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Just as we humans need to breathe, our houses also need to breathe in order to be in good shape for us to feel well when we are inside. When we renovate our homes we want to be energy smart, so we add more insulation, change to more climate smart windows and make the façade airtight so that we can keep the heat inside. So far, so good. What we don’t often speak about is indoor air in connection with renovation. To help raise awareness and hopefully create greater interest, we have introduced a mini-series specifically on the theme of indoor air and indoor climate.

Why should you be interested in your indoor climate?

We spend about 90% of our time indoors and often the indoor air is significantly more polluted than the outdoor air. Generally, because we do not always remember to ventilate properly when we renovate buildings.

We humans contribute to air pollution ourselves. Partly because we exhale carbon dioxide, which above a certain level leads to headaches, drowsiness, difficulty concentrating and poor sleep. And partly because of our activities, such as cooking, burning in wood stoves, using everyday items such as cleaning products, paint, perfume, scent sprays, new furniture / carpets and various building materials. These contaminants can lead to a variety of health problems such as headaches, nausea, cough, dizziness, nose, throat and skin irritation. There has also been a clear connection between a bad indoor climate and an increased risk of asthma and allergies in children.

The ventilation system’s main task is to transport these pollutants out of the building and replace it with fresh air. Historically by natural ventilation and leaks in the façade, but in more modern buildings it is solved through some form of mechanical ventilation.

How do you know if the indoor climate is bad?

In addition to the health problems mentioned, there are some simple ways to check if the air exchange and ventilation are insufficient:

  • Do you have water vapour and condensation on the inside of your windows, especially when it is cold outside?
  • Do you have water vapour and condensation on the bathroom mirror that stays on for more than half an hour after you shower?
  • Are there small black dots on the ceiling or walls in the bathroom? This is probably a sign that the humid air is not removed by the ventilation.
  • If the smell of food is spread in the house, it may be that the ventilation goes in the wrong direction. The air must be ventilated out of the kitchen via the kitchen fan.
  • Also keep in mind that it is important that the duct for the kitchen fan is separated from the other ventilation ducts.

If you are interested in knowing more about your own indoor climate, there are many different types of monitors and air quality meters on the market. Search for “measuring air quality at home” on the internet (or air quality sensors, air quality monitors) and lots of exciting products will appear.

Always keep the airways clear

It is not uncommon that people, unknowingly, disturb or block the air flow of the ventilation system or fresh air valves. These systems and products can be compared with our own airways and thus need to be kept free for the air to flow in and out of the house. If we close the fresh air valve when we clean, or change the setting of it, the balance of the system can be affected. This leads to a poorer indoor climate. In some cases, you may also experience problems with noise.

Some last tips if you want to check your indoor climate at home

  • If you don’t have a MHVR system, make sure that your house has enough fresh air valves. It is through the fresh air valves that new air can enter your home. Approximately 1 fresh air valve is needed per 25 square meters of living space.
  • Be careful when cleaning the fresh air valves so that the air flow is not disturbed.
  • Check if air is actually passing through the air valves. Hold a plain piece of paper against the valve. At a supply air valve, the paper should “flutter” out of the valve. At an exhaust air valve, the paper should be sucked in. Those are clear signs that everything is working as it should. The exhaust air valves are placed in “hot and damp” areas, such as bathrooms and laundry rooms.
  • Remember to change filters of your fresh air valves, or in your ventilation unit if you have one. If someone in the household has pollen allergy, you should change them both spring and autumn. That is before and after the pollen season.

Last but not least, please get in touch if you want more information, more tips or have a chat. If you want to read more posts on the same topic, you can find them here.