re: winter humidification wastes energy
18 nov 2004
gary r. lloyd wrote:
>>>at what outdoor dewpoint temperature do we need to start adding
>>>moisture in order to maintain our 70f and 40% rh?
>>when 160x0.075(wi-wo) < 0.0116, ie wo < wi - 0.000966 = 0.005319 and po
>>= 29.921/(0.62198/wo+1) = 0.2357 "hg and td = 9621/(17.863-ln(pi))-460
>>= 40.2 f.
>it seems that when outdoor temps start dipping below freezing at night,
>our options are to humidify or to accept lower indoor humidity.
i wonder why you wrote that. another option is air sealing to raise the rh.
btw, we've only discussed the outdoor dewpoint (vs. dry bulb) temperature.
>on the other hand, if our humidity drops below 40% before the outdoor
>temps drop below freezing at night, then we need to seal up the house.
air sealing is good in any case. "make it tight, and vent it right."