What is the difference between the six different humidity metrics shown? Why does this program show two different values of specific volume? There appears to be error in the calculations when converting from one unit system to
#QUALITY IN ASHRAE PSYCHROMETRIC MANUAL#
Load Calculation Applications Manual IP Unit (Second Edition) By Sai Naung. User may override default input by selecting and entering new value. Web application for thermal comfort visualization and calculation according to ASHRAE Standard 55 Article History. Site elevation for Dayton, OH - 997 ft amsl (306 m) based on the ASHRAE HOF. Sea Level Pressure - 14.7 psia / 101.3 kPa / 29.92 in Hg / 760 mm Hg (Default when 'ActualĪverage Barometric Pressure in Dayton, OH - 14.18 psia / 97.7 kPa / 28.86 in Hg / 733 mm Hg At the end of the calculation, the user has the option to convert from the English to the SI (or vice versa) unit system. The user then enters a desiredĭry Bulb temperature and one of three humiditymetrics:ĭew Point temperature. Sensible heat ratio (SHR), humidity ratio scale in grains/lb, and two. To calculate properties, the user must enter either a site elevation (from which an average barometric pressure is calculated) or an actual barometric pressure. Reprinted with permission from ASHRAE Inc. It will also provide a number of other thermodynamic properties not found on a typical psychrometric chart. This on-line program calculates typical psychrometric state point properties. The psychrometric ratio is the ratio of the heat transfer coefficient to the product of mass transfer coefficient and humid heat at a wetted surface. This is the t axis, the abscissa horizontal axis. For years, we have worked with ASHRAE to develop mobile applications related to a number of their standards and Handbook of Fundamentals chapters including ASHRAE 62. Instructions for the Psychrometric Calculator ASHRAE Fundamentals Handbook (SI) Mass of water added per unit mass of dry air is (W. ANSI/ASHRAE Standard 62.1-2013, Ventilation for acceptable indoor air quality.