Assessment of energy saving due to a flexible indoor air quality control

This work deals with the assessment of the benefits, in terms of energy saving, given by the measurement of the CO2 concentration inside the cabin of an electric crane to control the air recirculation. An experimental set-up, where a flux of 66 g/h of pure CO2 is introduced inside the cabin, to simulate the breathing of a driver, is used to compare two different ventilation strategies, in heating and cooling conditions. With the first control strategy the air recirculation is always off. With the second one the air recirculation on/off system is controlled on the bases of the CO2 levels in the cabin air. The power consumed by the positive temperature coefficient (PTC) heater (in heating mode) and by the compressor of the refrigeration cycle (in cooling mode) is measured in the two cases. The value of the energy consumption along the test duration is used as parameter to assess the energy saving effect of the air recirculation. The results show that the air recirculation based on the CO2 concentration inside the cabin allowed an energy saving of the 53.8% and 72.6% in the cases studied in heating mode and of the 0.8% and 9.0% in the cases considered in cooling mode.