Kitchen exhaust
Under kitchen exhaust is generally understood that a kitchen free or forced air flowing. This loaded kitchen exhaust, the so-called vapors , produced during cooking processes and consists mostly of water vapor, food odors and grease. A legal and technical distinction is made between private and commercial kitchen exhaust air.
Private kitchen exhaust
In private households, the kitchen exhaust air is the saturated kitchen air produced in the kitchen during cooking and roasting processes.
Often the kitchen exhaust air only reaches the outside through window ventilation , shaft ventilation or joint ventilation from the kitchen area. However, the largest proportion of fat from the vapors is deposited on walls and furniture. The smells spread in and around the house. Depending on the weather and the neighborhood, the untreated release of the kitchen exhaust air can lead to unpleasant odors.
The supply air flows in freely or is supplied via a ventilation system.
Tenants must accept cooking and food smells from the neighboring apartment. At most extreme odor nuisances can be objectionable (decision LG Essen ZMR 2000, 302).
Recirculation hood
Private households often use ventilation hoods, so-called extractor hoods . In recirculation mode, the fan sucks in the kitchen exhaust air above the hob from below, guides it through a filter mat (if necessary with an upstream grease trap), and then blows it back into the kitchen through a ventilation grille above. Fat grids separate fat droplets from the vapors. They should be checked and cleaned regularly, e.g. B. in the dishwasher. Fine fat particles can get through the fat grids. These are absorbed by the replaceable filter mat, which is mostly made of a plastic fleece or special filter cardboard. The filter mats must also be checked regularly and replaced if necessary.
Filter mats with an inner activated carbon layer are commercially available. The activated carbon layer also absorbs the odors from the kitchen exhaust air.
The exhaust fan should switch in stages, be encapsulated in a grease-tight manner and made of fire-proof plastic.
In contrast to the exhaust air hood, the recirculating air hood does not generate negative pressure, which is why it can be operated at the same time with a controlled living room ventilation , a fireplace or a gas boiler. It is therefore also suitable for use in a low-energy house .
Exhaust hood
The commercially available exhaust air hood for private households has an exhaust air connection to blow the kitchen exhaust air through a pipe into the open. The fan can usually be switched to several power levels. The exhaust pipes of newer models have a diameter of up to 150 mm. This enables the exhaust air to be extracted more quietly.
Flexible corrugated pipes made of plastic or aluminum are often laid. Since these can hardly be cleaned of grease residues, the exhaust air hood should only be operated with a grease filter in this case.
Operation without a grease filter is only appropriate if the exhaust air pipe is easily accessible and so short that it can be cleaned regularly without difficulty. The accumulation of grease in the pipe system must be avoided, as grease fires are difficult to extinguish and represent a considerable fire load . If a frying pan filled with fat is left on the stove, the overheated fat can ignite by itself. The flames quickly set fire to the plastic filter of the extractor hood and spread through the duct system.
Odor neutralization
The odor neutralization in a circulating air or exhaust air hood can be achieved technically with an activated carbon filter, a UV-C lamp, an ozone generator or an ionization device with an ionizer. In addition to active kitchen exhaust air treatment, the room air in the kitchen can also be odorless.
Legal aspects of odor nuisance from private kitchen exhaust air
The OLG Cologne (WuM 1997, 453) condemned an apartment owner of an apartment complex to install an extractor hood in order not to bother the tenant living upstairs with kitchen smells. At the same time, the court pointed out that cooking smells were common in the area and the installation of an extractor hood could only be mandatory in exceptional cases.
There is a controversial debate among experts as to whether exhaust air hoods with air intake openings in the building envelope or recirculating air hoods with activated carbon filters are preferable in low-energy buildings .
Commercial kitchen exhaust air from gastronomy, industrial kitchens and in the production of food
Kitchen ventilation systems in the commercial sector are subject to approval and monitoring and are subject to the applicable building regulations for design , installation, operation, ongoing maintenance and monitoring. In Switzerland, when registering a business, any odor nuisance caused by cold or warm kitchen exhaust air is queried and appropriate ventilation technology is required.
A distinction is made between exhaust air systems in kitchens with less than 25 kW connected load and those in kitchens with more than 25 kW.
