Hybrid heating

LK "Green-Climate-System (GCS)" Warm Air Heater

The Climate Protection Act has been in force since August 2021.
The German government has tightened climate protection targets and enshrined the goal of greenhouse gas neutrality by 2045. By 2030, emissions are already to be reduced by 65 percent compared with 1990.

Warm air heater RBW
LK Warm air heater RBW

LK Metallwaren offers three innovative solutions for the heating, ventilation and air conditioning of production, logistics and industrial halls. In order to achieve the climate protection targets in non-residential buildings, LK Metall has combined the RBW warm air heater and the REKU ventilation system with heat pump technology , as well as developing the new “Green Climate System”, which heats industrial halls without using gas as a fuel.

LK Warm air heater RBW with condensing boiler and heat pump technology
LK Warm air heater RBW with condensing boiler and heat pump technology

The hybrid heating system with gas and heat pump technology

The very efficient RBW warm air heater with condensing technology is extended with a heat pump package. The combination of gas as a fuel and heat pumps for heat exchange creates the hybrid heating system. Here, the heat pump takes over the heat generation mainly in the transitional period, i.e. in autumn and spring. In winter, on the other hand, the gas heating only switches on when the outside temperatures are too low to heat mainly with the heat pump.

With the air-to-air heat pump, the air is used as a heat source and thus an efficient and environmentally friendly operation is realized. The heaters in the warm air heater are piped to the heat pump and filled with R32 refrigerant. Additional fan units make independent operation of warm air heater and heat pumps possible. The air-to-air heat pumps used with the new R32 refrigerant significantly improve energy efficiency.

Comparison of the greenhouse potential of refrigerants
Graphic - Global Warming Potential (GWP) over 100 years
Graphic – Global Warming Potential (GWP) over 100 years
Source: IPCC Fourth Assessment Report. Global Warming Potential (GWP) over 100 years.

Compared: 2,088 (R410A) vs. 675 (R32). The advantages of hybrid heating are obvious. Hybrid heating reduces CO2 emissions by up to 30%, significantly reducing the need to burn fossil fuels. Another advantage of hybrid heating is the cooling function, which is provided by the heat pumps at all times. Especially in summer, this additionally improves the hall climate for the staff. LK hybrid heating is used in production and logistics halls. In the case of renovation, a gas hybrid heating system is subsidized by BAFA with up to 30 %.

The ventilation system REKU combined with heat pump technology

The LK ventilation systems REKU are often used in aerosol polluted production areas such as machining fabrications, welding shops and areas with high process waste heat. Filtrations up to class F7 ( New: ISO ePM 2.5) can be used in supply and exhaust air. The filter class can be adjusted depending on the application. With the integrated heat recovery system, up to 84% of the thermal energy contained in the exhaust air is transferred to the supply air via a plate heat exchanger using the counterflow principle. The outside air drawn in is thus heated and fed into the hall. With this technology, the supply air and exhaust air flow is separated from each other. Thus, heat from polluted air can also be used.

LK Ventilation system REKU with heat pump package
LK Ventilation system REKU with heat pump package

In summer, the process waste heat is discharged directly to the outside. The heat recovery is bypassed via a bypass to avoid unnecessary heating. A combination of the LK ventilation system REKU and an air-to-air heat pump does not require fossil fuels. As with the other system combinations with heat pumps from LK Metallwaren, the heating element can be operated for heating (direct condenser) or for cooling (direct evaporator). This added value helps to significantly improve the hall climate. Another advantage is that this combination is also subsidized by up to 35%.

The LK Warm Air Generator Green Climate System
The LK Warm Air Generator Green Climate System

The new LK “Green-Climate-System” (GCS) warm air heater

In order to conserve finite resources, the LK design engineers have developed the new CO2-neutral LK “Green-Climate-System (GCS)” Warm Air Heater developed for industrial halls from 4 m hall height. The “Green Climate System” does not use fossil fuels. The LK warm air heater is installed under the hall roof and draws in either hall air or outside air. Ventilation is provided by highly efficient radial impellers with EC motor technology. The passing air is heated via a heating coil connected to the heat pump. An upstream filter cleans the fresh and hall air supply from impurities. In case of very cold outdoor temperatures, it is possible to use an electric reheating coil. This covers peak loads without having to resort to a fossil fuel.

The system behaves similarly to the heating element in the heat pump in the domestic sector. Here, as in the systems already mentioned above, a heat pump with R32 coolant is used. The new system can thus heat and ventilate the hall during the winter months. In summer, ventilation and cooling is possible. With the new LK warm air heater “Green-Climate-System”, LK Metall relies 100% on the medium electricity and thus on regenerative energy sources. This makes the new plant system particularly eligible for subsidies.

Conclusion: LK Metall relies on energy efficiency and resource-saving systems with its entire plant technology in hall heating.