Energy Saving by Novel Bed-Integrated Local Exhaust Ventilation

High quality indoor environment in hospitals is important for patients’ healing and performance of the personnel. A novel method for minimizing spread of bio-effluents generated from hospitalized patients lying in bed was developed. The method consists of ventilated mattress (VM) which is able to suck the human bio-effluents at the area of the body where they are generated before they spread in the room. The air polluted with released bio-effluents is exhausted into the mattress near the body and is either cleaned and released back in the room or is removed from the room by connecting the mattress to the exhaust of the room background ventilation system. Comprehensive research reveals that the method is highly efficient for removal of bio-effluents. The energy saving potential of the VM combined with constant air volume (CAV) ventilation operating at reduced ventilation rate in a single-bed hospital patient room (1.3 air changes per hour (ACH)) and double-bed patient room (1.6 ACH) was assessed by means of dynamic computer simulations. The estimated annual energy consumption for the rooms using the VM combined with CAV was compared to the annual energy consumption when the CAV ventilation was used alone at 4, 6 and 12 ACH. The air exhausted through the mattress was 1.5 L/s. The occupants were present 24 hours every day including weekends. Compared to the CAV ventilation used alone at 4, 6 and 12 ACH the use of the VM in the single-bed room decreased the annual energy consumption respectively with 55%, 71.1% and 85.9% and in the double room with 39.3%, 60.0%, and 80.4%. The use of the VM with reduced background CAV ventilation is an effective energy saving strategy for both double and single patient hospital rooms.