Quality ventilation in a commercial kitchen space is essential. It’s the first line of defense for fire prevention, and a requirement for many health, fire, and insurance inspection codes. Restaurant exhaust hood systems are designed to remove heat, smoke, and grease-laden vapors generated via high-heat cooking. This ensures your kitchen space continues to run safely and efficiently.

With proper airflow established, a good range hood system also reduces odors, enhances air quality, and lowers energy consumption.

Read also: The ABCs of Restaurant Health Inspections

When Are Exhaust Hood Systems Required?

Exhaust hoods are required in commercial kitchens wherever heating elements, such as ranges, stoves, fryers, grills, etc., are used. The size and type of hood system required is dependent on the type of equipment and number of cooking units.

Note that many manufacturers now offer ventless hood systems that are ideal for limited spaces, pop-up kitchen spaces, ghost and delivery only kitchens, food trucks, and more. These units are self-contained, don’t require any construction or duct work for ventilation, and greatly open up opportunities for kitchen design and additional equipment uses.

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Restaurant Hood Cleaning

The size and style of the restaurant exhaust hood system needed vary greatly depending on the equipment and local codes. It is recommended to work through your kitchen layout with an industry expert. Our team of knowledgeable product consultants is always ready to help.

For information on system requirements, refer to:

Types of Exhaust Hood Systems

Restaurant hood systems are available in different types and styles, depending on the intended use. The two most prominent types are Type I and Type II.

Type I Exhaust Hoods

Type I restaurant exhaust hoods are used to collect and remove grease and smoke. These always include grease filters or baffles for the efficient removal of grease, and required over restaurant equipment that produces such, including fryers, ranges, griddles, broilers, ovens, tilt skillets, and the likes.

Type II Exhaust Hoods

Type II restaurant exhaust hoods, often referred to as condensate hoods, are used to collect and remove steam, vapor, heat, and odors. These are installed over equipment where grease is NOT a byproduct. Equipment may include the likes of dishwashers and steam tables, and can occasionally be used over ovens, steamers, or kettles if determined they do not product smoke or grease-laden vapors.

Restaurant Exhaust Hood System

As previously noted, ventless exhaust hoods are becoming more popular, given their unique set of benefits. These include, but are not limited to:

  • Increased flexibility, enabling operations to set up shop in places where before they couldn’t, such as mall kiosks or high-rise building
  • Quick setup of remote kitchen spaces, such as ghost kitchens
  • More mobility, ideal for new foodservices or restaurants operating in a leased space
  • No extensive duct work required
Ventless hoods allow commercial kitchens to set up cooking operations anywhere.

Six Styles of Exhaust Hoods

There are six main styles of restaurant exhaust hoods, each determinant on specific kitchen layouts.

1. Wall-Mounted Canopy

Mounted flush with a wall and used for all types of cooking equipment located against a wall.

2. Single Island Canopy

Ceiling-mounted over a single line cooking island and used for all types of cooking equipment.

3. Double Island Canopy

Ceiling-mounted over a back-to-back cooking island. Used for all types of cooking equipment.

 

4. Backshelf Hood

Used for counter-height equipment. Normally located against a wall, but are also used as freestanding units.

5. Eyebrow Hood

Used for direct mounting to ovens as well as some dishwashers.

6. Pass-Over Style Hood

Used over counter-height equipment when a plate pass-over configuration is required.

 

The Four Components of a Restaurant Exhaust Hood System

The four main components of a restaurant exhaust hood system include:

1. Vent Hood

Vent hoods are what’s placed over the cooking equipment, designed to remove steam, grease, smoke, odor, gas, etc. Available in Type I or Type II.

2. Baffle Filters

Exhaust hoods require filters. These are available in stainless steel, galvanized, or aluminum; and can feature a welded or riveted construction (more details below). Baffle filters are a series of vertical baffles housed within the hood to capture and drain away grease. They’re designed for easy removal for cleaning.

Read also: Restaurant Hood Cleaning Made Easy: Hood Cleaning, Care, and Maintenance

3. Make-Up Air Unit

These units bring in clear air, usually from the outside through duct work, to circulate throughout the kitchen, making up for the grease-laden vapors being suctioned out by the exhaust fan. In addition to eliminating potential fire hazards, these also help create a more comfortable environment for the staff. These units are typically installed on the outside of the building, unless you opt for a ventless hood system.

4. Exhaust Fans

Exhaust fans activate the air within the exhaust hood system, funneling the low-quality air out of the kitchen. These, like the make-up air unit, are also installed on the outside of the building. There are two types of exhaust fans:

  1. Belt-driven exhaust fans that operate via a motor pulley. The biggest drawback to these types of exhaust fans is the friction caused by the belt that can decrease efficiencies and sometimes lead to more repairs.
  2. Direct-drive exhaust fans feature a blade fan within the wheel that’s directly attached to the axel. This is a more efficient system with less moving parts and required maintenance.

What Type of Exhaust Hood Filter Should I Use?

Exhaust hood filters prevent flames from entering the exhaust duct, capturing moisture and grease vapors. Baffle filters are the simplest and most common configuration, although a high-velocity cartridge filter offers a greater surface area.

