Air conditioning
Engine Cooling
Air conditioning
HVAC module
Optimal thermal comfort is very important in passenger cars and commercial vehicles. Comfort is not the only focus, however, since safety aspects are part and parcel of comfort. A relaxed driver can concentrate better on what is happening in traffic. Behr covers the entire market with its HVAC modules, from compact cars to the upper class, as well as heavy-duty commercial vehicles. Behr can realize up to four climate zones and various climate styles in the vehicle cabin (e.g. with the climate control system PHYSIO-CONTROL®). For passengers in the second or third row, individual climate comfort is assured by using a rear HVAC module. Mini fans, which can be installed in air ducts, for example, allow passengers in the rear to individually adjust air volume and distribution.
Climatic heat exchanger
The compressed refrigerant is expanded in the evaporator; it evaporates, which cools it greatly, and thus takes the heat out of the cabin air. In 2002, Behr became the first to bring a flat-tube evaporator into serial production. In comparison with the plate/fin evaporators previously used, flat-tube evaporators take up less room for the same performance. BehrOxal®, an environmentally friendly coating technology developed by Behr, ensures optimum water drainage, preventing odors from microorganism deposits. The BehrOxal® surface also provides for better corrosion protection without the use of chrome(VI) and thus complies with the guidelines of the EU Directive on End-of-Life Vehicles.
For heating the vehicle cabin, the heater core has to make use of the heat emitted by the engine, i.e. the temperature of the refrigerant. The heater cores from Behr are perfectly adapted to the respective engines and their heat output. They are highly stable, have a low packaging depth and low refrigerant pressure drops.
Comfort Vent
Vehicles in the middle and upper segments of the market are expected to provide the qualities of comfort, safety, and functionality, and to meet individual customer requirements in every respect. A serious shortcoming in air conditioning systems has long been the fact that the flow of air from the A/C unit was focused too directly on the vehicle occupants. The resulting draft meant that air conditioning systems were often not used to the best effect.
Unlike conventional vents, the "comfort vent" has not one, but two air ducts: a helical diffuse duct and a centered spot duct. The geometry of the diffuse duct generates a swirl effect, spreading the flow over a wide area and creating a "cloud" of air within the vehicle cabin. Instead of irritating the occupants, this is experienced as a diffuse, draft-free airflow. In contrast, the spot channel in the middle provides a highly focused and precisely directed flow of air.
The vehicle occupants can mix and match these two types of flow according to the conditions and their personal comfort preferences, creating a range of ventilation options:
- Draft-free ventilation: airflow through the diffuse duct, spread over a wide area in the cabin.
- Direct ventilation: in this case, the air passes through the spot duct, so the flow can be directed at a specific point.
- Maximum airflow: a combination of diffuse and focused air, providing the maximum possible airflow.
So for the first time, the customer is able to adjust not only the direction and rate of airflow, but also the type of flow pattern required. The comfort vent gives customers full control of their air conditioning experience.
Blower
Thermal and acoustic comfort is decisive in a vehicle, yet the blower is one of the main sources of noise. Behr’s current blower design concepts meet three separate requirements: they save valuable packaging space in spite of boosted airflow performance, are highly efficient, and quiet-running, which provides excellent acoustic comfort from the climate control system. To stay ahead of the competition in this area, Behr is researching aerodynamic details using the latest simulation procedures and precise measurement methods.
Air quality
Air quality in the vehicle interior will become increasingly important in the future: filters, pollutant sensors, coating of the evaporator, elimination of germs in the HVAC and individual “air refinements,” e.g. by a subtle scent, are increasingly common in vehicles.
PTC auxiliary heater
Today’s fuel-efficient engines do not always deliver enough waste heat to enable rapid heating of the cabin, particularly for cold starts and in certain driving conditions. To keep windows clear and obtain optimum thermal comfort in these situations, additional heating is provided with electric PTC auxiliary heaters, running on energy from the vehicle electronics. By integrating the PTC into the main heater, even extreme space restrictions can be accommodated without compromising comfort. PTC heater boosters are being used increasingly outside of the HVAC module, e.g. in seats, headrests or in footwells.
Parking air conditioning for trucks
In 2001, Behr was the first supplier to start serial production of a parking air conditioning system for trucks integrated in the HVAC module. This unit keeps the cabin pleasantly cool for up to eight hours after the engine has been switched off. While the vehicle is on the road, a cooling battery absorbs surplus cold from the refrigerant circuit, which it then progressively releases. Under normal driving conditions, it takes just three hours to reload the cooling battery.
The Thermo-Structure Module® (TSM®)
Behr’s TSM® is a compact, ready-to-install module comprising an HVAC module, hybrid crossbeam, air ducting and connecting elements. The integration of these components creates more packaging space in the cockpit. Also, by optimizing the entire air ducting system from air intake to the dashboard vents, a high level of acoustic comfort can be achieved. Due to its high moment of inertia, the hybrid beam fulfills the critical strength requirements specified for the crossbeam area.
