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What is Legionella (Legionnaires disease)?
Legionnaires disease is a bacterial disease that can cause pneumonia. Although in most of the times these cases are isolated, there is also the possibility of occurrence of an outbreak of this disease.

Where does the name of Legionnaires disease come from?
In Philadelphia, in 1976, cases of this disease were detected in people attending a state convention of the American Legion. So, it was decided to give such name to the disease. Later, the bacterium that causes the disease was identified and named Legionella pneumophila.

Is this a new disease?
No. Even though the identification of the bacterium is recent, there are records of this disease as early as 1947 (and may even have occurred other cases in previous years).

Where cases of this disease occurred?
Legionella cases have been detected in all industrialized countries. In England, for example, about 200 cases occur every year.

Where are the Legionella bacteria?
Legionella organisms can be found in stagnant water in various types of systems for hot and cold water, in cooling towers and large air conditioning systems.

How is Legionella transmitted?
The disease spreads from the water through the air and it is never transmitted from a person to another. Legionella outbreaks occur when people have inhaled aerosols from contaminated water systems.

Who can be affected by Legionella?
Although this disease affects people of all ages, it is true that cases tend to be more frequent on people over 50 years and, in general, mostly men than women.

What are the symptoms?
Early symptoms of Legionella are similar to a cold and muscle aches, fatigue, headache, dry cough and fever. Some patients also have diarrhea and a feeling of dizziness. These symptoms usually lead to cases of pneumonia. While the mortality rate in healthy people is around 10-15%, in other groups of patients the percentage may be higher.

When do the first symptoms appear?
The incubation period can be between 2 and 10 days, but usually tends to be between 3-6 days. There are rare cases where symptoms reveal three weeks after the exposure to bacteria.

What is the treatment?
The antibiotics administered to fight infection are effective in treating the disease.

How is the disease diagnosed?
Once the main symptoms of the disease appear, it is possible to establish a quick diagnosis based on urine analysis.

Essential to prevent Legionella
Throughout Europe, Legionella led to a change of the habits and regulations in use on each country.
The main causes of Legionella outbreaks are evaporators-concentrators and air conditioning systems (cooling towers), thermal springs and dampers spray or even evaporative cooling equipments.
Some water systems may be contaminated with Legionella, which fall into the trays of cold water storage of large cooling equipments.

The Legionella is only able to develop in systems of distribution of sanitary water, when high temperatures occur, in the presence of the adequate nutrients or in stagnant water.
The water distribution systems must comply with the sanitary regulation of each country concerning this matter.
With some regularity, water samples must be collected and analyzed to identify possible cases of Legionella.

The main issues focused on national legislations are:
• Two methods to combat this pathogen: thermal or chemical shock
• The high temperature of heaters (use water heaters with minimal storage system or none)
• All water heaters with storage must be equipped with a draining valve located in a handy place, on the lower part of the system, so that the accumulated water can be easily drained.
• Avoidance of continuous chemical treatments
• Usage of recirculation systems
• Confirmation that the desired temperature is reached at all levels of the circuit
• Location of mixing valves must be as close as possible to the point of use
• Mixing valves must include check valves
• Equipment should be easy to clean and disinfect
• In case only one mixing valve is used for different showers, it should be cleaned frequently
• Distribution network must be designed in a way that the return water temperature is not below 50 °C (55 °C in Belgium and the UK, and 60 °C in the Netherlands)
• Hot and cold water distribution pipes must be properly insulated (never together)
• Remove and clean faucets, pipes, mixing valves and showers, at least once a year

The first positive sign for the families who choose this technology of power microgeneration is obtaining a reduction on the monthly bills of power or gas, since the very first ones after the installation. A well sized system saves up to 70% of the energy needed to heat the water we use at home.

Depending on sze and use of the system, the thermal solar panel is amortized between 5 and 7 years. Considering the existing incentives, the turnaround time may be only 4-6 years.

The solar thermal panels convert sunlight directly into thermal energy for heating water or other purposes, while photovoltaic panels convert solar energy directly into electrical power.

- Solar radiation focuses on the glass cover existing on the upper part of the solar collector, penetrating inside the solar panel.
- Heat is transferred to the fluid that circulates through the pipes becoming less dense, rising from the collector to the tank.
- The exchange is made to the drinking water, the heat transfer fluid cools and descends into the collector, closing the cycle.
- The tank must be always placed above the solar collectors.

- Solar radiation focuses on the glass cover existing on the upper part of the solar collector, penetrating inside the solar panel.
- Heat is transferred to the fluid that circulates through the pipes.
- The warm fluid circulates in closed circuit and transfers the heat through the coil of the tank to the drinking water.
- The circulation of the fluid is managed by the differential controller and by the circulating group according to the measured temperatures.

- The thermosiphon system consists of a tank above the panel, the investment is lower and simpler to install. It works independently, without using pump to assist the movement of solar fluid.. Maintenance is simpler. However, it is not possible to use backup boiler and, in most installations, the tank is placed on the roof, which should be prepared to bear such weight. Moreover, looking at a tank on a roof is not aesthetically pleasant.
- The closed loop system has a higher performance, since the energy management is more effective while being commanded by a differential controller. The water tank can be placed inside the building. For anyone who cares about the aesthetics of the panel and the building, this is a good solution, as it allows better architectural integration.

Yes, the system will be installed contemplating this situation by including a solar module, and the boiler will come into operation automatically spending only the gas needed over the pre-warmed water, to reach desired temperature.

Yes. On average the available solar energy in winter supplies about 60% of the needs in terms of flat panels. On vacuum tubes systems that value stands at 70%. When there is not enough sun, in either case the backup system goes into operation.

Yes, it can be installed with an electrical resistance, thereby ensuring hot water.

Time to install a thermosiphon system: 48h.
Time to install a closed loop system: 72h.

No. There are other possible places (terraces, floor or other areas without shadows).

The thermal solar systems are built to last about 20 years with energy saving, caring for the environment. However, an annual preventive maintenance is required, to make sure their lasting time without losing efficiency.

It can be installed in any season. In winter, installations can take longer given the rain periods.

Yes, as long as the shadow covers the panel only in the first two hours after sunrise or the last two hours before sunset.

A house with solar thermal panels has better conditions of getting a good result in a energetic certification process than an equivalent one without collectors.

Yes, the panels are certified with SolarKeymark in accordance with the international requirements.

It can always be installed. The better orientation of the system is between southeast and southwest. For situations where the orientation is outside the predefined, the customer must discuss and agree with the installer the placement of an additional structure.

It can and should be used with a second heat source and thus act as a hybrid system.

Thermal solar systems may be adapted to all the backup systems, making use of natural gas or any other.

The thermosiphon tank does not include any exchanger coil, therefore it cannot be directly connected to a second heat source. It must be verified at the time of the installer’s preliminary visit, if there is a possibility of doing some kind of connection to the existing backup system. If this is possible, the necessary equipment and installation will be quoted.

No. This accessory (extra system) may be recommended because it’s an advantage in case of large temperature variations, helping to balance the pressures across the system. The installation is an option of the customer.

No, the closed loop system water tank has to be placed in stand up position.