Saving on heating: Experts expect more mold damage in apartments

Enlarge image

Nasty blossom: Mold on a window

Photo: blickwinkel / IMAGO

According to experts, the more economical heating this winter will cause more mold damage in apartments and houses.

"The risk of mold growth as a result of inappropriate heating and ventilation behavior can definitely be classified as high," said Stefan Betz, chairman of the Federal Association for Mold Remediation, the dpa news agency.

From the point of view of the energy consultant association GIH, there is a lack of information about the correct heating and ventilation.

SectionWhy do cold rooms grow mold?open

"Moulds need moisture and nutrients," explains microbiologist Ziemer.

We produce them non-stop in our apartment: we shower, we cook, we hang out our laundry to dry.

Colder room air can absorb less moisture.

The moisture condenses on windows and walls - especially in winter, when the dew point shifts inwards due to the cold outside temperatures.

These are optimal conditions for fungal spores, explains Ziemer.

The moisture provides the necessary environment, the substrate, such as the plaster, can serve as a source of nutrients.

In addition to the factors that can be influenced, such as air exchange and temperature - i.e. ventilation and heating - the building envelope can also play a decisive role - windows, walls and roofs.

Their different nature makes it difficult to set general temperature limits and recommendations.

Expand areaHow do I have to heat to avoid mold?

If the temperature drops to 16 to 18 degrees or below in autumn and winter, the risk of mold growth increases massively, according to the Federal Environment Agency.

A temperature of 19 to 20 degrees during the day and a slight drop to 18 degrees at night is recommended.

It is also important to ventilate any moisture that has formed as quickly as possible.

AreaProper ventilationopen

• Ventilate regularly, especially when there is a lot of moisture - for example when cooking, showering or drying laundry

• It is best to ventilate the room instead of opening the window for a long time - this also saves energy.

• The UBA recommends ventilating for five minutes two to three times a day and five to ten minutes directly after cooking and showering.

• If the thermal insulation is poor, it is recommended not to place solid furniture directly against the outer walls, especially in winter.

"Mould damage will increasingly occur in older existing buildings, and here above all in the poorly insulated apartment buildings from the 1960s and 70s," estimates Betz.

In principle, kitchens, bathrooms and bedrooms are more at risk in all buildings because a lot of moisture is produced here.

"If less heating is used here than in previous years to save energy costs, but the ventilation behavior is not adjusted, increased moisture can enter the walls, room corners, but also furniture and fabrics, and this can lead to mold," said the expert.

There is a lot of advertising for saving energy, but not enough information about correct user behavior, says Lutz Badelt, chairman of the GIH regional association in Berlin-Brandenburg.

He is aware of a case in which the residents of a house no longer heat, but use the heat from cooking.

This is how the humid air gets into the other rooms – a danger for mould.

Energy please!

Tips that can save a lot

expand pane

Illustrations: Noa Gunter / DER SPIEGEL

There are many energy saving tips.

But here we have some that are easy to implement, don't cost much and can even be sustained.

Section Tip 1: Child's play!open

Illustrations: Noa Gunter / DER SPIEGEL

Make a game out of it!

Because the savings effect, regardless of the measure, is greater the more family members take part.

Then whoever turns up the thermostat last scores;

it gets a deduction in whose room the light is still on when they leave.

Important: no dangerous exaggerations, everyone according to their possibilities.

Area Tip 2: Always open blue

Illustrations: Noa Gunter / DER SPIEGEL

Be economical with hot water – that is vague.

Better: set all single-hand mixers to blue.

Most people would intuitively place them in the middle position.

However, lukewarm water is mixed in this way, although cold water is completely sufficient for most occasions.

Area tip 3: You money saver!open

Illustrations: Noa Gunter / DER SPIEGEL

The debate about Robert Habeck's shower habits was not well received.

However, one would like to know specifically what energy-conscious showering actually brings.

The shower calculator from the North Rhine-Westphalian consumer advice center (here you can get there directly) will help.

There you can see how much money can be saved - even if you don't stand under ice-cold water.

In the example: If you heat the water to 36 instead of 38 degrees and shower for only seven minutes instead of eight minutes, you save 150 euros in energy costs per year.

Area Tip 4: Who am I actually heating for here? open

Illustrations: Noa Gunter / DER SPIEGEL

Overheated rooms cost energy, every degree less saves six percent.

How do you adjust radiators accordingly?

A short video of a thermostat with photos of politicians on the dial recently circulated on Twitter: Turning the heating up to "4" makes the Gazprom lobbyist Gerhard Schröder happy, while at "5" Putin laughs up his sleeve.

Electronic thermostats can also help: »20 degrees« is still more specific than »2«.

Area Tip 5: Open the window!

(But short.) open

Illustrations: Noa Gunter / DER SPIEGEL

If you want to heat well, you have to ventilate properly.

This is not new, but because many people now think of Corona when they hear the word "shock ventilation", it's worth remembering.

Because it saves a lot of heating energy if you briefly air the room two or three times a day with the window wide open in winter instead of tilting the window for hours.

Section Tip 6: Let us help you open

Illustrations: Noa Gunter / DER SPIEGEL

Even those who consume little electricity indirectly save gas, part of the electricity supply in Germany is ensured in gas power plants.

Power strips and timers are tried and tested tools for saving electricity, because they can be used to reliably disconnect the many electronic devices from the mains that are still drawing power when they are switched off.

Caritas provides individual advice at Stromspar-Check.de.

And best of all: you can sometimes get these small tools there for free.

Area Tip 7: Open the lid

Illustrations: Noa Gunter / DER SPIEGEL

An example from the small livestock department: When cooking, you save a lot of energy by putting a lid on the pot.

Of course, this is not possible with some dishes, pasta, for example, is best cooked in an open pot.

But even here you can bring the water to a boil with the lid on and only remove it when the pasta is added.

Area Tip 8: Unfold an extra layer

Illustrations: Noa Gunter / DER SPIEGEL

Multi-layer windows are good thermal insulation - if you don't have one, you can equip your old windows with insulating film, which is available in hardware stores.

The Hessian state energy agency calculates that with single-glazed panes, 25 euros per square meter can be saved in energy costs per year.

And shows step by step how to do it.

Mold is also sometimes a taboo subject.

"Especially in the older generation, mold is associated with uncleanliness," says Badelt.

That's why people don't like to talk about it and the problem doesn't get solved.

Victims would also be stigmatized.

»Sometimes people are accused of not ventilating properly.

But that cannot be said in general terms.

Residents of poorly insulated buildings often have no chance of avoiding mold.«

"If a tenant discovers mold damage, there is a high probability that he will first contact his landlord," says Betz.

This phase often leads to arguments about the cause.

“It often takes weeks and months for damage to be reported to a restructuring company or a lawyer,” says the expert.

Usable figures will therefore only be available in six months to a year.

mamk/dpa-AFX