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Confined-Space Ventilation

Air that keeps people safe.

Air-change rates, gas dilution and extraction to keep plant rooms and confined spaces safe. Built for plant and safety engineers.

A worked example

Forced extraction

Gas-dilution air-change design

The figures shown are an indicative worked example. Every result Tenselo produces shows the inputs it used and the method behind it, so the work can be checked rather than taken on trust.

Inputs
Room volume 120 m³
Hazard Chlorine
Air changes 12 /h
Fan Auto
Results
1,440 m³/h
Required airflow
12 /h
Air changes
400 L/s
Extract fan
120 m³
Room volume
Chlorine
Hazard gas
High-level
Intake

Why it matters on the job

Air changes to the code

Ventilation rate set to the hazard and the standard, not a round number.

Gas diluted safely

Dilution airflow sized so a leak stays below exposure limits.

Fans that deliver

Extract duty and intake placement worked so the room actually clears.

What is in this category

9 Ventilation & Safety calculators

Every calculator in this category, by its reference code. Running them needs a Tenselo subscription — subscriptions open soon.

  • HVC-001 Hydronic Heating Design Calculator

    Heat load, underfloor circuits / radiators / fan-coils, pump flow & head, heat-pump / boiler size, buffer tank and running cost (AU, location-driven)

  • HVC-002 Reverse Cycle Air Conditioner Sizing

    Split / ducted / shed / container / commercial cooling + heating load from location design temps, insulation, glazing & orientation -> recommended kW + running cost

  • SAF-001 Battery Room Hydrogen Ventilation

    Ventilation airflow & natural vent opening to keep H2 below 4% (IEC 62485-2 / EN 50272-2)

  • SAF-002 Confined Space / Wet-Well Purge

    Pre-entry purge time and continuous air changes for a tank / wet well from the blower airflow (AS 2865)

  • SAF-003 Diesel Engine-Room Ventilation

    Combustion air + radiated-heat + radiator airflow for a diesel pump/genset room (screening - confirm with the engine data)

  • SAF-004 Gas / Chlorine Room Ventilation

    Extraction fan airflow for a gas store/dosing room from volume x air changes (AS 2927 / plant-room practice)

  • SAF-005 Pump / Plant-Room Ventilation

    Extraction airflow to remove motor/engine heat and hold a room temperature rise, plus minimum air changes

  • SAF-006 Safety Shower / Eyewash (AS 4775)

    Required flow, 15-minute water volume and supply pipe size for emergency showers & eyewashes (AS 4775 / ANSI Z358.1)

  • SAF-007 Switchboard / Enclosure Cooling

    Multi-component heat load + location ambient (hot shed / sun) -> natural vent, fan (m3/h) or AC (kW) (Rittal / NHP / Phoenix, IEC 60890)

Subscriptions open soon

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