Mixing and displacement ventilation compared in classrooms; distribution of particles, cat allergen and CO2

• Mixing ventilation and displacement ventilation were compared in an intervention study in classrooms. Particles, cat allergen and CO2, were measured in classroom air at different levels above the floor, during regular lessons. With mixing ventilation, the particle concentration tended to decrease with height, with a stronger gradient occurring for larger particles. With displacement ventilation, the particle concentration increased with height, except for particles >25 µm. The displacement system thus tended to have a slight upward displacement effect on most of the particles. Significant correlations were found between concentrations of cat allergen and particles in the size fraction 1–10 µm. The particle and cat allergen concentration at breathing height did not, however, differ significantly between the two ventilation systems. CO2 was about 10% lower with displacement ventilation. A fairly high level of physical activity of the pupils is believed to have had significant dispersing effect on the airborne contaminants.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Samhällsbyggnadsteknik -- Husbyggnad (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Civil Engineering -- Building Technologies (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Strömningsmekanik och akustik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Fluid Mechanics and Acoustics (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Industriell bioteknik -- Annan industriell bioteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Industrial Biotechnology -- Other Industrial Biotechnology (hsv//eng)

Keyword

Mixing ventilation

Displacement ventilation

Particles

Cat allergen

Schools

Classrooms

Air quality

Ventilation

Building engineering

Byggnadsteknik

Fluid mechanics

Strömningsmekanik

Bioanalytical engineering

Bioanalytisk teknik

Publication and Content Type

ref (subject category)

kon (subject category)