ventilation

Regional climate change in cities is the most documented phenomenon of climate change . Higher urban temperatures are  documented experimentally for more than 450 major cities in the world. Numerous investigations demonstrate that the mean magnitude of the temperature increase may exceed 4-6 C, while at the peak it may exceed  10 C. The serious increase of the frequency and the strength of heat waves creates strong synergies between the global and regional climate change and intensify the magnitude of the overheating 

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. 

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. Indeed, most of the new residential buildings, which must be low-energy buildings to comply with the RT 2012 energy performance regulation, are equipped with such systems. Feedbacks from two long-term studies show the durability of the humidity sensitive components and show the robustness of this system to bad maintenance or use by occupants.

The modelling of air flows to investigate indoor air quality and energy issues has been a topic at the AIVC for all of its 40 years. Models have been developed that range in complexity from single-zone algebraic expressions that can be calculated by hand to complex multi-zone approaches that integrate contaminant transport and other functions.

The purpose of this summary is to review Air Infiltration and Ventilation Centre activities, as reflected in its publications, related to indoor carbon dioxide over the 40 years that have transpired since its creation. These activities, like most applications of indoor CO2 to the fields of ventilation and indoor air quality, have focused on the following: control of outdoor ventilation rates, i.e., demand control ventilation; use as a tracer gas to measure outdoor air change rates; providing an indicator or metric of IAQ; and, directly impacting human health, comfort and performance.

A demonstration house was previously built and commissioned in Iqaluit, Nunavut, Canada. The purpose of the overall effort is to evaluate the performance of a high-performance building located in the Canadian Arctic, while considering the unique social, economic and logistical challenges associated with its remote location. Previous work consisted of monitoring and reporting on the energy consumption due to heating between April 2016 and April 2017.

The Arctic environment is challenging for housing ventilation and heating systems. Energy consumption and demand for space heating for northern remote community residential buildings are very high. Airtight built northern homes require energy efficient and effective ventilation systems to maintain acceptable indoor air quality and comfort, and to protect the building envelope from moisture damage.

Radon gas is a well-known building´s pollutant which can affect negatively people´s health (WHO, 2009). Radon´s source is the soil underneath buildings. Radon moves from the soil to the buildings by advection through cracks and joints, and diffusion through porous materials. Once radon enters buildings it can accumulate in lower areas due to lack of ventilation. Ventilation is one of the main ways to prevent radon from accumulating in enclosed spaces in the case of moderate radon concentrations up to 600 Bq/m3 (Collignan, 2008).