The air processed in the ventilation or air conditioning center is transported through ventilation ducts , which are predominantly made of galvanized sheet steel. Aluminum sheet, stainless steel sheet, plastic or fiber cement panels are used less frequently. Masonry or concrete with coated surfaces can also be used as building materials. The ventilation ducts must be tight and have the smoothest possible surface on the inside. The lower the roughness of the inner surface, the lower the pressure loss. The ventilation ducts outside the kitchen are usually not cleaned or only rarely cleaned, as foreign bodies are kept away by filter systems.
In contrast, the ventilation ducts of the kitchen exhaust air system must be oil and grease tight and regularly checked and cleaned, in particular the sections directly adjacent to exhaust air openings or kitchen hoods or kitchen ceilings. The VDI guideline 6022 sheet 1 "Hygiene requirements for ventilation and air conditioning systems and devices" describes hygiene requirements with regard to planning, installation and maintenance of ventilation and air conditioning systems, as well as the technical requirements and hygiene knowledge for the maintenance of these systems.
A commercially used kitchen ventilation system consists of a supply air and an exhaust air system. The ventilation ducts are often provided with thermal insulation to reduce heat loss . In the case of pipes carrying cold air (fresh or outside air pipes), the outside of the insulation must be provided with a vapor barrier to prevent moisture penetration due to condensation on the surface of the ventilation duct.
The electric motor of the exhaust air fan must be separated from the kitchen exhaust air flow, specially encapsulated, and designed with protection class IP54 in order not to be impaired by the remaining fat content of the kitchen exhaust air . An oil drainage hole is provided in the fan housing in order to drain off the grease particles deposited on the housing by the centrifugal force of the rotor.
In residential areas in particular, the authorities issue requirements to minimize and eliminate odor nuisance or make the operating license dependent on compliance with the emission values.
Heat recovery
In the case of grease-laden kitchen exhaust air, it is hardly possible to use heat exchangers for energy recovery, as these would quickly become greasy and their function would be impaired. If it is proven that grease separation is very good, the use of special plate heat exchangers and fire dampers with special certification marks (instead of fire sealing) in the kitchen exhaust duct system is permitted. If the supply air and the kitchen exhaust air are spatially separated, the heat recovery can take place via a closed circuit system (KVS), with heat transfer fluid circulating between the supply and exhaust air ducts.
Commercial recirculation hoods in the catering industry with less than 25 kW kitchen connection power
Commercial recirculation hoods are subject to more stringent technical and hygienic requirements than extractor hoods used in private areas.
For hygienic reasons, recirculation mode (or partial exhaust air mode) is only permitted for cold ( sushi ) or minimally warm dishes ( pizza ). Design, installation and operation require special approval from the building and trade supervisory authorities or the food inspectorate, which is usually only issued in subway stations or in critical construction situations, if no exhaust air ducting to the outside is possible. Particularly efficient grease grids and filter mats are then required. Aerosol separators can separate the smallest grease droplets and vapors and must be cleaned in the dishwasher every day.
Kitchen hood
Kitchen exhaust hoods for commercial kitchens cover the entire hob and are usually made of stainless steel.
Due to the increased fire risk of deep fryers, extinguishing systems are installed in or below the kitchen hood, which extinguish a local fire automatically or via emergency switches.
High-quality kitchen hoods are equipped with a sensor-controlled, stepless automatic control system, which enables more efficient operation.
Kitchen ceiling
Commercial kitchens are often equipped with ventilation ceilings in the form of a suspended ceiling with stainless steel cassettes. The kitchen ceiling combines aerosol separators, supply air outlets, collecting equipment and lighting.
Such a system ceiling essentially consists of exhaust air, supply air, passive cassettes and collecting channels made of a special stainless steel alloy . Square, cross-arched ceiling cassettes measuring 500 × 500 mm show a uniform ceiling appearance. Aerosols rising in the thermal current are separated in the double-shell exhaust air cassettes and discharged in collecting channels. This increases the cleaning intervals compared to conventional systems. The ceiling cassettes and collecting channels are cleaned in the dishwasher. An extinguishing system can also be integrated.
Grease trap elements in kitchen exhaust systems
Aerosol separators can only separate solid and liquid particles. Steam must therefore first be condensed in scrubber or induction systems.
Grease or oil caught in separators must be handed over to specialized disposal companies.
Aerosol separator in the kitchen hood
Aerodynamically shaped grease grids separate the grease from the sucked in kitchen exhaust air and guide it into collecting channels inside the kitchen hood. These aerosol separators separate the grease using the centrifugal force created by turbulence in special profile elements.
