Various studies show a deterioration in indoor air quality after renovation and energy saving measures. NZEB dwellings are at the moment at an airtightness level, that the old slogan make buildings airtight and ventilate right is an very import solution for a good IAQ, but not without source control.
The first step in controlling indoor air quality is to avoid the emission of contaminants in the air such as, candles, cooking on gas and smoking. The second step is reduce the unavoidable harmful emissions by source control. For cooking fumes, a range hood is the most effective way to minimize the exposure. For PM2.5 from ambient, filters can be applied in the mechanical supply of the ventilation system. Step 3 is a whole house ventilation system. With sufficient source control, the control of the ventilation system, can be smart, that means the ventilation only goes to a higher level because of odor control of human sources. Step 4 are stand-alone air purifiers, for cases where, the emissions of pollution cannot be reduced, e.g. in case of window airing. Based on literature an overview has been set up of examples of these steps and their effectiveness.
To estimate the combined effect of these measures on PM2.5 exposure simulations with TRNFLOW/ COMIS have been executed. A 50 percentile emission pattern for PM2.5 has been set up based on a year lasting monitoring with optical particle sensors in 100 Dutch dwellings. A cooker hood with 95% capture efficiency reduces the average exposure in the living room / kitchen with 51%. In combination with an F7 filter in the air supply the exposure in the living room is reduced with 82% in a NZEB dwelling. The combination of these two relative simple measures almost halves the total yearly exposure. This can be explained by the fact that the F7 filter not only cleans the air towards the kitchen/living room but also for the sleeping room in which relatively much time is spend.
A positive example of how to combine energy savings with a good indoor climate is through a performance contract or even a renovation as a service. The main air borne pollutant with regard to health for such a contract or service could be PM2.5 and CO2 could serve as an indicator for ventilation and odor control.
Indoor air quality in Nearly Zero Energy Buildings, reduction of exposure
Year:
2019
Languages: English | Pages: 9 pp
Bibliographic info:
40th AIVC - 8th TightVent - 6th venticool Conference - Ghent, Belgium - 15-16 October 2019