EU

Ventilative cooling (VC) is an application (distribution in time and space) of air flow rates to reduce cooling loads in spaces using outside air driven by natural, mechanical or hybrid ventilation strategies. Ventilative cooling reduces overheating in both existing and new buildings - being both a sustainable and energy efficient solution to improve indoor thermal comfort. In new buildings VC, may save cooling energy and thereby make it easier to fulfil future energy legislation for buildings.

Over the course of the four-year research project of the IEA EBC Annex 62, Ventilative Cooling (VC) has been proven a robust and highly energy efficient solution to support summer comfort in both residential and commercial buildings. Furthermore our findings show that VC can be successfully applied in both cool and warm temperate climates. 

Aeroseal technology utilizes air laden with fine aerosol particles (2-20 μm) to pressurize a duct system, resulting in deposition of those particles at the leaks within that duct system. By reducing leakages of duct systems by 90% in average Aeroseal sealing technology allows reducing leakages to a standard better as air tightness class D or ATC 1 for a complete system. Aeroseal technology can be applied in new constructions as well as in existing systems to improve energy efficiency, cleanliness of ventilation systems, IAQ and comfort.

The implementation of the Energy Performance of Buildings Directive 2010/31/EU recast puts increasing pressure to achieve better building and ductwork airtightness.  

In this context, Eurovent Certita Certification decided to establish a new certification programme for Ventilation Ductwork Systems, opening a new chapter in the history of the Eurovent Certified Performance (ECP) certification mark, which concerned only products, not systems, until then.  

This paper summarizes the most recent results of the French database of ductwork airtightness. This database was created in 2016. It is fed through measurements performed by qualified testers according to a national scheme regarding ductwork. Measurements are mainly performed in building applying for the Effinergie + label which requires class A for ductwork airtightness. Therefore, results discuss in this paper only apply to the buildings of the database and cannot be generalized to all new buildings in France.

A ductwork system that has limited air leakage, within defined limits, will ensure that the design characteristics of the VAC system are sustained. It will also ensure that energy and operational costs are maintained at optimal levels. 

Does the UK have any requirements regarding ventilation ductwork airtightness and how does the UK assess the installed performance of ducted mechanical ventilation systems? 

Duct leakage airflow in existing ductwork can reach values of over 20% of the design air handling unit (AHU) airflow, undermining efficiency and effectiveness of HVAC systems. We have measured, in an existing building where ductwork was installed 20 years before, with no special care on duct leakage and tight building construction schedules, operational duct leakage rates between 10% and 40% of the AHUs airflows. 

In order to better address energy and indoor air quality issues, ventilation needs to become smarter. A key smart ventilation concept is to use controls to ventilate more at times it provides either an energy or IAQ advantage (or both) and less when it provides a disadvantage. This would be done in a manner that provides improved home energy and IAQ performance, relative to a “dumb” base case. A favorable context exists in many countries to develop smart ventilation strategies.

In 2017, the Air Infiltration and Ventilation Centre (AIVC) identified smart ventilation for buildings as a new and important topic to be addressed. One of the tasks was to agree on a definition of smart ventilation, which was published in March 2018. The purpose of this presentation is to explain and illustrate the smart ventilation definition by AIVC.

Amid the contaminant issues, air pollution has awakened more interest due to its potential health risk and its direct effect on human productivity. The overall indoor environment quality depends on the contribution of both the indoor and the outdoor air quality. The outdoor air pollutants penetrate indoor environments through mechanical and natural ventilation as well as by infiltrations through cracks and leaks in building’s envelope. The interaction between the indoor and outdoor air may be studied by the air exchange rate.