Safe Building Operation Under Epidemic Conditions

As we move cautiously towards phase 2 of reopening our economy, some businesses have been mandated to follow strict and clear guidelines while others were left to use their best judgement. This has left many property managers, facilities managers and business owners with a lot of questions over which measures to implement that would suit their operation best and provide the highest level of protection to their building residents, employees and customers.

Mann Energy Solutions commitment to our clients continues as we pass through this critical phase of our fight against the pandemic. To assist our clients with evaluating the options available to them to operate safer buildings, our HVAC experts have reviewed the latest documents released by ASHRAE that address the risk of virus particles spread through the HVAC system and the guidelines proposed.

Below we present the answers to some of the most frequently asked questions by our clients and proposed solutions:

Can the Corona virus (SARS-COV-2) spread through my building HVAC system?

On April 14th, 2020 ASHRAE released a document outlining its position on Infectious Aerosols. The document aims to address the concerns of the possible spread of SARS-COV2 (Corona Virus) through buildings HVAC systems in the form of infectious aerosols.

Below are the two statements outlining ASHRAE’s position:

Statement on airborne transmission of SARS-CoV-2: Transmission of SARS-CoV-2

through the air is sufficiently likely that airborne exposure to the virus should be controlled. Changes to building operations, including the operation of heating, ventilating, and air-conditioning systems, can reduce airborne exposures.

Statement on operation of heating, ventilating, and air-conditioning systems to

reduce SARS-CoV-2 transmission: Ventilation and filtration provided by heating, ventilating, and air-conditioning systems can reduce the airborne concentration of SARS-CoV-2 and thus the risk of transmission through the air. Unconditioned spaces can cause thermal stress to people that may be directly life threatening and that may also lower resistance to infection. In general, disabling of heating, ventilating, and air-conditioning systems is not a recommended measure to reduce the transmission of the virus.

(ASHRAE position on Infectious Aerosols – April 14th, 2020)

What strategies should I adopt to control the virus spread through the HVAC system?

ASHRAE recommends using various strategies to control the flow of infectious aerosols through the HVAC system. These strategies include optimizing airflow patterns, directional airflow, zone pressurization, dilution ventilation, in-room air cleaning systems, general exhaust ventilation, personalized ventilation, local exhaust ventilation at the source, central system filtration, UVGI, and controlling temperature and relative humidity.

The recommendations were further detailed in ASHRAE Epidemic Task Force, Building Readiness document. The are 7 items to consider for non Health-Care buildings specifically.

1- Increase outdoor air ventilation (disable demand-controlled ventilation and open outdoor air dampers to 100% as indoor and outdoor conditions permit).

2- Improve central air and other HVAC filtration to MERV-13 (ASHRAE 2017b) or the

highest level achievable.

3- Keep systems running longer hours (24/7 if possible).

4- Add portable room air cleaners with HEPA or high-MERV filters with due consideration

to the clean air delivery rate (AHAM 2015).

5- Add duct- or air-handling-unit-mounted, upper room, and/or portable UVGI devices in

connection to in-room fans in high-density spaces such as waiting rooms, prisons, and


6- Maintain temperature and humidity as applicable to the infectious aerosol of concern.

7- Bypass energy recovery ventilation systems that leak potentially contaminated

exhaust air back into the outdoor air supply.

(ASHRAE Epidemic Task Force, Building Readiness – Updated 05-21-2020)

While different buildings will implement some or all the above recommendations depending on the type of building, increased ventilation is a common factor. The same is recommended by several government of Ontario COVID-19 workplace guidelines. Using more outside air in Canadian climates is an energy intensive and costly option, requires a thorough examination of the entire HVAC system and often several modifications.

Another important measure that is simpler and quicker to implement, provides increased occupant protection at the source and customer confidence, is in-room air cleaning.

While the approach chosen will depend on the building type, alignment with Public Heath recommendations for different businesses, HVAC system type, foot traffic and budget available, Mann Energy Solutions has taken the approach of providing a solution for adding portable room air cleaners with medical grade HEPA filters and sufficient clean air delivery rate.

As mentioned in our previous news letter we have partnered with a reputable air filter manufacture who successfully supported hospitals in fighting the COVID-19 with their special clean room medical grade H13 grade air purifiers (see the photo marked by the red dots). Microbes removal efficiency is 99.53% with 100m2 room coverage. This is a perfect application for apartment lobby, restaurants, and high foot traffic areas. Being a Medical grade air purifier, it can be used in a doctor office, hospital registration, intensive patient care, and other similar areas.

As your engineering consulting service provider, we have put together a proposal to guide you through the process of selecting the best option for your space.

Request a proposal at:

Contact us today to learn more about our volume discount limited time offer at

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