What should you know about humidity at home

When we check the temperature in the nursery, we less often think to look at humidity too. Yet the two are closely linked, and the air’s moisture affects how warm we feel. If we make sure our child’s skin and mucous membranes are not drying out during the day and at night, we do a lot for their health and can help avoid frequent respiratory illnesses.

Air always contains water vapour, and the amount constantly changes. If we want optimal humidity at home, it is worth learning a few key things about how it affects the body, what signs to watch for when it is lacking, and the ways we can humidify the air.

Relative humidity - what we actually feel 

Our sense of dampness lines up with the air’s relative humidity, so this is what we subjectively notice. If it is too low, dry air can cause unpleasant symptoms depending on how sensitive we are. If it is too high, the environment around us can become unhealthy.

Relative humidity is simple to grasp. It is a percentage showing how much water vapour the air contains at a given temperature compared with the maximum it could hold. At 100 percent relative humidity the air is fully saturated and cannot take on more moisture, and we may see fog, mist or dew.

It helps to know that warmer air can hold more moisture than cooler air, because in cooler air condensation happens more easily.

Too little humidity in the room 

Air with relative humidity below 40 percent feels dry, which can have several negative effects on a baby’s skin and mucous membranes:

• the lining of the airways dries out and can become fragile

• we may notice dry mouth and a scratchy throat

• a dry cough may appear in little ones

• sleep can be restless

• eyes can feel dry

• skin can become dry, and eczema or atopic dermatitis can appear

• defences against pathogens can be reduced, so harmful bacteria may settle more easily

• overall comfort can be poor

• sleep problems can occur

• with a cold, dry air makes things worse, while humidifying can help with croup symptoms too

Too much humidity in the room

Humidity above 70 percent can cause condensation and mould. Pay special attention to this if you regularly dry laundry indoors. In clay walled houses the air can become distinctly musty if humidity stays high. In such cases, a better drying solution is needed. A tumble dryer or dehumidifier can significantly reduce indoor moisture if available.

Where does mould appear

At the building’s cold spots the air cools, reaches the dew point, and moisture condenses. If dampness is constant, mould spores can become active within a few days.
Above 70 percent, how warm we feel also changes, because sweating cools us less effectively. At 24 degrees and 75 percent humidity, house dust mites thrive for reproduction.

What is the ideal indoor humidity 

Between 40 and 70 percent can be considered acceptable, although the extremes can already feel uncomfortable. For the nursery, if we want the best setup, choose 50 to 60 percent at a room temperature of 20 to 22 degrees for children. Below 45 percent, dust mites disappear from the environment. This can be useful information for children and family members with dust allergies.

What tool measures indoor humidity 

A hygrometer is a small display device that shows a room’s temperature and humidity. If we want a true picture of the nursery, it is important to place it near the cot, since humidity can differ widely room to room. Think how much these values can shift during the day, for example when we cook or shower and steam spreads through open doors to other parts of the home.

Help during autumn-winter colds and allergy seasons 

From the September start of nursery and school right through to early summer, little ones can often be unwell. When air is dry, sensitive mucous membranes cannot protect well against pathogens and allergens. Because of allergens, children often struggle with long lasting blocked noses and coughs.

If both temperature and humidity are higher, mould and house dust mites can multiply indoors. These can trigger not only respiratory reactions, but skin related allergies too. It is worth assessing the home for natural air exchange, how much condensation appears on windows, and whether there is mould. Modern windows allow less slow air exchange, so regular, gentle airing helps in such cases.

How can we humidify at home 

There are several ways to raise humidity. The simplest is water evaporating from a tray, which you can speed up by placing it on a radiator. This often does not achieve enough, because to change the air meaningfully we would need many containers placed around the home to create sufficient water surface. The decorative little radiator pots often serve more as ornaments than as effective humidifiers.

Mist based humidifiers can look attractive, but in many cases they produce droplets that are too large for the air to hold, so they simply fall. In other words, they do not help enough. Ultrasonic misters are quieter and create microscopic droplets. Unfortunately, they also atomise limescale present in the water, leading to dust deposits in the room, which is not healthy.

If we want to avoid dust, we can lay clean, water dampened towels or textiles near the baby’s bed. Drying laundry indoors can help if the fabrics are free from unnecessary chemicals and softeners, which would evaporate into the room air and end up in the baby’s lungs.

With any method, it is wise to check occasionally whether we have reached the intended effect. We often feel we have done enough, yet the air has barely changed because the evaporating surface area was too small.

Have you heard of salt evaporation

Evaporating salt can improve indoor air quality. Salty air has an anti inflammatory effect and supports the airways’ self cleaning. It can be helpful with bronchitis, sore throat, sinusitis and middle ear infections.

In salty air, sodium ions can reach parts of the lungs where tiny dust particles, pathogens and allergens can settle. Salty air can bind these, and with coughed up mucus they may be cleared. This can be a good option for older children.

Because salty air can worsen certain conditions, for example it can trigger an attack in a child with asthma, you should always seek the advice of your GP or a specialist first.

Have you been to a salt room with your child

The effect is the same, only the salt concentration is higher. Time here passes in a pleasant environment at 70 to 80 percent humidity and 20 to 22 degrees. The air in salt rooms and salt caves is well suited to helping treat respiratory illnesses, clean the airways and support the immune system.

We recommend always having a humidity meter at home and keeping levels optimal for children’s health.

Sources:

NHS inform — Damp and mould indoors

Allergy UK — House dust mite allergy factsheet