Smart home or toy for men: temperature control
I wanted to continue the cycle of articles about the smart home by choosing the heating system, because Winter is ahead, and a poll in one of my previous articles showed that 32% of readers are interested in this topic. But, having prepared the article, I thought that you first need to agree on basic things, such as temperature control, how it works, what accuracy and speed it should be maintained, as well as electricity control and why it is needed.
Temperature control in a country house is definitely needed by those who often come there on weekends and holidays. Also, those who do not lower the temperature there below + 5 ° C. But is it necessary for those who live there permanently or for those who have the possibility of maintaining the temperature there in the region of + 20 ° C?
When asked if you need a smart home, you often get an answer: I have a boiler, the temperature is constant, I live in a house all the time, why do I need a smart home?
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And really, you think, why does he need something else? But in the depths of consciousness it’s gnawing at the thought that a boiler with heated floors and / or radiators cannot give a constant temperature in the house due to high inertia. But the man says that the temperature is constant and there is no reason not to trust him. After all, he looks at the weather station, according to him. How can you not believe?
And then I conducted an experiment. It must be said casually. I put 2 different sensors and a weather station nearby. Calibrated and began to monitor the readings. One sensor is completely “bare”, without a box and other insulating materials. The other one in the box, already serious, is a whole board. Well, the usual weather station. It turned out that the first sensor is very sensitive (which is not surprising). The second one is much "slower" than the first. Well, the weather station reluctantly reacted to the opening of the balcony door. After 3 minutes of airing at an outdoor temperature of about + 10 ° C, the first sensor already showed a decrease in temperature by 1 ° C, the second one by 0.5 ° C, while the weather station showed a decrease of only 0.1 ° C. The figure shows the behavior of 2 sensors. The delay of one from another is from 10 minutes to half an hour and even an hour.
Sensors are so different not because some of them are bad or good. And because the goals of these measurements are different. There are special requirements for the installation of thermometers, such as hanging them only at 1.5-2 m on the inner wall away from the sun and doors, etc. But there are no requirements for speed measurements. Yes, and they can not be, because in different cases they are different. So, the person who is heated by the boiler looks at the weather station with a strongly inhibited reaction, and, possibly, also with low accuracy. And it is also good if it is a digital meteorological station, and not an analogue (alcohol wall thermometer). In the case of analog, everything is clear. There accuracy and speed can not wait. A digital weather station can show only in whole degrees (without tenths and hundredths) or with tenths. But a person can “read” with rounding to whole numbers. Yes, and the weather station can be very late, as in my case. I opened the balcony door, aired 5 minutes and closed it. The meteorological station reduced the readings by 0.1 ° C, then everything warmed up again, and again it rose by 0.1 ° C, as if nothing had happened.
So, what I really want to say is that all the sensors are correct, but is it necessary to measure the temperature so accurately and quickly? To what accuracy do you need to be able to measure it and at what speed? Or does the perfectionist say this to me?
Let's figure it out. We are talking about comfort in all its senses. For comfort, it is best to keep the temperature exactly at the same level, regardless of the open-closed window, door, etc. During the day there can be one temperature, at night - another. Our well-being may be different at the same temperature. It can be cold at + 23 ° C and can be hot at + 21 ° C. Here you can only advise to dress according to your well-being. Sometimes, freezing, just look at the thermometer and, seeing that the temperature is + 23 ° C - immediately warm up. But this is self-digging. Another topic.
The temperature must be objectively constant in a particular place. For example, at night in the bedroom - near the bed, and not near the heater. In the afternoon in the kitchen - away from the sun and cooking stove.
So, we come to the understanding that the temperature should be objectively constant. Desirable with high accuracy and speed. When you open the window, almost immediately the instantaneous heating device with the necessary power should be switched on with adequate compensation of heat losses. When closing - turn off. At the same time, he should not disturb our sleep. If it turns on and off every 2-3 seconds, we just won’t fall asleep, it’s not comfortable. And this is the reason for the following thoughts.
The example in the figure below shows the day of control of the central heating radiator in the kitchen in a city apartment. The side is sunny, so the battery is disconnected during the day. The window is micro-winding. There is no strong gust of wind.
