IAQ

The Book of Proceedings of the 42^nd AIVC - 10^th TightVent - 8^th venticool Conference: "Ventilation Challenges in a Changing World" held in Rotterdam, Netherlands on 5-6 October 2022

The Presentations at the 42^nd AIVC - 10^th TightVent - 8^th venticool Conference: "Ventilation Challenges in a Changing World" held in Rotterdam, Netherlands on 5-6 October 2022

Climate change is a growing global concern and building stock, in particular, is responsible for the emission of greenhouse gases, largely due to its poor energy efficiency. This problem is especially serious in educational buildings, where it is necessary to encourage energy efficient retrofitting under the parameters of nearly Zero Energy Building (nZEB), an objective which in Europe has been set for 2050. This is expected to produce economic, energy saving, hygrothermal comfort and health-safety benefits.

The energy performance of new and existing residential buildings needs to be radically improved to meet ambitious climate change goals and residential buildings are by far the largest component in the total building stock. A central boundary condition in constructing energy efficient buildings is doing so while maintaining a healthy, acceptable and desirable indoor environment.

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.

Ambitious goals regarding CO2 neutrality put the energy renovations of apartment buildings in the top places on the energy efficiency & sustainability agenda in Denmark. Improved airtightness and maximum primary energy requirements imply utilization of ventilation with heat recovery. The control of ventilation installed during renovations often considers a whole dwelling as one climate zone, which neglects differences among individual rooms. Increased insulation and tightness leads to higher sensitivity to solar and occupancy gains, moisture loads and pollutants.

Humidity-based DCV systems have been widely used in France for 35 years and are considered as a reference system, including for low-energy residential buildings. The on-going Performance 2 project delivers the new results of a thirteen-year monitoring in twenty-two social housing apartments. The involved consortium is composed of Cerema, Univ. Savoie Mont Blanc and two industrials partners: Aereco and Anjos. 

IEA-EBC Annex 86 “Energy Efficient IAQ Management in residential buildings” aims to propose an integrated rating method for the performance assessment and optimization of energy efficient strategies of managing the indoor air quality (IAQ) in new and existing residential buildings. Our goal is to work in an international collaboration so that the different approaches to design and operation of ventilation in different countries are accounted for.

The level of airtightness is increasing in newly built Australian apartments. An appropriate ventilation rate is needed to provide occupants with a healthy environment. In 2022, a significant proposed change in the Australian National Construction Code (NCC) would require building tested as achieving less than five air changes per hour at 50Pa to have a continuous flow exhaust.

This paper shows the results of a survey conducted among 10 AIVC members countries about air quality in garages and current requirements and regulations in this regard. Large differences were found among countries, not only in terms of the scope of the regulations, but also in relation to the parameters that are considered.