Door and Fan Control Logic

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Matt

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Jun 19, 2019, 2:09:38 PM6/19/19

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The attached has a couple of applications of control logic.

This includes:

1. A ‘door’ physically opening and closing to reflect a pressure differential across the door.

Application: its quite common in the UK to use doors as the replacement air path, to literally be pulled ‘open’ when a lobby for example is depressurised by smoke extract. The normal way I see this done is to using an arbitrary 200mm or 300mm wide hole in a door for example. That approach doesn’t reflect the actually pressures which may result. So the example uses ‘real’ door pressures to open and close the door. It’s a bit jumpy, but in a more realistic scenario (large floor plate ) it performs OK. Its actually known in the UK as a ‘floppy door’ solution.

2. A ‘fan’ which reacts to pressure differentials in a ‘remote’ location, i.e. pressures between a stair and lobby.

Application: In the UK we use pressure sensors (diaphragms) across stair/ lobbies to ramp extract rate down when a door closes. Again this is typically done manually in FDS with predetermine fan responses to doors opening (but without knowing the pressure it’s a guess). The attached actually uses the pressure differential in a similar way to a ‘real’ situation. When the lobby door is opened by the fire service for example the system ramps up, and when closed drops down.

These aren’t perfect of course, but I thought i'd share share - There’s probably a simpler way of doing it anyway😊