TO: AC Transit Board of Directors
FROM: Michael A. Hursh, General Manager
SUBJECT: Coach Ventilation During COVID-19 Response
BRIEFING ITEM
RECOMMENDED ACTION(S):
Title
Consider receiving a report on positive air flow tests and procedures to ventilate coaches during the COVID-19 response.
Body
STRATEGIC IMPORTANCE:
Goal - Safe and Secure Operations
Initiative - Service Quality
This briefing item provides details of staff's efforts to promote a safer environment onboard AC Transit vehicles by improving the positive airflow to reduce the amount of exposure to particulates in the cabin space.
BUDGETARY/FISCAL IMPACT:
There are no budgetary or fiscal impacts directly related to this report.
BACKGROUND/RATIONALE:
Various sources have published recommendations for air circulation and ventilation procedures during the COVID-19 pandemic. These recommendations include opening roof hatches and bus windows, therefore, allowing fresh air to enter the cabin.
To have a better understating, District staff collaborated with Safety Committee Members from ATU Local 192 to conduct a practical evaluation. Three tests were developed with a goal to understand how air particulates travel through a bus and to determine the most efficient means of achieving positive air flow on the coach. The process involved discharge of smoke inside the coach to mimic interior cabin air and particulates as the coach was in motion. Various methods to ventilate the coach were deployed at that time. The attributes of the smoke were indicators of how air movement was influenced by the current ventilation method in use.
TEST #1 All windows closed with the Operator's window open
Creates a vacuum. All smoke moved towards the front of the coach then exited through the driver's window with full exposure to the operator.
Test #2 Four to six windows opened with the Operator's window closed
Creates an uncontrolled air environment. Initial air moved towards the rear then circled back to...
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