The importance of Commercial Kitchen Ventilation (CKV) Systems in Commercial Cooking Facilities cannot be overstated. Today’s CKV Systems have become extremely customized heavily engineered systems, consisting of a multiple components. Components such as CKV hood(s), exhaust and make up air system(s), grease extractors and secondary pollution control units, CKV fire suppression system(s), Illumination, Electrical and Life Safety control package(s) some of which may include Demand Ventilation Controls (DVC) and/or Energy Management System(s) (EMS).
The following CKV Education Center is provided in a frequently asked question format and is designed with the intent that it be an unbiased source of information related to CKV hood design, code compliance, performance and operation. The reader is encouraged to review all of the material in the CKV Education Center upon their first visit.
Please do not hesitate to contact Streivor Air Systems with any of your CKV questions that you do not find answers for in our Commercial Kitchen Ventilation System Education Center.
The CKV Hood is where the design of the CKV system starts.
UL 300 is a fire testing standard administered by Underwriters Laboratories (UL). In order for appliance companies to receive UL labels on their products, each individual model must be submitted to Underwriters Laboratories for testing. The appliances must meet specific requirements in order to be approved and certified as UL 300.
Before 1994, most commercial cooking involved animal fat. The deep fryers that were used were poorly insulated which made cooking temperatures inconsistent and in-efficient. The extinguishing unit that protected those kitchens was a dry-chemical system which would smother the fire. Today, vegetable oils are used in commercial cooking and they heat to cooking temperatures quickly. Today’s deep fryers have excellent heat retention and are well insulated.
Dry chemical systems are no longer capable of extinguishing and sustaining an extinguished fire. UL 300 systems use wet chemicals which serve two purposes: 1.) To smoother the fire, similar to the way dry chemicals did; and 2.) To cool the liquids so they don’t re-ignite, something dry chemical systems couldn’t do. Although a system might be labeled as wet chemical, it may not necessarily be rated to the UL-300 standard. If you have any questions about your system, contact your suppression service company.
The Energy Standard for Buildings
National Standard ASHRAE 90.1 provides the minimum requirements for energy-efficient design of most buildings, except low-rise residential buildings. It offers, in detail, the minimum energy-efficient requirements for design and construction of new buildings and their systems, new portions of buildings and their systems, and new systems and equipment in existing buildings, as well as criteria for determining compliance with these requirements. It is an indispensable reference for engineers and other professionals involved in design of buildings and building systems.
ASHRAE 90.1 and the State of California’s Title 24 Energy Code are standards that mandate Demand Control Kitchen Ventilation (DCKV) or other energy saving strategies are incorporated into the commercial kitchen ventilation design, whenever a total kitchen has exhaust airflow rate greater than 5,000 CFM. Streivor’s DemandAire™ Control Systems meet these standards.
A CKV Hood is a device that is designed to capture and contain, heat, steam, and other effluents that are generated from commercial cooking.
CKV hoods are separated in to two Type of Hoods: Type I and Type II.
A Type I hood is hood that can be used to exhaust heat, steam, grease and other effluents generated from commercial cooking. The code and standards detail construction requirements for Type I hoods that depict a hood that is much more substantial than a type II hood. A Type I hood must be designed withstand the demands of continuous high temperatures grease laden cooking. (see example to the right)
A Type II hood is a hood that can be used to exhaust heat and steam only. A Type II hood cannot be used to when grease other effluents other than heat and steam are generated during the cooking process. (see example to the right)
The primary function of a CKV hood is to serve as a fire control and safety device. The CKV Hood Must be manufactured and installed in compliance with all local, state and national prevailing codes. Do not even start down the design path with a hood manufacture until you are convinced that their hood will meet all of the requirements of the prevailing codes and standards that apply to your specific installation.
CKV Hood Codes and Standards
You should contact the Authority Having Jurisdiction (AHJ) such as the building and/or fire department that will be issuing you your building permits. The AHJ will notify you which codes and standards your project will have to adhere to and comply with.
