CBE Thermal Comfort Tool for EN-15251

Inputs

Select method:

Air temperature

°C

Use operative temp

Mean radiant temperature

°C

Air speed

m/s

Relative humidity

Metabolic rate

met

Clothing level

clo

Create custom ensemble

Outdoor running mean outdoor temperature

°C

Reset Set pressure SI/IP ? Help

Local discomfort Globe temp

PMV =

PPD = %

Category =

Adaptive chart

NOTE: In this psychrometric chart the abscissa is the dry-bulb temperature, and the mean radiant temperature (MRT) is fixed, controlled by the inputbox. Each point on the chart has the same MRT, which defines the comfort zone boundary. In this way you can see how changes in MRT affect thermal comfort. You can also still use the operative temperature button, yet each point will have the same MRT.

NOTE: In this psychrometric chart the abscissa is the operative temperature and for each point dry-bulb temperature equals mean radiant temperature (DBT = MRT). The comfort zone represents the combination of conditions with the same DBT and MRT for which the PMV is between -0.5 and +0.5, according to the standard.

NOTE: This chart represents only two variables, dry-bulb temperature and relative humidity. The PMV calculations are still based on all the psychrometric variables, but the visualization becomes easier to understand.

NOTE: Method is applicable only for buildings without mechanical cooling systems and where there is easy access to operable windows and occupants may freely adapt their clothing to the indoor and/or outdoor thermal conditions. The criteria for the spaces are the following: (a) There is no mechanical cooling or heating system in operation; (b) Metabolic rates ranging from 1.0 to 1.3 met; (c) Occupants are allowed to freely adapt their clothing insulation.