There are two things to consider when selecting the right hood filter for your needs:

  1. The volume of product being cooked
  2. The visibility of the kitchen to the customers

Durability is the primary concern when it comes to filter construction. A high-volume kitchen requires a heavy-duty filter to withstand the rigors of frequent use. Filters constructed of stainless or galvanized steel work best here. In fact, Type I exhaust hoods don’t usually come in aluminum mesh construction anymore since they’re not as durable to hold up against extreme heat.

If the kitchen space is visible to patrons, a shiny filter, such as one constructed with stainless steel, is most attractive.

Exhaust Hood Filters

Pros and Cons of Exhaust Filter Material and Construction

There are three common types of material used to manufacture exhaust hoods:

1. Stainless Steel

Stainless steel exhaust hoods are the most durable and easiest to clean. They’re best for high-volume, heavy-duty use and feature an attractive, shiny finish. However, stainless steel is the most expensive material option.

2. Galvanized Steel

Exhaust hoods made of galvanized steel are strong and long-lasting, offering high performance at a moderate, affordable price point. It can withstand degreasers and cleaning chemicals, but may become discolored after a while due to the harshness of certain chemicals.

3. Aluminum

Aluminum is lightweight and an affordable exhaust hood filter solution featuring an attractive, shiny finish. However, it is much more prone to corrosion and damage as compared to its stainless or galvanized counterparts. It is not recommended to use harsh degreasers or cleaning chemicals on aluminum filters.

In addition to selecting the right filter material, choosing the best exhaust hood construction is an important consideration. There are two key construction types:

1. Welded

A welded construction refers to baffles made from the same single piece of metal as the frame. The back and front are welded together for a rigid and durable design that won’t easily bend. Welded baffle exhaust filters are heavy-duty and long-lasting.

2. Riveted

A riveted exhaust hood filter construction refers to multiple pieces held together by rivets. In other words, a series of dividual baffles fitted together inside the filter. These are a bit more flexible which can result in loosening over time. It’s a more affordable, albeit less durable, exhaust filter option.

When Should I Replace My Exhaust Hood Filter?

The frequency of filter replacement typically depends on the quality of the filter and extent of use. There is no standard, one-size-fits-all time frame. In some kitchens, a filter could last a couple of years while in others, it may only last six to eight months. Key factors that play into replacement frequency include:

  • The type of filter
  • Type of operation
  • The degree of regular maintenance

Hint: a welded stainless steel filter is much more likely to outlast a riveted aluminum filter.

It is important to regularly inspect hood filters for wear or damage. When a filter is damaged, it cannot effectively do its job, thus paving the way for a potential fire hazard and health inspection citation. If a filter is word, clogged, damaged, or has excessive grease build up, it should be replaced right away.

Read also: Restaurant Hood Cleaning Made Easy

When purchasing a new exhaust hood filter, it is important to keep in mind the actual size of the filter is approximately half an inch less than the size listed. There is no standard sizing for hood filters. Keep baffles vertical to measure your filter and know the vertical dimension is followed by the horizontal dimension.

Example:

  • Actual advertised size: 9-5/8”x15-3/4”x1-3/4”
  • Filter size: 10”x16”

Hood Filter Cleaning

Regular filter upkeep keeps your kitchen safe, your staff comfortable, and your business out of hot water as far as local codes are concerned. If filter maintenance in neglected, grease can build up and cause several issues including poor air quality, excess heat, increased utility costs, fire hazards, etc. A regular cleaning schedule will prolong the life of your filter and the overall exhaust hood system, while keeping a safe and clean kitchen space.

Read also: Having a Plan: The Importance of Planned Maintenance

It’s always best practice to follow the manufacturers cleaning instructions that are often unique to their filters. However, if cleaning instructions are not available, here are some quick tips.

  • If the filter is dishwasher safe, run in through on the highest temperature. Avoid harsh cleaners and inspect that all residue was removed before drying.
  • A soak tank can be a worthwhile investment that saves time and labor. If using a soak tank to clean your exhaust hood filter, fill it with water and add a safe cleaner. Soak the filter overnight and rinse in the morning before installing.
  • If washing the filter by hand, use hot, soapy water and a non-abrasive sponge. Avoid using harsh chemicals and dry immediately after washing.

For more cleaning information, read our guide on Restaurant Hood Cleaning Made Easy.

Additional Restaurant Exhaust Hood System Considerations

  • Replacing air systems – to make up for exhausted air, replacement air must be brough in from outside the kitchen. Replacement air should be filtered, and, depending on the climate, possibly heated or cooled. Discuss these issues with your product consultant before purchasing an exhaust and make-up air system, as well as advise whether your kitchen will be air conditioned. This will require special considerations.
  • Duct cleaning – Most cleaning is done by power washing the duct and hood interior. If the duct leaks, it’s possible that mold may form within the enclosure assembly. Therefore, it is important the ductwork be liquid-tight and pressure tests conducted to ensure operational sanitation and efficiency.
  • Environmental issues – Kitchen stack smoke and odors are a concern in many communities. Often, local pollution laws mandate that an establishment must eliminate all exhaust pollution if a neighbor complains. Dilution or bleeding outdoor air into the roof fan installation is a simple solution. For smoke concerns, try reducing the fat in the cooking product.

Read also: Improve Sustainability Inside the Kitchen

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