The resulting CO2 levels and the heating/cooling consumption of apartments with balanced ventilation versus window ventilation

Four apartments have been monitored for an entire year. Two apartments were ventilated with a balanced ventilation system, and two apartments were ventilated by manual opening of windows. CO2 values have been registered as indication of indoor air quality in each living room and the available bedrooms. The opening of windows and doors was registered, from which an airing factor was calculated. The heating and cooling consumptions was also registered for each apartment. The CO2 levels in all rooms of the apartments with balanced ventilation was lower than the manually ventilated apartments, with less variation between hours and seasons. The percentage of hours exceeding 1000 ppm is below 1% of the year for the apartments with balanced ventilation and 30-60% of the year for window ventilated apartments. Space heating and cooling use are investigated by energy signatures of the four apartments. The balanced ventilation - including recovery - not only brings a higher indoor air quality, but also a lower heating (-24%) and cooling use (-50%) as follows from the specific heating slope and specific cooling slope in the energy signatures.publishedVersio