The CKV restaurant hood most often is required to adhere to and comply with National Mechanical Codes, such as the International Mechanical Code (IMC), Uniform Mechanical Code (UMC), state Mechanical Codes such as California Mechanical Code (CMC) and the National Fire Codes such as The National Fire Protection Agencies Standard 96 (NFPA 96).
To learn more about how to insure that you choose a code compliant CKV Hood read, “Specifying and Inspecting Commercial Kitchen hoods”
The major factor in determining if you will need to install a Type I or Type II restaurant hood will be the cooking equipment that you install under the hood regardless of what type of products and/or cooking technique you plan on using. An example of this is, if you are installing an enclosed convection oven and you only plan on using that oven for baking, the code implies that you can install a Type II hood because the products being cooked and the cooking technique will only create effluents of heat and steam. However, the AHJ may demand that a Type I hood be installed do to the fact that enclosed convection ovens can also be used to cook other food products such as proteins, in which case the effluents would contain grease laden particles.
The ultimate determination of the Type of CKV hood that you will need to install will be made after your cooking equipment plan and menu are reviewed with the AHJ.
A Type II hood is used when performing holding, reheating, baking, or using an enclosed deck type pizza oven that produces only heat and steam.
International Mechanical Code – Type II Hood
According to the International Mechanical Code, Type II hoods are to be installed above dishwashers and appliances that produce heat or moisture, and do not produce grease or smoke as a result of the cooking process. Type II hoods are required to be installed above all appliances that produce by-products of combustion and do not produce grease or smoke as a result of the cooking process.
Note: that you will have to consult with the Authority Having Jurisdiction for final determination.
A Commercial Kitchen Hood, like other products such as electrical appliances, can obtain a listing through a third party testing and certification laboratory (laboratory). A hood manufacturer can contract with a laboratory and have their product tested to the prevailing standard. If the manufacture proves that they can meet all of the requirements of the prevailing standard they then can contract with the laboratory to place the laboratories mark on their product. The manufacturer will be subject to quarterly unannounced inspections to insure the listed product is manufactured in accordance with its listing. The manufacturer can continue to display the laboratories mark as long as the manufacturer is in good standing and can prove they are in compliance with their listing to the laboratory.
The two certification and testing laboratories that are currently listing CKV hoods in the United States of America are Intertek (ETL) and Underwriters Laboratories Inc (UL). The hood may be referred to a UL Listed and/or ETL Listed hood based on the Laboratory that the hood is currently listed with.
The California Energy Code, or Title 24, Part 6 of the California Code of Regulations, also titled The Energy Efficiency Standards for Residential and Nonresidential Buildings, were established in 1978 in response to a legislative mandate to reduce California’s energy consumption. The standards are updated periodically to allow consideration and possible incorporation of new energy efficiency technologies and methods.
The Energy Commission adopted the 2008 Standards on April 23, 2008, and the Building Standards Commission approved them for publication on September 11, 2008. The 2008 Residential Compliance Manual was adopted by the Commission on December 17, 2008, and the 2008 Non-residential Compliance Manual was adopted January 14, 2009.
The requirement for when the 2008 standards must be followed is dependent on when the application for the building permit is submitted. If the application for the building permit is submitted on or after 1/1/10, the 2008 standards must be met.
- The Energy Commission adopted the 2008 changes to the Building Energy Efficiency Standards for a number of compelling reasons:
- To provide California with an adequate, reasonably-priced, and environmentally-sound supply of energy.
- To respond to Assembly Bill 32, the Global Warming Solutions Act of 2006, which mandates that California must reduce its greenhouse gas emissions to 1990 levels by 2020.
- To pursue California energy policy that energy efficiency is the resource of first choice for meeting California’s energy needs.
- To act on the findings of California’s Integrated Energy Policy Report (IEPR) that Standards are the most cost effective means to achieve energy efficiency, expects the Building Energy Efficiency Standards to continue to be upgraded over time to reduce electricity and peak demand, and recognizes the role of the Standards in reducing energy related to meeting California’s water needs and in reducing greenhouse gas emissions.
