Healthcare Facility Operation Under Epidemic Operating Conditions
By: Doug Johanson
We are currently living through unprecedented times with the current global pandemic. This pandemic has been both frightening and educational, especially in how we manage potential risks through indoor air quality. The purpose of this article is to help shed light and provide you with tools to help ensure the effectiveness of your facilities HVAC system.
ASHRAE has determined that the transmission of SARS-CoV-2 (Covid-19) through the air is sufficiently likely that airborne exposure to the virus should be controlled. How can a healthcare owner demonstrate to their patients, staff and visitors that their facility is in compliance with these recommendations?
The following excerpts from the ASHRAE Epidemic Task Force on Building Readiness updated on 10-20-20 that provide practical information and checklists on how your building should be operating.
Building Readiness Team
ASHRAE recommends that a qualified Commissioning Provider be included on the Building Readiness Team. Cooper Commissioning meets and exceeds all of the qualifications recommended by ASHRAE. We have more than 30 years of experience in the healthcare environment and have performed numerous commissioning projects in hospitals and clinics.
Modes of Operation
Epidemic Operating Conditions
Most recent design HVAC documents
Original equipment submittals
Control drawings and sequences of operation
BAS trend reports
Most recent commissioning reports
Commissioning providers routinely compile this information during any commissioning project.
Perform a System Evaluation to determine where existing problems may exist.
Commissioning providers routinely perform this function during any retro-commissioning project.
Building Automation System (BAS)
Cybersecurity evaluation needs to be addressed.
Ensure that all changes made to implement epidemic measures are carefully documented to allow a controlled return to non-epidemic conditions.
Commissioning provider can perform an analysis to determine if the existing BAS is capable of supporting necessary epidemic measures.
ASHRAE recommends increasing outside airflow to reduce recirculation air back to patient care areas. Changing operation settings or turning system off without an effective understanding of the system will likely have unintended consequences, which may themselves favor the spread of viruses. Careful consideration is needed before implementing these changes:
Will the AHU system be able to maintain space conditions (temperature & humidity)?
Could AHU equipment possibly be damaged during cold outside air conditions?
Will building space pressure be affected?
Will Isolation and Negative Pressure patient rooms be affected? How will they be monitored?
Monitoring based commissioning can provide a real-time display of outside air flow rates, pressure relationships and space conditions to alert building operators when problems arise.
IAQ Flushing Strategy
If increasing the amount of outside air is not feasible, ASHRAE recommends utilizing a pre-occupancy purge with outside air of at least 4 hours. Is this control strategy desired?
Is CO2 Demand Control Ventilation being utilized in your facility? Has it been curtailed while in epidemic operating conditions?
Monitoring based commissioning can provide an easy way to monitor purge rates and CO2 levels to alert staff if any problems arise.
Upgrading Air Filtration
ASHRAE recommends filter efficiency be at least MERV 13 or higher to mitigate the transmission of infectious aerosols. Many existing HVAC systems were designed to operate using MERV 6-8 filters.
A qualified commissioning provider can help evaluate any intended upgrades to an AHU to ensure the HVAC system will be able to handle the increased pressure drop and airflow loss.
Energy Savings Considerations
Increasing outdoor airflow minimums and filter efficiency ratings will definitely have a negative impact on energy usage. Implementing optimized control strategies can help mitigate some of this increase and help lower costs. Has a plan been put in place to put these sequences in place?
Monitoring based commissioning can easily identify numerous energy savings opportunities along with their cost savings to help prioritize these energy savings measures.
Energy Recovery Ventilation
Have energy recovery units been evaluated to determine how much re-entrainment of contaminants are occurring?
Commissioning provider can perform an analysis to determine if contamination is occurring and possible solutions to the problem.
Building Shut Down
Have any buildings or portions of a building been shut down temporarily? ASHRAE does not recommend completely shutting off HVAC to a building during a temporary shut down due to loss of control of space conditions. How are these areas being monitored to ensure issues do not occur? Have the following systems been address?
Domestic Water & Plumbing Systems
Fire Alarm Systems
Monitoring based commissioning can easily monitor areas of your facility that have been shut down to ensure local space conditions remain acceptable.
Post-Epidemic Operating Conditions
Confirm new occupancy schedule
Consider implementing morning purge sequence of control
Operate HVAC systems for at least 24 hrs before occupancy. Monitor BAS data to ensure proper temperature and humidity levels are maintained. Review data to ensure that cooling and heating systems are performing as designed.
Address any areas of concern or anomalies in the monitored data before allowing occupancy.
Monitoring based commissioning can provide real-time information on air changes per hour (ACH), building pressure relationships, humidity levels and comfort levels for any area of your facility.
Evaluate any temporary filtration changes that were made under Epidemic Operating Conditions. Will these levels of filtration be maintained or will they be scaled back to original levels?
Commissioning provider can perform a cost analysis to help make this determination.
Building Automation System
Consider upgrading BAS programming to allow for “Epidemic Mode” operation manually selectable by building operators.
Ensure CO2 Demand Control Ventilation and minimum air settings are returned to normal. Monitor BAS data to ensure performance.
A well-qualified commissioning provider can provide guidance on possible ideas that could be utilized to enable these control sequences.
ASHRAE recommends AHU filters be checked on a regular basis for proper seating to prevent any air bypass.
Commissioning provider can perform a survey to determine filter condition and performance.
If you do not already have a GOOD technical commissioning team on board, I highly encourage you to get into contact with us.
Cooper Commissioning can perform or coordinate the analysis, testing, design, control programming, balancing, and maintenance services to make the needed adjustments to achieve the performance outlined in the ASHRAE recommendations
I feel strongly that meeting with us in person would help clarify how we can make building operation easier for everyone involved. We would be happy to do a walk-through with you in your facilities to give you an idea of the expertise and attention to detail that our agents bring to bear.