English

Common metrics used for assessing air quality are based on guidelines and/or standards for regulating concentrations that should not be exceeded over a period. Exceeding those values would represent problematic situations. A lack of agreement on appropriate norms or standards deem this approach sub-optimal. Moreover, this approach does not relate a proportion of exceedance to specific health outcomes.

A Personalized Environmental Control System (PECS) aims to condition the immediate surrounding of occupants. This approach is fundamentally different from typical HVAC systems, which aim to create uniform indoor environments, regardless of the occupant preferences. PECS has several advantages including allowing occupants to adjust their immediate surroundings according to their preferences, which could improve their satisfaction with the indoor environment, and may lead to higher productivity.

Personalized Environmental Control Systems (PECS) condition the immediate surroundings of occupants, and they are expected to provide increased comfort, health, and productivity. Studies have reported on their benefits and limitations in addressing individual Indoor Environmental Quality (IEQ) factors, especially in terms of thermal comfort and indoor air quality. The COVID-19 pandemic and risks associated to climate change, such as heat waves, highlight the necessity for PECS that can address multiple IEQ factors.

Personalized Environmental Control Systems (PECS) with the functions of heating, cooling, ventilation, lighting, and acoustics have the advantage of controlling the localized environment at occupant’s workstation by their preference instead of conditioning an entire space. This improves personal comfort, health of the occupants, and energy efficiency of the entire heating, ventilation and air-conditioning (HVAC) system substantially. Some of the major advantages and limitations of PECS are summarized. 

Personalized Environmental Control Systems (PECS) have advantages of controlling the localized environment at occupants’ workstation by their preference instead of conditioning an entire room. A new IEA EBC Annex (Annex 87 - Energy and Indoor Environmental Quality Performance of Personalised Environmental Control Systems) has recently started to establish design criteria and operation guidelines for PECS and to quantify their benefits. This topical session will provide an introduction to the objective/scope, activities, and intended outputs of the annex. 

This work is part of two French research projects “Durabilit'air1” (2016-2019) and “Durabilit'air2” (2021-2024), that aim at improving our knowledge on the variation of buildings envelope airtightness through onsite measurement and accelerated ageing in laboratory-controlled conditions.   
During a past AIVC conference, a publication of the Durabilit’air1 project has presented and discussed an experimental protocol for characterizing assembly of products for buildings’ airtightness in laboratory controlled conditions.   

The content presented comes from the Technical Note (TN) 71 “Durability of building airtightness” published on Airbase, the AIVC bibliographic database.

The content presented comes from the Technical Note (TN) 71 “Durability of building airtightness” published on Airbase, the AIVC bibliographic database.

This work is part of two French research projects “Durabilit'air1” (2016-2019) and “Durabilit'air2” (2021-2024), that aim at improving our knowledge on the variation of buildings envelope airtightness through onsite measurement and accelerated ageing in laboratory-controlled conditions.   
The content presented in this paper is based on two publications in past AIVC conferences (Moujalled et al., 2019, 2018) and a research paper (Moujalled et al., 2021) about the mid-term and long-term changes in building airtightness through on-site measurements in low-energy houses. 

This study sets out to investigate to what extent the air permeability of a building envelope of a dwelling remains constant over longer periods of time. This was evaluated by executing an air pressurisation test in 30 dwellings located in Belgium and comparing these results to the initial measurement results obtained shortly after the construction of the buildings. The time span between both measurements ranges from 293 days to 4045 days. On average, the air infiltration rate of the building envelope increased with 24%, i.e. an increase of 64 m³/h at a 50 Pa pressure difference.