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Copyright © 2009 - FAST SpA
- Health directives
- Technical directives/norms
- AHUs FM-H: technical details
Presentation index
Copyright © 2009 - FAST SpA
The term legionellosis(legionnaire’s disease)
identifies forms of pulmonary
infection caused by different
species of aerobic bacteria of
the type Legionella (Legionella pneumophila is
the species most dangerous)
Problem of Legionella
Copyright © 2009 - FAST SpA
� Legionella infections are difficult
to distinguish from other types of
pneumonia
� The Legionella (especially in the variant
"legionnaire's disease") is a serious disease, with high
lethality
Problem of Legionella
Copyright © 2009 - FAST SpA
Problem of Legionella
Reference 15/12/2011: http://www.eurosurveillance.org/ViewArticle.aspx?Articleid=753
Copyright © 2009 - FAST SpA
Responsibilites
“Due to recent incidents that occurred in hospitals with
episodes of deaths, dedicated institute opened a criminalinvestigation against the directors of the hospitals on charge
of negligent injury, wrongful death and violation of the law
626/94 on the protection of workers. It 'clear, however, that
can potentially be called into question all those involved in the
process of design, implementation, testing, maintenance, use
of the system: designers, general contractors, equipment
manufacturers, installers, test technician, maintainer, owner,
manager .“
Extract from UNI communication
Problem of Legionella
Copyright © 2009 - FAST SpA
All plants that pose a
moderate heating of water
and its spray (hospitals,
nursing homes, rest, hotels,
schools, spas, swimming
pools, ...) are potentially
under the risk
Especially, HOSPITALS
Dangerous environments
Problem of Legionella
Copyright © 2009 - FAST SpA
Conditions for the development of Legionella
1 Optimal temperature for growth range from 25 to 42° C (best 37° C)
2 Aerobic (ambient with oxygen) and humid environment
3 Presence of nutrients: biofilms, slag, limestone and iron ions, other
microorganisms
4 Spraying water droplets forming with diameters ranging from 1 to 5
microns
Problem of Legionella
Copyright © 2009 - FAST SpA
Mode of transmission
• Spread by breathing contaminated water
aerosols (main cause of transmission)
• Alcohol, Smoking
• Sex (men, mainly)
• Advanced age
• chronic lung disease
Problem of Legionella
Copyright © 2009 - FAST SpA
Guidelines for the protection and promotion of health in confined spaces
Scope of the document
Structure of the document
“To provide technical guidelines, to promote the
development of initiatives ... on pollution of indoor
environments (IAQ)"
� Part 1: introduction
� Part 2: prevention for indoor environments
� Part 3: strategic lines for actuation of «prevention for indoor
environments»
Copyright © 2009 - FAST SpA
Strategic lines of the risks dell'IAQ (summary)
• Carry out a survey on the health of existing buildings
• Prepare guidelines for designers and constructors of buildings
• Prepare protocols relating to the maintenance
• Prepare a reference standard for the protection of health
• Verify the effectiveness of taken actions
Guidelines for the protection and promotion of health in confined spaces
Copyright © 2009 - FAST SpA
General guidelines
• in paragraph 5.2.6 of the guidelines refer directly to the
“Guidelines for the prevention and control of legionellosis”
• to ensure compliance with the hygienic requisites of indoor air,
should refer to the provisions of ENV 12097 ("network of pipelines.