At night it got colder, the temperature dropped several times below 22 ° C. In the picture below this time is selected in detail. In short-term transitions below 22 ° C, an electrothermal servo actuated , opening the heating radiator. Sometimes he did not have time to fully open, as the temperature was already above the set at 22.1 ° C to turn off the drive. It began to close, and the temperature again fell below 22 ° C. It turns out that at some points the servo was in a state of incomplete opening. Since this is a kitchen, at night you can turn the servo on and off for at least a few seconds. It will not prevent anyone from sleeping. The servo itself is silent, but the controllable socket slightly clicks when turned on and off.
Heating devices are different. It can be a central heating radiator, underfloor heating, an oil or infrared heater and much more. All of them can be controlled using a smart home. The most inertial of them is infrared. But it glows at night (carbonic). Every 2-3 seconds on and off also does not help falling asleep, because both the socket and the heater will click. There are fan heaters, but they will also interfere with the sleep of their fans. There are oil heaters and radiators with heated floors. They are quite silent, but very inertial. Therefore, in each room and even at different times of day, you can use different types of heating. You can even combine: heated floors and radiators can be kept at low temperatures, say, 2-3 ° C below targets, and already heated with accurate heaters. In principle, as I noted, many do. Many who have heated floors and / or radiators, are also ordinary electric heaters.
Another side to maintaining temperature accuracy is energy efficiency. It is known that an increase in temperature of 2 ° C leads to a 15% excess energy consumption when the temperature difference between the house and the street is 40 ° C. That is, for example, you want to maintain the temperature at 22 ° C. Outside -20 ° C. The boiler heats the coolant, which then goes to the warm floor and / or radiators. The volume of coolant is 100-150 liters. To heat it all up, say, at 10 ° C (from 50 to 60), it will take, say, 15 minutes. This coolant diverges around the house and heats the materials around it (floors, radiators, air, etc.). This is a huge mass. And this mass warms up, say, in another 15 minutes. And it does not heat up to 22 ° C, but to 30 ° C or even higher. You have a warm floor sensor with a low reaction rate and low accuracy. Well, if digital. After 15 + 15 = 30 minutes, a temperature change will reach him, and he will be thinking for another 3 minutes. Then, realizing that there is already enough, he gives the command to the controller to turn off the heating. The command is sent to an electrothermal analog servo, which according to the passport fulfills an on-off cycle in 5 minutes. It overlaps the required circuit for 3 + 5 = 8 minutes, and the mass heated to 30 ° C heats up further from the coolant with a temperature of 60 ° C.
And now the question. To what values ​​will the temperature drop while the heat carrier is heating up and that same mass: 20-30 minutes? If at 21.9 ° C heating of the heat carrier began, and outdoors -20 ° C. It may well be that the temperature actually drops to 2C for a short period of time. A thermometer does not see this because of its inhibition and / or not quite correct installation. At a glance, the weather station will show + 22 ° C. Well, 21.9 ° C. But it will actually be + 20 ° C. So then the reverse action will begin. Everything will heat up in 15 + 15 + 3 + 5 = 38 minutes and will not really turn off soon due to the large heated mass. This means that after the controller makes a decision to turn off the heating water, the house will heat up above the set temperature by the same 2-3 ° C. A thermometer according to habit will show + 22.2 ° C with the actual temperature already + 24 ° C and higher.
And so it seems that the temperature is constant, judging by the readings of the weather station. But in reality, it jumps to ± 2 ° C. Those. The range of temperature changes will be 4-5 ° C. At the same time, + 2 ° C is a net overrun (-15% rubles from a pocket), and -2 ° C is discomfort. So it turns out, in addition to our well-being, the objective factor of temperature jumps. And so it is cold at + 23 ° C, and here it’s actually the temperature of only + 21 ° C. Those. and there is no comfort and the extra money goes to heating the street.
The temperature sensor used by the boiler controller is installed in one place and with one accuracy and speed of reaction, the weather station sensor is in a completely different place. Both the time of its reaction and its accuracy can greatly differ from that of the sensor.
All this affects the comfort and energy saving, although at first glance, the temperature is normal, constant, and, moreover, I'm used to it. In any case, if the boiler is already standing, the equipment is working properly, then there are no questions. And if the house is new and there is no heating system yet? This is a reason to think.
No super smart home can be comfortable in temperature, if the temperature sensor is not installed correctly and / or use inertial heating devices.
In conclusion, I want to conclude that the temperature must be objective, accurate, and at high speed. High speed and accuracy can always be reduced by the logic of the controller and / or the executive module. On the contrary - no way. Then the heat loss will decrease and the comfort will increase.
