Free tool

Air changes & room airflow

Pick a room type and enter dimensions. Get indicative ACH and supply/extract airflow in L/s for preliminary chats — not a design certificate.

Guidance only. Indicative air-change ranges for preliminary sizing only. Summarised in the spirit of CIBSE Guide A practice tables and Irish Technical Guidance Document F (ventilation) design culture. Not a verbatim extract of either document. Always confirm against the project specification, TGD Part F, and the designer of record.

Results

Room volume
64.8 m³
Indicative ACH
4–6
Supply / extract (low ACH) ★
72.0 L/s
Supply / extract (high ACH) ★
108.0 L/s

Formula: L/s = ACH × volume(m³) × 1000 ÷ 3600. Icons ★ mark calculated values (not colour-only).

Email-gate: guidance PDF

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