- To meet the West Coast Governors’ Global Warming Initiative commitment to include aggressive energy efficiency measures into updates of state building codes.
- To meet the Executive Order in the Green Building Initiative to improve the energy efficiency of nonresidential buildings through aggressive standards.
UL 710 refers to Underwriters Laboratories Inc Standard #710. Type 1 Commercial Kitchen Ventilation Hoods are tested to and must comply with UL 710 to obtain a listing.
The UL 710 Standard covers Type 1 CKV exhaust hoods intended for placement over commercial cooking equipment. Exhaust hoods with and without exhaust dampers are covered by these requirements.
CKV Type 1 Exhaust Hood Testing
Exhaust hoods are evaluated relative to minimum exhaust airflow required and maximum supplied airflow allowed for capture and containment of cooking effluence under laboratory conditions.
Code Compliance
All exhaust hoods are intended for use with fire extinguishing systems in accordance with NFPA 96, the Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations.
Exhaust hoods covered by these requirements are intended for installation in accordance with codes such as the International Mechanical Code (IMC), Uniform Mechanical Code (UMC), and NFPA 70, the National Electrical Code.
Currently there is only a standard to test Type I hoods, the UL 710. Type II hoods have no UL Listing.
Not necessarily. Listed hoods provide insurance that the product should have met the current codes and standards when it was manufactured, however the listing does not guarantee that the hood currently meets all of the current prevailing codes and standards. This is one very good reason that purchasing a used a hood is not a good idea unless the purchaser is an expert on hoods and up to date on all of the prevailing codes and standards. The codes are in continuous change and there is no guarantee that a hood that was Listed in the past is still compliant with the prevailing codes and standards.
Listed CKV hoods have the advantage of arriving to your installation with the mark of a third party testing and certification listing. Thus you have the guarantee of the manufacture that they are manufacturing their product per their listing and also that the laboratory is certifying that product is being inspected to insure the product is being manufacture in accordance with its listing and the current standard.
Listed CKV hoods also have the advantage that the hood is only required to exhaust the minimum amount of exhaust air that its listing dictates and not the minimum amount the prevailing code dictates.
The prevailing codes provide detailed information on the design and construction requirements that a CKV hood must adhere too. A qualified sheet metal mechanic can design and manufacture a hood to the prevailing codes and thus the hood can meet the codes requirements. CKV hoods do not have to be Listed to be installed in a commercial kitchen.
Non-Listed hoods will most likely undergo a more detailed inspection process by the Authority Having Jurisdiction as a result of the lack of third party testing and certification laboratory.
A Non-Listed hood has the advantage of not having to be manufactured to a specific set of length, height and/or depth dimension as well any specific geometric shape depicted in the manufacturer’s hood listing. Therefore a Non-Listed hood can be made in any combination of size and/or shape as long as it meets the requirements of the code. This flexibility can be an advantage when things such as columns, beams or other building conditions dictate such things notches, irregular shapes or the position of the exhaust plenum in the CKV hood.
Hoods range from Listed to Non-Listed, rectangular to round
There are an infinite amount of different CKV hood designs. CKV Hoods for design purposes are broken down into Listed or Non-Listed hoods. Listed hoods will need to be manufactured in accordance with their size and shape listing requirements. Non-Listed hoods can be made any size or shape as long as they meet the requirements of the prevailing code. Streivor can design and engineer Listed and Non-Listed hoods for your unique needs.
Photo Gallery
Streivor’s gallery contains examples of some of our custom hoods
Island Canopy Octagon Design Hood
There are several steps that you will need to take in determining the restaurant hood design that is best for you and your installation.
Step 1: determine the type and amount of cooking equipment that you will be installing in your kitchen. Obtain specification and installation sheets for that cooking equipment. Produce a drawings that shows the positioning of the cooking equipment in the building.
Step 2: obtain and/or detail a set of building condition drawings depicting the area where the hood is going to be installed. It is essential that the hood designer know of any obstructions in the hood area, pipes , ducts, beams, ceilings, walls and the availability of a path way that can facilitate the installation of a duct system that will be the sized to meet the exhaust air requirements of the hood.
Step 3: consult with a person that is a n expert in the field of restaurant hood design and installation. You can contact any of Streivor sales offices or representatives for assistance in choosing the best restaurant hood design for your installation.
The most common CKV hood design is an exhaust only wall mounted canopy box design Hood (WCBD). The WCBD is designed for the back of the hood to be mounted against a wall, over the top of the cooking equipment and the cooks and is manufacturing in the shape of a rectangle (box). The WCBD design is the most commonly installed hood because of its flexibility, performance and costs.
Flexibility. The WCBD type CKV hoods will accommodate almost all types commercial cooking equipment, including various combinations of that equipment. Equipment such, broilers fryers, griddles and ovens can usually be installed under a WCBD hood.
Performance. WCBD type hoods are very efficient at capture and containing effluents and exhausting them will lower amounts of exhaust air than some other CKV hood designs. The WCBD takes full advantage of an enclosed back wall and large canopy overheard to enhance capture and containment capabilities.
Value. WCBD type CKV Hoods make up the a large share of the market place thus they are produced in larger quantities, the larger production rates of the WCBD design reduces the market price the WCBD type CKV hoods.
The minimum amount of exhaust air that is required in a CKV hood is determined by the type of cooking equipment that will be installed under the hood, the temperature at which that cooking equipment will be cooking at, the design of the hood and the amount of open sides that the hood has, i.e. how many sides of the hood are up against a wall or is the hood installed in an island application.
Listed hood designs are individually tested for capture and containment over temperature controlled cooking equipment by a third party testing and certification lab. The results of capture and containment test are documented and included as part of the hoods listing. The manufacture can then engineer the minimum exhaust air flows of that hood design per the details of that hoods listing.
Non-listed CKV hood designs must meet the requirements of the prevailing codes. The prevailing codes generally provide formulas that are dependent on the type of cooking equipment and the temperature that the cooking equipment is intended to operate at, as well as the amount of open sides of the hood. Some code formula also take into consideration the distance that the CKV hood will be form the cooking equipment.
The minimum amount of air that a Listed CKV hood is required to exhaust is determined by capture and containment tests that were observed by the third party testing and certification laboratory on each specific design. Each Listed hood design has its own listing requirements and must be installed in accordance to them.
SmartAire CKV Hoods meet the Title 24 Standards
Yes, there are definitely some kitchen hoods that are manufactured with more efficient designs that allow the hood to operate at lower exhaust air flows. Streivor’s patented SmartAire™ hoods can give up to a 40% savings in energy efficiency over conventional kitchen hoods, which meet the Title 24 standards.
Containment Panels reduce exhaust flow rates
Streivor’s containment panels, can contribute up to a 10% reduction in exhaust flow rates.
The position of the cooking equipment and the inclusion of adjacent back and side walls or the lack thereof can have a significant effect on the amount of exhaust air that is required to obtain full capture and containment. Positioning the cooking equipment with the hottest cooking temperature closest to the center of the hood can reduce exhaust airflow requirements and vice a versa, positioning the cooking equipment with the hottest cooking temperatures closet to the sides of the hood will increase exhaust air flow requirements.
Walls adjacent to CKV can significantly reduce the minimum amount of exhaust airflow that is required to achieve capture and containment. Hoods that are installed against a back wall will generally require 50% less exhaust airflow than hood that are installed in a Island application with no walls.
Yes!
Active Front Edge Air Curtain
The capture and containment efficiency of a CKV hood can be greatly increased by mechanically introducing streams of air to the lower front edge of the hood. The air streams create an active edge increase the hoods ability to capture and contain effluents at lower exhaust air flow. The streams of air must be made up of an extremely low volume of air while at the same time maintaining a very high velocity of travel. Hoods with an active front air edge can be as much as 40% more efficient than hoods with similar designs without an active front air edge.
Containment Panels
Containment panels are usually made of the same material as the CKV hood and are either fastened or welded to the open side of the hood. The containment panels enclose the hood and reduce amount of hood open area. The containment panels also significantly reduce the negative effects of makeup air or other air currents round the hood. Containment panels generally come in two sizes heavy duty and light duty. Hoods with heavy duty or light duty containment panels can be as much as 20% and 10% respectively more efficient than similar hoods without containment panels.
You should consult the prevailing codes and AHJ before installing a CKV hood to verify the required clearances to a type I Hood. Generally a Type hood will require 18” of clearance to a combustible material, 3” to a limited combustible material and 0” to a non-combustible material. Most CKV manufacturers offer accessories called stand offs or air spaces that can be added to the CKV hood to insure proper clearances are maintained and enclosed.
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The minimum amount of exhaust air that is required in a type II CKV hood is determined by the type of cooking equipment that will be installed under the hood, the temperature at which that cooking equipment will be cooking at, the design of the hood and the amount of open sides that the hood has, i.e. how many sides of the hood are up against a wall or is the hood installed in an island application.
Is the minimum amount of exhaust air required different for Listed and Non-Listed Type II CKV hoods?
There is no current standard for listing Type II CKV hoods in the United States of America, thus the prevailing codes and standards should be consulted for determined minimum exhaust air flows.
Make up air refers the air that must be introduced into the kitchen to replace air that is being removed by the CKV exhaust system.
Make up air balances the air pressure
Restaurant kitchen exhaust systems are often very powerful, removing thousands of cubic feet of air per minute. When this air is removed from the kitchen, it needs to be replaced with fresh air. Without this replacement air, you can wind up with all sorts of unpleasant and even dangerous conditions like negative air pressure, poor temperature control, back drafting and air quality problems. Also, these issues may negatively impact your energy usage. The problem can be compounded in newer buildings constructed to be airtight, which prevents the natural flow of outside air into the kitchen space. To avoid these issues a make up air unit will usually be installed on the roof (if available) or in a mechanical room, and provide a steady stream of outside make up air or tempered make up air into your kitchen.
The current codes generally mandate that the exhaust system create no more than a .02 inch water column negative pressure in the kitchen.
The most common ways of introducing make up air into the kitchen are:
- through the CKV hood,
- through perforated supply plenums either mounted to the CKV hood or in the ceiling around the CKV hood
- through ceiling diffusors located in the general are of the CKV hood
- through the buildings HVAC system
- through a combination of 1, 2, 3 & 4
Many CKV hood manufactures have hood designs that include a make up air plenum as part of the hood. The make up air is introduced into the hood from the make up air system and exits through the hood into the room.
The advantages of introducing make up air through the CKV Hood are:
- CKV hoods have the potential to provide a large diffused area for the return of the make up air, thus facilitating a potentially lower air speed of the make up air returning into the kitchen.
- Reduces the amounf of space the make up air system my occupy in the attic and ceiling.
- Potentially Simplifies the Design and Installation processes by eliminating the need to engineer a makeup air diffusor system with multiple diffusors thought put the kitchen.
- Potentially lowers the cost of the make up air system and the installation of it by eliminating multiple duct runs and diffusors.
- space by eliminating the need for additional plenums or diffusors located outside of the CKV hood.
Several advantages are listed below:
- Perforated Supply Plenums have the potential to provide a large diffused area for the return of the make up air, thus facilitating a potentially lower air speed of the make up air returning into the kitchen.
- Potentially Simplifies the Design and Installation processes by eliminating the need to engineer a makeup air diffusor system with multiple diffusors thought put the kitchen.
- Potentially lowers the cost of the make up air system and the installation of it by eliminating multiple duct runs and diffusors.
Most National Mechanical and Fire Codes and Standards require that the CKV Type 1 hood systems shall be designed and installed to automatically activate the exhaust fan whenever cooking operations occur. If the CKV Exhaust fan is not manually turned on when the cooking equipment is in use, then an auto fan start will automatically turn on the exhaust fan.
CKV hoods can be fitted with temperature monitors that have an adjustable temperature setting. The temperature monitors are set to a point slightly above the standard ambient operating kitchen temperature. When the temperature monitors detect temperatures above the standard ambient kitchen temperature, the monitor closes a switch that can be used to energize the CKV hood exhaust fan.
Most National Mechanical and Fire Codes and Standards require that the CKV Type 1 hood systems shall be designed and installed to automatically activate the exhaust fan whenever cooking operations occur. If the CKV Exhaust fan is not manually turned on when the cooking equipment is in use, then an auto fan start will automatically turn on the exhaust fan.
Auto Fan Start in Streivor Enclosure.
CKV hoods can be fitted with temperature monitors that have an adjustable temperature setting. The temperature monitors are set to a point slightly above the standard ambient operating kitchen temperature. When the temperature monitors detect temperatures above the standard ambient kitchen temperature, the monitor closes a switch that can be used to energize the CKV hood exhaust fan.
The CKV hood that is considered the most energy efficient is the hood that can be installed over cooking equipment and exhaust the lowest amount of exhaust air.
An example of an energy efficient hood is a hood that uses advanced aerodynamic technology that incorporates airstreams into the front lower edge of a hood that create an active front edge that reduces the amount of exhaust air that is required to facilitate capture an containment in similar hoods by as much as 40%.
Unfortunately no. The only part of a CKV hood system that can qualify for LEED point credits for Demand Control Kitchen Ventilation (DKCV) Systems. Streivor’s DemandAire™ qualifies for LEED points and has met the technical requirements to receive the EPA’s ENERGY STAR® Emerging Technology Award.
Demand Ventilation Controls can be added to the CKV Systems to vary the exhaust and make up air fan during different levels of operations, such as peak or off peak cooking times.
Demand Control Kitchen Ventilation (DCKV) is a system that incorporates sensors that monitor the state of the CKV hood, CKV hood duct, and/or cooking equipment. The monitors provide information on the state of the CKV components and send information to a control panel that varies the amount of power that is supplied to the exhaust and make up air fans. A DCKV system will reduce the amount of energy the CKV System is using by turning down the fan power during off peak cycles.
Yes, Grease filters or grease extractors are required in all type I CKV hoods.
The name implies that the most important function that the grease filter or extractor is to extract grease from the exhaust air stream. Extraction is important but not the primary function. The primary function is to provide a fire barrier which prevents a fire traveling from below the filter up into the duct system.
No, the percentage of grease extraction efficiency is dependent on the design of the grease filter. Grease Filters are engineered to extract grease and results may vary according to the type of cooking appliances used in the kitchen. Choosing the right grease filter would be dependent on your preferences and unique cooking environment. Streivor has a variety of grease filters design for heavy, medium and light duty CKV environments. All are engineered for use in commercial kitchen type 1 hoods requiring a filter that is Listed to the UL 1046 Standard.
The national codes and standards require that all grease filters for Type I CKV hoods be Listed to the Underwriters Laboratories Standard #1046.
The Standard for Grease Filters for Exhaust Ducts
UL 1046 is the standard by which Grease Extractors are tested.
Products covered by these requirements are single-stage and multi-stage grease filters. These grease filters are intended for installation and use in accordance with the Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations, NFPA No. 96 and the International Mechanical Code (IMC).
CKV Hood Grease Filter Testing
The test methods described in this standard pertain to filters used in exhaust hoods for commercial cooking operations. The primary function of these devices and the capability of devices tested in this standard are to prevent flames from penetrating into the exhaust system beyond the hood collar.
