• A steady and quasi-steady state analysis on the CO2 hybrid ground-coupled heat pumping system 

      Jin, Zhequan; Eikevik, Trygve Magne; Nekså, Petter; Hafner, Armin (Journal article; Peer reviewed, 2017)
      This article contains the steady and quasi-steady state analysis on a CO2 hybrid ground-coupled heat pumping system for warm climates. The hybrid system uses a combination of ambient air and ground boreholes as a heat sink ...
    • Annual energy performance of R744 and R410A heat pumping systems 

      Jin, Zhequan; Eikevik, Trygve Magne; Nekså, Petter; Hafner, Armin; Wang, Ruzhu (Journal article; Peer reviewed, 2017)
      This work compares the annual energy performance of heat pumping systems using R744 and R410A as refrigerant. Focus is the annual energy efficiency of R744 hybrid ground-coupled heat pumping system. The hybrid system uses ...