smart ventilation

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.

Assessment methods to assess smart ventilation, in most countries focus only on comfort as criteria for the indoor air quality (IAQ), (Guyot et al., 2019). This is an issue as in doing so, pollutants that are known to cause harm to the human health are not taken into consideration while the exposure to VOCs will be elevated if the smart ventilation system lowers the ventilation flowrates to save energy (De Jonge and Laverge, 2021).

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.

A balanced ventilation system can be combined with an air-to-air heat pump. Such system combines the refreshment of the air in a house with heating and cooling of the fresh air in order to influence the indoor conditions like temperature and humidity. Depending on the season in the year, various modes are used to deliver fresh air and condition the incoming air to the desired levels.  

A smart ventilation system is generally equipped with a range of sensors. The data – or data derived from it - collected by these sensors can be used by both building owners, occupants and managers. A new generation of IoT  enabled residential ventilation systems allows collecting and analysing this data at scale to get a better view on typical IAQ conditions in dwellings. In this paper, the results from such an analysis on the first 900 installed devices of a new model with respect to moisture in relatively new Belgian dwellings is presented. 

The Proceedings of the 39th AIVC Conference "Smart Ventilation for Buildings", held in Antibes Juan-Les-Pins, France, on 18-19 September 2018.