Requirements for components to facilitate maintenance of
networks of pipelines" - January 1997 ")
• test procedures for limits in the pipelines should follow the
methodology described in the documentation prepared by NADCA
- National Air Duct Cleaners Association
• The maintenance should be logged
Guidelines for the protection and promotion of health in confined spaces
Copyright © 2009 - FAST SpA
“Guidelines for the prevention and control of legionellosis”
Prevention strategies in plant systems (summary)
• prevent standing water;
• limit the possibility of biological niches by making periodic
cleaning of equipment;
• maintain efficient drift eliminators and filters;
• avoid the critical temperature of water (25-55° C);
• eliminate with proper treatment the biofilm (nourishment for
Legionella)
• provide for water treatment;
Copyright © 2009 - FAST SpA
Prevention strategies in plant systems (summary)
• To program inspections on the installation of air conditioning to
check the status of humidifiers, evaporative cooling towers, the
location of the external sockets and the state of drainage
systems;
• To check maintenance schedule and log
• To design the air flow system to ensure accessibility for
maintenance operations;
“Guidelines for the prevention and control of legionellosis”
Copyright © 2009 - FAST SpA
Specifications for components (summary)
“Guidelines for the prevention and control of legionellosis”
Copyright © 2009 - FAST SpA
• Silencers
- Must have surface finishes such as to limit the nesting of dirt, and to
ensure the ease of cleaning;
- Must be placed at an appropriate distance from humidifiers;
• Inlet for Fresh air
- must be sized for speed <2 m/s
- must be fitted with guards to prevent water from entering;
- should be placed away from sources of pollution;
“Guidelines for the prevention and control of legionellosis”
Specifications for components (summary)
Copyright © 2009 - FAST SpA
• Filters:
- class F7 upstream of UTA;
- class F8 / F9 downstream of the UTA and any silencers;
- class F7 on the fresh air intake;
- must be serviced (cleaning and replacement)
“Guidelines for the prevention and control of legionellosis”
Specifications for components (summary)
Copyright © 2009 - FAST SpA
• Heat exchangers:
- cleaning often the heat exchanger;
- Sloping the drain pans
- make the pans with dedicated materials to prevent corrosion.
• Adiabatic humidification
- Not suggested
- Checking the quality of water
- Cleaning often the system
“Guidelines for the prevention and control of legionellosis”
Specifications for components (summary)
Copyright © 2009 - FAST SpA
• Ducts:
- Compressed air system for cleaning is suggested
• Logbook of maintenance
- ordinary and extraordinary maintenance on water systems and air
conditioning systems must be registered.
“Guidelines for the prevention and control of legionellosis”
Specifications for components (summary)
Copyright © 2009 - FAST SpA
Norm UNI CTI 5/716
Abstract
• air conditioning systems must be provided of accesses for
technical and hygiene inspections by qualified personnel. Each
control must be registered.
• Inspection of tech and hygiene must involve ducts, local and
technical components of the air handling unit
Copyright © 2009 - FAST SpA
• Allowable limits for the concentration of particulate matter and
bacteria in the canals, for the test methods and limits for
bacterial contamination of components in CTA refers to the
technical documentation NADCA
• Checkings, cleaning, disinfection must be carried out according to
a checklist proposed in a table
• training of personnel hygiene facilities must be provided:
• Category A: hygiene managers
• Category B: for simple personal
Norm UNI CTI 5/716
Copyright © 2009 - FAST SpA
Guidelines ASHRAE 12-2000
Scope of document
Giving directions to minimize the risk of Legionellosis
associated with water systems, swimming pools, air
conditioning systems, etc..
Abstract
The guideline addresses the problem with a comprehensive
approach is to identify areas characterized by higher critical
plant, consider the application situations (hospitals, hotels,
etc..) And propose intervention methods emphasizing the
aspect of prevention to stop the rise to the chain of
transmission of legionellosis.
Copyright © 2009 - FAST SpA
Technical solutions inside FM-H
Problemi diigiene - salute pubblica
Strumenti giuridici enormativi
Progetto FM-H :
soluzionetecnica
Attività di ricerca e sviluppo
FAST
Copyright © 2009 - FAST SpA
Range
0 5.000 10.000 15.000 20.000 25.000 30.000 35.000
Portata aria [m3/h]
FM-H 20
FM-H 28
FM-H 35
FM-H 42
FM-H 50
FM-H 57
FM-H 69
FM-H 82
FM-H 105
FM-H 119
FM-H 154
FM-H 194
FM-H 237
FM-H 286
FM-H 342
Mo
dell
o
Velocità frontale sul pacco di
scambio termico [m/s]
2,52
Technical solutions inside FM-H
Technical
solutions
inside FM-H
construction (easy to clean, inspected, materials used, envelope leakage)
Technical characteristics of the components of the various sections
Copyright © 2009 - FAST SpA
Technical solutions inside FM-H
Copyright © 2009 - FAST SpA
Construction
Cleaniness
• internal profile and edges
with angles less than 90 ° C
are connected
• Drainable floors
• Avoided holes, spaces
Technical solutions inside FM-H
Copyright © 2009 - FAST SpA
Construction
Inspectability
• Access doors for every section
• Every section is provided with adequate lighting to
facilitate cleaning
Technical solutions inside FM-H
Copyright © 2009 - FAST SpA
Fresh air inlet
• rated for speeds up to 2 m / s
• have effective systems (backward cowls) to prevent
water or dirt from getting inside the CTA
• should be placed away from sources of pollution and
expulsion of ambient air (instructions on the manual)
Technical solutions inside FM-H
Technical characteristics of the components
Filters
• Eurovent certification is agreeding on the
efficient use of filters F 8-9
• F7 filters will be positioned upstream of the CTA
• F8 / F9 filters will be located downstream of the CTA and
downstream silencers
• F7 filters will be positioned on vents
• the filter section shall be equipped with optional differential
pressure switch
• UV lamps may be installed upon request
• activated carbon filters may be installed upon request
Copyright © 2009 - FAST SpA
Technical solutions inside FM-H
Technical characteristics of the components
Copyright © 2009 - FAST SpA
Heat exchangers
• materials can be (tube / fins):
- Cu / Cu (standard)
- Cu / Cu tinned (optional)
- Steel / Cu (optional)
- Stainless steel / steel (optional)
• the casing of coils and related rails are made of stainless steel
• Electric coils are made of stainless steeel
Technical solutions inside FM-H
Technical characteristics of the components
Copyright © 2009 - FAST SpA
Heat recovery devices
• PHE
• RAC Coils
• RWE is not suggested!
