Improving ventilation in the building

Modern, properly designed and constructed ventilation can significantly improve both indoor air parameters and the overall comfort. Unfortunately, not every house is equipped with a system like this. Older structures usually offer gravitational ventilation only, which is less efficient and does not always meet the residents’ expectations. How to improve ventilation in the building to make it more efficient?

Why do buildings have ventilation?

Air, and more specifically its ingredients, is essential to people's lives. Staying inside an airtight structure without any inflow of external air will shortly lead to oxygen depletion and obstructed breathing, followed by asphyxiation. An additional problem is the exhaled carbon dioxide which replaces oxygen and further accelerates fatigue and malaise.

Single- and multi-family houses are also equipped with heating and cooking equipment. The natural gas or propane-butane it runs on generates by-products in the form of harmful exhaust gases. When we add indoor fireplaces or central heating boilers to this list, you can imagine the amount of harmful substances released into the atmosphere. The purpose of ventilation is to remove these contaminants outside the building and replace them with pure, oxygen-rich air.

When considering ventilation for a building, one should pay attention to new trends in the construction industry. Energy-efficient or passive houses are extremely tight, which is why clean air cannot enter them. The only way to ensure its exchange is an efficient ventilation system. 

Building ventilation and its types.

According to construction regulations, ventilation is a mandatory equipment of each and every building. These regulations also specify the parameters of the system, and particularly the volume and speed of air exchange in different rooms.

For centuries, gravitational ventilation has been installed in buildings. Its structure consists of ductwork with adequate cross-sections, as well as building inlets and exhausts. Air exchange is driven by so-called convection. In practice, this means that lighter, less condensed, and warmer indoor air goes up while cold, heavier outdoor air travels downwards in a duct.

The function of gravitational ventilation is limited by the technical conditions of the building. Since it is an unreliable system that is not fully efficient, various improvements have been introduced. Therefore, buildings are nowadays fitted with:

• mechanical ventilation,
• mixing ventilation,
• displacement ventilation,
• hybrid ventilation,
• mechanical ventilation with heat recovery.  
  

Each type of ventilation applies specific physical phenomena or auxiliary devices such as AHUs, fans, or recovery units. It makes the system more efficient and often brings additional benefits. One of them is the recovery of heat.

What is the mechanical ventilation system?

As the name suggests, mechanical ventilation consists of additional devices that assist air exchange. It is therefore called forced ventilation. Gas flow is induced by a fan driven by an electric motor. The fan can move at different speeds, allowing the air flow rate to be adjusted. This function is important when, in certain periods of the year or when performing certain activities, faster air exchange in the building is recommended.

The mechanical ventilation system is usually equipped with a control device that provides control over the fan. The heat recovery system is a more advanced type of mechanical ventilation. 

Recovery as a form of mechanical ventilation.

The purpose of typical gravitational or mechanical ventilation is to remove and replace used air from the room and replaced it on the fresh air. When the used gas mixture is evacuated, heat is also removed. This is a big problem in winter when building interiors need to be heated using a central heating system. The more heat escapes through ventilation, the more fuel must be burned to make up for the temperature loss inside the building. This means that the cost of heating and fuel purchase will grow.

Recovery is a simple way of keeping heat inside the home. The recuperator contains two ducts, in which the suction and discharge air streams pass. When this happens, heat is transferred from one stream to another, returning to the inside.

• The most important advantages of heat recovery are: 
  reducing the cost of building maintenance by reducing heating expenditure
• creating a healthy environment in the building, with a clean and oxygen-rich atmosphere. 
  

Best ways to improve ventilation in the building.

Those who live in old buildings often wonder how they can improve ventilation in their building? With gravitational ventilation, an air-tight building and thermal insulation limit the function of the natural system. The fastest way to improve its performance is to install air diffusers, including their mechanical versions. Chimney caps may also prove helpful. They help to achieve greater vacuum in ventilation ducts. Unfortunately, their operation is dependent on the presence of wind.

Air handling units with heat recovery.

Installing an air handling unit with heat recovery, e.g. one from the VENTUS Compact series by VTS Group, may prove to be a game-changer. Air handling units with heat recovery make the building comfortable to stay in and contribute to reduced maintenance costs.