How do I size a commercial kitchen canopy?

Enter cooking equipment types and ratings. The calculator applies DW172 thermal convection coefficients to estimate canopy extract and make-up air.

What is the difference between thermal convection and capture velocity methods?

DW172 provides both approaches. Thermal convection is common for equipment schedules; capture velocity applies where hood geometry is defined.

How much make-up air is required?

Typically 85–95% of extract for balanced systems, with the remainder from transfer air. Higher make-up percentages reduce building infiltration.

BuildFlo Design Guide · Ventilation · DW172

Commercial kitchen canopy calculator

DW172 thermal convection canopy extract and make-up air from equipment schedule. Free commercial kitchen ventilation calculator.

What this calculator does

Kitchen canopy helps UK building services engineers with dw172 thermal convection canopy extract and make-up supply from equipment schedule. The calculation follows DW172 methods used in everyday MEP design — enter your project inputs below for a first-pass result.

Whether you searched for "kitchen canopy", "kitchen canopy calculator", or "how to kitchen canopy", this page gives you a working tool plus the context to use it on a real job.

When to use it

Use this for early-stage sizing and sanity checks on UK building services work. It is not a substitute for issued calculations — verify against the project specification, drawings, and relevant standard before sign-off.

How to use it

1. Fill in the inputs for your scenario (defaults are starting points only). 2. Click Calculate — results include the method and assumptions where applicable. 3. Verify against the project specification and relevant standard before issuing.

Typical output unit: m³/s.

Kitchen canopy calculator

DW172 thermal convection canopy extract and make-up supply from equipment schedule

Canopy type

DW172 canopy factor applied to theoretical extract

Dedicated make-up air (fraction)

Fraction of extract provided as dedicated supply (default 0.85)

Diversity / simultaneity (fraction)

Applied to theoretical extract before the canopy factor (1 = all appliances full duty)

Canopy plan length (mm)

Optional — with width, used for average face velocity (m/s)

Canopy plan width (mm)

Optional — with length, used for average face velocity (m/s)

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Tips

Defaults are indicative — replace with project-specific values from the architect, structural, or MEP spec.
For issued calculations, save results in your BuildFlo project and attach to the calculation folder.
Need the regulation citation? Open BuildFlo chat in the app and ask about kitchen canopy under UK standards.

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Frequently asked questions

How do I size a commercial kitchen canopy?: Enter cooking equipment types and ratings. The calculator applies DW172 thermal convection coefficients to estimate canopy extract and make-up air.
What is the difference between thermal convection and capture velocity methods?: DW172 provides both approaches. Thermal convection is common for equipment schedules; capture velocity applies where hood geometry is defined.
How much make-up air is required?: Typically 85–95% of extract for balanced systems, with the remainder from transfer air. Higher make-up percentages reduce building infiltration.