{"id":2955,"date":"2023-01-04T12:50:15","date_gmt":"2023-01-04T12:50:15","guid":{"rendered":"https:\/\/csiag.eu\/?p=2955"},"modified":"2023-01-04T12:58:17","modified_gmt":"2023-01-04T12:58:17","slug":"smarthome-dew-point-calculation","status":"publish","type":"post","link":"https:\/\/csiag.eu\/en\/blog\/2023\/01\/04\/smarthome-taupunkt-berechnen\/","title":{"rendered":"SmartHome \u2013 Calculate dew point"},"content":{"rendered":"<span class=\"span-reading-time rt-reading-time\" style=\"display: block;\"><span class=\"rt-label rt-prefix\">Reading time<\/span> <span class=\"rt-time\"> &lt; 1<\/span> <span class=\"rt-label rt-postfix\">minute<\/span><\/span>\n<p>The dew point describes the temperature that must be fallen below in order for dew or mist or condensation to form at constant air pressure and given humidity.<\/p>\n\n\n\n<p>Required hardware:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Homematic temperature-humidity sensor outside <a href=\"https:\/\/de.elv.com\/homematic-funk-temperatur-luftfeuchtesensor-hm-wds10-th-o-fuer-smart-home-hausautomation-076923\" target=\"_blank\" rel=\"noreferrer noopener\">HM-WDS10-TH-O<\/a><\/li>\n\n\n\n<li>Homematic wall thermostat <a href=\"https:\/\/de.elv.com\/homematic-funk-wandthermostat-hm-tc-it-wm-w-eu-fuer-smart-home-hausautomation-132030\" target=\"_blank\" rel=\"noreferrer noopener\">HM-TC-IT-WM-WE<\/a><\/li>\n<\/ul>\n\n\n\n<p>The program:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-large is-resized\"><img decoding=\"async\" src=\"https:\/\/csiag.eu\/wp-content\/uploads\/2023\/01\/image-1-1024x264.png\" alt=\"\" class=\"wp-image-2956\" width=\"840\" height=\"216\" srcset=\"https:\/\/csiag.eu\/wp-content\/uploads\/2023\/01\/image-1-1024x264.png 1024w, https:\/\/csiag.eu\/wp-content\/uploads\/2023\/01\/image-1-300x77.png 300w, https:\/\/csiag.eu\/wp-content\/uploads\/2023\/01\/image-1-768x198.png 768w, https:\/\/csiag.eu\/wp-content\/uploads\/2023\/01\/image-1-1536x396.png 1536w, https:\/\/csiag.eu\/wp-content\/uploads\/2023\/01\/image-1-2048x528.png 2048w, https:\/\/csiag.eu\/wp-content\/uploads\/2023\/01\/image-1-1560x403.png 1560w\" sizes=\"(max-width: 840px) 100vw, 840px\" \/><figcaption class=\"wp-element-caption\">Program \u2013 dew point calculation<\/figcaption><\/figure>\n<\/div>\n\n\n<p>The code:<\/p>\n\n\n\n<p><code>real T = dom.GetObject(&quot;T_actual_FH&quot;).Value();WriteLine(&quot;T_FH&quot;);WriteLine(T);<br>real rF = dom.GetObject(&quot;F_actual_FH&quot;).Value();WriteLine(&quot;rF_FH&quot;);WriteLine(rF);<\/code><\/p>\n\n\n\n<p><code>if (T &lt; 0.0) { T = 0.0; } real TK = T + 273.15; !Temperature in Kelvin real a = 7.5; real b = 237.3; !for T &gt;= 0<br>real R = 8314.3; !J \/ (kmol * K)(universal gas constant)<br>real mw = 18,016; !kg \/ kmol (molecular weight of water vapor)<br>real pp = (a * T) \/ (b + T); !Calculate the power of the following formula<br>real SDD = 6.1078 * (10.0).Pow(pp); !Saturation vapor pressure in hPa<br>real DD = ((SDD * rF) \/ 100.0); !Vapor pressure in hPa<br>real v = (DD \/ 6.1078).Log10();<br>real TP_null = (b * v \/ (a - v));WriteLine(&quot;TP_null&quot;);WriteLine(TP_null); !Dew point<br>real TP = (TP_null).ToString(1); !Temperature switching threshold for