Konvekta, a German manufacturer of CO2 (R744) heat pump systems for commercial electric buses (e-buses), has announced a refrigerant charge balancing” system that it says improves the efficiency of heating and cooling and the range for e-buses.

Last year Konvekta reported that more than 60% of German e-buses in 2021 used its heat pump system.

The optimal refrigerant charge in an e-bus’s heat pump system can vary according to heat demand, outdoor temperature or operating mode, impacting system performance. To address this, Konvekta’s refrigerant charge balancing module enables the refrigerant charge level to be “precisely controlled, ensuring that the optimal quantity of refrigerant is always available to the system,” the company said.

In Konvekta’s CO2 heat pump, which consists of one circuit for heating and one for cooling, the energy-intensive heating operation increases the demand for refrigerant. At that time, the refrigerant charge balancing module instructs the inactive circuit – the cooling circuit – to provide the active circuit with the missing quantity of refrigerant. “The performance of the system is thus significantly optimized so that efficiency is increased and energy consumption is reduced,” said Konvekta. “This saves costs and conserves environmental resources.”

Another advantage of the refrigerant charge balancing is that the system “always operates in an optimal range” due to the targeted control of the filling level, reducing the load on the components in the overall system, explained Konvekta, adding, “This extends the life span of the system and reduces maintenance requirements.”

Last year, Konvekta announced a new software module – “Additional Energy Storage (AES) Mode” – that eliminates the need for an electric heater in electric buses, reducing both costs and energy consumption.

“The performance of the system is thus significantly optimized so that efficiency is increased and energy consumption is reduced.”

Konvekta