Rooftop units
Configurable complete solution for air conditioning and renewal
Product seriesWarehouses, industrial buildings, shopping centers, supermarkets, cinemas, restaurants - rooftop units have a wide range of uses. As varied as these spaces may be, they all have one thing in common: they need to be heated in winter and cooled in summer. This results in specific requirements for temperature and air quality for the various applications.
Thanks to the wide range of possible configurations and equipment options, rooftop units are ideally suited to meet your project-specific requirements. Whether heating or cooling, pure recirculation mode or outside air supply, humidification or dehumidification, with or without heat recovery - our rooftop units always offer the right solution.
What are rooftop units and how do they work?
Definition and functionDefinition and function
Rooftop units are compact air conditioning units that are usually installed on the roof and deliver the conditioned air directly or via a duct system to the room below. They work on the same principle as room air conditioners, but do not require indoor units and have additional functions.
As in air conditioning systems, roof air conditioners also contain air-to-air heat pumps, which extract heat from the outside air when heating and transfer it to the room to be heated. When cooling, the process is reversed. However, the entire refrigeration circuit is located in the outdoor unit. Instead of refrigerant, only the heated or cooled air is brought into the interior with fans.
In addition to the heat pump, all other components are also installed in the compact outdoor unit. If there is a need for an outside air supply, the basic model (recirculation mode) is supplemented by a mixed air chamber in which the exhaust air can be mixed with outside air. Under suitable conditions, it is possible to use only the outside air temperature to cool the room. In this particularly economical case, the term "free cooling" is used. Other components installed include air filters and, if selected, heat recovery, humidifiers or dehumidifiers, and various types of reheating systems.
The main difference between ventilation systems and rooftop air conditioning units lies in their primary purpose. While ventilation systems are mainly designed to ensure good indoor air quality, rooftop units focus on maintaining the desired target temperatures and thermal comfort. The components required for this are integrated in all variants, while an outside air supply is optional.
Overall, they are the ideal solution for achieving air renewal and thermal comfort in a single device.
Why rooftop units?
benefitsbenefits
Flexibility and small footprint
In addition to the flexibility in selecting the right solution for your project, there are other arguments in favor of rooftop air conditioning systems. Their compact design makes them easy to handle and install. The small footprint is particularly advantageous for buildings with complex structures. The units are pre-filled with refrigerant at the factory, so no additional refrigerant lines need to be installed. Once the unit has been installed on the roof, all that remains is to connect the air ducts on site. The connection direction of the ducts (front, bottom, right, left) can be freely selected.
High ease of maintenance
Regular maintenance can be carried out quickly, as there are no hard-to-reach air filters in the indoor units that need to be replaced or cleaned. Instead, all maintenance work is carried out on the outdoor units, which are usually easily accessible on the roof. If filters become clogged, the unit detects this and issues a message to ensure smooth operation. The units are also designed so that the outer panels are easily removable and the interior is easily accessible for maintenance, service, and cleaning.
Reduced operating costs thanks to optimal device design
Thanks to their standardized configurations, rooftop units are also a cost-effective alternative to complex central ventilation systems. Efficient heat pumps and fans are already integrated, as is a control system that optimally coordinates the interaction of the components. This ensures that the room is always at the right temperature while consuming as little energy as possible. Rooftop units can reduce the operating costs of buildings and improve their carbon footprint.
An alternative to hall heating
WSM3 rooftop seriesWSM3 rooftop series
Our WSM3 rooftop series is ideal for cooling medium to large spaces and volumes (warehouses, manufacturing facilities, shopping centers, or exhibition centers) in summer and heating them in winter, while also providing outside air when needed. Instead of using fossil fuels to heat and cool these halls, which is harmful to the climate, the WSM3 series offers an efficient, electricity-based solution.
About the WSM3 series (75 - 111 kW) About the WSM3 series (122 - 314 kW)
Heat recovery in our rooftop units
heat recoverySave energy – reduce operating costs
If outside air is supplied to a room and the exhaust air is released into the environment, heat recovery can be worthwhile. By recovering unused heat from the exhaust air, energy efficiency can be significantly increased. Instead of completely heating up the freezing cold outside air with the heat pump in winter, it is preheated. This means that the integrated heat pump requires less power to raise the temperature to the desired level.
With our rooftop units, you can choose between these types of heat recovery:
Free thermodynamic heat recovery (HR-F version)
In free thermodynamic heat recovery, the device has an outlet for exhaust air, through which the exhaust air is directed directly to the external heat exchanger of the refrigeration circuit. To overcome pressure losses and ensure a constant air flow rate, this process is supported by additional EC fans at the outlet. This allows the heat pump to operate under better conditions and does not lose performance even at very low or high temperatures.
With refrigerant booster (HR-B version)
The refrigerant booster works in a similar way to free thermodynamic heat recovery. The difference is that, in this case, an additional heat exchanger is integrated directly into the exhaust air outlet. Part of the refrigerant is routed through this heat exchanger. In cooling mode, this results in additional subcooling (higher performance), and in heating mode, the refrigerant has a higher pressure and the compressor has to work less (higher efficiency).
With cross-flow heat exchanger (HR-P version)
The cross-flow heat exchanger enables energy exchange between outside air and exhaust air. The warm exhaust air and the colder outside air flow past each other in separate ducts in a cross-flow pattern. In the process, the exhaust air transfers its thermal energy to the incoming outside air. This conserves resources and increases the efficiency of the building and the rooftop air conditioning unit. The complete separation of the two air flows means that a large proportion of the heat is recovered and exhaledCO₂, pollutants, and pathogens are replaced by fresh air.
With rotary heat exchanger (HR-E version)
Rotary heat exchangers are wheel-shaped. The wheels have many small channels through which the exhaust air flows on one side and the outside air on the other. The wheel rotates and the exhaust air transfers its heat to the storage mass and from there to the incoming outside air. This type of heat recovery is the most efficient. However, it should be noted that the two air flows are not completely separated. This means that latent heat, i.e. moisture, can also be transferred. This reduces the risk of rooms becoming too dry, especially in winter, and moisture can be removed from the building in summer.
- Free thermodynamic heat recovery
- With refrigerant booster
- With cross-flow heat exchanger
- With rotary heat exchanger
HR-F: Airflow diagram (top outlet)
HR-F: Airflow diagram (bottom outlet)