Self-ventilated houses are a common type of construction in the country, especially when it comes to older buildings. Unlike new houses which often have modern ventilation, older houses rely on natural forces such as temperature and pressure differences when it comes to ventilating the home.

Unfortunately, older homes are prone to various ventilation-related problems. This in turn negatively affects the indoor environment. Fortunately, you can take a number of cost-effective measures yourself to reduce the risk of this happening.

Therefore, in this guide we will focus on providing you with practical tips on how to improve ventilation in a self-contained house. This will help you create a healthier indoor climate but also contribute to greater comfort for everyone in the household!

Book a free consultation with Airmove

Take the opportunity to book a free consultation with one of our experts. We offer advice via phone, video call and in some cases a home visit. During the call, we will discuss the existing ventilation in your home and provide you with advice on various improvements.

What signs can indicate that you have inadequate ventilation?

Identifying the signs of poor ventilation is the first step towards solving the underlying problem. When it comes down to it, you first need to know where to start before you can fix it! That's why we've compiled a number of common symptoms below that you need to pay special attention to:

 

●      Moisture stains : If you have moisture stains on your walls, you need to be extra careful as it could be a sign of poor ventilation.

 

●      Musty smell : If you experience a musty smell, it is a clear signal that the ventilation is not sufficient.

 

●      Condensation : If condensation forms on the inside of the windows, especially during winter, it indicates that air circulation is not sufficient.

 

●      Health problems : Do you often experience unexplained fatigue, headaches or breathing difficulties when you are in your home? This may be due to poor air quality.

 

Of course, there may also be other causes of poor ventilation, but the above symptoms are often the culprit.

How are you affected by poor ventilation?

Bad air can affect your health in several ways. For example, you may feel tired, have difficulty staying focused, or even experience a sickly feeling. If you also suffer from allergies or asthma, bad air can make things worse.

 

When you effectively replace indoor air, you will also reduce levels of carbon dioxide, moisture, and other harmful pollutants that tend to be present in polluted air. Other signs that you need to review your air quality may include:

 

●      Headaches : If you often experience headaches, especially upon waking up, it may be a sign that there is not enough fresh air in the bedroom.

 

●      Cough : If you have a recurring cough, without an underlying cold or flu, it may be a sign of poor air quality.

 

●      Eyes : If your eyes are often red and irritated, it is important to review the ventilation and air quality immediately as this may be a sign of mold.

How does natural draft ventilation work?

Natural ventilation is by far the oldest form of ventilation in Swedish houses. It is based on thermals, meaning that you rely on warm air rising upwards. When you rely on natural ventilation, the warm air will disappear through air ducts as it rises.

 

This in turn creates a negative pressure when the air from outside enters through leaks, such as poorly insulated windows. However, you will get the most out of natural ventilation during the winter months when the differences between the temperature inside and outside are large.

 

At the same time, it is precisely during the winter that natural ventilation is needed most, especially when it comes to older houses. Another important detail in this context is that natural ventilation works more effectively in multi-storey buildings.

Self-draft ventilation: Airflow versus temperature difference

The graph below is based on a study from Karlstad University and demonstrates the clear relationship between temperature difference and airflow in houses that rely on natural draft ventilation.

 

How to optimize ventilation in a self-contained house

A common problem with natural ventilation is limited supply air flow. By installing an automatic supply air valve like Airmove 3.0 in all rooms (except wet rooms and kitchens), you create conditions that make it possible to supply a higher proportion of supply air than before.

 

It is also not uncommon for air to have difficulty flowing out of the house because the existing solution is not efficient enough. Should this prove to be the case, it is recommended to install an exhaust fan in wet areas to optimize the airflow.

 

Many older houses have also been built with basements, which places additional demands on good ventilation. This is especially true if you decide to convert the basement space, using the wet area as a laundry room and shower.

 

In addition to getting rid of musty basement smells and high humidity, you will also reduce the risk of mold and expensive repairs. A cost-effective solution is to invest in a basement vent that costs less than a thousand kronor!

 

Tip ! Install fresh air vents in different areas of the home . A rule of thumb is to use one supply air vent per 25 m2. For wet rooms, you need to further strengthen the natural draft with extra fans. Focus especially on fans that are constantly in operation, while being able to be adjusted depending on the amount of moisture in the wet room.

Suggested solution

If we play with the idea that you live in a villa with natural ventilation of 150 m2 with four bedrooms, a living room and two bathrooms, you will need 6 fresh air valves - preferably with auto-regulation - to be able to meet your needs as follows:

 

●      1 fresh air vent for each bedroom.

●      2 fresh air vents for the living room.

●      1 exhaust fan for each bathroom.

 

We have based the above need on 1 fresh air vent per 25 m2 of living space by dividing 150 m2/25, which in turn results in 6 fresh air vents.

Closing words

Improving ventilation in a self-contained house doesn't have to be particularly difficult or expensive. Regular maintenance, cleaning of ventilation ducts and installation of heat exchangers such as Airmove 3.0 can do wonders for the indoor climate.

 

If you are unsure of how to proceed, or have any other concerns, we recommend that you get in touch with us at Airmove . We can provide you with recommendations regarding improvements and products - completely free of charge!

Frequently asked questions

What are the most common reasons why self-supporting houses are negatively affected?

When changes are made to the house, for example in connection with renovations in the form of additional insulation or the installation of a new heat source such as a wood stove, this can lead to a negative impact on natural ventilation.

What does enhanced natural ventilation mean?

You can enhance your natural ventilation by installing a fan on the roof. The unit also needs to be located near the exhaust air ducts. By getting a little more speed on the exhaust air, you will also increase the airflow and therefore improve ventilation.

Is it recommended to turn off the valves during the winter?

It is not uncommon for homeowners to choose to turn off supply air vents to reduce their heating costs. However, we advise against doing this as it will lead to both poor indoor air quality and moisture problems.