ventilation<\/code><\/p>\n\n\n\n<p><code>dom.GetObject(&quot;Dewpoint_FH&quot;).State(TP);WriteLine(&quot;Dewpoint&quot;);WriteLine(TP);<br>real AF = (10.0).Pow(5.0) * (mw \/ R) * DD \/ TK;<\/code><\/p>\n\n\n\n<p>The two variables <code>T<\/code> and <code>rF<\/code> are read from the respective temperature\/humidity sensors in an external program and are thus passed on to all other programs without having to query the sensor again (in order to minimize the <em><a href=\"https:\/\/csiag.eu\/en\/day\/dutycycle\/\" data-type=\"post_tag\" data-id=\"392\">DutyCycles<\/a><\/em>) made available.<\/p>","protected":false},"excerpt":{"rendered":"<p><span class=\"span-reading-time rt-reading-time\" style=\"display: block;\"><span class=\"rt-label rt-prefix\">Reading time<\/span> <span class=\"rt-time\"> &lt; 1<\/span> <span class=\"rt-label rt-postfix\">minute<\/span><\/span>Der Taupunkt beschreibt die Temperatur, die unterschritten werden muss, um bei konstantem Luftdruck bei gegebener Luftfeuchte, damit sich Tau oder Nebel, bzw. Kondenswasser bilden kann. Ben\u00f6tigte Hardware: Das Programm: Der Code: real T = dom.GetObject(&#8222;T_actual_FH&#8220;).Value();WriteLine(&#8222;T_FH&#8220;);WriteLine(T);real rF = dom.GetObject(&#8222;F_actual_FH&#8220;).Value();WriteLine(&#8222;rF_FH&#8220;);WriteLine(rF); if (T &lt; 0.0) { T = 0.0; } real TK = T + 273.15; !Temperatur in&hellip;&nbsp;<a href=\"https:\/\/csiag.eu\/en\/blog\/2023\/01\/04\/smarthome-taupunkt-berechnen\/\" rel=\"bookmark\">Read More \"<span class=\"screen-reader-text\">SmartHome \u2013 Calculate dew point<\/span><\/a><\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_lmt_disableupdate":"","_lmt_disable":"","neve_meta_sidebar":"","neve_meta_container":"","neve_meta_enable_content_width":"","neve_meta_content_width":0,"neve_meta_title_alignment":"","neve_meta_author_avatar":"","neve_post_elements_order":"","neve_meta_disable_header":"","neve_meta_disable_footer":"","neve_meta_disable_title":"","footnotes":""},"categories":[346,347],"tags":[747,748,752,749,191,750,391,370,441,470,751],"class_list":["post-2955","post","type-post","status-publish","format-standard","hentry","category-smarthome","category-smarthome-im-wohnmobil","tag-berechnen","tag-gaskonstante","tag-kelvin","tag-luftdruck","tag-molekulargewicht","tag-saettigungsdampfdruck","tag-schaltschwelle","tag-smarthome","tag-taupunkt","tag-temperatur","tag-wasserdampf"],"modified_by":"Achim Goerner","_links":{"self":[{"href":"https:\/\/csiag.eu\/en\/wp-json\/wp\/v2\/posts\/2955","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/csiag.eu\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/csiag.eu\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/csiag.eu\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/csiag.eu\/en\/wp-json\/wp\/v2\/comments?post=2955"}],"version-history":[{"count":0,"href":"https:\/\/csiag.eu\/en\/wp-json\/wp\/v2\/posts\/2955\/revisions"}],"wp:attachment":[{"href":"https:\/\/csiag.eu\/en\/wp-json\/wp\/v2\/media?parent=2955"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/csiag.eu\/en\/wp-json\/wp\/v2\/categories?post=2955"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/csiag.eu\/en\/wp-json\/wp\/v2\/tags?post=2955"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}