In order to ensure the healthy functioning of internal microclimate environments where we live and work it is necessary to periodically clean and sanitise the ducts, filters and other components. It is necessary to carry out a video inspection in order to verify exactly which part of the system needs intervention, starting from the vents outside and continually right through the ventilation system.
- Number 3_ ASCS (Air systems cleaning specialist) – VSMR (ventilation system mold remediator)
- Number 2_ VMT (Ventilation Maintenance Technician).
Energy efficiency produces numerous environmental and economic benefits
‘We intervene’ to analyse, plan and execute plans for action in the plants and warehouses of our clients.
The regular cleaning and maintenance of air ducts has often been underestimated by hospitals, companies, schools, hotels, shopping malls and airports.
The legislative decree 626/94 marked a significant turning point, and started to treat the matter more specifically, including it in the matters that an employer must undertake in order to safeguard the health of its employees in the workplace. In article 33, it is stipulated that ventilation systems should be functional and efficient and that any sediment or dirt which could be a health hazard contributing to air pollution are eliminated quickly.
The 13 of March in 2000, the Ministry of Health published the following guidelines for the prevention and control of Legionnaires disease , whereby the standing conference that establishes the relationships between the state, the regions and the autonomous provinces, included heating systems, ventilation systems, air conditioning systems and their parts within the list of components which may boost the spread of airborne diseases including legionella being of particular danger. In addition to legionella, other contaminants may be the cause of many ailments and diseases.
On the 27th of November in 2001 an official agreement between the Ministry of Health and the regions and autonomous provinces was published in the official Journal in relation to the following document: ‘the Guidelines for the prevention and promotion of health in confined spaces’, in which a check of the air ducts becomes mandatory with the activation of a system in order to ensure that it is clean when installed- the limit for particular matter deposited in air ducts considered not clean must not excess of 0.1 g/m2.
In addition, the agreement recommends regular maintenance and technical inspections along with frequent hygienic checks where any eventual contaminations must be highlighted and cleaned, if necessary by qualified personnel. It also states that a system shall be considered to be maintained clean only when all the surfaces of the system 8in particular the air ducts) do not show deposits of anything deemed unacceptable. On July 2nd, 2002, the Liguria Regional Council approved the law N. 24, which governs the discipline for Construction, Installation, Maintenance and Cleaning of Air Vent Installations.
This law provides for the obligation of cleaning of the entire HVAC system, in both the phase of installation and also in those of maintenance, guaranteeing the safety of its hygienic condition through periodic inspections of the air ducts and accompanying parts.
The HVAC system is considered clean when all surfaces, including the air ducts have a quantity of particular matter of less than 1 g /sqm. An implant is considered contaminated when the presence of pathogens exceeds a concentration level equal to 15,000 CFU/g and Bacteria 30,000 CFU/g.
Air conditioning systems, therefore must undergo thorough maintenance interventions in order to prevent the accumulation of bacteria and sediment which pollute the microclimate environment.
The Air Handling Unit , or better known as an A.H.U. is a machine used to treat air in closed environments. It’s usually made up of a heat exchanger for cooled water (where the evaporation occurs in the vaporiser of the fridge ), and hot water, both for cooling and heating, or a direct expansion coil inside circulates the cooled gas where the evaporation takes place in the battery itself, within the premises of use from an air filter and a suction/discharge fan on a low setting.)
A larger air handler that conditions 100% outside air, and no recirculated air, is known as a makeup air unit (MAU).
The parameters used in the air handling unit are:
For each of these parameters there is component of the machine that is able to control it, regulate it and or modify it. The A.H.U. is defined by the simple fact that the machine is equipped with a ventilator capable of sucking the air and pushing it towards the top points of distribution in the environment. The A.H.U usually consists of :
A recuperatore (when indicated)
An air filter
A battery for pre heating (when necessary)
A battery for cooling and dehumidification
A humidifying section
A battery for post heating
A high efficiency filter (only in specific applications)
A fan with an air vent
An intake/exhaust air fan
In the case of a plant recirculating air only, there is also a zone which mixes the fresh air, channelling it back into the plant which can be placed either at the beginning or in the middle of the unit. There are also units that do not have heat recovery systems, and even those which are not equipped with heating batteries because the latter can be accomplished on a peripheral level. (after the heating of the area).
How it works:
First it is necessary to select between the winter and summer programs.
During winter, the air follows the following cycle: ( Shutter) Seranda- filter, pre heating, humidifier, post-heating, filter, fan.
The cold battery does not need to be used.
In summer the following cycle is followed:
Seranda- filter, cold battery, post heater, fan
The pre heating battery and the humidifier are not in use.
The A.H.U. has a lot of connections with other equipment. In addition to the air vents, the machine must be connected to the hot water system, chilled water (for batteries), room temperature water (for the humidifier). There are also electrical connections (fans, control units, engine dampeners) and drains for the sewerage (condensation, water offspray).
They must be installed outside, almost always on the rooftops of buildings, in the case in which the location is indoors, an air channel must be created, starting from an external point.