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Ninety per cent of New Zealand classrooms are naturally ventilated by opening windows. Achieving a suitable ventilation level will rely on teachers. A survey showed that less than half of the teachers opened windows during teaching time. Due to the high occupant density in classrooms and a low natural ventilation rate, it is challenging to provide adequate ventilation during the southern hemisphere winter months (June to September). From 9 am to 3 pm, school hours align well with the optimum solar radiation, providing opportunities for solar ventilation.

Low or Zero Energy buildings are becoming increasingly popular and the use of passive-house principles are providing a solid foundation for achieving energy consumption targets and good indoor quality. However, this design methodology has been well received in central and northern Europe than in south and the Mediterranean, where people are used to houses that are open to the external environment. This habit is in contrast to the basic principles of the good airtightness, the energy efficiency and the achievement of a good Indoor Air Quality.

The AIVC is preparing a series of VIP on national regulations and trends in airtightness for various countries (numbered VIP 45.XX), detailing for both building and ductwork airtightness: 

The AIVC is preparing a series of VIP on national regulations and trends in airtightness for various countries (numbered VIP 45.XX), detailing for both building and ductwork airtightness: 

The AIVC is preparing a series of VIP on national regulations and trends in airtightness for various countries (numbered VIP 45.XX), detailing for both building and ductwork airtightness: 

The AIVC is preparing a series of VIP on national regulations and trends in airtightness for various countries (numbered VIP 45.XX), detailing for both building and ductwork airtightness: 

The common demand control approach for MVHR systems using one CO2 sensor within the ventilation unit is assessed based on a typical residential apartment situation using CONTAM models. The simulation results confirm that air flow and therefore fan electricity and ventilation losses can be reduced compared to constant flow control, in particular for higher nominal air exchange rates. However, under certain boundary conditions, e.g. unevenly occupied dwellings indoor air quality in certain rooms may suffer with this DCV strategy.  

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. 

Many countries have mandated the use of mechanical ventilation with heat recovery to limit heat loss in residential buildings. Nearly all these devices use temperature sensors to modulate bypass dampers and adjust heat recovery. These controls track a reference temperature for the supply or return air while maintaining exhaust temperatures above freezing. As a result, nearly all air-handling units (AHUs) come equipped with temperature sensors before and after the heat exchanger for both airflows.