Understanding DW172 2018 Thermal Convection for Kitchen Ventilation Systems

In the high-stakes environment of commercial kitchens, efficient ventilation is not a luxury – it’s a necessity. Proper ventilation protects health, ensures fire safety, and enhances comfort for kitchen staff, all while supporting optimal performance of kitchen appliances. With the rise of modern, high-efficiency cooking equipment, increasing safety regulations, and compact kitchen layouts, ventilation design is more critical than ever before.

To achieve these outcomes, industry standards like the DW172:2018 play a pivotal role. Developed by the Building Engineering Services Association (BESA), DW172 is widely recognized as the authoritative specification for commercial kitchen ventilation systems across the UK and many parts of the world.

Despite its importance, applying the DW172’s Thermal Convection Method requires technical knowledge and meticulous attention to detail. That’s why Klima Global has created a free online calculator to help engineers, consultants, and kitchen planners streamline this process while improving accuracy and confidence in their ventilation design.

What is DW172:2018 and Why It Matters?

DW172:2018 is the latest edition of BESA’s kitchen ventilation specification. It builds on earlier standards with significant enhancements that reflect:

• Advancements in commercial cooking technologies

• New approaches to energy efficiency and sustainability

• Greater menu diversity and more intensive cooking practices

• Changing regulations around workplace health, safety, and hygiene

DW172 is now widely adopted as a benchmark for kitchen canopy design, airflow calculation, ductwork layouts, and compliance with health, fire, and environmental regulations. It offers designers a robust framework for ensuring that every ventilation system meets both operational and legal standards.

For global consultants, DW172:2018 is also a reference document that supports consistent quality in commercial kitchen design, especially in areas where regional ventilation codes may not be as clearly defined.

The Thermal Convection Method – Simplified

DW172 mandates the Thermal Convection Method as the most reliable and accurate way to calculate airflow requirements in a commercial kitchen ventilation system. This method considers real-world cooking dynamics rather than relying on outdated or oversimplified metrics like generic air-change rates.

Here’s how it works:

• Every cooking appliance emits a mix of radiant and convective heat.

• DW172 assigns a thermal convection coefficient to each appliance type based on surface temperature and energy source (gas or electric).

• Designers calculate the plan area (top surface dimensions) of each appliance.

• Multiply the area by its corresponding coefficient to determine the required extract volume (in m3/s).

• Combine values for all appliances under a ventilation canopy or ceiling.

• Apply a canopy factor, which adjusts for hood shape and position (e.g., wall-mounted, island, enclosed).

The final figure provides the total airflow needed to effectively remove heat, steam, grease, fumes, and odors from the kitchen workspace.

Key Parameters in DW172 Calculations

To achieve accurate ventilation sizing, several parameters must be considered:

• Appliance Coefficients: These vary based on cooking intensity, equipment type, and energy source. For example, gas-powered woks and fryers typically require higher airflow due to their intense heat.

• Plan Area: This is the physical footprint of each appliance. Even small miscalculations here can skew the total airflow requirement.

• Canopy Factors: A correction factor that accounts for hood design. Island hoods, for instance, are more exposed to cross-drafts and require greater airflow than enclosed wall-mounted canopies.

These factors are essential for ensuring compliance and maintaining a safe, functional kitchen environment.

Common Pitfalls in Manual Calculations

While DW172 provides a clear methodology, manual airflow calculations can be challenging in practice. Common issues include:

• Misapplication of appliance coefficients

• Overlooking canopy factors

• Underestimating total equipment footprint

• Failing to account for special conditions like solid fuel appliances or combination ovens

Such mistakes may lead to:

• Inefficient extraction performance

• Fire safety risks

• Excessive energy use

• Discomfort for kitchen staff

Even experienced professionals can struggle with repetitive, manual processes, especially when managing multiple project layouts or changes.

Introducing the Klima Global DW172 Calculator

To address these challenges, Klima Global has created a powerful, free-to-use DW172 Kitchen Ventilation Calculator. This tool is engineered to:

• Simplify complex thermal convection calculations

• Reduce risk of human error

• Accelerate ventilation design workflows

Key features include:

• Accurate DW172:2018 logic built-in

• Preloaded appliance types with coefficients for gas and electric versions

• Automatic area and flow rate calculations

• Adjustable canopy factor selection

• Mobile and desktop friendly interface

• Export or save your calculations

Whether you’re working on a small café kitchen or a large food court, this tool saves time and helps ensure your designs are compliant and optimized.

Benefits of Using Our DW172 Tool

Using the Klima Global calculator brings multiple advantages:

• Saves Time: No need to reference tables manually or build spreadsheets. Calculations are immediate.

• Improves Accuracy: Built on the official DW172 framework with zero guesswork.

• Supports Global Standards: Aligns with UK, EU, and international commercial kitchen design best practices.

• Enhances Team Productivity: Perfect for consultants, MEP engineers, architects, and kitchen designers.

• Supports Education: Useful as a training resource in HVAC programs or internal company onboarding.

This calculator is designed not only to boost efficiency but also to elevate the quality and consistency of kitchen ventilation designs across the industry.

How to Use the DW172 Calculator

Getting started with our DW172 calculator is easy:

1. Select your appliances from the drop-down list.

2. Enter plan dimensions (length and width) for each unit.

3. Choose the power source (gas or electric).

4. Select the canopy type to apply the correct multiplier.

5. Get your results instantly. You’ll see the total extract airflow required (in m3/s).

Users can:

• Get their project data as a summary

• Print or download results

A Sample Report Image

Conclusion

Ventilation is the invisible backbone of a safe and efficient commercial kitchen. As energy costs rise and regulations tighten, getting your airflow calculations right is more important than ever. DW172:2018 offers a trusted method for determining those values — and Klima Global’s calculator brings this method to your fingertips.

With our free tool, you can reduce complexity, speed up your process, and design ventilation systems that are safe, sustainable, and future-ready.