Keeping the hood clean and hygienic allows to prevent and eliminate annoying problems of efficiency of the entire ventilation system and at the same time ensures the maintenance of a low fire risk.
Beside fire risk, problems associated with odours produced by cooking food, are wide-spreading and represent an increasing issue.
The substances responsible mainly include fat-acids, aliphatic and aromatic hydrocarbons, aromatic amines and aldehydes. The type and quantity of pollutants emitted depend mainly on what kind of product has been cooked, the cooking methods and the means used for cooking. There are many ways to filter odours, but there are no specific rules on “olfactory pollution”.
Odour is a complex phenomenon to understand not just for the wide range of potentially odourous substances, but mainly because the ability of a substance to be perceived by our olfactory system depends on different aspects that are both objective (volatility, water solubility, etc) that subjective (physiological and psychological of the observer) but can also involve the environment (temperature, pressure, relative humidity of the air, speed and direction of the winds). This means that the same substance, at a distance from the source, is perceived differently by different people.
Fragrance components can pose a significant problem between the restaurant / hotel / food service and the surrounding environment, as odours can easily spread over large areas through winds.
The ideal ventilation system in a large professional kitchen should include a portion containing UV system, possibly together with Titanium Dioxide (TiO2) and electrostatic precipitators. For the maintenance of cleanliness and a prolonged effect on the elimination of odours, it is often necessary to consider the application of UV Kitchen lamps in combination with Ozone emission.
UV Kitchen lamps are mercury vapour bulbs that emit the specific wavelength of the C band (UV-C), capable of breaking the bonds of fat compounds by breaking them down into simpler molecules (H2O, CO2, etc.) creating what is scientifically called “cold combustion”. Some of these lamps are made of special transparent quartz at a wavelength of 180 nanometers, which is able to “transform” the molecules of Oxygen into molecules of Ozone (O3). The properties of ozone are both ultra-clean and persistent over time; ozone is in fact a highly unstable molecule, which tends to re-transform into oxygen soon. Nevertheless, the application in the kitchens’ ventilation channels is very effective in eliminating odours precisely because ozone is able to “follow” the smells along with the ductwork, eliminating them before they are released outside.
As soon as ozone comes into contact with an organic matter, an oxidation reaction is triggered. Basically, molecules are oxidized, they are transformed into harmless molecules, thus eliminating any form of bad smell. Furthermore, Titanium Dioxide has a specific action on the elimination of VOC and NOC (organic and non-organic flying compounds) as it acts as a catalyst capable of degrading numerous organic compounds. By exploiting its properties we are able to destroy the deposited organic compounds and activate its self-cleaning and de-polluting capabilities. When applying this type of system, the only precaution is to mount it downstream of mechanical filters that micronize fat molecules like common mesh or labyrinth filters. The UV Kitchen technology, therefore, offers excellent results in the management of fat fumes and in the treatment of odours, with great benefits on several fronts.
In addition to those just listed, great advantages can be found especially with the combination of different technologies, achieving improvements for the management of the entire ventilation in kitchens.
There are various ways of UV Kitchen applications like UV, UV + Ozone and UV + Ozone + Titanium dioxide filters Once the specific situation has been analyzed, it is important to consider these essential points: