The recent cases of pneumonia in Lombardy have brought the issue of legionellosis to the forefront of public opinion. However, this is not new: official data from the European Disease Surveillance Center show a growth trend in Italy of legionella pneumonia, from 1000 cases in the 2011 to more than 1500 in the 2015.
The need for prevention is evident to avoid the spread of the disease and the risk of epidemics.
What is Legionella?
Legionella is a bacterium that can lead to infectious diseases affecting the respiratory system. The most severe form occurs with pneumonia and is called "Legionnaires' Disease" following the pneumonia epidemic that occurred in Philadelphia in the 1976 among the participants in a gathering of American war veterans (American Legion Convention).
Legionella lives in natural and artificial water basins and in spring waters, including thermal waters. From these environments it can reach distribution networks, water systems, reservoirs, fountains and swimming pools.
Legionella bacteria survive at temperatures between 20 and 55 ° C and die faster as the temperature is higher. For this reason, in the water systems it is always expected to be one thermal disinfection, with forced circulation of hot water above 60 ° C.
The disease is generally transmitted by respiratory route by inhalation of vaporized water containing the bacterium.
Health consequences can occur where legionellae are present in large concentrations. Therefore, the users and plants most at risk are:
- hospitals, clinics, nursing homes and similar;
- hotels, barracks, campsites and accommodation facilities in general;
- facilities for sports and school activities;
- buildings with cooling towers, air conditioning systems, sanitary systems;
- swimming pools and spas, spa and wellness;
- decorative fountains and artificial waterfalls.
Prevent legionella risk with instantaneous production of ACS.
The possibility of guaranteeing total disinfection is very difficult. For this reason it is preferable to limit the problem at the source and use systems that do not have hot water, but produce it in an instantaneous way. In this way, the bacterial proliferation environment (DHW storage) is eliminated and direct contact between the accumulated and the used water is avoided.
To respond to this need, Rossato proposes Aqualda, a preassembled group for instantaneous production of ACS, designed specifically for medium and large installations.
At the time of the request by the user, the hot water accumulates through the exchanger of Aqualda and transfers heat to the sanitary water without ever coming into contact with it. This ensures absolute sanitary water hygiene and immediate delivery.
Aqualda is equipped with a brazed plate heat exchanger of generous dimensions that guarantees water flow up to 150 liters per minute and, with cascade installation, up to 1200 l / min. However, it remains a compact station that can be installed on the wall or directly on the storage tank.
Perfect combination with heat pumps and solar systems
The exchanger is sized to deliver a high flow rate even at low temperatures (with 50 ° C) and this allows you to combine Aqualda efficiently with condensing boilers, heat pumps and solar systems.
The combination with a solar system is, moreover, particularly advantageous because the cooled water returns to the accumulation with temperatures between 11 and 23 ° C, with a consequent increase in the yield of the plant.
Not only hygiene, but also energy saving
The accurate design and selection of components makes the Aqualda a much more efficient solution than the withdrawal of water from an accumulation.
- The pump is high efficiency and low consumption.
- The electronic regulation modulates the operation of the pump according to the water request: if there is little demand, the lower the pumping and consequently the current consumption will be reduced. This is not possible with a thermostatic regulation and the saving is particularly evident on high flow rates.
- The electronic regulation also starts the heat generator only during the actual use hours with the possibility to set the desired value and the hysteresis in order to minimize switching on / off.
- The generous size of the exchanger allows a total transfer of heat to the sanitary water, maximizing the efficiency of the system.
Always in step with the times
The Rossato R & D experts are working to make Aqualda even more performing and with a more appealing aesthetic.
Soon we will launch the new Aqualda 2.0!
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