The air-conditioning expert partner Eberspaecher Suetrak presented integral solutions for sustainable and efficient thermal management for electric and hybrid buses at Busworld. As a world debut, the company showed its pioneering AC 230 – a roof-top air-conditioning system with innovative heat pump, which works on the air flow reversal functional principle. Other highlights are the new, flexibly usable control unit for bus air-conditioning systems as well as the current All-Electric version of the AC 136 G4 air-conditioning system for electric buses and the AC 403 E G2 for the driver’s seat and passenger compartment air-conditioning in city buses.
The efficient, ecological and sustainable new products presented at Busworld fulfil the requirements with respect to lightweight construction, optimum energy balance and environmental compatibility of the closed refrigerant circuits, and also offer the possibility of using new refrigerants in the future.
Innovative air flow reversal function
The biggest advantage of the functional principle for which a patent has been applied, is its simplicity: the new AC 230, which is celebrating its world premiere at Busworld 2015, works according to a classical refrigerant circuit with the special feature of air flow reversal. This significantly simplifies the refrigerant circuit of a heat pump, which until now was complex. Individual parts and connections could be reduced.
“Thanks to the numerous damper positions, we can implement all operating states within one system without extra effort”, stresses Director of Research & Development Jens Nies: “The spectrum ranges from cooling through ventilating and heating – in each case with or without fresh or exhaust air – through to thawing of the external heat exchanger.” In addition, the system enables a seamless transition from the cooling to heating mode. Standstill times, which are required for reverse circulation in conventional systems, are eliminated.
The AC 230 is designed as a modular platform solution based on common refrigerants, but is also designed for use of CO2 in the future. Furthermore, Eberspaecher Suetrak is offering numerous options for customer-specific adaptation. This includes using additional plate heat exchangers for tempering the vehicle battery as well as the installation of further heat exchangers for efficient use of residual sources of heat. In this way, it can cover almost every heating or cooling requirement.
The AC 230 is especially customized to the central roof-top air ducts in electric, hybrid and trolley buses and impresses through greater efficiency and climate comfort. For passengers, the even flow of air is extremely pleasant. The energy balance is very favorable given the lower thermal loss at the side windows and the optimized ventilation. Moreover, the new AC 230 can be adapted optionally for buses with roof-top air ducts at the sides.
New control unit
The new control unit from the Klimalogic family fulfils the basic requirements as well as the considerable demands placed on high-end applications. Eberspaecher Suetrak demonstrated it for the first time at Busworld 2015. The modular structure ensures a high level of flexibility. Through the consistent separation of operating device and control components, highly individual customer requests can be accommodated. The control unit can be combined with every CAN-compatible operating device. Furthermore, depending on the requirement and complexity, the main CAN module can be expanded by an adequate number to CAN sub-stations. All operating states of the air-conditioning and heating components can be set and controlled using the new system. The system can also be networked through the vehicle interface with GPS data or telematic services and thereby enable diagnostic or predictive functions within a professional fleet management system.
The display is intuitively operable. The modern design of the interface provides maximum user convenience: to do so, the developers at Eberspaecher Suetrak have taken account of current design trends, but also referred back to the self-explanatory MMI sign language of automobile passenger compartments. The dimensions are identical to the predecessor devices.
Low weight, electric, efficient: air-conditioning systems for driver and passengers
Through the consistent expansion of the proven AC 136 G4 family to the AE (All Electric) version, Eberspaecher Suetrak is offering additional performance-optimized lightweight solutions for electric roof-top air-conditioning systems. The advantages at a glance: 50 kilograms lighter than the predecessor version, a large number of similar components, identical dimensions and interfaces within the complete product family as well as the option of choosing between the two performance classes of 20 and 28 Kilowatt.
Independent of the vehicle drive, Eberspaecher Suetrak has further expanded its product range to electric solutions. For the air-conditioning of the drivers’ cabins and partial air-conditioning of passenger compartments in accordance with 236/1 VDV (German Association of Transport Companies), the latest product generation of roof-top air-conditioning systems is recommendable: the AC 403 E as well as its split version K 403 E with electrically-driven compressors on a 24V basis, are available in the new design and characterized by a constant cooling power. They are optionally equipped with a heating as well as a fresh air function, which is simple and easy to mount and thereby also suitable for retrofitting.