Sefaira includes a "Test Tolerance" control on some of our thermal comfort features. This article explains why it's there and what it's for.

Why is it there?

When EnergyPlus converges on each time-step and reports on space temperatures, it is not uncommon for spaces that are air-conditioned to end up with temperatures that are slightly outside of the desired temperature band.

For example

• You set the temperature setpoints are 21-24°C (70-75°F).
• EnergyPlus may report many hourly space temperatures like 24.009 °C or 25.07°F.

We did not want these values to appear as failing hours for the first simulation, because from an occupant point of view, they are effectively a pass. The test tolerance provides an additional window for space temperatures to be considered a Pass, so that the results make sense the first time you run the analysis.

What is the pop-up for?

We expected that there will be times that customers would prefer we didn't apply this value. The pop-up provides a way to set the tolerance to zero so a strict interpretation of the setpoint range can be enforced for the calculations.

Similarly we didn't know whether our assumed tolerance setting would be right for all users. By making it adjustable, users can decide what range works for them.

More control over controls

The Tolerance range also serves another purpose, which is to give you more control over the way a building is controlled. For example, if you want natural ventilation controls to work to a different operational setpoint to what you actually want to achieve for comfort, then this value can be used to control the windows to a different setpoint to the actual comfort setpoint.