{"id":671,"date":"2015-08-16T20:28:13","date_gmt":"2015-08-17T00:28:13","guid":{"rendered":"http:\/\/blog.uvm.edu\/cwcallah\/?page_id=671"},"modified":"2018-01-27T06:08:56","modified_gmt":"2018-01-27T10:08:56","slug":"psychrocalc","status":"publish","type":"page","link":"https:\/\/blog.uvm.edu\/cwcallah\/psychrocalc\/","title":{"rendered":"Psychrocalc"},"content":{"rendered":"<p>Psychrocalc is a free Excel(TM) add-in that makes psychrometric calculations easier. Currently the following calculations are supported with Excel(TM) friendly functions:<\/p>\n<ul>\n<li><strong>RH_TDB_TWB <\/strong>(TDB, TWB, P) &#8211; Calculates relative humidity (RH, %) for a known dry-bulb (TDB, F) and wet-bulb (TWB, F) temperature at a given pressure (P, PSIA)<\/li>\n<li><strong>RH_TDB_W <\/strong>(TDB, W, P) &#8211; Calculates relative humidity (RH, %) for a known drybulb (TDB, F) and humidity ratio (W, lbw\/lbda) at a given pressure (P, PSIA).<\/li>\n<li><strong>TDB_RH_W <\/strong>(RH, W, P) &#8211; Calculates drybulb (TDB, F) for a known relative humidity (RH, %) and humidity ratio (W, lbw\/lbda) at a given pressure (P, PSIA).<\/li>\n<li><strong>TWB_TDB_RH <\/strong>(TDB, RH, P) &#8211; Calculates wet-bulb temperature (TWB, F) for a known dry-bulb (TDB, F) and relative humidity (RH, %) at a given pressure (P, psia).<\/li>\n<li><strong>TDP_TDB_RH <\/strong>(TDB, RH, P) &#8211; Calculates dew-point temperature (TDP, F) for a known dry-bulb temperature (TDB, F) and relative humidity (RH, %) at a given pressure (psia)<\/li>\n<li><strong>W_TDB_TWB <\/strong>(TDB, TWB, P) &#8211; Calculates humidity ratio (w, lbw\/lbda) for known dry-bulb temperature (TDB, F) and wet-bulb (TWB, F) at a given pressure (P, psia)<\/li>\n<li><strong>T_Wsat <\/strong>(Wsat) &#8211; Calculates the temperature (Tsat, F) corresponding to a given saturation humidity ratio (w, lbw\/lbda)<\/li>\n<li><strong>Wsat_T <\/strong>(T) &#8211; Calculates the saturation humidity ratio (w, lbw\/lbda) for a given temperature (Tsat, F)<\/li>\n<li><strong>Tsat_P <\/strong>(P) &#8211; Calculates the saturation temperature (Tsat, F) of water vapor for a given pressure (Psat, PSIA)<\/li>\n<li><strong>Psat_T <\/strong>(T) &#8211; Calculates the saturation pressure (Psat, psia) of water vapor for a given temperature (Tsat, F)<\/li>\n<li><strong>Pvap_TDB_RH<\/strong> (TDB, RH, P) &#8211; Calculates the vapor pressure of water (Pvap, psia) in air for a given dry bulb temperature (TDB, degF), RH (%) and total pressure (P, psia) as inputs.<\/li>\n<li><strong>hfg_T<\/strong> (T) &#8211; Calculates the specific enthalpy of evaporation at a given temperature (T, degF).<\/li>\n<li><strong>Interpolate <\/strong>(x, x1, x2, y1, y2) &#8211; Calculates y (unknown) given x and four known table lookup values (x1, x2, y1, y2) using a linear interpolation.<\/li>\n<li><strong>hda_T <\/strong>(T) &#8211; Calculates specific enthalpy of dry air (BTU\/lb) at a specified temperature (T, degF).<\/li>\n<li><strong>hsa_T <\/strong>(T) &#8211; Calculates specific enthalpy of saturated air (BTU\/lb) at a specified temperature (T, degF).<\/li>\n<li><strong>ha_T_RH <\/strong>(T,RH) &#8211; Calculates specific enthalpy of a air water mixture (BTU\/lb) at a specified temperature (T, degF) and relative humidity (RH).<\/li>\n<li><strong>Tda <\/strong>(h) &#8211; Calculates a specific temperature for dry air of a specific enthalpy.