The counterattack on biological threats
The potential threat of biological or chemical attacks has increased recently. One way to protect
people from airborne contaminants in buildings is to utilise detection mechanisms, but presently
such mechanisms are not rapid enough to alert building occupants to a broad range of chemical and
always imperceptible biological hazards. Indeed, the only practical way to protect people against
chemical and biological agents in buildings continues to be through systems that are continuously
in place – i.e. through the effective filtering of all air brought into the building on a continuous
basis.
Of particular concern are occupants in buildings equipped with mechanical heating, ventilating,
and air conditioning (HVAC) systems. These systems can become an entry point and a distribution
system for hazardous contaminants. Once contaminated air enters a building, the ventilation system
can transport it rapidly to various parts of the building with serious consequences.
Airborne contaminants can spread extremely easily through a building that is not equipped with
an efficient filtration system (a). LIFA’s filters effectively stop the spread of these contaminants (b).
A cost-efficient and powerful solution
In order to protect buildings and their occupants from airborne hazards LIFA has developed, in co-operation
with the Technical Research Centre of Finland (VTT), advanced low flow resistance, high efficiency supply
air filters that are capable of removing both particulate and gaseous contaminants from the supply air
(the Lifa 3G Filter and the Lifa High Security Filter). The filters are installed in ductwork near the air
terminal device or diffuser in each room that needs safe and healthy indoor air quality.
The Lifa 3G Filter removes harmful contaminants effectively, while the Lifa High Security Filter combats the
smallest and most hazardous biological or chemical agents. LIFA also offers mobile units for hospitals and
other emergency purposes, for example ambulances. With the Lifa High Security Filter, filtration efficiency
exceeds 99.99% for 0.1 µm sized particles and 99.5% for gases. NBC active carbon filters can be
tailor-made to protect against various types of gaseous contaminants. With regular Lifa 3G Filter as pre-filters,
the service life of High Security filter can be cost-effectively extended.
The Lifa High Security Filter is
a multi-stage filtration system. It achieves truly efficient filtration by equipping an electrostatically
charged filter with both a particle charging section and a gas filter made of activated carbon media. A
nanoelectric UV light can be added to the system to effectively destroy any airborne virus of bacteria, even
small molecules.
Airborne diseases, like SARS, Legionella and Tuberculosis, and recently substantially increased potential
threat of biological or chemical terrorist attacks have also increased the need for an improved indoor
Air Quality (IAQ) solution.
The best protection against airborne hazardous materials is high efficiency filtration (U.S. Army, 2001).
However, if the efficiency of the supply air filtration is improved with solutions based on old technology,
large and expensive modifications in the ventilation systems are needed.
In order to protect buildings and their occupants from airborne hazards Lifa Air has developed in co-operation
with VTT Technical Research Centre of Finland advanced low flow resistance, high efficiency LIFA supply air
filters which are capable for removing both particulate and gaseous contaminants from the supply air, without
extensive modifications.
Of particular concern are occupants in buildings equipped with mechanical heating, ventilating, and air
conditioning (HVAC) systems. These systems can become an entry point and a distribution system for an intentional
release of toxic chemicals or biological aerosols (fine particles) near air intakes or inside buildings.
Once contaminated air enters a building, the ventilation system can transport it rapidly to various parts of
the building with serious consequences.
Most strategies for protecting people from airborne hazards require a means of detection - determining that a
hazard exists. Although effective and inexpensive devices are widely available to detect, for example, smoke
and carbon monoxide, there are no detectors that can rapidly alert occupants to a broad range of chemical
and biological hazards.
The possible control strategies for indoor air contaminants include more efficient supply air filtration for
buildings with mechanical ventilation or use of high efficiency air cleaners. However, the removal of gaseous
contaminants requires gas filters, which are not commonly used in standard air handling units. Moreover, the removal
of fine particles from the supply air requires efficient HEPA-grade filtration system. Existing ventilation systems
seldom have the space or available static pressure for high efficiency filters. The efficient removal of both
fine particles and gaseous contaminants therefore has not been feasible with the present technology.
On the other hand, high efficiency air cleaners require floor area, they are noisy and they usually do not have
efficient filtration system for gaseous contaminants. Most importantly, they rather dilute contaminants to
lower level than prevent the contaminants from entering into the occupied space.
Lifa Supply air filters
The new Lifa 3G Filters filters have been developed to remove harmful airborne contaminants efficiently. Moreover,
Lifa High Security filters have been developed specifically against biological or chemical agents.
The new technology combines an electrostatically charged filter with both a particle charging section and a gas
filter made of activated carbon media. The pressure drop of such a unit is low, permitting installation without
the need for expensive changes in the existing ventilation system i.e. the building infrastructure.
The primary application of the Lifa filter is buildings with mechanical ventilation: offices, public buildings,
and manufacturing facilities. In addition to removing outdoor pollutants, the Lifa filter technology is effective
against contaminants that are generated indoors and dispersed due to air re-circulation. The filters are intended
for installation in ductwork near the air terminal device or diffuser in each room that needs safe and healthy
indoor air quality. There are also mobile units for hospital and other emergency purposes.
Lifa TJ 3G Filter
Lifa TJ 3G Filter is developed mainly for airborne contaminants typical in urban environments. It is designed is
to prevent contaminants such as fine particles, volatile organic compounds (VOCs), ozone and odours from entering
room air and to maintain healthy indoor air quality.
Lifa High Security Filter
The Lifa High Security Filter system is specifically designed to provide protection against both biological
and chemical agents. Equipped with the Nanoelectric UV light it is the only scientifically tested and proven
filter solution to be (killing) effective against any airborne virus or bacteria, also sizes below 0,3 microns,
which is the current, and insufficient, industry standard.
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