DC Heat pump

The EcoShopping aimed at providing concepts and development of a small medium renewable energy (RE) powered DC Heat Pump (HP) with variable speed compressor, which is later integrated to the existing HVAC system of the demonstration building, aiming at exploiting free energy with high energy efficiency, the HP offers cooling and heating as base supply and reduces the usages of the conventional energy system and thus reduces the fossil energy.
In the general concept, it is shown that HP is becoming a more popular technology for HVAC system and DCHP has great potential in energy efficiency enhancement. Benefits and main advantages of having DCHPs are also concluded, which consist of enabling partial load, and the possibility to directly connect to RE sources as photovoltaic or wind power, benefit the distributed generation system and micro-grid and a potential consumer contribute the generation-consumption balance.

This DCHP is part of the HP system in the demo building, depending on the situation and needs, the HP can be used in different places and buildings.
DC powered HPs present several advantages for their integration in RES systems, as this is the case of study at the IKVA shopping centre in Sopron.
From one hand, DC compressors work usually with better efficiency than AC compressors, and better compressor efficiency means better HP efficiency.
From another hand, since the RE sources such as photovoltaic and wind power produce DC power normally, the use of DCHPs will be able to directly connect to these renewable technologies without using any DC/AC converter and loosing energy in the conversion, thus increase the overall energy efficiency.
In details, DCHPs can bring more benefits compared to the conventional ACHP beside the energy efficiency improvements:
• Lower noise: thanks to the balance in spinning of the motor, the HP will have less vibration and thus reduce the noise.
• Increase the temperature control accuracy: the control heating/cooling production is realized by changing the speed of the compressor, the temperature control can even be realized with real ±1ºC, thus increase the comfort control.
• Fast in changing temperature: when the target temperature is far from the current actual temperature, the HP can work in a full load mode and deliver the nominal power, hence the target temperature can be quickly changed depending on the power of the HP.
• Higher flexibility in adapting start-up voltage. Unlike conventional AC compressor, the DC compressor could adapt a wider range of input voltage.
• Adaptability in ambient temperature: the HP can even work in low temperature areas.

More detail is available in our online courses