Very few countries have mandatory requirements for ductwork airtightness.
Frequently Asked Questions
This section answers some frequently asked questions for those who require a background knowledge to ventilation. As an additional reading, the AIVC suggests its’ handbook, "A Guide to Energy Efficient Ventilation", which reviews ventilation in the context of achieving energy efficiency and good indoor quality.
There are two major systems to classify ductwork airtightness, one based on European standards,…
The airtightness of a building is quantified by means of the measured air leakage rate through…
A blower door is a device used to measure the airtightness of buildings.
Requirements depend on the country and the context of the measurement.
Leakage in ventilation duct systems is important to keep to a minimum in order to save energy…
Building airtightness (also called envelope airtightness) is a general descriptive term…
Ductwork airtightness can be defined as the resistance to inward or outward air leakage through…
Detecting the location of leakages in the building envelope is useful in order to reduce the…
The relationship between the air flow rate (Q) and the pressure difference (ΔP) is often modeled…
<p>The definition given by AIVC for smart ventilation in buildings is:</p>
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n50 is a number used to quantify building airtightness.
Air penetrates through porous building materials and through joints in the building…
The most direct way for countries to ensure good building airtightness is to define mandatory…
A building airtightness test is a method for directly measuring the air leakage rate created by…
To improve the air tightness of existing air ducts, a method of sealing the ducts by applying a…
Duct leakage is not only detrimental to energy efficiency, but also to indoor air quality (in…
Existing methods to estimate building airtightness include:
Air infiltration adds to the quantity of air entering the building but may also distort the…
The ductwork airtightness test is made by attaching a measured airflow to the system and…
Wind creates a heterogeneous pressure distribution around the building and induces a…
An important point for improving the air tightness of air ducting systems is the use of ducts…
Good building airtightness is achieved in 3 steps: Plan - Build - Check.
Inside a ductwork a flow rate undergoes pressure drop due to friction and dynamic losses. …
Airtightness durability is a growing issue in Europe and the US.
When a ductwork is leaky, part of the flowrate generated by the fan comes from (for extract…
Poor building airtightness results in excessive air infiltration and resultant uncontrolled…
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Odour can be regarded as a 'pollutant' or as an indicator of…
Approximately 30% of the
Steady state pollutant concentration: The pollutant concentration in a space depends on…
Ventilation is needed to provide oxygen for metabolism and to dilute metabolic pollutants (…
Ventilation is accomplished by introducing ‘clean’ air into a space.
Calculation
Indices of ventilation efficiency characterise the mixing behaviour of air and the distribution…
Frequently, the dominant pollutant is ‘heat’ itself.
Ventilation needs and strategi
Poor ventilation can be associated with unhealthy buildings.
The quantity of ventilation needed depends on the amount and nature of
Too often it falls upon ventilation to accomplish tasks for which it is not appropriate.
Ventilation energy demand can be reduced considerably by adopting a variety of energy efficient…
This is the uncontrolled flow of air into a space through adventitious or unintentional gaps and…
Natural ventilation: Traditionally, ventilation needs have been met by ‘natural’ ventila…
The severity of climate influences the degree of heating or cooling that is necessary to…
Although close contact transmission is the dominant transmission route, long-range airborne…
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REMARK: The answers that follow were developed in November 2020.
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The Air Infiltration and Ventilation Centre's first
Various units are used to describe the rate of ventilation.…
Measurements are needed to verify the performance of ventilation systems and to test the air-…
Outdoor air may be ‘cleaned’ by filtration.
Definitions covering ventilation and the flow of air into and out of a space include: