A Complete Guide to Purchasing Commercial Kitchen Ventilation Equipment for Restaurants - for Owner

As a restaurant operator, the design and equipment selection of the kitchen ventilation system are directly related to the working environment, food safety, and long-term operating costs of the restaurant. An efficient ventilation system can not only extract fumes and hot air in time and keep the kitchen air fresh but also effectively reduce the risk of fire, improve the work efficiency of chefs, and meet increasingly stringent environmental protection requirements.

This article will systematically introduce the types, functional characteristics, purchase points, and installation and maintenance strategies of commercial kitchen ventilation equipment to help you build a kitchen ventilation system that meets both hygienic and safety standards and is cost-effective.

We will deeply analyze the differences in ventilation needs of different types of restaurants, interpret the technical parameters of fume purification equipment, compare the performance characteristics of various exhaust fans, and provide practical budget planning and supplier evaluation methods.

I. Clarify Restaurant Type and Ventilation Needs

Restaurant type is the primary factor in determining the design of kitchen ventilation systems. There are significant differences in the amount of fumes, heat load, and odor intensity generated by different types of restaurants, which requires us to adopt differentiated ventilation solutions. Unthinkingly copying the ventilation design of other restaurants often leads to poor results or a waste of resources.

1. Restaurant Type

Chinese restaurants, especially Sichuan and Hunan cuisine, use a lot of high-temperature cooking methods such as stir-frying and frying, which produce a lot of oil fume particles and high temperatures. Hence, they need to be equipped with a large air volume exhaust system, while Western restaurants have relatively less oil fumes. Still, the heat load generated by equipment such as ovens and griddles cannot be ignored, and it is necessary to focus on overall ventilation and cooling.

2. Kitchen Size and Number of Stoves

The size of the kitchen and the number of stoves directly determine the basic parameters of the Ventilation Equipment. When preparing my restaurant, I first accurately measured the total area, net height, and work area layout of the kitchen. These data are the basis for calculating the required exhaust volume. According to industry experience, each standard stove requires about 1500-2000m³/h of exhaust volume, while a strong stir-fry stove requires 2000-2500m³/h.

My restaurant has 6 stoves (2 of which are stir-fry stoves). After calculation, the basic exhaust volume demand is about 13,000m³/h. Considering the system loss and future expansion, I finally chose the main exhaust fan 35 with a volume of 16,000m³/h. A small restaurant may only need an exhaust capacity of 4,000-6,000m³/h, while a large hotel kitchen may require a large air volume system of more than 30,000m³/h.

3. Cooking Method

Cooking methods and menu composition have refined requirements for ventilation systems. During the planning stage, I discussed the menu design and cooking process in depth with the chef and found that the pollutants generated by different cooking methods are very different: steaming and boiling produce mostly water vapor, frying and stir-frying produce fine oil mist, and a lot of smoke and odor accompany barbecue.

To this end, we divide the kitchen into hot kitchen areas (stir-frying stove, frying oven), pastry area (steamer, oven), and cold kitchen area, and we design targeted exhaust solutions for different areas. For example, the hot kitchen area uses a low-hanging hood to capture oil smoke at close range, while the pastry area uses an umbrella-shaped hood to take into account heat dissipation. This zoning treatment method not only ensures the effect but also avoids energy waste.

4. Environmental Protection Regulations and Emission Standards

Environmental protection regulations and emission standards are the red lines that cannot be crossed in the design of ventilation systems. With increasingly stringent environmental protection requirements, local emission standards for catering oil smoke are constantly improving.

During the site selection stage, I consulted the local environmental protection department and learned that the oil smoke emission concentration must be lower than 1.0mg/m³, and non-methane total hydrocarbon emissions are also subject to corresponding restrictions. These standards directly determine what level of purification equipment we need to configure.

I was impressed that a colleague installed an unqualified purifier for cheapness. As a result, he was not only fined a high amount but also required to suspend business for rectification, and the loss far exceeded the cost saved at the beginning. It made me realize that meeting environmental protection requirements is not an option but a basic prerequisite for operating a restaurant.

5. Building Structure and Installation Conditions

Building structure and installation conditions are often overlooked but are crucial. Factors such as the direction of the exhaust duct of the existing building, the outdoor emission location, and the power configuration will affect the design of the ventilation system and the selection of equipment.

My restaurant is located in an old commercial building. The original exhaust duct is insufficient in size and complex in direction. According to calculations by a professional company, direct use will result in excessive system resistance and more than 30% air volume loss.

In the end, we decided to re-lay a dedicated exhaust duct. Although the initial investment increased, the system operation efficiency was guaranteed. In addition, factors such as the load-bearing capacity, sound insulation requirements, and distance of the rooftop equipment also need to be evaluated in advance to avoid structural safety or neighborhood disputes after installation.

Summary

Through the detailed research and analysis at this stage, I established a clear ventilation system demand framework, laying a solid foundation for subsequent equipment selection. This systematic planning method helped me avoid the embarrassing situation of discovering poor exhaust after opening and also gave me a more accurate estimate of the overall investment.

II. Detailed Explanation of Core Ventilation Equipment: Functions, Types, and Applicable Scenarios

The fume purifier is the core component of the commercial kitchen ventilation system, and its performance directly determines whether the fume emission meets the standard. According to the different purification principles, the mainstream fume purification equipment in the market can be divided into three categories: electrostatic, UV photolysis, and composite, each with its own characteristics and applicable scenarios. In the process of operating a restaurant, I deeply understand the importance of choosing the right purification technology.

1. Electrostatic fume purifier

The electrostatic purifier uses a high-voltage electric field to charge the fume particles and then adsorb them on the dust-collecting plate. The purification efficiency can reach more than 90%, which meets the needs of most Chinese restaurants. 

This type of equipment has low operating resistance, relatively low energy consumption, and can be washed and reused, and the long-term operating cost is relatively economical. In actual use, I found that the electrostatic purifier is particularly effective in treating oil mist particles of 0.1-10 microns, which is the main range of pollutants produced by Chinese stir-frying.

However, electrostatic equipment needs to be cleaned regularly (usually once every 1-3 months). Otherwise, the efficiency will be significantly reduced, and the ability to treat gaseous pollutants (such as odor molecules) is limited.

Based on these characteristics, electrostatic purifiers are particularly suitable for Chinese restaurants, canteens, and other places with large amounts of oil smoke but no strict requirements on odor.

2. UV Photolysis Purifier

The UV photolysis purifier uses ultraviolet rays to irradiate the catalytic plate to produce oxidants to decompose oil smoke molecules and is particularly good at dealing with odors and volatile organic compounds. This type of equipment has a significant deodorizing effect and can effectively decompose aldehydes, sulfides, and other odor-producing substances in oil smoke so that the exhaust air no longer disturbs people. During the trial operation of my restaurant, the UV photolysis equipment successfully eliminated the barbecue odor problem that troubled nearby residents.

However, the oil fume purification efficiency of this type of equipment, when used alone, is usually only 70-80%, and it often needs to be used in combination with other technologies. The lamp tube needs to be replaced regularly (about once a year), and the maintenance cost is high. Therefore, UV photolysis purifiers are more suitable for barbecue restaurants, Western restaurants, and other places with high requirements for odor control.

3. Composite Purifier

The composite purifier combines multiple purification technologies (such as electrostatic + UV + activated carbon) to achieve more comprehensive pollution control. This type of equipment has a high and comprehensive purification efficiency, usually reaching more than 95%.

It can simultaneously treat particulate matter and gaseous pollutants and meet strict emission standards. In my high-end restaurant, we chose a composite system of electrostatic + UV photolysis, which not only ensures the fume purification effect but also solves the odor problem and has won unanimous praise from the environmental protection department and surrounding residents.

However, the composite system is expensive, occupies a large area, and is more complicated to maintain. Based on these characteristics, the composite purifier is more suitable for high-end restaurants, catering places located in sensitive areas, or areas with particularly strict environmental protection requirements.

4. Commercial Smoke Exhaust Fan

The smoke exhaust fan is the "heart" of the ventilation system, responsible for providing sufficient power to overcome the system resistance and to exhaust the smoke outdoors. According to different working principles, the smoke exhaust fans commonly used in commercial kitchens are mainly centrifugal, axial flow, and mixed flow, each with its performance characteristics and applicable scenarios.

(1) Commercial Centrifugal Fan

Centrifugal fans are particularly suitable for smoke exhaust systems with long pipes and large resistance due to their high wind pressure characteristics. This type of fan can generate a static pressure of more than 2000Pa and can ensure sufficient exhaust volume even if the pipeline is tens of meters long. In actual application, I found that the performance curve of centrifugal fans is relatively flat, the air volume is less affected by changes in system resistance, and the operation is stable and reliable.

However, centrifugal fans are usually large and relatively noisy (65-85 decibels), requiring a dedicated machine room or sound insulation measures. Therefore, centrifugal fans are more suitable for places with complex smoke exhaust systems and long pipelines, such as large restaurants and hotel kitchens.

(2) Commercial Axial Flow Fans

Axial flow fans are characterized by large air volume and low air pressure. They are suitable for systems with short pipelines and low resistance or direct through-the-wall exhaust. This type of fan has a compact structure, is easy to install, and is relatively inexpensive. In my small chain store, axial flow fans meet basic smoke exhaust needs with their high cost-effectiveness.

However, the air pressure of axial flow fans usually does not exceed 500Pa. When the pipeline is slightly extended, or the number of elbows increases, the air volume will drop sharply. Based on these characteristics, axial flow fans are more suitable for small catering places such as snack bars and fast food restaurants where smoke exhaust requirements are not high.

