Too much humidity in your home can cause headaches, allergies, lead to mold and expensive moisture damage. Read how to measure the humidity and how to get it down.
The humidity is too high in many homes. Just by being present and doing common chores in the home such as bathing, washing clothes and cooking, a person emits approx. three liters of water a day, while a family of four emits 10-12 liters of water, which has to leave the home, so that the walls and interior do not absorb it.
Normal humidity – what should the humidity be in homes?
The relative humidity should be between 25-65 percent.
5 tips for a suitable air humidity in the home
Your own behavior can significantly reduce the humidity in your home. Here are five things you can do:
1. Air out with a draft several times a day
The most important thing you can do to keep moisture out of your home is to air out several times a day.
Open all windows and let the draft carry the humidity out- preferably three times a day for 5-10 minutes – also in winter. Also ventilate when and after cooking and showering. It limits the amount of moisture, mold, dust mites and harmful substances in the air.
If you have a mechanical ventilation system, you do not need to air out in this way, as the system itself provides an adapted ventilation flow. But it’s always good to vent anyway.
Leave the interior doors open so that ‘pollution’ and moisture spread to other rooms. However, close the door to the bathroom and kitchen when you shower or cook, and ensure ventilation during and afterwards, as the humidity can reach 100 percent, especially during bathing (shown by the mirror fogging up).
Also remember:
Keep pots covered when cooking.
Switch on the hood with exhaust to the outside.
Dry up after you have showered.
Repair water damage quickly after it occurs.
2. Ventilate extra well when the heating season begins
Warm air can contain more water than cold air. This means that during the summer, furniture, floors and carpets absorb a lot of moisture from the air, which has a high humidity. When it becomes winter, the air humidity drops, and in order to come into equilibrium with the air, the materials give off a lot of water.
On top of that, the lack of insulation in Portuguese homes causes condensation to form on walls, windows and exterior doors, which exacerbates the problem.
Therefore, prepare your home for winter by thoroughly airing all rooms for several hours. Leave windows and doors wide open while you are at home.
3. Ventilate the washroom well
Washing machines and tumble dryers will always release moisture, and it is important that there is good ventilation from the rooms where they are located.
Hang the laundry outside or in a drying cellar or in a drying loft or use the tumble dryer. A typical wash of 6 kilos of clothes evaporates 2-2.5 liters of water while it hangs on the clothesline, and if you dry clothes inside, the moisture ends up in the home.
4. Avoid unheated rooms
Cold rooms attract the moisture, and when the warm air enters unheated rooms, the relative humidity rises and condensation can form.
The temperature in a room should not be below 17-18 degrees, and there should not be more than a 4-5 degree difference between warm and cold rooms, as it condenses to water, which is absorbed by wallpaper and the like.
5) Give the air free passage in the exhaust and valves
Check every autumn whether there is free passage in the flues in external walls and/or ceilings. Clean the extractors if there is, for example, dust, cobwebs, wasp nests or bird nests!
Also clean fresh air vents in windows.
Why is high humidity bad?
It is crucial for your well-being that the air in your home and workplace contains the right amount of moisture. Most problems with the indoor climate are due to high humidity, which, among other things, can create a breeding ground for house dust mites and mold.
If mold grows in the home, you can experience problems such as irritated mucous membranes in the eyes, nose, throat and airways, fatigue, breathing difficulties and headaches. In the extreme, you can develop allergies and asthma.
The home itself can also be damaged by excessive humidity. Moisture and mold can spread and in the worst case cause a fungal attack, which can eventually infect the entire home.
High humidity – this is how you discover it
Preferably measure the air humidity continuously with a hygrometer. Otherwise, you can. ‘see’ high humidity by:
The fog on the inside of the double-glazed window extends more than 2 cm into the glass from the frames.
Bottom moldings in the windows are damp and discolored or smooth. It may be a sign of a minor attack of mold inside.
Paint is peeling off.
The wallpaper is loose.
There is a musty or stuffy smell like in a basement or a summer house, which can be a sign of mold.
What is relative humidity?
Humidity is a measure of how much water vapor the air contains. The humidity is measured either as absolute humidity or relative humidity.
The relative humidity, which is the relevant parameter for the quality of the indoor climate, is the ratio between the current amount of water vapor in an air mass and the maximum amount of water vapor that the air mass can contain, which is a ratio of the air mass’s temperature and pressure. Relative humidity is usually expressed as a percentage with values from 0-100 percent.
The amount of water vapor that air can hold increases with increasing temperature. Therefore, the relative humidity of an air mass will decrease if the air is heated, and correspondingly increase if the air is cooled.
With continued cooling, the relative humidity will at some point reach 100 percent and the water vapor will begin to condense. It usually happens daily when the dew falls in the evening.
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