There are many questions when it comes to heating in times of energy crisis. Energy expert Carsten Herbert has the most important tips ready.
The big guesswork about heating starts again. When the temperatures outside go into minus again for the first time, many people turn on their heaters straight away – but is this advisable when it comes to saving energy? Carsten Herbert, energy expert, qualified civil engineer and author of “Everything you need to know about saving energy” (Herder), answers the most burning questions about this year’s heating season in an interview with the news agency spot on news.
The first minus degrees in Germany are here, but temperatures are currently rising to up to 12 degrees. Many people then ask themselves when is the best time to turn on their heating so as not to waste energy. What is your recommendation?
Carsten Herbert: The typical temperature at which you start heating in a typical old building is around 15°C. However, this often doesn’t have to be on the first day when heating has to start. The last few weeks in particular have shown how things can work. First of all, the house has stored a lot of heat due to the warmer days before. This gives you a few days buffer before you actually have to turn the heating on. In addition, warm days and lots of sunshine bring new heat into the house and store it. In the transitional period, the motto is “Let the sun in”. Now it’s important to use every ray of sunshine possible to recharge the house with heat. Only when it drops below 15°C permanently during the day and at night will you no longer be able to avoid going to the heating switch.
When heating starts, what is the best way to save as much energy as possible?
Herbert: If you have the opportunity, you should definitely take care of the heating control settings. Unless you have already changed it, it is always set so that much more heat is produced than is actually needed by the radiator. This is simply because when the heating system is rebuilt and the specialist company leaves the boiler room, the tradesman naturally wants to have satisfied customers. Satisfied customers mean that it definitely has to be warm enough. In order not to take any risks, he selects appropriately high temperatures for the heating control settings.
There is probably no measure that is more effective, but at the same time so unknown, than optimizing heating control. I know of examples in which people have saved 40 percent energy by optimizing their heating. This is of course an extreme case. In most cases it is at least five to ten percent. And all of this is available for 0 euros. The only thing it costs is a bit of time in which I have to worry about my heating. By the way, I explain how it works in my YouTube episode “DIY – optimize heating – save heating costs – without costs – by adjusting the heating curve”.
At what height should you set the heating thermostat in autumn and at what height in winter?
Herbert: It is a common misconception that you have to change the setting of the control knob on the radiator when the outside temperature changes. With most thermostats you can choose the setting from 1 to 5 or turn it off completely. The 2 stands for 18°C. The distances between the numbers are three degrees.
If I now set my thermostat to 3, the heating valve stays open until the thermostat measures 21°C. If the temperature is above 21°C, the valve remains closed and the radiator no longer receives any new heat. If it falls below 21°C again, the valve opens and the game starts again. This means that the temperature at setting 3 is always around 21°C. Anyone who understands this principle also understands that there is no point in turning up the thermostat if it doesn’t get really warm. If the thermostat is set to 3, but it is only 18°C in the room, then the heating valve is already open. You can’t go more open than open, so setting the thermostat to 5 doesn’t help at all in this case.
If it gets less warm in my room than the thermostat setting suggests, then the reason usually lies somewhere else. For example, the valve may be stuck or the heater may need to be bled. If neither of these is the case, then either the radiator is too small or the heating control is not set correctly. It is very rare for a radiator to be too small. This is usually due to the heating control settings.
Similar to a new smartphone or a new television, in order to regain access to the most important apps or to receive all programs, you have to deal with these devices. This is exactly what you should do with your heating control so that it is always sufficiently warm but uses as little energy as possible.
What do you do with the heating if you are away for a longer period of one or two weeks – turn it off or just turn it down?
Herbert: You need it warm when you’re at home. If I’m not at home, I don’t need a warm room. Therefore, you should reduce the temperatures in the interest of saving energy when you are away. In principle, something like a frost protection is sufficient. Most thermostats have their own setting for this, which is marked with a snowflake. If the thermostat is set to the snowflake position, the valve opens when the temperature in the room falls below 6°C.
However, there is also a disadvantage to this reduction in temperature. When I come back and it’s 6°C in my apartment, it sometimes takes two to three days until it’s pleasantly warm in the apartment again. That’s how long it takes until all walls, ceilings and furnishings are warmed up again.
If that bothers you, you have the option of working with smart and internet-enabled heating thermostats. Then you can remotely turn the heating back on a day or two after returning home and you come back to a warm, cozy apartment.
You should also adjust the temperature if you are outside during the day, for example. B. is in the office?
Herbert: If you are away for a very short time, it is not worth lowering the temperature, as reheating will negate the savings. For a temperature reduction to be worthwhile, the absence should be at least five hours or more. Here, too, it is colder when you return to your apartment. Therefore, in this case too, smart thermostats with programming functions are certainly a clever solution to save energy without having to freeze.