Build Health International

Project Introduction

BHI partnered with Dartmouth Thayer School of Engineering to create a design guide of alternative ventilation strategies to reference when laying out future hospitals in Haiti and other under-resourced nations. The resulting guide includes solutions to prevent the spread of airborne diseases by designing isolation rooms that rely on minimal mechanical elements to provide effective airflow and cooling effects within the budgeted cost of construction.

Build Health International

Project Information

  • Timeline
    September, 2017 - March, 2018
  • Operational Partner
    Dartmouth Thayer School of Engineering
Plan
& Design
Advise
& Research
Build Health International

Project Description

BHI partnered with Dartmouth Thayer School of Engineering to create a design guide of alternative ventilation strategies to reference when laying out future hospitals in Haiti and other under-resourced nations.

The project found that natural ventilation alone cannot be relied on to sufficiently ventilate isolation rooms, but the ceiling fans already used by BHI for comfort can, if positioned properly. The resulting guide provides solutions that prevent the spread of airborne disease through proper ventilation by designing isolation rooms that rely on minimal mechanical elements, provide a cooling effect, stay within the current cost of construction, and are feasible to construct in Haiti. The guide also contains recommendations on optimizing building layout for passive airflow (as a supplement to the mechanical system) by including a central courtyard, sloped ceilings, roof overhangs, and outdoor corridors.

Testing conducted by the Dartmouth team centered on optimizing exhaust airflow from ceiling fans. Computational Fluid Dynamics (CFD) software can model how ceiling fans move air within structures. Forty-eight isolation room designs were simulated in a Design of Experiment (DOE) to determine which construction factors allow the ceiling fan to exhaust air most effectively. Roof shape is the most important factor in promoting airflow, while more openings and lower ceilings also help. A cupola, or roof pop up, placed above the ceiling fan gives over 200 ACH (Air changes per hour, or number of times the air is replaced in a room per hour) when the fan is on maximum power- significantly more than the minimum 12 ACH. Open windows and furniture in the room either increase or do not affect airflow. With the exception of the flat roof models, most of the models we tested easily achieve the minimum ACH. Therefore, BHI has flexibility in the future when choosing a design based building location, minimizing cost, optimizing mechanical airflow, or maximizing natural ventilation.

The guide includes a full architectural model of an isolation ward that uses these principles to maximize mechanical and natural ventilation while also minimizing costs. Although this project focused on ventilating isolation rooms in Haiti, the principles presented in the design guide can be applied to ventilate different rooms in other locations. When BHI plans their next facility, they can consult our design guide to minimize costs, maximize patient comfort, and reliably prevent the spread of airborne disease.

Project Information

Major Funding Partners