QUNDIS water meters at a glance

In almost all federal states, there is now an obligation to bill for cold water in residential buildings. This is a good thing, because the installation of cold water meters leads to significant savings in water consumption and to a consumption-based allocation of costs among tenants. You can find out whether there is an obligation in your federal state in the relevant state building regulations.

QUNDIS supplies two types of domestic water meter: mechanical meters with a rolling counter and electronic meters with a digital display.

With mechanical water meters, the consumption level in m³ counts up continuously. Therefore, the reading must be carried out exactly on the due date (e.g. 31 December). If there is a radio add-on module on the meter, the metering pulses are transmitted directly to the metering service by radio on the due date. For subsequent checking, it is advisable to read the meter on the due date using the rolling counter.

Electronic water meters normally show the cumulative volume, a segment test, the meter reading date and the annual consumption value on the display in regular alternation.

Calibration law stipulates that hot and cold water meters must be calibrated every six years. The owner of the house or apartment is responsible for ensuring that the calibration requirement is met.

The year of calibration can be seen on the water meter via the adhesive label. For newer metering devices that are placed on the market in accordance with the provisions of the European Metering Instruments Directive (MID), a CE M mark replaces the national calibration mark. This is printed on the casing. The letter ‘M’ stands for metrology, while the number printed to the right of it within the black box (e.g. ‘21’) stands for the year of the conformity assessment. The above calibration validity periods also apply without restriction to these metering devices.

QUNDIS hot and cold water meters with a flow rate of Q3 = 2.5 m³/h (MID) are ideally suited for the consumption-based billing of water consumption in a single residential unit. If the property to be equipped has up to 30 residential units, the water consumption of the house connection can also be measured using our equipment – usually with the electronic Q water 5.5 surface water meter (Q3 = 4 m³/h, installation length 130 mm).

When making the selection, all the important factors of the local water supply should always be taken into account, including, for example, its stability. The decisive factors for the correct selection are almost always the maximum predicted flow rate in m³/h and the pressure loss.

Discrepancies between the meter reading of the house connection and the cumulative consumption values of the water meters in the apartments are part of everyday life. This is due, for example, to leaking sections of piping, unrecorded communal taps, very low flow rates or varying accuracy classes or installation positions of the water meters. The legally tolerated measurement limits for water meters are ± 5 per cent.

However, this does not disadvantage residents in any way, as these differences occur in all apartments. Apartment water meters are used only for consumption-based cost allocation. The consumption values of the main water meter are used to bill the actual building consumption on the basis of cost units.