X-Git-Url: https://defiant.homedns.org/gitweb/?a=blobdiff_plain;f=humidity.py;fp=humidity.py;h=9e4d43958a6a0e1d0b5e1b60b2023439f0123d46;hb=1e900f8150af092dd46c690a48b2541a36a6bca0;hp=0000000000000000000000000000000000000000;hpb=6af0c706c1dd1b0ae4cbc38adf1f056a8686aae4;p=pyshared.git

diff --git a/humidity.py b/humidity.py
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index 0000000..9e4d439
--- /dev/null
+++ b/humidity.py
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+#!/usr/bin/env python
+# -*- coding: iso-8859-15 -*-
+
+RS = 8314.3 # J/(kmol*K) universelle Gaskonstante
+MW = 18.016 # kg/kmol Molekulargewicht des Wasserdampfes
+
+# Openweathermap
+STATION=2911298
+API_ID="41ff32c10636d35b4c7a46000cb1a6a1"
+
+import urllib
+import json
+
+# Sättigungsdampfdruck in hPa
+def calc_saturation_vapor_pressure(temp_c):
+	if temp_c >= 0:
+		a = 7.5
+		b = 237.3
+	else:
+		a = 7.6
+		b = 240.7 
+	
+	return 6.1078 * 10**((a*temp_c)/(b+temp_c))
+
+
+# https://www.wetterochs.de/wetter/feuchte.html
+def calc_humidity_abs(temp_c, humdity_rel):
+	temp_k = temp_c + 273.15
+
+	# Dampfdruck in hPa
+	SDD = calc_saturation_vapor_pressure(temp_c)
+	DD = humdity_rel/100.0 * SDD
+	humidity_abs = 10**5 * MW/RS * DD/temp_k
+	return humidity_abs
+
+
+def calc_humidity_rel(temp_c, humidity_abs):
+	temp_k = temp_c + 273.15
+	SDD = calc_saturation_vapor_pressure(temp_c)
+	DD = humidity_abs*temp_k * RS / (10**5*MW)
+	
+	humdity_rel = DD/SDD*100
+	return humdity_rel
+
+def get_weather_current():
+	query = urllib.urlencode({'id': STATION, 'APPID': API_ID, 'lang': 'de'})
+	url = "http://api.openweathermap.org/data/2.5/weather?units=metric&%s" % query
+	response = urllib.urlopen(url)
+	results = response.read()
+	return json.loads(results)
+
+def check_ventilate(temp_indoor, humdity_rel_indoor):
+	dWeatherCurrent = get_weather_current()
+	temp_outdoor = dWeatherCurrent["main"]["temp"]
+	humdity_rel_outdoor = dWeatherCurrent["main"]["humidity"]
+
+	humdity_abs_indoor = calc_humidity_abs(temp_indoor, humdity_rel_indoor)
+	humdity_abs_outdoor = calc_humidity_abs(temp_outdoor, humdity_rel_outdoor)
+
+	print "Wassergehalt Innen: %.2f, Außen: %.2f" % (humdity_abs_indoor, humdity_abs_outdoor)
+	return humdity_abs_indoor - humdity_abs_outdoor
+
+
+if __name__ == "__main__":
+	check_ventilate(21, 50)