What happens to your indoor climate when the outdoor temperatures drop?

When it gets cold outside, humidity levels drop, affecting the indoor climate. When we are ventilating our homes, we’re letting dry air inside. When we at the same time also turn up the heating, the air becomes even drier.

In older buildings, a lower humidity level can sometimes be beneficial, but in modern apartments, especially those built with concrete, this can often cause problems. As the indoor air dries out, wooden floors, walls, countertops, and furniture can crack and split. Perhaps more concerningly, it can also impact residents’ health.

A burden for residents

The team at the Asthma and Allergy Shop (Astma-Allergi Shoppen) knows all about the issues that dry indoor air can cause: “Many people experience problems with dry air in the winter – it triggers asthma and irritates sensitive mucous membranes. For some, it can even lead to nosebleeds,” they explain.

Issues generally begin when humidity drops below 30%. In winter, it can go as low as 7%, which can cause problems for residents with asthma and allergies.

The list of potential discomforts is long: aggravated asthma, dry mucous membranes, sore throat, headache, rough and dry skin, cracked lips and other irritations.

What can be done about it?

First and foremost, it’s essential to keep an eye on indoor climate and humidity. Indoor climate sensors that measure temperature and humidity are ideal for this purpose.

Modern, wireless humidity sensors, like the ones Brunata uses for indoor climate monitoring, can also notify residents and administrators when relative humidity remains at a critical level for an extended period.

It’s always a good idea to air out your home, both in summer and winter. But when outdoor temperatures drop below 0°C, airing out won’t increase indoor humidity, as the humidity outside is low – even if it’s raining.

That’s why moisture needs to be added in other ways. For instance, keeping plants that require regular watering can help. Another option is to dry laundry indoors or shower with the bathroom door open so moisture spreads throughout the flat. But be cautious and avoid letting humidity become too high.

Make it a habit to vent your home frequently

Whether humidity is too high – i.e., over 60% – or too low – i.e., below 40% – it’s important to air out daily. It can be hard to remember to air out in a busy daily routine, but make it a habit, for example, by airing out in the morning while brushing your teeth, when you get home from work, and again in the evening before bed.