Chronothermostat operating instructions
 Chronothermostat operating instructions |
Chronothermostat operating instructions
Along with the increase in gas prices for the population, many of our compatriots began to think about ways to increase the efficiency of their own heating systems. The logical step in this case is to replace outdated equipment with newer and more economical. However, the installation of a new boiler should not be limited, as there are many more ways to improve the efficiency of the heating system. Among them, such as reducing heat loss, more rational use of hot water and improving the quality of regulation of the heating system. We will consider the last item from this list in more detail today. Why is high-quality regulation of indoor air temperature so important, and why should it be given the closest attention? The equation of the thermal balance of the house will help us to understand this: For a correct comparison of options, we will designate the area of the room and the territorial location of the apartment. So, let's take a small private house with an area of 100 sq.m. located in the Kharkiv region.
The need for thermal energy to heat the room.
Typical specific heat losses in a private house for an average structure q = 90-110 W/m2 at design temperatures tpp = -23 ° C.
We will take 100 W/m2:
Estimated heat loss by apartment:
Qr = F * q = 100*100 = 10000 watts.
To determine the energy consumption for the heating period, the so-called "average temperature for the heating period" is used. For the Kharkiv region, it is tp = -1.5 ° C for the duration of the heating period n = 179 days (outdoor temperature tn ≤ 8 ° C).
Average heat losses during the heating period:
Qot.p. = Qr * (tvn – tsr)/(tvn – tzr), W
Where tvn = 20 ° C is the indoor air temperature.
Qot.p. = 10000 * (20 – (-1,5))/(20 – (-23)) = 5000 Tue
If we reduce the air temperature to 18 °C, then
Qot.p. = 10000 * (18 – (-1,5))/(18 – (-23)) = 4800 Tue
The amount of thermal energy during the heating period at a room temperature of 20 ° C:
M = Qot.p. * n * 24 * 3600 = 5000*179*24*3600 = 77,320 GJ
The amount of thermal energy during the heating period at a room temperature of 18 ° C:
M = Qot.p. * n * 24 * 3600 = 4800*179*24*3600 = 74,230 GJ
If we take the average caloric content of gas equal to 31 MJ / m3, and the average efficiency of a modern boiler for the heating period equal to 89%, then the gas consumption will be accordingly:
Ggvs = M/(K*0,89) = 77,320 *109 /(31*106 * 0,89) = 2802,5 m3. At tvn =20 °C
Ggvs = M/(K*0,89) = 74,230 *109 /(31*106 * 0,89) = 2690,5 m3. At tvn =18 °C
The difference is 200 m3 per year or more than 7%. At the same time, the difference between the indoor air temperature of 20 and 18 ° C is practically not felt by a person.
As can be seen from the above example, the gas consumption is directly proportional to the indoor air temperature, and a slight decrease of one or two degrees can give significant savings without additional investment and a decrease in comfort for users.
Naturally, the present equation, which is used to calculate the heat loss of a building, is much more complex, but the simplified example given here will help our reader to understand the essence of the process more fully.
The device that controls the temperature of the air in the room is a room thermostat. This device is installed in a support room (where residents spend more time, for example, a living room) and is connected to the boiler.
Thermoregulators, room thermostats, room temperature sensors are all variants of the name of the same device.
The principle of its operation is that it turns off the boiler whenever the temperature in the room in which the thermostat is installed rises above the value set on it and gives the command to turn on the boiler when this temperature becomes lower than the set one.
There are also room thermostats in which you can programmatically set different temperature and time intervals, so for example, you can set such a thermostat operation mode so that during the stay of people in the room, the air temperature in the room rises to a comfortable level (20-22 ° C), and when no one is at home, it decreases to an economical (16 – 18 °C). Such thermostats are called chronothermostats, and if they can set a program for each day of the week, then the prefix "weekly" is also added.
It is also necessary to clarify the operation of the boiler in conjunction with the room thermostat. As a rule, the temperature of the coolant that enters the heating system is set on the boiler control panel. And the boiler tries to maintain this temperature by turning on/off the burner or adjusting its power within the limits allowed by the factory characteristics of the device. In this case, the thermostat will turn off the boiler regardless of the temperature of the coolant, if the room temperature is higher than the set one.
How does it work? You set the room temperature you need on the thermostat, for example + 23 °C. When the air temperature drops by 0.25-1 ° C (the threshold of operation depending on the thermostat models), the thermostat commands the boiler to turn on – the boiler starts working for heating. As soon as the room air temperature reaches +23.25 °C - + 24 °C, the thermostat turns off the boiler. Moreover, it turns off not only the burner, but also the pump.
The air in the room cools down much slower than the water in the heating system, and the frequency of boiler inclusions is reduced several times, which cannot but positively affect the increase in the service life of the device.
Now you do not need to adjust the temperature of the coolant on the boiler manually – you only work with a room thermostat.
It got warmer outside in winter, the temperature in the room increased – the boiler does not turn on, the sun warms the room through the window – the boiler does not turn on.
Thus, the main regulating device in the thermostat – boiler bundle is the thermostat, and the temperature of the coolant, which is set on the boiler control panel, will only affect the heating system heating rate.
During the transitional period of the heating season (autumn and spring), very frequent boiler starts occur for a short period of time. As a rule, the boiler is switched on – once every 3 minutes for 1-2 minutes. That is, the boiler is constantly working in on-off mode.
At the same time, the circulation pump of the boiler works constantly, and not depending on whether the gas is burning in the boiler or not.
The power consumption of a double–circuit boiler with a capacity of 24 kW during the heating period will not be difficult to calculate - this is about 60-90W per hour. And this is already 1.44-2.160 kWh per day or 258 - 374 kWh for the heating season. The use of a room thermostat can reduce the number of hours of operation of the boiler circulation pump by at least half, which will give us energy savings of about 160 kWh during the heating season.
If we briefly summarize all the benefits of using a weekly programmer (room thermostat), we get the following list:
• automatic maintenance of a comfortable room temperature for you
• more gentle boiler operation mode (reduced restart cycles).
• energy savings
• when using an uninterruptible power supply (UPS), a significant increase in the time of robots from the battery (if the network is lost, it is very important: the heating remains operational, for example, for a day or two days).
Boilers that are not controlled by a thermostat needlessly consume a large amount of gas and electricity, since an increase in room temperature above the required one, even by 1 ° C, in addition to noticeable discomfort, leads to a significant overspending of fuel.
Now you can raise your gas paybooks, calculate how much you paid for the last heating season. Subtract 25-30% from this amount - that's how much you would pay less for gas if you had a room chronothermostat installed.
Plus another 160 kWh of saved electricity for the heating season and another plus reduction of boiler wear, which is impossible to calculate.