(3) Mixed Flow Fans

Mixed flow fans combine the characteristics of centrifugal and axial flow fans, and their wind pressure and air volume performance are between the two. This type of fan has a moderate size, low noise, and high energy efficiency, making it an ideal choice for medium-sized restaurants. 

In my medium-sized restaurant, mixed flow fans avoid the high noise problem of centrifugal fans while ensuring sufficient exhaust volume, and their installation and maintenance are more flexible than axial flow fans. Therefore, mixed-flow fans are suitable for medium-sized restaurants, chain restaurants, and other places that require a certain wind pressure and have restrictions on noise and space.

5. Commercial Exhaust Hoods

The exhaust hood and duct system are channels that collect and transport oil smoke from the source to the purification equipment. The rationality of their design directly affects the overall exhaust effect. Depending on the kitchen layout and cooking methods, the commonly used exhaust hoods are mainly umbrella hoods, low-hanging hoods, and table hoods.

(1) Commercial Umbrella-shaped Exhaust Hoods

Umbrella-shaped hoods are the most common general-purpose exhaust hoods. They are usually installed at a height of 1.8-2.2 meters. They cover a large area and are suitable for areas where multiple cooking methods coexist. In actual use, umbrella-shaped hoods make good use of the natural tendency of hot air to rise and can effectively capture the heat load generated by equipment such as steamers and ovens.

However, the efficiency of umbrella-shaped hoods in capturing oil smoke is relatively low, about 60-70%, and it is easy to cause overall airflow turbulence in the kitchen. Therefore, umbrella-shaped hoods are more suitable for places such as Western kitchens and pastry areas where the heat load is large but the oil smoke is relatively small.

(2) Commercial Low-hanging Hoods

Low-hanging hoods (also called proximity exhaust hoods) have a low installation height (usually 60-90 cm from the cooking surface) and can efficiently capture oil smoke at a close distance, with an efficiency of more than 85%. 

This type of exhaust hood is particularly suitable for high-oil smoke cooking methods such as Chinese stir-frying and deep frying. In my hot kitchen area, the low-hanging hood is combined with an exhaust volume of 1500m³/h per stove, and the oil smoke can hardly be seen spreading into the kitchen air.

However, the low-hanging hood will take up more kitchen space, which may affect the chef's operation, and each stove position needs to be controlled independently. Therefore, the low-hanging hood is particularly suitable for high-oil smoke kitchens such as Chinese restaurants and Sichuan and Hunan restaurants that mainly serve stir-fry.

6. Design the Duct System

The design of the duct system is also crucial. I chose stainless steel ducts. Although the initial cost is higher than the galvanized sheet, it has strong corrosion resistance and long service life, which is more economical in the long run.

The duct design follows the principle of "short, straight, and smooth," minimizing elbows (each elbow increases the system resistance by 10-15%) and length, and the cross-sectional wind speed is controlled at 8-12m/s (too low is easy to accumulate oil, too high is noisy). These detailed designs ensure the efficiency and economy of the system's operation.

7. Commercial Air Supply System

The air supply system is an easily overlooked but crucial part of kitchen ventilation. A complete ventilation system should not only consider "exhaust" but also "supply"; otherwise, it will cause excessive negative pressure in the kitchen, reduce the smoke exhaust effect, and even make it difficult to open doors and windows. According to different air supply methods, there are two main forms of air supply: natural air supply and mechanical air supply.

(1) Natural Air Supply

Natural air supply introduces outdoor air through the gaps between doors and windows or specially designed air supply windows. It is the most economical air supply method. However, in actual application, I found that the natural air supply is greatly affected by external wind pressure and temperature, and it isn't easy to control the air supply volume accurately.

In addition, directly introducing cold air in winter will cause the kitchen temperature to drop sharply, affecting the working environment. Therefore, natural air supply is only suitable for small restaurants or as an auxiliary air supply method.

(2) Mechanical Air Supply

The mechanical air supply system actively introduces outdoor air through a fan and can accurately control the air supply volume and air supply position. In my restaurant, we use a mechanical air supply system with a heat recovery function. The fresh air is filtered and sent to various areas of the kitchen by a dedicated air duct. 40% of the fresh air is preheated (in winter) or precooled (in summer) by a heat exchanger, which significantly reduces energy consumption.

Although the initial investment is high, it improves the working environment and increases employee satisfaction, which is worthwhile in the long run. Therefore, mechanical air supply systems are more suitable for medium and large restaurants, high-end catering venues, or areas with harsh climatic conditions.

Summary

Through in-depth understanding and actual use experience of this core ventilation equipment, I was able to make wise purchasing decisions based on the specific needs of the restaurant, which not only met the needs of smoke exhaust purification but also avoided unnecessary investment waste. Please stay tuned for the next blog for more knowledge.