The standard does not measure capture efficiency or physical robustness of the grease filter device or other factors that do not directly affect user or fire safety.
Note: Capture efficiency of a kitchen hood filter can be measured using ASTM F2519 “Standard Test Method for Grease Particle Capture Efficiency of Commercial Kitchen Filters and Extractors”.
CKV Type II hoods do not require grease filters. Type II hoods are designed to be used primarily over non-grease producing cooking appliances where there is a need to exhaust excess heat, vapor and odor from the air. The main goal of using a Type II hood is to create a more comfortable cooking environment for those working in the kitchen.
Some grease filters have adjustable features incorporated in their designs that allow the static pressure created by the filter to be increased or decreased. The ability to increase or decrease the static pressure can be beneficial in controlling airflows with in the CKV hood.
There are basically three types of Grease Filters for Type 1 hoods: Baffle, High Velocity High Slot Cartridge, and Multi-Stage Filter. These filters range in price and efficiency depending on the manufacturer. The more economical baffle filters are available in aluminum or stainless steel construction. The cartridge filters are typically made in more durable stainless steel. The cartridge filter is also generally more efficient than the baffle filter.
All commercial kitchen type 1 hoods require grease filters that are Listed to the UL 1046 Standard.
Baffle Filter
High Slot Cartridge Filter
Multi Stage Cartridge Filter
There are no current national codes or standards that include a minimum grease extraction efficiency that a filter for a CKV Hood must achieve; currently there are several air quality management districts that are considering minimum grease extraction efficiency requirements for filters for CKV hoods.
Multi Stage Filter Cartridge with Filtration Mesh
A multi-stage grease filter is a filter that has a primary filter and additional stages of filter downstream of the primary filter. ExtractAire™ HVCMS Filters are engineered for use in CKV hoods requiring a filter that is Listed to the UL 1046 Standard. The ExtractAire™ HVCMS Filter design and construction provides the ultimate fire protection and the highest level of grease extraction available in CKV Grease Filters. ExtractAire™ HVCMS Filters can withstand the harshest CKV environments. The HVCMS Filter assembly incorporates Streivor’s sustainable, organic, replaceable, and biodegradable Absorb Filters
Multi-stage filters generally have significantly higher grease extraction efficiencies when compared to single stage filters. The ExtractAire™ HVCMS Filter design and construction provides the ultimate fire protection and the highest level of grease extraction available in CKV Grease Filters. ExtractAire™ HVCMS Filters can withstand the harshest CKV environments. The HVCMS Filter assembly incorporates Streivor’s sustainable, organic, replaceable, and biodegradable Absorb Filters
The most commonly used metals that CKV hoods are manufactured from are Stainless Steel, and Aluminized Steel.
304 Stainless Steel for Canopy Hood
Streivor’s standard is to build the hood canopy using high quality 304 Grade Stainless Steel. 304 Stainless Steel is a non-magnetic alloy that has lower carbon to minimize carbide precipitation and is used in high-temperature applications. Its resistance to corrosive acids makes it ideal for cookware, appliances, sinks and tabletops.304 grade stainless steel is comprised of no more than 0.8% carbon and at least 50% iron. The chromium binds oxygen to the surface of the product to protect the iron from oxidation (rust). Nickel also enhances the corrosion resistance of stainless steel. Therefore, the higher the nickel content, the more resistant the stainless steel is to corrosion.
430 Stainless Steel for Canopy Hood
430 is in the “Ferritic” group of stainless steels, containing more chromium, no nickel, and carbon from .6% to 35%. It is magnetic and does not respond to heat-treatment. SS 430 has good corrosion resistance and is highly resistant to atmospheric oxidation and strong oxidizing solutions. It can be readily drawn and formed, and it is weldable by common techniques. Type 430 contains a negligible amount of nickel (0.75%) and therefore has a reduced corrosion resistance (is more likely to rust than 18/8 or 18/10 but still high quality) and is magnetic.
