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DUCTED UVGI AIR
TREATMENT SYSTEMS
Function
Used for infection control in Medical, Commercial, Residential, and Industrial
applications.
Models
Custom-made per application, to virtually any size (cfm) and configuration.
All units are sized to create a high UV Dosage based on the air flow.
Smaller units can be made as simple inserts installed into existing duct.
Some larger units can be similarly designed to fit into air handlers if
there is enough space available. Most systems come mounted in a galvanized
steel enclosure.
Technology
Ultraviolet Germicidal Irradiation (UVGI) : UVGI has been proven
as a means of destroying airborne bacteria and disease, as airborne microorganisms
have been shown to be destroyed when subjected to certain dosages of UV
radiation. One important aspect of this is that viruses, which are very
susceptible to UVGI, cannot be trapped by media filters because they are
too small in size, so that one of the only ways of eliminating viruses
is by UVGI. Please review the sheet showing dosage of UV-C necessary for
complete destruction of various airborne pathogens.
Applications
Most systems are installed in or before air handling units (AHU), whether
in commercial, industrial, or residential use, so that all of the air
being sent throughout the system has been treated. Sometimes used in supply
ducts to help keep air entering rooms free of bacteria and disease (clean
rooms) or extend the life of the HEPA filters, and these systems can also
be used in exhaust ducts to clean air as it leaves contaminated rooms
(so it can be recirculated or exhausted outside). Typical customers include
homes, commercial offices, government buildings, laboratories, hospitals,
and manufacturing facilities.
Features/Benefits
Cleans air, not just filters/coils: Anyone can place a UV bulb
in an air stream and claim that it will destroy bacteria and viruses.
However, in order for them to truly work, what is important is the UV
dosage that is created. (micro-watt seconds per cm2) UV dosage
is a determined not only by the intensity of the UV lamps, but also by
the residence (dwell) time that the bacteria is exposed to the light.
Our units are therefore sized based on the air flow of the system and
the intensity needed to create the desired UV dosage at that airflow,
so that bacteria and viruses passing by the UV ducted system can be destroyed.
Most UV systems on
the market today are just one or two lamps (of lower intensity) that you
install either before filters or before the air conditioning coils. Their
goal is to simply bathe the filter/coil in UV light, to prevent mold or
bacteria from growing on them. While this may be of use in many applications,
it is important to understand that the UV in these cases will only prevent
bacteria growth on the area in direct contact with the light. So only
the surface of the filter or beginning of the coil will remain clean,
as the back side of the filter/coil will still be susceptible to bacteria
growth. NQE can make inexpensive units to meet this goal upon request,
but preventing growth on a portion of a filter/coil is of much less importance
than having clean air to breathe. This is why our systems can be more
expensive: our systems work to solve the problem (bacteria/virus contamination),
not deal with the effects of the problem (dirty filters/coils).
Custom made
Can incorporate different technologies including high efficiency filtration,
ozone, carbon, or other.
SIZING UV DUCTED
SYSTEMS
Following is the minimum information needed to size UV Ducted units. All
sizing must be done by NQEs Engineering Staff, given that each unit
is custom-made for the application:
1- Provide full information
on the air handling system in the building: air flow, duct size, actual
size of the Air Handling Unit (AHU), static pressure available, the amount
of space in and around the AHU and/or where the unit is to be installed,
etc..
2- Does the customer
want to install one large system in one central area (like in the AHU),
or smaller units throughout the building (in various supply ducts)?
3- Are any additional
components/technologies desired? (i.e. carbon, ozone, HEPA or other filters,
LED for the UV, timer, minihelic, etc..). A prefilter is typically included
with the system.
4- Do we to supply
a fan/blower? If HEPA filters or Carbon are desired and the customer does
not have much external static pressure available, then we will need to
supply a blower because the HEPA filter(s) and the carbon take up a lot
of static pressure. In other words, it takes a lot of air force to travel
through the HEPA and carbon, and the existing systems blower may
not be able to provide enough.
5- Provide a diagram
of the layout of the HVAC system (assuming it is an existing system).
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