Engine cooling
Cooling modules
Cooling modules comprise a number of engine cooling components, as well as the condenser which forms part of the A/C circuit. For maximum efficiency, all components are optimally matched. The modules are put together according to the vehicle design concept, reducing development, production and logistics expenses.
Radiator
The most important part of the cooling module is the radiator, which consists of the radiator core and plastic tanks with all of the required connections and fastening elements. The radiator core is usually made of aluminum, while the coolant tanks are made of fiber glass-reinforced polyamide.
In 1998, Behr was the first supplier to start serial production of the all-aluminum radiator. This radiator is lighter than the version with plastic tanks, has a much smaller packaging depth, and is fully recyclable.
Charge air cooler
There are many benefits from using charge air/air or charge air/coolant coolers to cool the combustion air of supercharged engines: higher power at all engine speeds, lower fuel consumption and emissions, less thermal stress on the engine, etc. There are two forms of charge air cooling: direct cooling with the surrounding air, or indirect cooling via the coolant to the surrounding air.
The trend is towards indirect charge air cooling which is preferable in terms of packaging size and dynamic response. With indirect charge air cooling, the charge air cooler is placed very close to the engine rather than in the front end. The additional low-temperature radiator needed for indirect charge air cooling is an integral part of the cooling module. Due to the smaller depth of the low-temperature radiator compared to a conventional charge air cooler, more space is available in the front end, which can then be used for pedestrian protection, for example. The location close to the engine allows shorter charge air lines, cutting the pressure loss by about 50%. The higher density of the cooled charge air and lower pressure loss means there is more air available to the engine for combustion. The result: improved engine response.
Stricter emission regulations will lead to increased demand for indirect charge air cooling design concepts for trucks. That means charge air coolers will have to withstand high pressures and temperatures, particularly for heavy trucks. With our strength-optimized charge air coolers, we will be able to meet this requirement, and development will continue to focus on strength improvements.
Condenser and KOMO® condenser module
The condenser (part of the A/C circuit) is incorporated into the cooling module. Behr produces brazed flat-tube condensers, delivering high power in spite of their small package size. This ensures rapid cooling of the vehicle cabin, thanks to optimum matching of heat transfer and pressure drop on the coolant side and air side.
The KOMO® module developed by Behr is a brazed unit comprising a flat-tube condenser and a receiver/expansion tank with integrated drier. The benefits of the module include stable control of the refrigeration circuit over a long period, lower fuel consumption and savings on logistics and assembly costs. The second generation of the condenser module, KOMO® 2, is lighter than its predecessor, but with the same level of power. It requires less space in the cooling module and less coolant.
Exhaust gas heat exchangers
The new emission standards for diesel-powered cars and trucks can no longer be met with adjustments to the engines alone. An ideal way to comply with the new limits is cooled exhaust gas recirculation. This involves removing a portion of the main exhaust flow between the engine outlet and the turbine, cooling it in a special heat exchanger, and mixing it back into the inlet suction air after the charge air cooler. This lowers the combustion temperature in the engine, thus reducing the formation of nitrogen oxides (NOx).
Behr was a pioneer in the development of EGR technology right from the start, bringing cooled exhaust gas recirculation systems for cars into serial production in 1999. A feature of Behr’s laser-welded exhaust gas heat exchangers is their very high corrosion resistance.
In 2005, Behr launched another innovation in the marketplace, with the switchable exhaust gas heat exchanger featuring a bypass section integrated into the cooler’s housing. To keep pollutant emissions constantly at a low level, the bypass disables the recirculated exhaust gas cooling function in certain driving situations, e.g. during the cold start phase.
Oil coolers
In highly stressed engines the engine oil has to be cooled. This allows longer periods between oil changes and increases engine life. The oil cooling function is performed by oil/air heat exchangers or coolant-cooled oil coolers. Vehicles with automatic transmissions and highly stressed manual transmissions require transmission oil coolers. There are two types: air-cooled and coolant-cooled. The latter can be incorporated in the coolant tank or engine block, or fitted externally on the engine, transmission, cooling module, or oil filter housing, as required.
Visco® fans
Effective heat discharge from truck and high-powered auto engines requires not only high-performance radiators, but also fans and fan drives to supply the cooling air as efficiently as possible.
Behr’s electronically controlled Visco® fans enhance driving comfort and cut fuel consumption, thanks to lower idling speeds and rapid engagement and disengagement. Even in vehicles with a very high air demand, these fans can operate at idling speed without any additional electric-powered fans. Optimum adjustment of cooling output to demand is provided by the Visco® fan drive, specifically designed for this type of fan. The fan drive detects all relevant temperature values for cooling and air conditioning purposes, and sets the exact required fan speed.
The new fan generation from Behr guarantees high efficiency with a minimum sound pressure level, and also ensures optimum ventilation of the Visco® fan drive, even when it is under a high level of thermal stress.
In addition to Visco® fans and fan drives, Behr also develops electric fans. These fans are used on less powerful car engines. Aerodynamic matching of engine cooling module and fan guarantees efficient engine cooling at optimum cost.
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