Monitoring the operation of the heating system can be carried out in several ways. For this, various types of equipment are installed: mixing units, automation for timely recharge, security groups. But regardless of the type, each of them necessarily has pressure and temperature sensors in the heating system. The functional characteristics and types of these devices should be known to each owner of an autonomous or centralized network.
Purpose of measuring instruments
What does heating of any type have in common? This is a periodic change in the temperature of the coolant and, as a consequence, its pressure. To control the indicators of the degree of expansion of water, pressure sensors in the heating system are needed. With their help, you can observe the current data and in case of deviation from the norm, take appropriate measures.
Temperature sensors for heating have a wider scope. In addition to a visual display of the degree of heating of the coolant in individual parts of the system, they can record air temperature data in the room or on the street. Together, two types of devices should form an effective tool for tracking, and in some cases, automatic stabilization of the parameters of the heating system.
How to choose the optimal water pressure sensor in the heating system or thermometer? The main criteria are system parameters. Based on this, the following requirements are imposed on measuring devices:
- Measuring range. Not only accuracy, but also the relevance of the information depends on this. So, a temperature sensor in a heating system with an incorrectly selected upper limit will show biased data or fail;
- Connection method. If you need to know the level of heating medium with high accuracy - you should choose immersion models of thermometers. The classic pressure sensor for heating can only be mounted directly in the heating main of the house, boiler or radiators;
- Measuring method. The method of taking readings affects the inertia of the device - the delay in displaying the actual data. It also determines the appearance and visualization of parameters - arrow or digital.
In an open system, the pressure parameter is not important, since it is almost always equal to atmospheric. However, heating temperature sensors are installed in any circuit - gravity, with forced circulation or when connected to a central network.
For ease of monitoring the readings of the system, you can purchase a device that combines a pressure and temperature sensor. Despite the relatively high cost, it is much more convenient to use it to take current data on the state of heating.
Temperature sensors for heating
Even at the stage of heating design, it is necessary to choose thermal sensors for heating - types and their characteristics. First of all, they differ in the place of installation - directly in the system or for remote control of other temperature indicators. The latter are used in conjunction with room thermostats.
Submersible sensors
Designed to take readings about heating water in pipes. Their installation is carried out in certain areas of the system. Some models of solid fuel boilers do not have temperature sensors for heating. Therefore, it is absolutely necessary to eliminate this.
The choice of model depends on the method of taking readings.
- Bimetallic. The design of these temperature sensors for the heating system consists of a dial indicator and two metal plates made of different metals. When heated, one of them begins to deform, creating pressure on the arrow of the indicator. This technique is characterized by high accuracy of readings, but has one drawback - a relatively high inertness. The average price is from 600 to 900 rubles;
- Alcohol. Compared with the above view, the inertia of the display of the value of water heating is practically absent. The principle of operation is largely similar to a conventional thermometer - an alcohol-containing composition is placed in a sealed flask, which expands when heated. Marks on the bulb of temperature sensors for heating this type indicate the current value of water heating. The design is simple but inconvenient to observe the readings. Cost - from 1900 rubles.
To install these heat sensors for heating, you first need to read the instructions from the manufacturer. It indicates the mounting dimensions for connection to the nozzle, boundary temperature values and recommendations for use.
When choosing immersion thermometers, the length of the sleeve must be considered. It can be from 120 to 160 mm.
Remote sensors
They are located outside the heating system, but can be connected to the boiler or programmer to adjust the parameters. Recently, wireless models that transmit information using auxiliary electronics have become popular. This makes it possible to install them almost anywhere - in a separate room or on the street.
Defining characteristics of sensors for monitoring the temperature of heating:
- Signal range;
- The presence of autonomous batteries - batteries;
- Measurement error.
For simple circuits, wired temperature sensors for the heating system can be installed. The signal is transmitted from the thermometer to the control device (or boiler) via wires. In this case, the probability of error or incorrect data is much less than that of wireless models.
For the best communication of remote thermometers with other equipment, it is best to choose models of the same brand (manufacturer).
Pressure sensors for heating
Pressure sensors in the heating system must be provided for in the circuit with forced circulation. In fact, they reflect the degree of expansion of the coolant as a result of heating. Therefore, experts advise the installation of pressure sensors in the heating system along with thermometers.
The main indicator for pressure gauges are the pressure limits. In an autonomous network of a private house or apartment, the normal indicator is from 1.5 to 2.5 MPa. Accordingly, the maximum permissible value for the water pressure sensor in the heating system must not be less than these data. In practice, installation of models with an upper limit of 6 MPa is recommended. An important factor is the mechanism by which the pressure gauge displays readings.
Spring sensors
A special tube acts as a sensitive element in the pressure sensor for heating. It can have a round or oval cross section. Under the influence of the coolant pressure, its displacement occurs, as a result of which the arrow moves on the dial.
The advantage of this type of device is reliability and affordable cost. The operating time depends on the frequency of exposure to the sensing element, as well as exceeding the maximum allowable pressure. In addition, the following requirements are imposed on spring pressure sensors in the heating system:
- Deviations from the error value are not allowed. If, in the absence of pressure, the arrow is not at zero, the device cannot be exported;
- Accuracy class for household pressure gauges must be at least 2.5;
- During mechanical impact on the device, the sensitive element of the pressure sensor may be displaced. Then changes in the heating system will not be recorded, or the error will exceed the permissible norms. To avoid this, check before starting the heating season.
Installation of spring-loaded water pressure sensors in the heating system is simple. To do this, install it on the threaded connection of the inlet pipe. Do not use the FUM tape - only reeling designed for critical values of pressure and temperature.
An alternative to spring pressure gauges can be membrane models of sensors. They give more accurate readings, but are prone to frequent breakdowns due to the sensing element.
Contact Sensors
They are an advanced model of a spring pressure sensor. They are used for heating with automatic adjustment of indicators. In addition to the main arrow in the manometer, there are 2 additional ones. They are set to the maximum and minimum pressure values. When one of them reaches the main arrow, the electrical contact closes and a corresponding signal is supplied to the control element. Similar devices are used in large autonomous systems. For autonomous heating, their installation is impractical.
It must be remembered that each pressure and temperature sensor in the heating system must display the actual values. Therefore, you should first make an accurate calculation of the entire system, and then, based on the obtained indicators, select the optimal model of the device.
In the video you can see the use of the temperature sensor in the design of the solar collector - one of the types of heating:
