In general, they can be configured  the following  types of systems:

1) powered hobs  to  gas  (methane  or  LPG,  Of  net  or  with  cylinders):  in  this  case  the technical regulations  of reference  it can be represented by the series of UNI 7129 and 7130 standards, directly applicable for thermal capacities not exceeding 35 Kw (30,000 Kcal / h).

In this case, it is always necessary to provide systems for the extraction of cooking fumes, and their removal to the outside, by:

A) extractor hood and connected smoke channel, with forced or natural extraction;

B) alternatively, with a wall mounted electric fan, installed directly on the wall or on the window frame of the room;

C) in the case of thermal capacities higher than 35 Kw, the Ministerial Decree of the Interior Ministry dated 12-04-1996 applies, with the specific technical and dimensional requirements;

2) electric hobs (induction, resistance, etc.).

For these equipments it is not applicable, any technical legislation that imposes the obligation of capturing and evacuating the cooking fumes to the outside. In this configuration, therefore, the prescriptive constraint of capturing and removing the cooking fumes would not be applicable; if, on the other hand, local regulations provide for it, also in this case, the specific system for capturing and evacuating the cooking fumes must be set up; in any case, the "cooking" phase determines the emission of fumes and vapors which must be captured and evacuated outside the preparation room;

3)  thermoventilated electric ovens, microwave ovens, resistance ovens.

They can be traced back to the typology identified in point 2) as regards the possibility of collection;

especially for ventilated areas,

the technical documentation provided by the manufacturer must always be checked, c

he establishes,  the possible ways in which the cooking fumes must be removed;

if the manufacturer foresees the necessity of capturing and removing the cooking fumes, the relative evacuation system must be set up;

4) wood-fired ovens, barbecues and the like,  direct or indirect cooking, depending on whether the fuel is placed in the cooking chamber or with combustion chamber separated from the cooking chamber;

In this case, the technical legislation,  for systems up to 35 Kw, it is represented by UNI  10683: 2005,

that  it always requires the ducting of the combustion fumes to the roof, with the characteristics of the terminal and buffer zones depending on the type of roof present (inclined pitch or flat roof).

Within the framework of the applicable regulations, the cases must take into account any provisions of the local building regulations,

hygiene, urban, etc, which could identify specific constraints for emissions deriving from hobs in general.

Where required by local regulations, the collection and removal of fumes must therefore be arranged, with flues or chimneys, according to the technical and dimensional criteria referred to in the regulations.

Within the same standards, it could also be envisaged not only the removal to the outside (direct discharge to the wall) but also the evacuation beyond the roof of the fumes, with different height and buffer zone according to the various local constraints.

In addition to the part specifically regulated by local regulations, other regulations of a technical nature may apply, which are mandatory depending on the type of hob and power supply used.

SYSTEMS FOR ABATEMENT AND TREATMENT OF COOKING FUMES AND VAPORS

Technological evolution has allowed the creation of various systems for the treatment of cooking fumes, in some cases specifically aimed at a precise product, in which the emissions are subjected to filtration and reduction of odors, of the greasy part and of any unburned dust.

These systems are in particular proposed when it is not possible to remove the fumes from the roof due to problems related to the conformation of the building, to aspects of architectural protection of the building or due to the objective impossibility of obtaining any authorization from other condominiums.

The matter is extensively and comprehensively dealt with in the "Operational guide for the prevention of vapors and fumes from combustion in living environments" of the Tuscany Region, 2012 edition.

In the technical document the technical conditions of realization of this type of plant are represented and examined, with all the constraints linked to this particular intervention modality.

Generally speaking,

the technical reference for this fume treatment line is represented by the UNI EN 13779: 2008 standard, which allows the fumes to be discharged directly to the wall only if the emission deriving from cooking is declassified from EHA4 to EHA2, through filtration and reduction of pollutants .

Paragraph III.2.2 contains all the technical information relating to the main smoke abatement systems;

It is emphasized that the choice of the preparation of plant systems dedicated to the treatment of fumes involves a considerable commitment not only from the point of view of the initial purchase cost, but also for maintenance during construction,

as the manufacturer outlines the methods, interventions and timing with which the system itself must be subjected to the cleaning of the filters, the replacement of the  set off,  at  any checks  Of  functionality,  etc.

This condition  needs to  be strictly respected and demonstrated by conductors, with documentation certifying the interventions  carried out;  appears  therefore  obvious  that  this  choice  turns out  more'  demanding compared to the provision of a direct evacuation system to the roof.

CONCLUSIONS

The complex and articulated regulatory architecture described must be combined with a careful review of municipal regulations.

In the case of requests for derogation from the evacuation of cooking fumes from the roof, where provided for by local regulations, first of all the competent municipal offices should provide for the possibility of derogating from this obligation, in case of proven impossibility to conduct the fumes beyond the cover.

Only in this case, it will be possible to analyze the possibility of replacing the roof evacuation with direct wall exhaust after treatment and abatement of the fumes, according to the technical criteria referred to in chapter 3.

Regardless of the type of collection and expulsion adopted,

when the on-site inspection checks reveal evidence of the presence of mold and condensation attributable to ineffective management of cooking vapors and fumes, mandatory prescriptions will be adopted for the adoption of suitable smoke evacuation systems or the improvement of existing ones.

It is highlighted that the situations that can arise in practice  sometimes they are immediately coincident or evidently  in  contrast with the regulations  municipal;

these guidelines are intended above all to indicate, as well as on certain occasions, the use of special technologies  more  recent  and  evolved, it can still involve the  full respect  of the  health content of regulatory standards.

However, it should be emphasized that a situation that may be acceptable due to the absence of health risks does not exclude and does not absorb the concept of normal tolerability and respect for the interests of third parties, which only the plant operators will be responsible for. on topic.

Finally, it is reiterated that the correct management of vapors must be associated with the correct management of odors, which must be confined to the preparation area only.