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re: evaporative cooler question
15 jan 2005
rich wrote:
>> >>a las vegas homeowner might do better with sam's portable 797895 arctic
>> >>breeze cooler mounted inside a house near an open low window and
>that unit may be able to cool a 9 x 9 room. not much more than that.
you have my numbers. would you have any evidence for your article of faith?
>> >you can't recycle the air in the house. you have to get rid of the moist
>> >air as it will not cool.
>> that's what the exhaust fan does, controlling the indoor rh precisely with
>> a humidistat, vs a swamp cooler without a humidistat.
>but the air is already quite humid when it enters the house.
think "portable swamp cooler, indoors."
>> >>turn on the cooler when the house temp reaches 80 f and turn on the
>> >>exhaust fan when the rh reaches 60% to keep the house air at the upper
>> >>right corner (80 f and w = 0.012) of the ashrae 55-2004 comfort zone.
>
>for an average good cooler pulling in 110 degree air at 10% humidity will
>lower the temperature to 80 degrees.
think "portable swamp cooler, indoors."
>the exhaust fan is working all the time if that dinky portable cooler
>can handle the load.
you have my numbers. would you have any evidence for your article of faith?
>> >> keeping that house 80 f while evaporating p lb/h of water into c cfm of
>> >> outdoor air means 1000p = (91.1-80)(128+c). p = 60c(0.075)(0.012-0.0066)
>> >> = 0.0243c makes c = 108 cfm and p = 2.62 lb/h, ie 7.6 gallons per day.
>> >> if the house has significant thermal mass (eg a floorslab), we can save
>> >> more water and energy by only running the cooler at night.
nick
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