What is BS EN 15665 – Performance criteria for residential ventilation systems about?
Building ventilation is important for airflow within the building spaces. It helps in keeping building spaces circulated with fresh air and minimizes the risks related to pollutant contamination from various sources.
BS EN 15665 is a European Standard that ventilation for buildings. BS EN 15665 is intended to give guidance to those with responsibility for producing requirements and standards for residential ventilation systems.
BS EN 15665 sets out criteria to assess the performance of residential ventilation systems (for new, existing and refurbished buildings) which serve single family, multi-family and apartment type dwellings throughout the year.
BS EN 15665 specifies ways to determine performance criteria to be used for design levels
in regulations and/or standards. These criteria are meant to be applied to, in particular:
- Mechanically ventilated building (mechanical exhaust, mechanical supply or balanced system)
- Natural ventilation with stack effect for passive ducts
- Hybrid system switching between mechanical and natural modes
- Windows opening by manual operation for airing or summer comfort issues.
BS EN 15665 considers aspects of hygiene and indoor air quality.
Note: Health risk from exposure to tobacco smoke is excluded from BS EN 15665.
Who is BS EN 15665 - Performance criteria for residential ventilation systems for? 
BS EN 15665 on performance criteria for residential ventilation systems is relevant to: 
- Manufacturers of ventilation and air conditioning systems
- Quality control and testing personnel
- Mechanical engineers
- Building designers and architects
- Standard developers
Why should you use BS EN 15665 - Performance criteria for residential ventilation systems?
Nowadays most ventilation requirements either in regulations or in standards are based on required airflow rates. Also, there is relatively limited knowledge about the basis for ventilation flow rates. Airflow rates are however probably the easiest way to express ventilation requirements.
Before designing a ventilation system, the people involved in regulations and/or standards shall answer lots of questions and assumptions that have to be taken into account for calculation. The result of this calculation can be expressed by a continuous explicit airflow rate (e.g. mechanical ventilation with constant airflow rate) or an equivalent airflow in terms of air quality according to conventional assumptions applicable in each country.
BS EN 15665 covers the way of proceeding for the determination of airflow rates and the criteria for the same.
BS EN 15665 takes into account the criteria of pollutant emission rates, humidity and the threshold of these parameters to calculate how much it is impacting the performance of the ventilation system.
BS EN 15665 also discusses the needs for residential ventilation, requirements for designing a ventilation system
Thus, it is recommended that future revisions of relevant regulations and standards should consider the content of BS EN 15665 such that pollutant contamination that negatively impacts ventilation in dwellings can be minimized.
