regarding gas-free as a future requirement also played a role in this decision.
The greatest challenges on the road to gas-free
As part of the design of the building, the choice was made to install a VRF system fed by heat pumps. Because the building was fully insulated – triple glazing was even installed – it became possible to provide heating at lower temperatures. This made the gas boiler redundant. The greatest challenge in the process was not the structural modifications or systems, but the installation of the more powerful electricity connection by the grid operator. Because this installation was behind schedule, an increase in connection could not be realised until four days before moving.
Ultimately, the expectations were realised and the system is performing well, even during the periods of extreme cold and heat in the past year. The system’s large capacity allowed for sufficient cooling and heating. In addition, the energy bill decreased considerably because there is no longer a gas connection.
Tenant Nuon is also happy with the climate system. Facility Host Ben Stegeman gets few complaints from users, and, when there are complaints, offering clear instructions with regard to the use of the system usually suffices. During the day, users can adjust the temperature a few degrees, and, at night, the settings are reset so that the basic settings are retained and the temperatures within the building do not diverge. One major advantage of this system is that the temperature is more constant than when using a conventional system with radiators. In addition, there are fewer air flows that may bother the users.
Conclusion: Sustainability efforts are worth it
When natural moments occur (for example, a relocation or renovation), it is worth it to carry out a thorough analysis of the sustainability options of the building. It will emerge that sustainability efforts and cost-savings can go hand in hand. The operational costs go down and cost-recovery times are well within the service life. Clear operating instructions for the users are important for the correct functioning of the systems and also to allow the users to contribute to the sustainability efforts.
Text: Youp van der Zande and Marnix Balke