Installation schemes of heat meters

Below are the most common schemes for installing heat meters in heating and water supply systems of residential and public buildings, as well as in industrial facilities:

1 Scheme - with a single-channel heat meter — equipped with a calculator, one flow meter, and two temperature sensors. The meter flow sensor is installed in the supply pipe, and the temperature sensors are installed in the supply and return pipes.

The advantage of this scheme is the requirement for a meter with the smallest set of equipment and, as a result, the lowest price. The disadvantage is the inability to control leaks and unauthorized withdrawal of the heat carrier.

This is the most common scheme for installing a heat meter, which is used for commercial metering in heating systems of residential and administrative buildings.

Scheme for installing a heat meter for heating

2 Scheme - with a single-channel heat meter and a control water meter — equipped with a calculator, two flow meters, and two temperature sensors. The flow meters and temperature sensors are installed on the supply and return pipelines.

This scheme is free from the disadvantages inherent in the first scheme and allows for taking into account the volume of heat carrier leakage, but does not take into account the amount of heat expended on heating the leaked water.

The amount of heat is determined based on the data from one flow meter and two temperature sensors, and the data on the flow obtained from the second flow meter is compared with the indicators of the first meter to determine the heat carrier leakage.

These schemes are used in objects:

with a high probability of water withdrawal from heating systems;
with underground piping after the heat meter installation point;
with a combined metering of heat for heating and hot water supply using a single heat meter;
with water heating installations for the hot water supply system connected in a closed circuit (through heat exchangers).

Heat meter installation diagram in the boiler room

3 Scheme - with a two-channel heat meter — equipped with a calculator, two flow meters, and three temperature sensors. Flow meters are installed on the supply and return pipelines, and temperature sensors on the supply, return, and cold water supply pipelines.

This scheme is used to measure heat consumption from the heat source to the consumer.

The released heat is determined as the difference between the heat calculated using the first channel and the heat calculated using the second channel:

The first channel - uses data on consumption from the meter installed on the supply pipeline and the temperature difference between the sensor installed in the supply pipeline and the cold water supply pipeline.
The second channel - uses data on consumption from the meter installed on the return pipeline and the temperature difference between the sensor installed in the return pipeline and the cold water supply pipeline.

This heat meter installation scheme determines the released heat, taking into account the heat used to heat water for the system. A water meter needs to be installed on the supply pipe for this scheme. The water meter is not connected to the heat meter.

Heat meter installation diagram for hot water

4 Scheme - with two single-channel heat meters — is used to account for the thermal energy consumed to heat hot water in the subscriber's hot water supply system, connected to the heating network in a closed circuit.

The flow meter of the first heat meter is installed on the cold water pipeline going to the heat exchanger, and the temperature sensors are installed in the cold water pipeline and the hot water pipeline at the outlet of the heat exchanger.

The flow meter of the second heat meter is installed in the circulation pipeline of the hot water supply system before entering the heat exchanger, and the temperature sensors are installed in the hot water pipeline and the circulation pipeline of the hot water supply system.

According to this accounting scheme, the first heat meter determines the amount of heat consumed to heat water, taking into account the heat lost through the circulation pipelines and actually used for heating the premises through which this pipeline passes, while the second heat meter only determines the amount of heat lost through the circulation pipeline.

The amount of heat lost through the circulation pipeline should be distributed among all apartment owners through whose apartments this pipeline passes in proportion to the number of circulation pipes in their apartments. The amount of heat measured as the difference between the readings of the first and second heat meters should be distributed in proportion to the readings of the water meters installed in the consumers' premises.

* Explanation of conditional graphic symbols in diagrams