Comparison Computherm Q8 RF vs Computherm Q7

How to connect the controller to the controlled device.

— Wired. Connecting with wires is the most common option. It is due to its main advantages — simplicity, reliability and low cost. On the other hand, the wiring itself can be quite troublesome and time-consuming.

— Wireless. Wireless connection — usually by radio channel. To do this, the kit usually provides an external transceiver connected to the controlled device. The main advantage of wireless models is obvious — they are much easier to install because no need to run extra wires. On the other hand, such a technique is much more expensive than wired, and communication has a limited range, which is further reduced if there are obstacles (such as thick walls) in the signal path.

— DIN rail. The phrase "on a DIN rail" traditionally refers to the method of installing the device (see "Mounting"); the connection is usually carried out by wire. However, this option is taken out separately for the reason that DIN devices are standardly mounted in a distribution cabinet — unlike conventional wired thermostats, installed directly in the room. However, sometimes it is an advantage: the distribution cabinet can be locked with a key, restricting unauthorized access to the thermostat. Models with such a connection usually refer to professional equipment used in industrial...facilities, warehouses, etc.

The way to install the thermostat.

— Into mounting box. Installation in a standard junction box. Simply put, the regulator is mounted into the wall in the manner of a conventional switch or socket (most often even the mounting dimensions are the same, although there are exceptions). For installation, most likely, you will have to work with a rotary hammer, but the device will be securely fixed and at the same time will take up a minimum of space.

— On wall. These thermostats usually have a flat shape with a small thickness. Wall mounting is easier than embedding, but somewhat less reliable — in case of an unfortunate set of circumstances, the device can be hit and seriously damaged.

— To boiler. Installing a thermostat directly on the boiler. This option is traditional for devices used in solid fuel boilers (see "Type") that control combustion through a chain connected to an air damper, but it can also be found in other types of regulators — for example, designed for gas boilers. In the first case, this method of installation is due to the design features of the device (see "Chain length"). In the second case, installation on the boiler simplifies the design and installation, but at the same time makes the regulator not very convenient: on the one hand, the design does not have a remote unit, the connection of which is associated with certa...in troubles, on the other hand, you will have to approach each time to adjust the thermostat. to the boiler, which is not always convenient.

— DIN rail. Mounting on a special metal rail, which can also be used for electrical grounding. Such rails are commonly used in distribution boards. Most often, this installation method is used in industrial equipment, although it can also be useful for residential premises. Note that there are several types and sizes of DIN rails. Therefore, before buying a regulator with such an installation, it is highly desirable to clarify its compatibility with the seat.

— Portable. Devices that do not require permanent installation in the same place. By definition, they use a wireless connection (see above). Most often, portable thermostats are equipped with stands for installation on a table or other flat surfaces and are designed more for desktop use than for the role of a portable remote control. Nevertheless, the design makes it easy to move such a device from place to place, which can be useful, for example, in a large house, where you have to be in different places at different times and it would be inconvenient to run to the wall or built-in thermostat every time. Among the disadvantages of portable thermostats, one can mention the rather high cost and the need to use a battery (respectively, a limited operating time).

— In socket. Thermostats plugged into a regular household outlet. Usually, such devices have their own socket on the case and play the role of an adapter switch through which an electric heater (or other device) is connected to the network. With this connection, the thermostat controls the power coming from the outlet: turns it off when the required temperature is reached and turns it on when necessary. Such devices are extremely easy to install. Moreover, they are easily rearranged from outlet to outlet. On the other hand, the very location of the thermostat is not very convenient — sockets are often located in hard-to-reach and not the best places for a temperature sensor.

It is the range in which the air temperature can be set on the regulator. The choice for this indicator depends on the expected conditions in the room. So, in a residential building, the lower temperature limit at the level of 5–10 °C is quite sufficient; the upper limit is within 30–40 °C (regardless of whether we are talking about air or floor temperature). But in control devices designed for industrial use, this range will be much wider — from sub-zero temperatures to the upper limit of 100 – 125 °C.

Automatic temperature control hysteresis provided by the device.

Hysteresis can be described as the difference between the on and off temperatures of a system controlled by a thermostat. Usually, the permissible deviations of the actual temperature from the nominal one in one direction or another are half the hysteresis. So, at a set temperature of 22 °C and a hysteresis of 0.5 °C, the controller will turn on the heating as soon as the room temperature drops to 21.75 °C, and turn it off when it rises to 22.25 °C. Accordingly, the lower this indicator, the more carefully the temperature is maintained and the fewer fluctuations. On the other hand, small hysteresis values require accurate and expensive thermal sensors, increase fuel/energy consumption and wear of the entire system, and create an increased risk of false alarms (for example, from a cool draft on the thermal sensor). In addition, relatively small temperature fluctuations are practically imperceptible in terms of human comfort. Therefore, many modern thermostats have a hysteresis of 1 °C — this, usually, is quite enough for domestic use.

Also note that this parameter can be both fixed and adjustable. The first option is simpler and cheaper, and the second provides additional options for setting the thermostat to the specifics of the situation.

The maximum communication range between the receiver and transmitter of the wireless thermostat (see "Connection"), ensured when working outdoors — or in any other situation when the units are in direct line of sight from each other and there are no obstacles in the signal path. It is the maximum possible theoretical communication range provided by the device. The receiver and transmitter are rarely installed in line of sight, so this parameter is mainly for a rough estimation of communication capabilities and comparison with other models.