The following article has been published Smart home or toy for men: electricity control
Temperature control in a country house is definitely needed by those who often come there on weekends and holidays. Also, those who do not lower the temperature there below + 5 ° C. But is it necessary for those who live there permanently or for those who have the possibility of maintaining the temperature there in the region of + 20 ° C?
When asked if you need a smart home, you often get an answer: I have a boiler, the temperature is constant, I live in a house all the time, why do I need a smart home?
')
And really, you think, why does he need something else? But in the depths of consciousness it’s gnawing at the thought that a boiler with heated floors and / or radiators cannot give a constant temperature in the house due to high inertia. But the man says that the temperature is constant and there is no reason not to trust him. After all, he looks at the weather station, according to him. How can you not believe?
And then I conducted an experiment. It must be said casually. I put 2 different sensors and a weather station nearby. Calibrated and began to monitor the readings. One sensor is completely “bare”, without a box and other insulating materials. The other one in the box, already serious, is a whole board. Well, the usual weather station. It turned out that the first sensor is very sensitive (which is not surprising). The second one is much "slower" than the first. Well, the weather station reluctantly reacted to the opening of the balcony door. After 3 minutes of airing at an outdoor temperature of about + 10 ° C, the first sensor already showed a decrease in temperature by 1 ° C, the second one by 0.5 ° C, while the weather station showed a decrease of only 0.1 ° C. The figure shows the behavior of 2 sensors. The delay of one from another is from 10 minutes to half an hour and even an hour.
Sensors are so different not because some of them are bad or good. And because the goals of these measurements are different. There are special requirements for the installation of thermometers, such as hanging them only at 1.5-2 m on the inner wall away from the sun and doors, etc. But there are no requirements for speed measurements. Yes, and they can not be, because in different cases they are different. So, the person who is heated by the boiler looks at the weather station with a strongly inhibited reaction, and, possibly, also with low accuracy. And it is also good if it is a digital meteorological station, and not an analogue (alcohol wall thermometer). In the case of analog, everything is clear. There accuracy and speed can not wait. A digital weather station can show only in whole degrees (without tenths and hundredths) or with tenths. But a person can “read” with rounding to whole numbers. Yes, and the weather station can be very late, as in my case. I opened the balcony door, aired 5 minutes and closed it. The meteorological station reduced the readings by 0.1 ° C, then everything warmed up again, and again it rose by 0.1 ° C, as if nothing had happened.
So, what I really want to say is that all the sensors are correct, but is it necessary to measure the temperature so accurately and quickly? To what accuracy do you need to be able to measure it and at what speed? Or does the perfectionist say this to me?
Let's figure it out. We are talking about comfort in all its senses. For comfort, it is best to keep the temperature exactly at the same level, regardless of the open-closed window, door, etc. During the day there can be one temperature, at night - another. Our well-being may be different at the same temperature. It can be cold at + 23 ° C and can be hot at + 21 ° C. Here you can only advise to dress according to your well-being. Sometimes, freezing, just look at the thermometer and, seeing that the temperature is + 23 ° C - immediately warm up. But this is self-digging. Another topic.
The temperature must be objectively constant in a particular place. For example, at night in the bedroom - near the bed, and not near the heater. In the afternoon in the kitchen - away from the sun and cooking stove.
So, we come to the understanding that the temperature should be objectively constant. Desirable with high accuracy and speed. When you open the window, almost immediately the instantaneous heating device with the necessary power should be switched on with adequate compensation of heat losses. When closing - turn off. At the same time, he should not disturb our sleep. If it turns on and off every 2-3 seconds, we just won’t fall asleep, it’s not comfortable. And this is the reason for the following thoughts.
The example in the figure below shows the day of control of the central heating radiator in the kitchen in a city apartment. The side is sunny, so the battery is disconnected during the day. The window is micro-winding. There is no strong gust of wind.
At night it got colder, the temperature dropped several times below 22 ° C. In the picture below this time is selected in detail. In short-term transitions below 22 ° C, an electrothermal servo actuated , opening the heating radiator. Sometimes he did not have time to fully open, as the temperature was already above the set at 22.1 ° C to turn off the drive. It began to close, and the temperature again fell below 22 ° C. It turns out that at some points the servo was in a state of incomplete opening. Since this is a kitchen, at night you can turn the servo on and off for at least a few seconds. It will not prevent anyone from sleeping. The servo itself is silent, but the controllable socket slightly clicks when turned on and off.
