Gas Condensing Heating Systems: Innovating Efficiency with Allengra

During the last ten years, more and more Ultrasonic Flow Sensors have conquered the market in gas-heating installations. One of the advantages is the use of no mechanical counters; they won’t wear out and will in no way suffer from calibration-performance degradation until the end of their lives. These heat meters are practically free of pressure loss and therefore will also reduce the energy losses of the circulation pump and they are now also very economically priced.

Together with a manufacturer of burners, heating systems, heat pumps and water heaters, Allengra created a new multifunction sensor that helps to continuously determine the efficiency of the systems and digitally balance and measure it according to the newly created German federal funding program for efficient buildings (BEG) and transform them into geared heat generators.

Allengra's Development Creates Market Advantages

The middle-sized appliance manufacturer of gas heating systems held its own research and development centre with hi-tech technicians, designers and engineers. Their work together with the Allengra team resulted in a high-performance device, embedding several sensors in an inexpensive, almost invisible miniaturised device that doesn’t require maintenance and can be plugged and set into their systems only once. The manufacturer got a lead on its competitors because of Allengra’s development work.

Efficient Multifunction Sensor 

These continuously operating condensing boilers waste less gas than usual compared boilers available in the field. Their efficiency is 15% higher than that of other systems which keep a constant water phase thanks to the controlled flow rate that the Volume Flow Sensor enables to keep the condensation boiler controls in the permanent condensing mode.

The tiny Allengra multifunction sensor – which was commercially produced from mid-2015 – is a utility heat metre in one, and is currently undergoing pilot production. The complete multifunction sensor with integrated Ultrasonic Flow Measurement, two temperature sensors for flow and return as well as pressure measurement, has been manufactured by Allengra in its own factory in Oradea, Romania, for five years and supplied to its customers in series. 

Fast and Reliable Data Transmission

The complete lack of mechanical counters or any moving parts in the Ultrasonic Flow Sensor can also be used to substantially reduce the dispersion-induced pressure losses and thus improve the overall efficiency of a heat generator. The self-diagnosis logic integrated in the sensor also reliably flags any air bubbles that may be sucked into the heating circuit, reducing the efficiency of the system and lowering the noise level. Any new data measured by the sensor are made available to the heater control in a straightforward manner via a bus interface. Should the need arise, the sensor will also transmit relevant values to the service technician so that they can detect and remove any breakdown components.

Easy Integration with Just One Connection

The probe sensor is mechanically flanged at one end and inserted into the burner/heat exchanger block and sealed with an O-ring, held in place by two screws. There are no mechanical-hydraulic connections and the sensor itself has no hydraulics seals required.

There are two temperature sensors, one in the flow and another in the return, reading the difference (ΔT) between the hot and the cold with good precision. ΔT with the controlled volume flow (measured by the ultrasonic sensor integrated on the system) allow instantaneous and cumulative thermal power (the amount of heat) to be calculated. The sensor is simply connected to the heater’s controller with a cable.

Heat Generators Eligible for Subsidies 

Since 1 July 2021, owners of residential and non-residential buildings are also supported by the German Reconstruction Loan Corporation (KfW) in digitalisation measures for the energy balance of a building during construction or renovation. In general, the federal grant for efficient buildings (BEG) will promote measures in these areas particularly favourably in the future. ‘In the building sector in particular, huge potential for CO2 savings would be opened up, especially if the opportunities of digitisation and renewable energies were to be used,’ said Dr. Ingrid Hengster, a Board member of KfW responsible for the domestic fund business.