Research results: ventilation at Kleiburg
- Commissie Duurzaam
- Jan 28
- 4 min read
Updated: Feb 9
Ventilation - introduction
The indoor climate in our apartments is a crucial part of our daily living experience. It not only determines whether a space feels comfortable but also influences our health and well-being. A good indoor climate is the result of a combination of various factors. It's a balance between heat, humidity, fresh air, CO₂, light, and sound.
A good ventilation system is essential to maintain a healthy and comfortable indoor climate.
Good ventilation prevents:
accumulation of CO₂, moisture, dust particles and all kinds of contaminants, which reduces complaints such as headaches, allergies, shortness of breath and fatigue;
mold and moisture problems in bathrooms, kitchens and bedrooms;
a musty, stuffy air and keeps the temperature and humidity stable.
Too much?
However, a ventilation system can also lead to excessive ventilation. This is called overventilation, resulting in unnecessary heat loss and drafts.
Modern ventilation systems, especially when combined with heat recovery (HRV) , ensure that fresh air is supplied without significant heat loss, keeping energy costs low and maintaining a comfortable climate in the home.
In this article we specifically discuss the possibilities of improving the ventilation system.
The ventilation system - the current situation
Fresh ventilation air is now supplied naturally. Metal sub-ducts —ventilation ducts ("suskasten") that channel air from outside to inside—are incorporated into the facade of each apartment.
These ventilation ducts actually form an open connection to the outside air and do not contain any insulation, sound insulation or smart control.
As a result, they can transmit a lot of cold air into the home in winter and heat in summer. This creates a less stable indoor climate and increases unnecessary energy consumption.
The exhaust air is extracted mechanically through shared ducts on the roof ( ventilation type C ). This system is constantly running and consumes a lot of energy.
The natural supply of fresh ventilation air can lead to heat loss in winter and the supply of overly warm outside air in summer.
Because the grille has to be opened and closed manually, there is a risk of insufficient ventilation or over-ventilation and draught.
Both the HU students and Steeds advies believe that an adjustment to the current situation is desirable in order to improve living comfort and save energy.
We see 3 possible improvements
Possibility 1. Ventilation type C+ ventilation type C is retained, only it is controlled by CO² sensors
The existing system C will be retained, but expanded with CO₂ sensors. These sensors measure the air quality in each room and automatically control the ventilation.
Operation
the supply of fresh air remains natural, through the existing ventilation grids and window or wall grilles;
The discharge is done mechanically and now only when necessary, based on the measured CO₂ and moisture content.
Advantages
energy saving: the system only runs when necessary, reducing heat loss and power consumption;
healthy indoor climate: automatic control ensures constant air quality and prevents mold and moisture problems.
Manual operation of the grilles will be maintained in this scenario. The existing ventilation boxes can be retained. These empty ventilation boxes can technically be filled with insulating material, but this will significantly reduce the ventilation capacity and may even be lost entirely.
Possibility 2. Ventilation system C+ Ventilation system C+, expanded with self-regulating grilles (ZR)
In this variant, the C+ system is combined with self-regulating grilles (ZR). These automatically adjust the air supply to changes in wind pressure or outside temperature.
Operation
A ZR grille operates mechanically thanks to an ingenious self-regulating valve. This valve automatically responds to changes in wind pressure and ensures that the incoming air volume remains constant as the wind increases. It works by using a flexible valve or spring mechanism that partially closes at higher pressure, preventing excessive cold air from entering and preventing drafts, noise, or energy loss.
When the wind pressure decreases, the valve opens again, ensuring sufficient ventilation even at low air pressure. No electrical components or motor are required; operation is entirely via the air pressure and the design of the grille itself.
Advantages
constant ventilation and more comfort, even in changing weather conditions;
A ZR grille has excellent thermal performance and contributes to the building's insulation. This is achieved through its design, which usually consists of aluminum profiles with a double or triple seal. This limits heat loss through the grille.
In combination with demand-controlled extraction (CO₂ and moisture), the efficiency can be approximately 75% higher than with standard grilles.
Points of interest
Self-regulating grilles require periodic maintenance to remain functioning properly (inspection, cleaning, lubrication). They are more expensive to maintain than manual grilles, but offer greater comfort and stability.
Existing soundproofing cabinets can be partially reused in this scenario, provided they are adapted for the installation of self-regulating and possibly sound-dampening grilles;
It is important to note that even the quietest ventilation grilles can still produce some noise under certain conditions, especially in strong winds or due to pressure differences.
#3. Ventilation system D balanced ventilation
In this system, both the supply and exhaust of air are mechanically controlled.
The system requires the installation of a network of air ducts. Installing this in existing buildings is complex and expensive. Therefore, in practice, it is only used in new-build homes.
Therefore, this possibility will be disregarded here.
Costs, subsidy and financing
Subsidies can be requested through the SVVE (for homeowners' associations) for energy-saving measures, including CO2-controlled ventilation systems and balanced ventilation with heat recovery.
The subsidy is a percentage of the construction costs
for one insulation measure: 15% of the costs, maximum €600 per apartment;
for two or more insulation measures: 30% of the costs, maximum €1,200 per apartment.
The CO2-controlled ventilation can also be further financed by a loan from the National Heat Fund.
Read all about saving, borrowing and subsidies here .
Sources & references
Utrecht University of Applied Sciences, Ventilation Research, 2024
SVVE (2024), Subsidy for energy-saving measures at homeowners' associations
National Heat Fund (2024), Financing for collective sustainability
Do you have any questions, ideas or would you like to share your experiences?
Email us at duurzaamkleiburg1@gmail.com . Together we'll chart a path toward a future-proof Kleiburg.
