Search results
Results from the WOW.Com Content Network
A psychrometric chart is a graph of the thermodynamic parameters of moist air at a constant pressure, often equated to an elevation relative to sea level. The ASHRAE-style psychrometric chart, shown here, was pioneered by Willis Carrier in 1904. [10] It depicts these parameters and is thus a graphical equation of state. The parameters are:
English: This psychrometric chart represents the acceptable combination of air temperature and humidity values, according to the PMV/PPD method in the ASHRAE 55-2010 Standard. The comfort zone in blue represents the 90% of acceptability, which means the conditions between -0.5 and +0.5 PMV, or PPD < 10%.
Figure 2: On a standard psychrometric chart, the air flow state points of the Cromer cycle are shown. The psychrometric process of the air passing through the system with four state points is shown on the psychrometric chart of Figure 2 as 1, 2, 3 and 4. The state points of the air are also depicted in Figure 1.
The wet-bulb temperature is the lowest temperature that may be achieved by evaporative cooling of a water-wetted, ventilated surface.. By contrast, the dew point is the temperature to which the ambient air must be cooled to reach 100% relative humidity assuming there is no further evaporation into the air; it is the temperature where condensation (dew) and clouds would form.
γ = Psychrometric constant (γ ≈ 66 Pa K −1) Note: Often, resistances are used rather than conductivities. = & = = where r c refers to the resistance to flux from a vegetation canopy to the extent of some defined boundary layer.
You are free: to share – to copy, distribute and transmit the work; to remix – to adapt the work; Under the following conditions: attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made.
Hands Down Software HDPsyChart Psychrometric Analysis Program: Author: Bob Hanna: Permission (Reusing this file) This work is free and may be used by anyone for any ...
The psychrometric constant relates the partial pressure of water in air to the air temperature. This lets one interpolate actual vapor pressure from paired dry and wet thermometer bulb temperature readings.