What is the difference between ambient air capture and source capture?
Safeopedia explains that ambient air is atmospheric air in its natural state, not contaminated by air-borne pollutants. In the Post COVID-19 era, where we have a heightened awareness of potential viruses that can hang in enclosed spaces, the term “Ambient Air” takes on a new meaning, simply, “the air around us”.
Source-capture is a term commonly used in Industrial Ventilation. As the term suggests, “source-capture” means that the operator has brought a hood directly to the source creating the air pollutant, and either enclosed it or covered it to contain the pollutant and draw it into the hood via negative air pressure. The pollutant is then drawn through ducting and either exhausted outside, where the outside air may dilute the pollution (allowance of this is depending on the type of pollution and jurisdiction), or into a filtration device where is it filtered or “scrubbed” before being redistributed either back inside the space or outside. In industrial settings, fume extractors capture hazardous airborne particulate and fumes at the source of emission (like welding), as opposed to systems that are designed to purify general room air.
Cleaning the “Ambient Air” in a space, .e.: Dental Operatory.
If a dental operatory space is 10’wide x 10’long x 9’high, there is 900 cubic feet in the space. A duct can be brought to the space, and 240 Cubic Feet / Minute (CFM) of exhaust air applied to the space through a typical ceiling tile. This would provide an additional 16 ACH to the operatory on top of any existing HVAC air changes that pre-exist. Does this mean the dentist and hygienist are adequately protected? NO!
Dentist and Dental Hygienists are directly exposed to bioaerosols due to the nature of their work. Even with an increased number of Air Changes / Hour (ACH) in that space, the Dentist and the Dental Hygienist are directly exposed to close contact risk of infection simply due to the nature of the work. To adequately protect the Dentist and Dental Hygienist, source capture MUST be applied.
Pura Air has applied the same source-capture protection strategies commonly used in Industrial ventilation to dental work. Using source capture hoods, a Pura Air Purification device will draw an appropriate amount of air through a source capture hood placed over the patient’s breathing area to capture and contain dangerous bioaerosols and viruses, which will then be passed through a UVC irradiation Chamber and HEPA Filtration to scrub 99.9% of viruses.
Does this mean the ACH drops? NO! If the air being drawn from the operatory remains unchanged from the example at 240 CFM, the air exchange remains at an additional 16 ACH in the same space with the additional necessary protection of Source-Capture applied.”