Heating devices are different. It can be a central heating radiator, underfloor heating, an oil or infrared heater and much more. All of them can be controlled using a smart home. The most inertial of them is infrared. But it glows at night (carbonic). Every 2-3 seconds on and off also does not help falling asleep, because both the socket and the heater will click. There are fan heaters, but they will also interfere with the sleep of their fans. There are oil heaters and radiators with heated floors. They are quite silent, but very inertial. Therefore, in each room and even at different times of day, you can use different types of heating. You can even combine: heated floors and radiators can be kept at low temperatures, say, 2-3 ° C below targets, and already heated with accurate heaters. In principle, as I noted, many do. Many who have heated floors and / or radiators, are also ordinary electric heaters.
Another side to maintaining temperature accuracy is energy efficiency. It is known that an increase in temperature of 2 ° C leads to a 15% excess energy consumption when the temperature difference between the house and the street is 40 ° C. That is, for example, you want to maintain the temperature at 22 ° C. Outside -20 ° C. The boiler heats the coolant, which then goes to the warm floor and / or radiators. The volume of coolant is 100-150 liters. To heat it all up, say, at 10 ° C (from 50 to 60), it will take, say, 15 minutes. This coolant diverges around the house and heats the materials around it (floors, radiators, air, etc.). This is a huge mass. And this mass warms up, say, in another 15 minutes. And it does not heat up to 22 ° C, but to 30 ° C or even higher. You have a warm floor sensor with a low reaction rate and low accuracy. Well, if digital. After 15 + 15 = 30 minutes, a temperature change will reach him, and he will be thinking for another 3 minutes. Then, realizing that there is already enough, he gives the command to the controller to turn off the heating. The command is sent to an electrothermal analog servo, which according to the passport fulfills an on-off cycle in 5 minutes. It overlaps the required circuit for 3 + 5 = 8 minutes, and the mass heated to 30 ° C heats up further from the coolant with a temperature of 60 ° C.
And now the question. To what values ​​will the temperature drop while the heat carrier is heating up and that same mass: 20-30 minutes? If at 21.9 ° C heating of the heat carrier began, and outdoors -20 ° C. It may well be that the temperature actually drops to 2C for a short period of time. A thermometer does not see this because of its inhibition and / or not quite correct installation. At a glance, the weather station will show + 22 ° C. Well, 21.9 ° C. But it will actually be + 20 ° C. So then the reverse action will begin. Everything will heat up in 15 + 15 + 3 + 5 = 38 minutes and will not really turn off soon due to the large heated mass. This means that after the controller makes a decision to turn off the heating water, the house will heat up above the set temperature by the same 2-3 ° C. A thermometer according to habit will show + 22.2 ° C with the actual temperature already + 24 ° C and higher.
And so it seems that the temperature is constant, judging by the readings of the weather station. But in reality, it jumps to ± 2 ° C. Those. The range of temperature changes will be 4-5 ° C. At the same time, + 2 ° C is a net overrun (-15% rubles from a pocket), and -2 ° C is discomfort. So it turns out, in addition to our well-being, the objective factor of temperature jumps. And so it is cold at + 23 ° C, and here it’s actually the temperature of only + 21 ° C. Those. and there is no comfort and the extra money goes to heating the street.
The temperature sensor used by the boiler controller is installed in one place and with one accuracy and speed of reaction, the weather station sensor is in a completely different place. Both the time of its reaction and its accuracy can greatly differ from that of the sensor.
All this affects the comfort and energy saving, although at first glance, the temperature is normal, constant, and, moreover, I'm used to it. In any case, if the boiler is already standing, the equipment is working properly, then there are no questions. And if the house is new and there is no heating system yet? This is a reason to think.
No super smart home can be comfortable in temperature, if the temperature sensor is not installed correctly and / or use inertial heating devices.
In conclusion, I want to conclude that the temperature must be objective, accurate, and at high speed. High speed and accuracy can always be reduced by the logic of the controller and / or the executive module. On the contrary - no way. Then the heat loss will decrease and the comfort will increase.
The following article has been published Smart home or toy for men: electricity control
Source: https://habr.com/ru/post/398301/
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