The largest number of individual cycles that the thermostat timer can set in one day.

The cycle is the period during which the thermostat operates on one set of settings. For example, if there are 2 cycles, you can provide turning off the heating while you are at work and turn it on shortly before returning home. However, most thermostats provide a noticeably larger number of cycles — up to 24.

Note that in weekly timers (see "Timer type") this parameter may differ depending on the day of the week. For example, weekdays usually have more extensive settings than weekends.

The shortest duration a programmable thermostat cycle can have (see "Programmable cycles per day").

The lower this parameter (with the same number of cycles per day) — the wider the possibilities for programming the operation of the thermostat, in particular, for its specific setting (for example, you can provide a short period of preliminary "intensive heating" after working at low temperatures). On the other hand, due to a certain inertia in the operation of heating systems, it makes no sense to make an interval shorter than 10 minutes — the thermostat simply does not have time to work out the specified settings in less time. And in the most "long" models, this parameter is about 30 minutes.

— Display. The presence of its own screen in the design of the regulator. Such a screen is usually a simple LCD matrix with segment digits. However, even on such a screen, very diverse data can be displayed (including temperature with an accuracy of fractions of a degree), and this function significantly expands the capabilities of the thermostat and makes it more convenient. Note that it makes sense to install the display primarily in electronic models (see "Device type"), for such thermostats it is almost mandatory (but in mechanical ones, on the contrary, it is almost never used).

— Protection of the pump from "souring". During non-working hours — for example, between heating seasons — deposits can form on the parts of the circulation pump of the heating system, which can make it difficult to rotate the impeller, reduce the efficiency of the pump, or even disable it altogether. This phenomenon is called "souring". To avoid it, automatic regulators may provide protection against acidification: periodically (once every few weeks) the pump is turned on for a short time, which prevents the formation of deposits (and removes those that have already formed).

— Holiday function. A special regime provided for in case of a long absence of people in the house (for example, during a vacation — hence the name). In holiday mode, you can set a certain temperature to...be maintained for several days (for example, a week; the maximum duration depends on the thermostat model). At the same time, in some models, this function is combined with frost protection (see below) and allows you to set only the minimum temperature (usually 5 °C); in others, the holiday temperature can be programmed.

— Random mode. A mode that provides for the inclusion of various heating functions in a random order (but without causing critical loads on the heating system). The most popular use of this feature is to simulate that someone is at home; this can stop intruders planning a theft in the absence of the owners.

— Management via the Internet. Ability to control the controller via the Internet. The device itself is usually connected to the network via Wi-Fi, and the control features may be different. For example, in some models you need to use a proprietary application installed on a smartphone or tablet, in others it is enough to open a special page in any browser. However, anyway, this function allows you to control the heating system remotely, from anywhere in the world. This can be extremely convenient in unforeseen situations — for example, if during the absence of the owner on the street it gets warmer. In addition, additional features such as advanced timer programming may be available with Internet control.

— Frost protection. A function that prevents freezing of the coolant in heating systems. Freezing water expands, which can lead to mechanical damage and depressurization of the system. To avoid this, regulators with this function are able to "monitor" that the temperature of the coolant does not fall below 5 °C, and, if necessary, turn on the heating to maintain the temperature. This function is relevant primarily for cases when the disconnected heating system must be left unattended for a long time during the cold season.

— Protection from children (blocking). The ability to lock the control panel of the regulator so that a curious little child cannot knock down its settings. The lock, usually, is turned on and off in such a way that an adult, but not a child, can easily do it — for example, by simultaneously pressing certain keys.

— Heater operating hours counter. Built-in counter that tracks the total heating time. This feature makes it much easier to keep track of the operating mode and heat costs, eliminating the need for the user to keep records manually and allowing you to track working hours even when there is no one nearby.

— Sensor calibration t. Possibility to calibrate the temperature sensor of the thermostat. In fact, situations may arise when the readings of the temperature sensor for one reason or another differ from the actual temperature in the room — for example, the controller is installed near an electrical appliance that generates heat and knocks down the setting, and neither device can be moved. For such cases, calibration is provided — an amendment to the readings of the temperature sensor. For example, if the thermometer in the middle of the room reads 20°C and the regulator's sensor reads 22°C, you can correct the thermostat to -2°C and the temperature displayed on the regulator will correspond to the true temperature. Of course, the correction can also be taken "in the mind" without reconfiguring the device; however, most often it is easier to set the necessary parameters in advance and not get confused in the calculations.

The type of power source used in the thermostat.

— Mains. Powered by a conventional 230 V power grid. A device connected to such a power supply can operate without interruption for almost unlimited time, which is especially important for thermostats and automatic regulators — during working hours they must be constantly turned on, otherwise, the very meaning of such devices is lost. In addition, the mains connection is suitable for controllers of almost any power consumption. The only drawback of this option is the need to run the wire to the device, but this moment is hardly critical.

— Battery. Powered by its own battery or a disposable battery, in this case, both options are allowed. This type of power supply is found in wireless thermostats (see "Connection"); its main advantage is its complete independence from sockets, which greatly simplifies installation and makes the outdoor unit completely wireless. In some models, it can even be removed from the mount and carried with you. At the same time, the power consumption of thermostats is small, and a small battery may well last for a year or even more.