Buildings Special Issue on "Research on the Airtightness of Buildings" open for submission

A special issue of Buildings (ISSN 2075-5309)  is now open for submission.

This Special Issue is motivated by the importance of the airtightness of buildings in terms of indoor air quality and the energy implications of heat transfer. Currently, it is not possible to design and construct nZEB buildings without taking this parameter into account, and it is essential that we can determine this parameter in buildings to be renovated in order to achieve a significant improvement in their final energy consumption. 


Restriction of Air Infiltration by an Air Curtain Optimized with Secondary Jets—A Numerical Investigation

Infiltration of unconditioned air through access openings and entrance doors with high recurrence can cause detrimental impacts to the energy performance, air quality and thermal comfort of buildings. Air curtains are of strategic importance to attenuate these negative impacts. In addition, air curtains are relevant in specialized HVAC applications for which the impediment of infiltration is also essential (e.g., reduction of smoke propagation in fire events, decrease of contamination hazard in clean rooms, preservation of refrigeration properties in cold rooms).

Three-Dimensional Characterization Of The Air Infiltration Path Using Infrared Technology

Air infiltration control is essential to guarantee thermal comfort, good performance of the ventilation systems, and more energy-efficient buildings. The evaluation of the global airtightness of the building envelope based on pressurization tests has been widely used combined with infrared thermography as a complementary tool to locate air leakage paths. This work proposes a new methodology whose main objective is the characterization of the air infiltration path using infrared thermography.

REMARK: This Q&A was part of the AIVC special COVID-19 newsletter published in February 2021. To subscribe to the newsletter please click here.

The AIVC of the 20th Century

This report reviews the activities of the AIVC during its first twenty years of operation. It identifies key projects and addresses them in the context of research activities and associated issues of the time. Early issues included the need for energy conservation and reducing air infiltration loss. Much work concentrated on assessing the performance of numerical models and acquiring input and validation measurement data. Towards the end of the period attention focused towards energy efficient ventilation systems for good indoor air quality and comfort.

Comparison between infiltration rate predictions using the divide-by-20 rule of thumb and real measurements

Across different territories there are various normative models for assessing energy demand of domestic dwellings, which use simplified approaches to account for the heat loss due to the air infiltration of a building.  For instance, the United Kingdom uses a dwelling energy model, known as the Standard Assessment Procedure (SAP), and this utilises a process where the measured air permeability value (q50), is simply divided by 20 to provide an infiltration rate (subsequent modification factors are then used for factors such as sheltering etc.).

On the experimental validation of the infiltration model DOMVENT3D

Buildings represent approximately 40% of global energy demand and heat loss induced by uncontrolled air leakage through the building fabric can represent up to one third of the heating load in a building. This leakage of air at ambient pressure levels, is known as air infiltration and can be measured by tracer gas means, however, the method is disruptive and invasive. Air infiltration models are a non-disruptive way to calculate predictive values for air infiltration in buildings.

Effects of Outdoor Environment on Air Exchange Rate

Indoor air quality is the chemical, physical and biological properties that indoor air must have to not cause any negative impact on occupants’ health and provide comfort: feel fresh, pleasant and stimulating. 

CFD modelling of fan pressurization method in buildings – The impact of dynamic wind on airtightness tests

Building airtightness tests have become very common in several countries, either to comply with minimum requirements of regulations or programs, or to justify input values in calculation methods. This raises increasing concerns for the reliability of those tests. Despite the extensive debates about how the building pressurization test standard ISO 9972 should address sources of uncertainties, no change has been implemented. According to the current standard, the zero-flow pressure shall not exceed 5 Pa for the test to be valid.

Experimental study on the measurement of Building Infiltration and Air Leakage rates (at 4 and 50 Pa) by means of Tracer Gas methods, Blower Door and the novel Pulse technique in a Detached UK Home

Air infiltration contributes to a heat loss typically representing up to one third of the heating demand of a building. The building airtightness, also quantified as air leakage, is the fundamental building property that impacts infiltration. The steady (de)pressurization method (blower door) is the widely accepted standard process for measuring building air leakage. However, this method requires the enclosure to be pressurised to a typical range of 10-60 Pa, which is not physically representative of the pressures experienced by buildings under natural conditions.