function relativeHumidity() { var T1 = document.forms["calc"].T1.value //temperature outside var T2 = document.forms["calc"].T2.value //temperature inside var RH1 = document.forms["calc"].RH1.value //relative humidity outside var RH2 //relative humidity you get when you heat the air to T2 var RH3 = document.forms["calc"].RH3.value //wanted relative humidity
var absMoisture1 //absolute moisture in the value that is calculated var absMoisture2 //wanted absolute moisture var absMoisureTot //difference
if(T1 == "" || RH1 == ""){ return; }
absMoisture1 = (RH1*0.42*Math.exp(T1*10*0.006235398)/10).toFixed(2); document.forms["calc"].absM1.value = +absMoisture1+" g/kg"
if(T2 == ""){ return }
RH2 = (absMoisture1*10/(0.42*Math.exp(T2*10*0.006235398))).toFixed(1) document.forms["calc"].RH2.value = +RH2+ " %";
/* ********the formula of the density******** */ var rho, A, RHr, p=101325, R=287.055, vp, //rho=density, vp=vaporized pressure, R=gascanstant of air, //RHr=relative humidity ratio, A=part of formula, p=pressure //var T = parseFloat(document.forms["calc"].T.value)//T=temperature (deg C) //var RH = parseFloat(document.forms["calc"].RH.value)//RH=relative humidity
vp = (parseFloat(RH1)/100)*((6.107*Math.exp((7.5*parseFloat(T1))/(237.3+parseFloat(T1))*Math.LN10)/10)); RHr = (0.62198*vp)/((p/1000)-vp*1); A = (R*(parseFloat(T1)+273.15)*(1+1.6087*RHr))/p; rho = ((1+RHr)/A).toFixed(2);
if(rho == null){ return; }
/* ***************end of the density*************** */
if(RH3 == ""){ return }
absMoisture2 = RH3*0.42*Math.exp(T2*10*0.006235938)/10; absMoistureTot = (Math.abs(absMoisture2 - absMoisture1)).toFixed(2) document.forms["calc"].absMtot.value = +absMoistureTot+" g/kg";
var V = document.forms["calc"].V.value //volume var l = document.forms["calc"].l.value //length var w = document.forms["calc"].w.value //width var h = document.forms["calc"].h.value //hight
if(V == null){ return }
if(l != "" && w != "" && h != "") { V = l*h*w document.forms["calc"].V.value = V } else { document.forms["calc"].V.value = V }
var water = (Math.abs(rho*V*(absMoisture1 - absMoisture2))/1000).toFixed(2); document.forms["calc"].water.value = +water+" l H2O" document.forms["calc"].rho.value = rho document.forms["calc"].water1.value = " "+water+" liter water" var re = document.forms["calc"].re.value var re2 = 100-re; document.forms["calc"].re2.value = +re2+"%" var vg = (water*(re2/100)).toFixed(2) document.forms["calc"].vg.value = +vg+" liter water/h" }
function clearForm(){
var form = window.document.forms["calc"]
for(var i = 0; i < form.elements.length; i++){
if(form.elements[i].type == "text"){
form.elements[i].value = ""
}
}
}
document.onkeypress = keyhandler;
function keyhandler(e) {
Key = (document.layers)?e.which:window.event.keyCode;;
if( Key == 13 || Key == 32 ){ //13 is ascii value for Enter key
relativeHumidity();
}
if( Key == 27){ //27 is ascii value for escape key
clearForm();
}
}