Renovation in hospitals: An experimental study of negative pressure and filtration

Abstract

Performing construction renovation and demolition activities in healthcare centers produces contamination that places visitors, staff, and, more importantly, hospitalized patients at increased risk of healthcare associated infections. Most all existing guidelines for the renovation of healthcare facilities encourage the implementation of a negative pressurization strategy to contain contaminants within the construction zone. However, definitive guidance regarding the optimum level(s) of negative pressure is limited. In this research, a series of experiments were conducted in an actual hospital under construction. Four different negative pressure levels were investigated to determine the effectiveness of each pressure level to limit particles from escaping the construction zone. The efficiency of negative air machines at various speed settings was also examined. Results show that introducing negative pressures in the construction zone significantly improved a barrier’s effectiveness. Furthermore, increasing the negative pressure in the construction zone does not proportionally enhance the barrier’s effectiveness. Negative pressures were more effective in containing smaller particle sizes inside the construction zone. Once particles escaped the construction zone, they behaved similarly regardless of the pressure differential. The data also established that the instantaneous number of particles outside the construction zone was significantly reduced by negative pressure.