AIVC

Pressurisation - Infiltration Correlation: Measurements

Pressurisation - Infiltration Correlation: Models

This report gives a critical review of steps taken in 10 countries (Belgium, Denmark, Finland, France, Germany, Netherlands, Japan, Sweden, UK, USA) with regard to testing and reporting schemes as well as overall quality approaches to improve building airtightness. The analyses are mostly based on contributions and discussions with 20 speakers invited to the AIVC-TightVent airtightness international workshop held in Brussels, 28-29 March 2012; they also include information from earlier publications as well as from the authors’ experience.

We collected information on existing envelope air leakage databases from countries that are involved in the AIVC-TightVent project “Development and applications of building air leakage databases”. This document summarizes the information from five countries: Czech Republic, France, Germany, UK, and USA. Even though our summary is not exhaustive of all existing data on whole-building envelope air leakage, it provides an overview of recent efforts from a number of countries. There are many reasons why different countries are collecting these data.

Energy use for fan operation can be significantly reduced by a 3-flanked approach: 

(1) The first step is prudent sizing of ventilation rates by minimizing the demand (e.g. low-emission building materials, passive cooling design), and by utilizing efficient air distribution. The latter reduces unnecessary over-ventilation by use of airtight ductwork, careful choice of room airflow principles (i.e. minimizing short-circuiting), and controls for demand-control of flow rate.

Due to the rapid urbanization and modernization of Korea, the demand for housing has increased considerably more than in other countries. As a result, the apartment building has become the prevalent housing type in many cities and suburbs in Korea. Today, the demand for an improvement in the qualitative aspects of housing is growing considerably due to the increase in the housing supply rate.

The Czech Republic is a landlocked country located in the centre of Europe. The area of the Czech Republic is 78,866 km² and its population is about 10.4 million people. The Czech Republic was part of the former Czechoslovakia until 1993 and it has been a member state of the European Union since May 2004. The Czech Republic is an industrialized country enjoying a decent gross domestic product (GDP) growth (6.6 percent in 2007). The GDP per capita is currently at about 82 percent of the average of the 27 EU member states.

Low income households in developed and less developed countries suffer from serious indoor environmental problems like heat stress, lack of comfort and poor indoor air quality. This has a very serious impact on the quality of life and health of poor citizens. More than 2 million deaths per year are attributable to indoor air pollution from inadequate use of fuels, while thousands of low income citizens die because of high indoor temperatures.

Because of specific urban characteristics, the potential of natural ventilation can be seriously decreased in the urban environment because of reduced wind speeds, high ambient temperatures and increased external pollutant and noise levels. Besides, the performance of hybrid ventilation systems is also affected and they are expected to work most of the times with mechanical ventilation.

Ventilation standards and guidelines typically treat ventilation as a constant and specify its value. In many circumstances a designer wishes to use intermittent ventilation, rather than constant ventilation, but there are no easy equivalencies available. This report develops a model of efficacy that allows one to calculate how much intermittent ventilation one needs to get the same indoor air quality as a the continuous value specified.