Aluminized Metal For Plenum Construction
Aluminized steel is standard steel with a thin coating of aluminum on the inside and outside. The aluminum forms an oxide layer to keep the steel beneath from corroding. Aluminized stainless steel is made of pure steel containing a certain percentage of nickel and chrome, which keeps the material from corroding under any conditions. This material is far cheaper and a bit lighter than stainless steel, making it the default choice for most exhaust systems. However, even a tiny scratch in the aluminum oxide finish can allow the metal beneath to rust, and the cut pipe ends remain exposed to air and moisture.
CKV hoods are manufactured form several type of stainless steel, The most commonly used material are 304 and 430 stainless steel.
Type 304 stainless steel is a high grade of stainless steel that includes a minimum of 8% nickel.
Type 430 stainless steel is a lower grade of stainless steel that includes a minimum of 4% nickel.
304 Steel
430 Steel
The benefit of using type #304 verses #430 stainless steel is that the #304 is better suited for the harsh environment that a Type I CKV must withstand. The 304 material will better withstand the harsh degreasers and other chemical that are used during the hood and duct cleaning, the chemicals that make up the kitchen fire suppression as well as the effluents that pass through and/or collect on the CKV hood as a result of cooking and kitchen cleaning applications.
The CKV hood should be designed to hold under regular use for up to 40 years. The increased cost of using type 304 verses 430 is a small price to pay for a lot of adding protection depreciated over a 40 year period.
Aluminized steel is steel that is coated with aluminum during the milling process.
Aluminized Steel Characteristics
Aluminized steel was developed for providing more structural durability and a high yield strength in highly corrosive environments. Aluminized steel is carbon steel coated, through the hot-dip process, with an aluminum-silicon alloy. This process assures a tight metallurgical bond between the steel sheet and its aluminum coating, producing a material with a unique combination of properties possessed neither by steel nor by aluminum alone.
The aluminum coating provides resistance to high temperatures and has a bright appearance. Aluminized steel is perfect for high-heat situations.
It retains its original appearance up to 900 degrees F, reflecting up to 80 percent of the radiant heat in its environment. This higher-heat resistance, combined with the superior corrosion resistance of the aluminum and silicon alloy coating, provides a better heat and corrosion solution than a lower melting temperature material such as zinc-coated (galvanized) steel.
Aluminized metal can be used in the non-exposed portions of a CKV hood, such as the exhaust plenum. When it is imperative to reduce the costs of the CKV hood, substituting aluminized metal in the non-exposed portions of the hood can be a consideration.
Listed variable volume dampers may be installed in the hood or ducts to facilitate CKV hood balancing.
Streivor’s BalanceAire™ variable volume, low profile, adjustable opposed blade, dampers are engineered to be installed in hoods or ducts which are in close proximity to the hood’s exhaust plenum. This unique design allows for locking, unlocking and/or adjustments to the opposed blades by accessing the BalanceAire™ through the hood. This eliminates the need to access the outside of the damper for adjustments.
The low profile opposed blade design is the perfect solution for balancing exhaust airflows in the extremely limited space, often available above or behind commercial kitchen ventilation hoods.
The opposed blade design of the dampers allows for an infinite amount of minute adjustments ranging from 100% open to 95% closed. This patented design is capable of facilitating airflow balancing by creating airflow restrictions from minor to major. BalanceAire™ Dampers are UL 710 listed and are approved for installation in exhaust hoods and grease ducts for commercial cooking equipment.
An opposed blade is a damper that has two or more blades that are fixed with the damper housing in an opposed position relative to each other. The blades are adjustable. By moving one or more of the blades the resistance created by the blades on the air passing through the damper can be increased or decreased. Streivor’s BalanceAire is a UL Listed Kitchen Hood Balancing Damper.
The advantage of using an opposed blade damper verses a guillotine damper, is that a guillotine damper is designed to create resistance to the air flowing through the duct by sliding a blade into the duct opening, usually from one side. This type of dampering will cause un even air flows through he duct system.
