diff --git a/src/functionObjects/field/comfort/comfort.C b/src/functionObjects/field/comfort/comfort.C
index 5aad71231c..be894e6ed2 100644
--- a/src/functionObjects/field/comfort/comfort.C
+++ b/src/functionObjects/field/comfort/comfort.C
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2019 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2019-2021 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -407,7 +407,7 @@ bool Foam::functionObjects::comfort::execute()
 
     Info<< "Calculating the predicted percentage of dissatisfaction (PPD)\n";
 
-    // Equation (5) in EN ISO
+    // Equation (5)
     tmp<volScalarField> PPD
     (
         volScalarField::New
@@ -417,13 +417,68 @@ bool Foam::functionObjects::comfort::execute()
         )
     );
 
-    return store(PMV) && store(PPD);
+    Info<< "Calculating the draught rating (DR)\n";
+
+    const dimensionedScalar Umin("Umin", dimVelocity, 0.05);
+    const dimensionedScalar Umax("Umax", dimVelocity, 0.5);
+    const dimensionedScalar pre("preU", dimless, 0.37);
+    const dimensionedScalar C1("C1", dimVelocity, 3.14);
+
+    // Limit the velocity field to the values given in EN ISO 7733
+    volScalarField Umag = mag(lookupObject<volVectorField>("U"));
+    Umag.maxMin(Umin, Umax);
+
+    // Calculate the turbulent intensity if turbulent kinetic energy field k
+    // exists
+    volScalarField TI
+    (
+        IOobject
+        (
+            "TI",
+            mesh_.time().timeName(),
+            mesh_
+        ),
+        mesh_,
+        dimensionedScalar(dimensionSet(0, 0, 0, 0, 0, 0, 0), 0)
+    );
+
+    if (foundObject<volScalarField>("k"))
+    {
+        const volScalarField& k = lookupObject<volScalarField>("k");
+        TI = sqrt(2/3*k)/Umag;
+    }
+
+    // For unit correctness
+    const dimensionedScalar correctUnit
+    (
+        "correctUnit",
+        dimensionSet(0,- 1.62, 1.62, -1, 0, 0, 0),
+        1
+    );
+
+    // Equation (6)
+    tmp<volScalarField> DR
+    (
+        volScalarField::New
+        (
+            "DR",
+            correctUnit*(factor12 - T)*pow(Umag - Umin, 0.62)*(pre*Umag*TI + C1)
+        )
+    );
+
+    return
+        store(PMV)
+     && store(PPD)
+     && store(DR);
 }
 
 
 bool Foam::functionObjects::comfort::write()
 {
-    return writeObject("PMV") && writeObject("PPD");
+    return
+        writeObject("PMV")
+     && writeObject("PPD")
+     && writeObject("DR");
 }
 
 
diff --git a/src/functionObjects/field/comfort/comfort.H b/src/functionObjects/field/comfort/comfort.H
index c0d3803256..a1839ffdf1 100644
--- a/src/functionObjects/field/comfort/comfort.H
+++ b/src/functionObjects/field/comfort/comfort.H
@@ -2,7 +2,7 @@
   =========                 |
   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
    \\    /   O peration     | Website:  https://openfoam.org
-    \\  /    A nd           | Copyright (C) 2019-2020 OpenFOAM Foundation
+    \\  /    A nd           | Copyright (C) 2019-2021 OpenFOAM Foundation
      \\/     M anipulation  |
 -------------------------------------------------------------------------------
 License
@@ -25,8 +25,14 @@ Class
     Foam::functionObjects::comfort
 
 Description
-    Calculates the thermal comfort quantities predicted mean vote (PMV) and
-    predicted percentage of dissatisfaction (PPD) based on DIN ISO EN 7730:2005.
+    Calculates the thermal comfort quantities predicted mean vote (PMV),
+    predicted percentage of dissatisfaction (PPD) and the draught rate (DR)
+    based on DIN ISO EN 7730:2005.
+
+    The draught rate is defined for velocities between 0 m/s and 0.5 m/s. Values
+    larger than 0.5 m/s will be set to 0.5 m/s. Furthermore, the draught rate is
+    defined between 20 degC and 26 degC. A temperature limitation is not
+    implemented. The draught rate is mainly used for HVAC analysis in rooms.
 
 Usage
     \table
@@ -34,11 +40,11 @@ Usage
         clothing      | The insulation value of the cloth | no   | 0
         metabolicRate | The metabolic rate      | no        | 0.8
         extWork       | The external work        | no        | 0
-        Trad          | Radiation temperature | no | -1
-        relHumidity   | Relative humidity of the air | no | 50
+        Trad          | Radiation temperature | no | 0
+        relHumidity   | Relative humidity of the air | no | 0.5
         pSat          | Saturation pressure of water | no | -1
-        tolerance     | Residual control for the cloth temperature | no | 1e-5
-        maxClothIter  | Maximum number of iterations | no       | 0
+        tolerance     | Residual control for the cloth temperature | no | 1e-4
+        maxClothIter  | Maximum number of iterations | no       | 100
         meanVelocity  | Use a constant mean velocity in the whole domain | no |\
         false
     \endtable