Airbase publication

Wind-driven single-sided ventilation (SSV) is present in many existing buildings across Europe and with new Near Zero Energy Building (NZEB) regulations for the refurbishment of the existing building stock, its attractiveness as a non-invasive, low energy solution is set to continue. As a strategy, however, in addition to its air change rate capacity, the distribution of fresh air is an important evaluating criterion for its performance.

Occupants in residential buildings usually control natural ventilation through window openings. However, few studies have developed simple rules based on the outdoor weather forecast that can inform the occupants to predict the indoor condition by applying natural ventilation for thermal comfort and indoor air quality (IAQ). This paper describes a model based on indoor/outdoor correlations, derived through simulations using EnergyPlus and CONTAM, to help occupants maintain internal environmental quality manually or through simple controls.

In future years the frequency, duration and magnitude of extreme heat events, such as heat waves, is expected to increase due to climate change. The population is exposed to higher thermal discomfort and risk at home and, at the same time, high external temperatures make it more difficult to cool their household through natural ventilation.

In order to propose adaptive measures, research should first assess the thermal resilience of the existing residential buildings when exposed to prolonged heat stress. Poorly insulated and non-equipped buildings typical of Southern

In the context of climate change, Building Performance Simulations are used to assess the ability of passive buildings to maintain acceptable comfort conditions, or to limit the air conditioning energy consumption during heatwaves. Climate projection data, including heatwaves, are needed to feed the Building Performance Simulation tools. A building, located in a given location, is likely to experience several heatwaves with different characteristics in the coming decades.

Many European programs offer eco-conditioned financial aid to support public policies for the decarbonization of buildings. This is the case, for example, of the 2017-2022 ERDF Operational Program, which financially assists social project management for energy efficient refurbishment operations of its building stock. The eligibility conditions for financial aids concern the energy consumption, the thermal insulation performance of the building envelope and the energy efficiency of heating, cooling and ventilation systems.

Room pressure differential is an important aspect in order to guarantee sufficient contamination control, but is difficult to control in airtight cleanrooms. This research uses simulation models to get an understanding and to quantify the room pressure controllability of airtight cleanrooms. The most influential parameters on the room pressure controllability are identified using a sensitivity analysis. The effects of the shell airtightness and overflow flowrates are quantified, and the effect of a flow/pressure cascade with three coupled rooms is investigated.

By 2050, the European council proposed to achieve total decarbonization in buildings. In this way, building energy models are key factors to predict the energy consumption in the design, use and retrofit stages. However, these models may present a relevant gap between predicted and measured energy performance, which should be minimised by cutting uncertainties with real data. Air leakage is one of the main uncertainties and causes of increasing building loads by renovating the indoor air in an uncontrolled way.

While the importance of air barrier systems in buildings has been understood for decades, it is only in the past decade or so that they have been given appropriate attention in the energy codes of most countries. While at least one country has had air barrier requirements in their codes since the mid-1980s, the “model energy codes” of others have largely ignored the issue until recently.

With the constant evolution of the French EP-regulations, good building airtightness has become mandatory to reach required energy performance. More than 60,000 airtightness tests are performed each year since 2015. Each measurement performed by a qualified tester must be recorded in a national database that is therefore growing fast (more than half million in 2020).

Worldwide, the demand for airtightness tests of tall buildings with a height of approximately 100 m is increasing. This report provides information on the planning and measurement concept for testing the entire building as a “single-zone” and presents the results and findings of the airtightness tests. The test set-up and the tests as such are based on the Passive House Institute's Guide to Measuring Tall Buildings [5] which includes recommendations that go beyond the ISO 9972 standard.