Special kitchen hoods work with blown support air, which blows rising vapors in the direction of the grease trap and thereby lowers the temperature in order to condense greasy aerosol particles.
Comfortable kitchen hoods also offer automatic cleaning systems for the aerosol separators.
Electrostatic air cleaner for grease separation
Electrostatic filter can filter out 99% of the fatty components of the exhaust air. As in the oil mist separators of machine tools, the fat components are separated and collected in a collecting pan. The collector plates are cleaned by spraying them with water.
Aerosol separator in the kitchen exhaust duct for separating grease
Instead of using the grease grids on the kitchen hood, the grease can be separated by aerosol separators in a cyclone, which also uses centrifugal forces to separate the fat particles. Automatic cleaning systems can clean the centrifugal separators automatically.
Odor neutralization of the kitchen exhaust air
The kitchen exhaust air , which has been freed of fat and solid particles, is still polluted with kitchen odors, which can be neutralized by various technical systems in order to minimize odor emissions and immissions .
UV technology or ozone generators
UV systems or ozone generators in the kitchen exhaust air system can reduce or completely neutralize odor nuisance through micro-oxidation with ozone. Ozone can be generated by irradiating the exhaust air with UV light in wavelengths smaller than 200 nm. Alternatively, the ozone is generated in separate ozone generators and fed into the exhaust air.
Activated carbon
After all fat components have been safely separated, the kitchen exhaust air can be fed through an activated carbon filter to eliminate odors . Due to the risk of fire, activated carbon filters are not suitable for separating grease.
Exhaust air chimney or weather protection grille
Depending on the local conditions and approval, the exhaust air from the kitchen can be released via a protective grille in the facade or via an exhaust air chimney, which is usually made of stainless steel.
HEPA pocket filter
HEPA filters cannot be used in commercial kitchen exhaust air systems for air purification as they would soak up grease and pose a fire hazard. When the ventilation system is switched off, HEPA filters soaked with grease spread unpleasant smells.
Legal aspects of odor nuisance from commercial kitchen exhaust systems
The guidelines VDI 2052 and DIN EN 16282 specify requirements for the hygiene of ventilation systems and fire protection for kitchen exhaust systems.
The Federal Immission Control Act (BImSchG) and the Odor Immission Directive stipulate that there must be no measurable environmental damage from odor nuisance.
The guideline VDI 2052 "Air conditioning systems for kitchens" is largely replaced by DIN EN 16282. Kitchens and associated areas are special rooms in which food is prepared and served, dishes and appliances are washed and food is stored. The EN 16282 regulates the ventilation treatment of commercial kitchens as well as the dimensioning and construction of the ventilation and air conditioning systems. It applies in conjunction with the complete work of DIN 1946. VDI 2052 does not apply to household kitchens, but does apply to commercial kitchens with a total connected load of more than 25 kW for heat and moisture-emitting devices (cooking appliances, dishwashers, etc.).
The Federal Court of Justice (BGH) ruled in September 2009 on noise protection in a residential and commercial building with a fish restaurant on the ground floor. The intake and exhaust air chimney of the ventilation system was led through an atrium over the roof. One tenant reduced the rent because of the noise pollution and requested that the ventilation system be stopped at certain times. The judges considered the claim to be unjustified, as the harassment does not lead to a deficiency in the apartment. Although the landlord must adhere to the technical standards at the time the building was erected, even without a special agreement, the exhaust air system did not exceed the emission guide values of the TA Lärm of August 26, 2006. (BGH, judgment of September 23, 2009, VIII ZR 300/08).
Despite checks by chimney sweepers or the trade supervisory authority , the operator is always responsible for the perfect condition of his kitchen exhaust air system (court ruling by the Federal Court of Justice with AZ .: VI ZR 11/87 of February 2, 1988). If, after a fire, the insurer proves inadequate or neglected cleaning as the cause of the fire, this usually leads to loss of claims settlement.
In England, the kitchen exhaust air in every commercial kitchen must be cleaned with an electrostatic air purifier before it is blown outside.
Air routing from associated rooms
The odors that arise in the grease separator room with the grease separator and the corresponding grease separator exhaust air system, the garbage room with its exhaust air system and the cold store with integrated refrigeration technology must also be removed by an exhaust air system and, if necessary, neutralized.
