How to calculate PMV in TRNSYS

Comfort indexes

TRNSYS can calculate the following comfort indexes.

  • Mean Radiant Temperature(MRT)
  • Operative Temperature(OT)
  • Predicted Mean Vote (PMV)
  • Predicted Percentage of Dissatisfied (PPD)

This post explains how to set up the PMV calculation in TRNSYS.

Some values are needed for the calculation. The values that are usually calculated by Type 56, such as temperature and humidity, as well as the wind speed, metabolic rate (met) and clothing factor (clo) are required.

In TRNBuild, wind speed, metabolic rate and clothing factor are defined as a comfort type. In order to calculate PMV, the definition of comfort type is required.

To set up a new comfort type, follow these steps.

  1. Add a new comfort type and define wind speed, metabolic rate, and clothing factor.
  2. Add the comfort type to the Zone (Airnode) where you want to calculate PMV.
  3. Add PMV (Ntype124) to the Outputs.

The following is an example of adding comfort type in TRNSYS18.

Define a new comfort type

  1. In the TRNBuild Navigator, right click on Comfort types under Regime Types
  2. Click Add Comfort in the menu.
In “Comfort Types”, select “Add Comfort”.

When the Comfort type dialog appears, enter a name for the new comfort type.

Enter a new ComfortType name
  1. Set the Clothing factor, Metabolic rate , External work and Relative air velocity as required.
  2. Click on the “✔” button to close the dialog.

You can find reference values for each setting in the TRNSYS document “5.2.6.5 Definition of Comfort Types”.

This is the end of creating a comfort type. Next, let’s add the created comfort type to a zone.

Adding the comfort type to a Zone

Add the created comfort type to a zone where you want to calculate PMV. Click the zone in the TRNBuild Navigator and follow these steps.

  1. Click on the “Comfort type” icon.
  2. Click on the “+” button in the Comfort type dialog to add the comfort type to the zone.
  3. Select the comfort type you have just created from the list.
  4. Click the “✔” button to close the dialog.
Assigning a comfort type to a zone

Setting the Output Data

In the Output Data dialog, add the PMV output.

  1. Select the Zone to be calculated from the list
  2. Click the “←” button to add a Zone to “Selected Thermal Airnodes”.
  3. Select the “comfort outputs”.
  4. Select “PMV” (NType 124) from the list
  5. Click the “←” button to add output
  6. Double-click “PMV”.
Select a Zone and assign the PMV output

At this point, a further setup screen will appear. Next, configure as follows.

  1. Select the comfort type from the list.
  2. Click the “←” button to add it to “Selected Comfort Definitions”.
  3. Click the “✔” button to close the dialog.
Assigning Comfort Type to PMV output

That’s all.

After returning to the Simulation Studio, select “Update building variable list” to add the PMV output to the Outputs entry.

You can add the PPD calculation in the same way.

Now you can evaluate the indoor environment using the comfort index.

Test Environment

It has been confirmed that the software works in the following environments.

Windows 10 Pro(64bit, 1809)
TRNSYS18.01.0001

Pocket

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