March 12, 2025, 2:07 pm | Read time: 4 minutes
Temperatures are already rising during the day in spring, but it often remains cool at night. How can you heat and ventilate properly during this transitional period to save energy and avoid mold in the home?
Spring has finally arrived! Days are lengthening, and temperatures are on the rise. Nevertheless, in many places, you still can’t do without heating. Proper ventilation and heating are particularly crucial during this time of year. One should avoid wasting energy by preventing excessive cooling of the home. On the other hand, there is still a risk of mold growth if there is insufficient ventilation. By paying attention to key aspects of ventilation and heating, you can achieve savings on heating costs, even with the unpredictable weather of spring. myHOMEBOOK shares what to bear in mind when ventilating in spring.
How to Heat in Spring
“This transitional period, characterized by fluctuating outdoor temperatures, presents significant potential for consumers to save,” explains Markus Lau, a technology expert from the German Liquefied Petroleum Gas Association (DVFG). The expert advises not to base heating too much on the fluctuating outside temperatures.
It’s advisable to keep the heating on a low setting, even during mild afternoon temperatures. This is especially true for poorly insulated old buildings. Turning the radiator thermostats up and down too often, on the other hand, would consume energy unnecessarily.
Ventilate Properly in Spring
The DVFG recommends ventilating three to four times a day for ten to 15 minutes each time in spring. In winter, three times a day for five minutes is sufficient. The reason is that warm spring air contains more moisture and absorbs additional moisture from the bathroom and kitchen less quickly. Efficient ventilation, therefore, requires more time, according to the association.
It is also best to air the room for the last time in the afternoon. “This is when the outside temperatures are still comparatively high and less room heat is lost,” explains Markus Lau. Therefore, it’s recommended to close the heating valves while ventilating.
Ideally, indoor temperatures should not drop below 15 degrees Celsius. Notably, the optimal bedroom temperature is around 18 degrees Celsius, which is two degrees cooler than the recommended temperature for living and dining areas.
Tip: For optimal air exchange, it’s beneficial to open multiple windows to facilitate cross-ventilation and generate a draft.
Vent and Dust off Radiators
If the radiators gurgle and do not heat up properly despite the thermostats being turned up, there could be air in the system. It may then be worth bleeding the radiators again in spring. Because: “Excess air in the system causes radiators to operate inefficiently, consuming more heating energy than necessary to achieve the desired temperature,” says Lau.
It also makes sense to use spring cleaning to clean dirty or dusty radiators. Because: “Accumulated dust and dirt impede the transfer of heat,” explains Lau. “Radiators with clean external surfaces and internal gaps work more efficiently again — and save costs.”
What to Do About Condensation?
If condensation collects on the window panes and runs onto the window sill, it is usually an indication that the humidity is too high. You should then ventilate more often to allow the moisture that would otherwise condense on the cold panes to escape. Additionally, if the heating is on under the windowsill, the water can quickly result in mold formation.
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What Should Allergy Sufferers Bear in Mind When Ventilating in Spring?
Even if you suffer from hay fever, you shouldn’t avoid airing your home in spring. However, in this case, it is advisable to avoid the morning and evening hours, as there is less pollen flying at this time. The lowest concentration of pollen in the air is between 6 and 8 a.m. in the city and between 7 p.m. and midnight in the countryside.
However, it’s important to ventilate in short bursts rather than leaving windows permanently ajar, as this can lead to excessive cooling of the apartment. Researchers at the Technical University of Munich also found this out when they measured and compared the pollen load indoors. The result: regular shock ventilation still allows less pollen to enter compared to a weak but continuous draught.