With a night reduction of the heating you can reduce the heating costs. This sweeping statement is not without controversy. A lot depends on the conditions on site, especially the insulation and the mass of the building. We show you how night-time heating reduction works, how much you can save and what you should bear in mind.
This is how the night setback works
If you turn down the thermostat on the radiator, less hot water flows through your radiator. The room cools down, but the heat (not needed at night) is still retained in the heating system. Simply turning down the regulator on the radiator is not a night setback and does not really help you save on heating costs.
When the heating is lowered at night, the temperature at which the heating water flows into the heating pipe system is reduced, the so-called flow temperature. Not only does the burner have to work less, it also reduces heat losses in the pipe system, which vary depending on the insulation of the pipes.
Especially with older heating systems, the settings required for night setback are very complicated to make. Even professionals often shy away from the control centers of old heating systems. However, heating modernization and networked smart home heating technology have made the operation and control of a night setback much easier.
Typically, a night setback reduces the supply temperature by 5 to 8 degrees Celsius. With it naturally also less hot water arrives at the radiators and these can deliver then less warmth. But this effect is just desired at night.
Another problem of temperature reduction overnight in apartment buildings are the different living habits. While for some a lowering is ideal starting from 22 o'clock, the "night-active" inhabitant of house must shiver so perhaps before its sleep time unpleasantly. This is relatively easy to clarify in the case of a gas heating system, but it leads to tangible conflict potential in large apartment buildings with central heating.
Switching off the heating completely at night – quite apart from the loss of comfort and the winter risks – makes little sense. More energy would be needed to heat up the rooms and the cooled down walls than would be saved by switching it off.
Heating temperature reduction only at night?
In addition to night setback, day setback can be just as useful. If no one is in the house during the day, the heating should also be reduced for a few hours. It is important to have a good time setting, so that the house is warm exactly when the residents want it to be. With a digital heating control – modern heaters have a corresponding interface, older heaters can be retrofitted – the desired temperature can be conveniently selected on the go.
Who saves the most with a night reduction?
As paradoxical as it sounds: Owners of uninsulated old buildings save more with a night setback than owners of new construction. What is the reason for this?? An old building without insulation cools down significantly more overnight than a new building. Without insulation, more space heat is simply lost. A good insulation, as well as a massive construction method, with which construction units heat up, affect themselves in punkto night sinking rather counterproductively. Just like a panel heating system, z.B. An in-floor heating system that simply responds too sluggishly and lowering the in-floor heating at night is not practical because of it.
Owners of old buildings thus save more energy with a night setback than owners of new buildings. Realistic savings from night setback are five to eight percent. Whether night setback actually saves energy, and if so, how much, is a matter of controversy among experts. Indeed, there are hardly any real, valid measurements on this subject. Who would like to save energy and heating costs with the heating as well as protect the environment is always better advised with a heating modernization.
What cost a modernization that makes the night setback unnecessary? Find out with the free renovation calculator from Effizienzhaus-online!
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Night setback becomes obsolete
Modern construction methods, efficient heating technologies and high-quality insulating materials and strict insulation regulations ensure that the night setback of the heating system is practically obsolete today. According to the energy turnaround concept of the federal government, the primary energy demand of buildings is to be further reduced, which also makes better and better building insulation necessary. And in a well insulated house night setback no longer makes sense. So, sooner or later, there will no longer be a meaningful night setback.
Risk of mold: Do not reduce room temperature below dew point
When rooms cool down at night, they can fall below the dew point temperature. This is the temperature at which natural humidity begins to condense on interior walls and window panes. In particular critical room parts such as window reveals or room corners can then quickly become damp at night. Then mold forms. It is essential to pay attention to the following when lowering the heating at night.