We often hear a statement relating to Ventsim which goes something like this;

“I’ve got a really good model. The quantities are spot on. Its only the pressures that are out”.

Quite simply this means the resistances are wrong!

With patience and commitment there is no reason why any branch or sets of branches can’t be adjusted to drive a certain measured quantity at a certain measured pressure and that is what happens when the resistances are correct.

When the resistances are correct confidence is enhanced and ventilation changes can be done in a fraction of the time.

If the accuracy of the model is high circuit changes can be done with adjustments to regulator differential pressures without measuring quantity’s until the check survey is done at the end of the process.

That is the level of confidence a good model can build. Once ventilation engineers get used to doing ventilation changes like that there is no going back!