An air lock or an appropriate air duct must ensure that no air can enter the kitchen from adjacent guest rooms in order to prevent the spread of germs. Particularly with show cooking ( front cooking ) in the guest room, special measures may be necessary to achieve this goal.
standardization
Europe
European standards
The following European standards apply to ventilation systems :
- EN 12237 [2003-07]: Ventilation for buildings - Air ducts - Strength and tightness of air ducts with round cross-section made of sheet metal
- EN 12792 [2004-01]: Ventilation for buildings - Symbols, terminology and graphic symbols
- EN 13779 [2007-09]: Ventilation for non-residential buildings - General principles and requirements for ventilation, air conditioning and space cooling systems
- EN 15780 [2012-01]: Ventilation for buildings - Air ducts - Cleanliness of ventilation systems
- EN 16282 : Equipment in commercial kitchens - Elements for ventilation
-
EN 1825 [2002-05]: Separation systems for grease
- Part 1: Construction, function and testing principles, labeling and quality monitoring
- Part 2: choice of nominal size, installation, operation and maintenance
Germany
The following DIN applies to ventilation systems throughout Germany:
-
DIN 1946 [2009-05] Raumlufttechnik
- Part 6: Ventilation of apartments - General requirements, requirements for dimensioning, execution and marking, handover / acceptance (acceptance) and maintenance
- DIN 16282 [2017-12] Equipment in commercial kitchens - elements for ventilation
- Part 1: General requirements including calculation methods
- Part 2: Kitchen ventilation hoods; Design and security requirements;
- Part 3: Kitchen ventilation ceilings; Design and security requirements;
- Part 4: Air outlets; Design and security requirements;
- Part 5: Air Lines; Design and dimensioning;
- Part 6: Separator; Design and security requirements;
- Part 7: Installation and operation of stationary fire extinguishing systems;
- Part 8: Systems for aerosol aftertreatment; Requirements and testing;
-
DIN 18017 [1987-02] Ventilation of bathrooms and toilet rooms without outside windows
- Part 1: Single shaft systems without fans
- Part 3: Ventilation with fans
-
DIN 18869 [2004-03] Large kitchen appliances - Devices for ventilation and extraction of commercial kitchens
- Part 1: Kitchen ventilation ceiling open design with ceiling pressure space
- Part 2: Kitchen ventilation ceiling, closed design with air chamber
- Part 5: Aerosol separators
-
DIN Technical Report 4108 [2010-09] Thermal insulation and energy saving in buildings
- Part 7: Airtightness of buildings - requirements, planning and implementation recommendations and examples
Employer's liability insurance association rules for safety and health at work:
- BGR 111 (previous ZH 1/37): Working in kitchens - rules for safety and health protection in kitchens
- 5.21.1 Exhaust systems may only be operated with a grease trap.
- 5.21.2 Grease trap filters in exhaust air systems must be cleaned in accordance with operational requirements, but at least every 14 days. This includes that daily cleaning may also be necessary in the event of a large amount of fat.
- 5.21.3 Kitchen exhaust air ceilings must be checked regularly, but at least every six months, for their degree of soiling and cleaned if necessary. This is especially true for the ceiling void.
- 5.21.4 Equipment of the exhaust air system must be checked at least every six months and cleaned if necessary. These are e.g. B. exhaust ducts, fans, aggregate chambers.
Austria (Tyrol)
Provincial Law Gazette for Tyrol 111th Law of October 8, 1998, with which fire police regulations for Tyrol are enacted (Tyrolean fire police regulations 1998):
Section 9 Plants requiring cleaning (3) Exhaust ducts, suction ducts and transport ducts, in which flammable residues can accumulate, as well as garbage disposal chutes are to be cleaned in such a way that the ignition of deposits is avoided.- §10 Cleaning and inspection obligation
(3) The facilities mentioned in §9 Paragraph 3 are to be cleaned or cleaned as required by the owner or by the person otherwise authorized to dispose of them.
USA: UL standardization
- UL 1046 of the US American Underwriters Laboratories - Flame transmission safety aerosol separators
See also
Web links
- Basics of kitchen ventilation. In: IKZ-Haustechnik , edition 8/2002, p. 40 ff.
