Potential energy savings with personalized ventilation coupled with passive chilled beams

Personalized ventilation (PV) is an individually controlled air distribution system aimed at improving inhaled air quality and thermal comfort of each occupant. Numerous studies have shown that PV may improve occupants’ health, comfort and performance in comparison with traditional total volume air distribution used today.

The potential of PV for energy saving has been studied little. In this study, the energy saving potential of desk mounted PV in conjunction with either mixing ventilation or a passive chilled beam system is compared to mixing ventilation alone by means of computer simulations. An open plan office in a building, located in a cold and dry climate was simulated.

Numerous simulations were performed to study the importance of number of room occupants, occupancy profile in time and room air temperature control. The requirements for indoor environment in office buildings as defined in the present standards were considered. The most effective energy saving strategy with PV in use was to expand the upper room temperature limit as defined in the present standards.

When PV was coupled with background mixing ventilation, the possible reduction of the air supplied to the room was approximately 20% (and up to 40% when extending the temperature in the room by 2 °C above the upper limit recommended in the standards) compared to mixing ventilation only. When PV was combined with passive chilled beams, the reduction of the supplied air was up to 80%.

This ventiltion strategy may lead to energy saving especially in spaces where occupants spend most of the time at their workplace.