Temp adjustment range
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.
Hysteresis
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.
Air temp sensor
The presence
of an air temperature sensor in the design or delivery set of the controller — such a sensor can be either built into the device or external.
Air temperature is one of the key parameters that determine the climate in the room and the comfort of staying in it. Accordingly, the air temperature sensor allows the regulator to evaluate the general conditions in the room and control the heating operation, taking into account how the microclimate corresponds to the desired one. However, note that such sensors are not always applicable. For example, in kitchens and bathrooms, they may not work correctly (when hot water, a gas stove or a water heater is turned on, etc.), so in such conditions it is better to use floor temperature sensors (see below).
Floor/heating medium temp sensor
The presence
of a floor or heat transfer fluid temperature sensor in the delivery set of the device.
The meaning of this function is that it is not always advisable to use a classic air temperature sensor, and it sometimes gives too high an error. For example, in a bathroom, the air temperature may rise when hot water is turned on — and the air sensor will turn off the heating, preventing the floor from warming up to a comfortable temperature. A floor or heat transfer fluid temperature sensor is better suited for such situations.
Sensor cable length
The length of the supplied cable in the wired thermostat sensor (see "Type"). The longer the cable, the further the temperature sensor can be installed from the device. At the same time, the principle “the more the better” is quite relevant: excess wire usually does not create any special problems, but if the length is insufficient, you will have to lengthen the cable, or even purchase another sensor.
Note that in modern models, the cable length usually does not exceed 4 m — this is usually enough when installing a thermostat in the same room but with the removal of the device outside the room, difficulties may already arise.