Project - Energy efficient ventilation heat pumps for houses

Per Henrik Pedersen

Your Contact

Contact me

Indtast venligst et validt navn
Or your phone number
Thank you for your message
Vi beklager

På grund af en teknisk fejl kan din henvendelse desværre ikke modtages i øjeblikket. Du er velkommen til at skrive en mail til Send e-mail eller ringe til +45 72 20 25 13.

Project - Energy efficient ventilation heat pumps for houses

Energy efficient ventilation heat pumps for houses.

Project start January 2019. Expected to end July 2022.


Nilan is the biggest manufacturer of heat pumps in Denmark and produces four different types of heat pumps. Nilan is specialized in building heat pumps, which are built into ventilation systems, and heat pumps for low energy houses. The company controls about 80 % of the Danish market for ventilation heat pumps and about 14 % of the EU market.

For many years, the Danish industry has worked towards a switch-over from HFC and HCFC to natural refrigerants. This switch-over is prevalent in the refrigeration industry, but the heat pump industry has still not made it that far. Despite several initiatives in different countries, the attempts to market competitive heat pumps with natural rrefrigerants or other low-GWP refrigerants have not yet been sucessful. The switch-over to natural refrigerants has been exclusively to larger, industrial heat pumps.

Nilan uses HFC refrigerants in its heat pumps, but several circumstances make it favourable to shift to a low-GWP refrigerant instead. One of the reasons is the jump in prices for high-GWP refrigerants due to the EU's reduction and quota system in the "F-gas-regulation". In less than a year, the cost price on R407C and R134a has fourfolded.

Therefore, a core part of this project is to develop new technology that uses low-GWP refrigerants in heat pumps, which will increase the energy efficiency and ensure the safety of Nilan's products. The new technology must be competitive on the global market. The results from the project will help to maintain Nilan’s position as the biggest Danish manufacturer of heat pumps and also to maintain and expand the production in Denmark.


The purpose of the project is dual:

  • to change Nilan's ventilation heat pumps for houses to low-GWP refrigerants, including natural refrigerants
  • to increase the energy efficiency in Nilan's ventilation heat pumps for houses

The goal is to increase the efficiency of heat pumps' exhaust air with 10 %, which will be examined by heating tap water. The efficiency will be tested in an accredited laboratory at Danish Technological Institute (DTI) after EN 16147:2017.


The content of the total project is divided into 6 work packages:

  1. Project management: This WP contains the formal management of the project which includes the direct relations to EUDP, chairing project meetings, write the periodical reports to EUDP and develop periodic accounts etc.
  2. State of the art: The purpose of this WP is to study the literature and contact key players within the research communities and the industry for refrigeration and heat pump technology.
  3. Development of simulation programme in order to analyze different concepts for heat exchange to the inlet air in ventilation heat pumps: The inputs for this are the results from WP2.
  4. Development of new concepts for exhaust air heat pumps: Both propane, other hydrocarbons and low-GWP HFCs (“HFOs”) are flammable, and this needs special attention and precautions when the design for new products with new refrigerants is developed.
  5. Building prototypes for test and analysis: A first generation prototype will be built and tested at Nilan and at DTI in Aarhus. The results will be analyzed and reported, and recommendations will be made for the design of a second generation prototype, which will be build and tested at Nilan and at DTI.
  6. Final report including analysis of energy efficiency, economy and impact on climate change.



Danish Technological Institute

Vonsild Consult

DTU Mechanical Engineering (DTU MEK)


The project is supported by Det Energiteknologiske Udviklings- og Demonstrationsprogram (EUDP).