- Aerosolate contamination in kitchen exhaust air systems - Preventive fire protection in kitchen exhaust air systems in commercial kitchens (PDF; 2 MB)
- BGI 5121 - ventilation of commercial kitchens. arbeitssicherheit.de
- GUV rule R111 - Working in kitchens - May 2007 edition. (PDF; 981 kB) publications.dguv.de
- Exhaust systems and technical devices in commercial kitchens www.berlin.de - State Office for Occupational Safety, Health Protection and Technical Safety
- Ventilation systems in gastronomy with heat recovery? In: IKZ-Haustechnik , edition 23/1996, p. 80 f.
- Energy-saving hood allows air volume to be reduced by 25–30% - kitchen ventilation (PDF; 492KB), imgruethag.ch
- Maintenance and cleaning of kitchen exhaust and extractor systems in commercial kitchens, according to VDI 6022 and VDI 2052 www.hutag.de
Individual evidence
- ↑ Care of extractor hoods: Clean the grease filter ( Memento of the original from September 15, 2013 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. www.wallstreet-online.de, accessed on August 28, 2013.
- ↑ Food smells are generally common social and household occurrences www.mietmigung.org, published on July 26, 2013, accessed on August 26.
- ↑ Extractor hoods in the kitchen must harmonize with the home ventilation. ( Memento of the original from August 31, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. www.luftwechsel.ch, accessed on August 27, 2013.
- ↑ Form commercial kitchens ( Memento of the original dated May 12, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 106 kB) Exhaust air from commercial kitchens www.awel.zh.ch Canton of Zurich, accessed on August 26, 2013.
- ↑ Instructions for the hygienic operation of supply air systems in small kitchens ( memento of the original dated September 3, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 844KB) Edition index 8.18 / 07 www.hydrocleangmbh.de - ASI - Arbeits-Sicherheits-Information + BGN Berufsgenossenschaft Lebensmittel und Gaststätten, accessed on August 26, 2013.
- ↑ Exhaust air cleaning for gastronomic and industrial kitchens ( Memento of the original from June 25, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. kuechenabluft.com, Christian Bundt AIRCLINO Consulting; Retrieved August 26, 2013.
- ↑ DOG system ceiling (according to DIN 18869) ( Memento of the original from August 29, 2013 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. oetjen-gmbh.de; Retrieved August 26, 2013.
- ↑ Operation of ventilation and air conditioning systems in public buildings (PDF; 3247 kB) ab-plus.de; Retrieved August 26, 2013.
- ↑ REVEN UV system ( Memento of the original from September 3, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 642 kB) kuechenlueftung.at, Rentschler Reven - Lüftungssysteme GmbH, edition 2007; Retrieved August 18, 2013.
- ↑ Exhaust air cleaning for gastronomic and industrial kitchens. ( Memento of the original from June 25, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. kuechenabluft.com; Retrieved August 19, 2013.
- ↑ Kitchen exhaust air without odors PR, tga-fachplaner.de; Retrieved August 19, 2013.
- ↑ Guidelines VDI 2052 and VDI 2052 (PDF; 77 kB) mannheimer.de, Rentokil Initial, accessed on August 19, 2013.
- ↑ VDI guideline committee 2052 “Air conditioning systems for kitchens”. ( Memento of the original from November 1, 2013 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. vdi.de; Retrieved September 6, 2013.
- ↑ Fat deposits in extractor hoods and exhaust ducts have long been known to pose an increased risk of fire. re-h-lueftungsreinigung.de, accessed on September 8, 2013.
- ↑ Guidance on the Control of Odor and Noise from Commercial Kitchen Exhaust Systems (PDF; 626 kB) gov.uk; accessed on August 23, 2013.
- ↑ DIN EN European standard ventilation baunormenlexikon.de; Retrieved September 5, 2013.
- ↑ DIN VDI in Germany ventilation baunormenlexikon.de; Retrieved September 5, 2013.
- ↑ BGR 111 (previous ZH 1/37) Working in kitchen operations - rules for safety and health protection in kitchens ( Memento of the original from May 14, 2014 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF507KB) kuechenlueftung.at, accessed on September 8, 2013.
- ↑ Provincial Law Gazette for Austria (Tyrol) 111. ( Memento of the original dated August 14, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , ls-henken.de, accessed on September 8, 2013.
- ↑ DIN 18869-5 aerosol separator ( Memento of the original dated May 12, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF; 481 kB) reven.de; Retrieved September 5, 2013.