• Fresh air inlet should be filtered with F7 filter
Technical solutions inside FM-H
Technical characteristics of the components
Copyright © 2009 - FAST SpA
Humidifier
• Only with steam
• the accumulation of water is
prevented taking into
consideration the distances from
the following component.
• Control stops the humidifier
when the air conditioning system
shuts down or fails
Technical solutions inside FM-H
Technical characteristics of the components
Copyright © 2009 - FAST SpA
Droplet eliminators
• They are expected after cooling coils
with velocity> 2.6 m / s after
humidification
• The droplet separator has fins
antibacterial treatment with frame and
stainless steel guides
Technical solutions inside FM-H
Technical characteristics of the components
Copyright © 2009 - FAST SpA
Fan sections
• They are fans of the type used
exclusively PLUG FAN ensuring easy
cleaning of both the impeller and the
floor (and media guides are
minimized)
• The fan support and the fan itself are totally
subjected to antibacterial treatment;
Technical solutions inside FM-H
Technical characteristics of the components
Copyright © 2009 - FAST SpA
Silencers
• They are equipped with polyethylene film to ensure a high
standard of hygiene, and the frame rails are stainless steel
• the formation of condensation thereon shall be avoided
while maintaining appropriate distances between
humidifiers and silencers as a function of speed and air
temperature and humidity conditions
• silencers will be installed horizontally to facilitate easier
removal
Technical solutions inside FM-H
Technical characteristics of the components
Copyright © 2009 - FAST SpA
Panels
• 50 mm thickness panels
• Drainable floor for all section, at least 3% slope
• materials (external / internal)
Galvanized steel precoated/aluminum with antibacteria
treatment
Aluminum/Aluminum wih antibacteria treatment
• Insulation:
• Polyurethane (standard)
• Mineral wool (different thickness)
Technical solutions inside FM-H
Technical characteristics of the components
Copyright © 2009 - FAST SpA
Casing
• Aluminum
• Aluminum, with thermal break
Base frame
• Galvanized steel or stainless stell
Technical solutions inside FM-H
Technical characteristics of the components
Copyright © 2009 - FAST SpA
Coating for Aluminum
• Internal panels can be treated with a patented anti-bacteria
painting
Technical solutions inside FM-H
Copyright © 2009 - FAST SpA
• antibacterial treatment has been patented with the claim
"air handling unit, particularly for environmental health
and hospital food, [...] characterized in that it comprises
bacteria-static to counter the emergence of bacterial
colonies [...] substances with bacteria-static or bactericidal
action”
• Patent: number PD2300A00272 at CCIAA, Padova
Technical solutions inside FM-H
Coating for Aluminum
• the bactericidal action of the treatment is tested by the
laboratories of the Department of Environmental Medicine and
Public Hygiene of the University of Padua
Copyright © 2009 - FAST SpA
Technical solutions inside FM-H
Coating for Aluminum
Copyright © 2009 - FAST SpA
Antibacteria
system for
internal panels
PLUG FAN
SS guides and rails
Filters,
SS casing
Droplet eliminator,
Antibateria treated
Technical solutions inside FM-H