CU Boulder Study Links 15 COVID-19 Cases to Shared Ventilation in 7-Story Spain Building
Updated
Updated · University of Colorado Boulder · May 12
CU Boulder Study Links 15 COVID-19 Cases to Shared Ventilation in 7-Story Spain Building
6 articles · Updated · University of Colorado Boulder · May 12
Fifteen COVID-19 infections across four vertically stacked apartments in a Santander building were most plausibly transmitted through shared bathroom ventilation, according to a PLOS One study published May 12.
Airflow tests, CO2 measurements in a vacant unit and genetic sequencing of residents’ samples pointed to virus movement between apartments without face-to-face contact.
The 1969 building used a natural-convection shaft system; the study found hot weather could reverse airflow, while a kitchen exhaust hood could pull air from a neighboring bathroom within minutes.
Researchers said similar risks can persist in older buildings worldwide, citing Hong Kong’s 2003 SARS outbreak that infected 321 people and killed 42 through shared building airflow.
The authors urged Spain to retrofit older buildings with backdraft-preventing fans and stronger ventilation standards, while recommending air purifiers and better indoor-air design more broadly.
Is your apartment's shared ventilation system secretly a highway for viruses from your neighbors?
Who is responsible for fixing the hidden ventilation dangers that allow viruses to travel between apartments?
COVID-19’s Secret Route: The Critical Role of Shared Ventilation in Building-to-Building Viral Spread
Overview
A groundbreaking study from the University of Colorado Boulder, inspired by a 2020 COVID-19 outbreak in Santander, Spain, revealed a hidden way the virus can spread in buildings. Researchers found that COVID-19 could move between apartments through shared ventilation systems, even when residents never met. The study focused on a seven-story building with a 'stack effect' ventilation system, a design common in older Spanish buildings. This discovery highlights that airborne viruses can travel through connected air systems, showing a major risk in many older buildings and urging a rethinking of how we manage indoor air and ventilation.