Photo: Colourbox

Heat pumps to use more climate-friendly coolant

Materials Construction and mechanics
Researchers will investigate how to replace the current coolant used in heating systems for single-family houses with new coolants with reduced climate footprint.

DTU Mechanical Engineering and company Nilan are collaborating on a new project that focuses on the use of a climate-friendly coolant for Nilan’s ventilation heat pump. The heat pump is designed for single-family houses that need to be heated in the colder months of the year and cooled down during the summer. Until now, the coolants used with the ventilation heat pump have a very big climate impact that is 1,430 times worse than CO2. In the future, the company wants to use propane, known from the gas grill, which has a very low climate impact.

“First and foremost, the focus has been on finding a substitute coolant that is climate friendly. It was also important to have several manufacturers making the product, so that Nilan wouldn’t have to buy into a monopolistic market. As well as finding a replacement for the coolant, we will also attempt to increase the efficiency of the existing heat pump,” says Wiebke Brix Markussen, Associate Professor at DTU Mechanical Engineering.

Boosting efficiency
Wiebke Brix Markussen is responsible for preparing mathematical models of the ventilation heat pump. The models will be used to determine how to construct the heat pump in order to use propane as a coolant and so that the heat pump uses as little propane as possible. Propane is flammable, and it is therefore important to limit the amount used, and there are also a number of safety regulations that the new heat pumps must meet.

“The models will form the basis for designing more efficient heat pumps in the future. They will help us determine how to design the various elements of the heat pump such as the evaporator, the condenser, etc. so they live up to these requirements,” says Lis Jacobsen, R&D Engineer at Nilan.

When the models are ready, tests will be carried out at the Danish Technological Institute, which also participates in the project. Subsequently, Nilan expects to be able to implement the changes in the production of its ventilation pump.

The project is funded by EUDP—the Energy Technology Development and Demonstration Programme.