Ashrae psychrometric chart no. 1 in color
If no value is input here, the component will assume a metabolic rate of 1 met, which is the metabolic rate of a seated human being. Acceptable text inputs include Sleeping, Reclining, Sitting, Typing, Standing, Driving, Cooking, House Cleaning, Walking, Walking 2mph, Walking 3mph, Walking 4mph, Running 9mph, Lifting 10lbs, Lifting 100lbs, Shoveling, Dancing, and Basketball. This input can also accept text inputs for different activities. This input can also accept a list of wind speeds representing conditions and this will produce several comfort polygons (one for each wind speed).Ī number representing the metabolic rate of the human subject in met. If no value is plugged in here, this component will assume a very low wind speed of 0.05 m/s, characteristic of most indoor conditions. This input can also accept a list of temperatures and this will produce several comfort polygons (one for each mean radiant temperature).Ī number representing the wind speed of the air in meters per second. If no value is plugged in here, this component will assume that the mean radiant temperature is the same as the connected dry bulb temperature (and the X-Axis of the Psychrometric Chart is for Operative Temperature instead of Dry Bulb Temperature). This value should be in degrees Celcius unless you have connected values in Farenheit to the dryBulbTemperature and you are seeing a chart in IP units. It is recommended that you connect the barometric pressure from the Import epw component here as the air pressure at sea level can cause some misleading results for cities at higher elevations.Ī number representing the mean radiant temperature of the surrounding surfaces. If no value is connected here, the default pressure will be 101325 Pa, which is air pressure at sea level. This input can also accept a list of relative humidity values representing conditions at different times or the direct output of relativeHumidity from of the Import EPW component.Ī number representing the barometric pressure in Pascals. Finally, this component can also acccept temperatures in Farenheit in order to draw a chart with IP units but, in order for this component to sense that the values are Farenheit, there must be at least one 'F' or '☏' in the stream of connected data.Ī number between 0 and 100 representing the relative humidity of the air in percentage.
Indoor temperatures from Honeybee energy simulations are also possible inputs. This input can also accept a list of temperatures representing conditions at different times or the direct output of dryBulbTemperature from the Import EPW component. Further information on how these polygons are calculated can be found here:Ī number representing the dry bulb temperature of the air in degrees Celcius. The information for the polygons representing passive strategies comes from the climate consultant psychrometric chart. Hoyt Tyler, Schiavon Stefano, Piccioli Alberto, Moon Dustin, and Steinfeld Kyle, 2013, CBE Thermal Comfort Tool.Ĭenter for the Built Environment, University of California Berkeley, Special thanks goes to the authors of the online CBE Thermal Comfort Tool who first made the javascript models in order to power the tool: Specific documentation on the comfort models can be found here:
ASHRAE PSYCHROMETRIC CHART NO. 1 IN COLOR SERIES
The comfort models that make this component possible were translated to python from a series of validated javascript comfort models developed at the Berkely Center for the Built Environment (CBE). The range of comfort is generally accepted as a PMV between -1 and +1 and this is what defines the range of the comfort polygon on the psychrometric chart.Īccordingly, this component will also output the PMV of the occupant for the input conditions as well as an estimated percentage of people dissatisfied (PPD) in the given conditions. Each interger value of the scale indicates the following: -3:Cold, -2:Cool, -1:Slightly Cool, 0:Neutral, +1:Slightly Warm, +2:Warm, +3:Hot. PMV is a seven-point scale from cold (-3) to hot (+3) that is used in comfort surveys. The specific human energy balance model used by the psychrometric chart is the Predicted Mean Vote (PMV) model developed by P.O. The input data will be plotted alongside polygons on the chart representing comfort as well as polygons representing the efects of passive building strategies on comfort. Connected data can include either outdoor temperature and humidty ratios from imported EPW weather data, indoor temperature and humidity ratios from an energy simulation, or indivdual numerical inputs of temperature and humidity. .pdf.Use this component to draw a psychrometric chart in the Rhino scene and evaluate a set of temperatures and humidity ratios in terms of indoor comfort.