<\/li>\n<li><strong>vda_T <\/strong>(T) &#8211; Calculates specific volume of dry air (ft3\/lb) at a specified temperature (T, degF).<\/li>\n<li><strong> vsa_T <\/strong>(T) &#8211; Calculates specific volume of saturated air (ft3\/lb) at a specified temperature (T, degF).<\/li>\n<li><strong> va_T_RH <\/strong>(T,RH) &#8211; Calculates specific volume of a air water mixture (ft3\/lb) at a specified temperature (T, degF) and relative humidity (RH).<\/li>\n<\/ul>\n<p>The calculations follow <a href=\"https:\/\/www.ashrae.org\/home\" target=\"_blank\" rel=\"noopener\">ASHRAE<\/a> Handbook &#8211; Fundamentals. 2005. Chapter 6.<\/p>\n<p><a href=\"http:\/\/blog.uvm.edu\/cwcallah\/files\/2018\/01\/PsychroCalcs.xlam\" target=\"_blank\" rel=\"noopener\">Download Excel(TM) Add-in<\/a>. Follow <a href=\"https:\/\/support.office.com\/en-nz\/article\/Add-or-remove-add-ins-0af570c4-5cf3-4fa9-9b88-403625a0b460#bmexceladdin\" target=\"_blank\" rel=\"noopener\">this guide<\/a> to activate the add-in in Excel(TM) after download. Please note: Install the Add-in before trying to open the sample spreadsheet below.\u00a0 When using the functions above, you should not have to include a full path to the add-in.\u00a0 Mac users: An error may occur with spaces being inserted into the path.\u00a0 To resolve this, delete the path and use only the function name.<\/p>\n<p><a href=\"http:\/\/blog.uvm.edu\/cwcallah\/files\/2016\/04\/Psychro-and-Steam-Table-Calcs-Example-2016-04-29.xlsx\" target=\"_blank\" rel=\"noopener\">Download Example Excel(TM) Worksheet<\/a>. This is an Excel(TM) workbook that includes an example worksheet with the Psychrocalc functions demonstrated.\u00a0 It also includes data from Table 2 and Table 3 of the ASHRAE reference.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Psychrocalc is a free Excel(TM) add-in that makes psychrometric calculations easier. Currently the following calculations are supported with Excel(TM) friendly functions: RH_TDB_TWB (TDB, TWB, P) &#8211; Calculates relative humidity (RH, %) for a known dry-bulb (TDB, F) and wet-bulb (TWB, F) temperature at a given pressure (P, PSIA) RH_TDB_W (TDB, W, P) &#8211; Calculates relative &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/blog.uvm.edu\/cwcallah\/psychrocalc\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Psychrocalc&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1174,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"open","template":"","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-671","page","type-page","status-publish","hentry","entry"],"featured_image_src":null,"featured_image_src_square":null,"_links":{"self":[{"href":"https:\/\/blog.uvm.edu\/cwcallah\/wp-json\/wp\/v2\/pages\/671","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.uvm.edu\/cwcallah\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/blog.uvm.edu\/cwcallah\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/blog.uvm.edu\/cwcallah\/wp-json\/wp\/v2\/users\/1174"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.uvm.edu\/cwcallah\/wp-json\/wp\/v2\/comments?post=671"}],"version-history":[{"count":11,"href":"https:\/\/blog.uvm.edu\/cwcallah\/wp-json\/wp\/v2\/pages\/671\/revisions"}],"predecessor-version":[{"id":1118,"href":"https:\/\/blog.uvm.edu\/cwcallah\/wp-json\/wp\/v2\/pages\/671\/revisions\/1118"}],"wp:attachment":[{"href":"https:\/\/blog.uvm.edu\/cwcallah\/wp-json\/wp\/v2\/media?parent=671"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}