English

Smartness is all around us. The HVAC industry is developing more and more products that have sensors, are intelligent, are connected to the Internet and are being controlled via apps. According to a recent European survey among installers, the request and demand from clients for installing home automation and smart products is the highest for HVAC installations. 

In future building regulations 2020, building performance is going to be extended to global performance, including indoor air quality (IAQ). In the energy performance (EP) field, successive regulations pushed for a "performance-based" approach, based on an energy consumption requirement at the design stage. Nevertheless, ventilation regulations throughout the world are still mostly based on prescriptive approaches, setting airflows requirements. A performance-based approach for ventilation would insure that ventilation is designed to avoid risks for occupant’s health. 

In the field of energy performance, successive regulations pushed a "performance-based" approach, based at least on an energy consumption requirement at the design stage for heating and/or cooling systems (Spekkink 2005). Nevertheless, in the field of building ventilation, regulations throughout the world are mainly still based on “prescriptive” approaches, using airflows or air change rates requirements.  

As a consequence of the sustainable politics demanding regulations that allow the use of more efficient ventilation systems, the IAQ Spanish regulations were modified and enforced in 2017. The new regulations became performance-based in order to accommodate the use of systems which are capable of adapting required ventilation rates to real needs. The new requirement is based on both CO2 concentration and a minimum ventilation rate. 

The new IAQ requirement is able to keep acceptable IAQ values and to reduce energy demand in relation to the previous IAQ requirement. 

Performance based approached for ventilation started to be used in Belgium in 2008 in the context of EP regulation. Until 2015, demand controlled ventilation (DCV) systems were considered as “innovative” products and were not directly taken into account in the EP calculation method. Their energy performance was then considered through a principle of equivalency. A first performance based approach was developed in this frame.  

Demand controlled ventilation (DCV) seems to be the main way to comply with both energy and internal air quality (IAQ) concerns. Largely spread in non-residential building since more than 2 decades (Fisk, 1998) because of large potential energy savings, its application for the residential sector is nowadays becoming the basis of ventilation systems for dwellings. Indeed, thermal regulations for residential buildings in several countries give targets that are difficult to reach with constant air changes rates.

The building airtightness is essential to achieve a high energy performance. In most countries however, it is not mandatory to measure the airtightness. In the Netherlands it is common practice to just take a couple samples in a housing project. These samples do not give a good indication for all the buildings in a project. It is therefore important to measure the airtightness of all the buildings.

Previous studies have compared the airtightness measurement of test enclosures utilising both the novel Pulse technique and the conventional blower door method.  Discrepancies between results of the two test methods were observed and it was concluded that differences either caused by wind or blower door installation integrity would have had an impact upon the results.

Building airtightness is a critical aspect for energy-efficient buildings as energy performance of a building can be reduced significantly by poor airtightness. The Pulse technique has been regarded as a promising technology, which measures the building airtightness at a low pressure of 4Pa by rapidly releasing a 1.5-second pulse of air from a pressurised vessel into the test building and thereby creating an instant pressure rise that quickly reaches a “quasi-steady” condition. However, questions have often been asked on the test viability due to the nature of the test.

Requirements for measuring the building airtightness have been proposed and included by many countries for national regulations or energy-efficient programs to address the negative effect of poor airtightness on building energy performance, durability and indoor environment. The methods for measuring building airtightness have continuously improved and evolved over a number of years.