Expert answers to your indoor air quality questions
No two organizations have the same indoor air quality (IAQ) challenges. To help you with your unique concerns, Ambius worked with microbiologist Dr. Gail Aitken and regulatory expert Andrew Leaf to answer your questions from our recent webinar as part of our COVID-19 and IAQ Q&A series.
As we learn more about COVID-19, an increasing amount of information (both speculative and factual) floods the airwaves. The sheer amount of technical guidance available on indoor air quality can be daunting, but your journey to healthy air doesn’t have to be difficult. We’re here to help you navigate the abundance of information coming your way so that you can make the best decisions for your facility.
Can we answer a specific indoor air quality question for your business? Our hygiene experts are standing by to help with a complimentary consultation.
How do HVAC MERV filters and air purifiers work together? Do you really need them both?
ANSWER:
HVAC MERV filters will clean the air as it enters the room; this may be a combination of recirculated and fresh air. Portable air purifiers help to additionally clean the air as it passes through the room, working as a supplement to the HVAC system.
When organizations like ASHRAE mention Air Changes Per Hour, does that reference fresh air or just total air changes?
ANSWER:
Air Changes Per Hour typically refers to natural ventilation in a room, such as windows or even from around closed doors. Clean Air Delivery Rate (CADR) is the measurement of airflow rate for purifiers, which clean and then recirculate the air.
Is a smoke test beneficial?
ANSWER:
Smoke tests can be conducted to show typical airflows within a room, which can be useful in helping to determine the optimal placement of air purifiers. Just be careful that you don’t accidentally set off any smoke alarms while conducting the test!
Some HVAC units cannot operate well with a higher MERV-rated filter and can cause malfunctions. What do you suggest instead?
ANSWER:
This is an important point. To achieve higher levels of filtration efficiency, such as those that are gained with higher MERV-rated filters, the filter medium (or material) must be packed more densely within the filter housing. This is normally achieved by folding or pleating. This increased density creates a higher resistance to the flow of air passing through the filter, which reduces its velocity and the rate of airflow. For this reason, it is not always possible to simply replace filters within existing ventilation systems, as it can adversely affect the volume of air passing through the unit. If your HVAC system cannot handle higher-rated MERV filters, then it can be supplemented using portable air purifiers with HEPA filters.
Is there a benefit to improving IAQ if I live in a city with polluted air?
ANSWER:
Building managers cannot do much about outdoor pollution, but we can make indoor air quality better. If there are high levels of pollution outdoors, indoor air quality may be lower, so this can be addressed with an air purifier. Using an air purifier may also help to reduce the risk of transmission of respiratory infections.
If I were in a restaurant, for example, would I be able to tell if the air quality has increased? Would it be a cooler airflow?
ANSWER:
No, measures taken to improve air quality will not have an effect on the physical properties of the air. Many businesses are now making physical postings about measures they are taking to help reassure customers that they are committed to safety. Some air purification units will also offer displays of indoor air quality (such as red, yellow, and green lights) so that employees and guests have a visual cue as to the measures being taken.
Does your business have immediate air quality or hygiene needs? Contact us today.
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