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The impinging jet ventilation (IJV) system has been proposed as a new air distribution strategy and is expected to overcome the disadvantages of the mixing ventilation system (MV), which is the most widely used system, and displacement ventilation, which provides better air quality than MV.  

Stratum ventilation (SV) is an energy-efficient solution to provide thermal comfort and improve air quality. The air distribution in rooms with SV depends on the room layout, location of supply and exhaust grills and indoor heat gains. Therefore, the commonly used methods to predict air temperatures in the occupied zone do not usually fit the indoor temperature distribution. At the same time, detailed simulations of indoor air distribution are still mainly used in complicated room layouts and research.

Ventilation in buildings dilutes the indoor air pollutants by replacing part of the air with outdoor air to guarantee an adequate indoor air quality (IAQ). In heating-dominated climates, the exchanged air has a lower mean temperature than the indoor air, which leads to a surplus heating demand in the building. A heat exchanger recovers part of the heat from the expelled air, contributing to the reduction of the extra heating demand. Smart ventilation systems work with reduced airflows, without compromising the IAQ and lowering the heating demand.

A balanced ventilation system can be combined with an air-to-air heat pump. Such system combines the refreshment of the air in a house with heating and cooling of the fresh air in order to influence the indoor conditions like temperature and humidity. Depending on the season in the year, various modes are used to deliver fresh air and condition the incoming air to the desired levels.  

In a context of energy use reduction, low energy buildings are becoming more widespread. This kind of construction requires a good envelop airtightness to prevent uncontrolled leakages of conditioned air leading to energy losses. As a result, more and more ventilation systems are installed to ensure a sufficient air change rate for a good indoor air quality. 

Energy efficient buildings are getting more and more airtight to avoid thermal losses through uncontrolled air leakage and rely more and more on mechanical ventilation to ensure a good indoor air quality. In practice ventilation systems are however not always perfectly installed, and several problems are often encountered on-site. 
In France the new environmental regulation for new buildings RE2020 now includes a mandatory inspection of ventilation systems for non-residential buildings.  

Single-family and low-rise multifamily homes in the United States have become tighter to save energy and enhance comfort. To ensure acceptable indoor air quality (IAQ), mechanical ventilation is also required. As these systems become commonplace in the U.S., various improvements and updates have been made to codes, standards, and voluntary programs such as ASHRAE Standard 62.2, International Mechanical Code, International Residential Code, USEPA Energy Star Home and Indoor Air Plus, and USDOE Zero Energy Ready Homes. 

For years, ventilation and air-conditioning systems have played an increasingly important role in ensuring sufficient air exchange in buildings. With time buildings are becoming more and more airtight to avoid energy losses through uncontrolled air leakage and mechanical ventilation systems are installed to ensure a good indoor air quality. What is a good approach in theory can fail in practice due to leaky ductwork.

Calcium Silicate fire protection boards can be used to construct fireproof ductwork for smoke extraction and/or HVAC services. In this paper, the airtightness of the duct system is evaluated. 

In a context of energy savings, new buildings are becoming more and more airtight. The good indoor air quality (IAQ) relies therefore more and more on mechanical ventilation systems with specific air flowrates to be met. However, in practice, ventilation ductworks are not always very airtight. The numerous issues induced by leaky ductwork have been well outlined in the literature and summed up in (Leprince et al., 2020). Yet the awareness is not forthcoming, and on-site workers do not always realize the consequences of ductwork leakages.