In Nordic countries, where cold winters can keep people indoors, buildings often feature what are known as "displacement ventilation" systems. A Spanish study now suggests that such technology may also help keep patients from acquiring infections while in hospitals.

According to scientists at the University of Cordoba, over 90 percent of hospitals utilize the more commonly-seen "mixed ventilation" systems. This means that new air is introduced from vents placed near the ceiling, after which it gradually mixes with air already in the room. Eventually, most of the room's "old" air gets diluted by the fresh air.

By contrast, displacement ventilation systems introduce new air from vents located near the floor, closer to the patient. That fresh air then pushes the old air up to removal vents near the ceiling, with the warmth of that old air helping it to rise. Described as working like a piston, this system results in a quicker, more thorough turnover of air within a room.

In U Cordoba tests that incorporated life-size mannequins equipped with simulated human respiratory systems, it was found that use of displacement ventilation systems in hospital rooms could significantly reduce airborne pathogens.

Additionally, the technology may help hospitals save money on power bills. While mixed ventilation systems are required to be capable of refreshing the air in a room 12 times per hour in order to sufficiently remove pathogens, it is estimated that displacement systems would only need to do so nine times an hour for the same level of protection from infections.

A paper on the research was recently published in the journal PLOS ONE.