On 3 September 2013 23:54, Lucas González <lucas.gonzalez...@gmail.com> wrote: > Interested. Would evaporative cooling work _at all_ in humid climates?
If you are close to 100% humidity: no. In particular since you want to cool down the air, you need to look at the amount of humidity in the _target_ temperature range; if you already have a pretty humid climate, then this might already be oversaturated at the target temperature, so nothing can be evaporated more. Swamp coolers are only useful in dry climates. It is relatively simple: you really just need to calculate the partial gas pressure of water vapor in the given target temperature (colder air can hold less water), and how much more could 'fit in' given the dryness of the climate (how much water vapor is already there per m^3 and how much more you can add). This looks like a useful resource: http://www.engineeringtoolbox.com/water-vapor-saturation-pressure-air-d_689.html With that, you can calculate the amount of water you can evaporate into a given volume. Given the required target temperature and knowing how much heat energy is supplied every second (estimate energy intake by the yurt area in sun in Joule (<< 1000 J/(m^2 * s) (1000W energy of sun per m^2, but most of it is reflected with aluminum covered sheets, hence the 'much less than' sign) + number of people * 100 J/s (typical heat 'exhaust' of a human is 100W) and the amount of energy taken by the water->steam transition (2260 J/g water evaporation heat) - you can calculate the grams water you need to evaporate per time unit (to fit the energy bill) and flow rate (to keep the air dry enough to be able to take on this mass of water per time-unit). -h > Perhaps with some modifications? I think not but haven't tried. > Sleepbreeze.com.uk does seem to work, but that's one body, not one room. > > Thanks, > > Lucas > > El 04/09/2013 08:32, "ken winston caine" <ken.winston.ca...@gmail.com> > escribió: > >> David is right. You definitely need to have an exhaust vent. Swamp cooling >> cools by moisture evaporating in dry air -- not by creating increasingly >> swampy air. You must draw fresh dry air in, and let the moist air out. >> >> Since the moist, cooler air falls to the floor, it is best not to depend >> upon a roof exhaust vent. A mid-height window, or open door will do the >> trick. >> >> RE: your test. You didn't tell us WHERE, what region, you were conducting >> the test in. Were you in a region with 30% or less relative humidity? If so, >> your test would be a good indicator of the effectiveness of the evaporative >> cooling, once you have the intake and exhaust set up correctly. If you were >> in a higher humidity zone, there is no point in running the test. It simply >> won't give you any indication of how the evaporative cooling will work in >> low-humidity, desert conditions. >> >> Hope that helps. >> >> ken winston caine >> >> >> On Tue, Sep 3, 2013 at 11:41 PM, David Kelso <david+goo...@kelso.id.au> >> wrote: >>> >>> A swamp cooler needs to be constantly moving fresh air in, humid air >>> out in order to keep cool. So you should aim to have a directional >>> airflow path. It can go up to the roof, or out to the door. You need >>> to make sure the outlets are big enough that the fan isn't fighting >>> any extra pressure inside the yurt. An outlet fan would help with that >>> but isn't strictly necessary >>> >>> The major factor in swamp cooler effectiveness is fan speed. Which fan >>> were you using? >>> >>> For anecdotal evidence, last year I was in a 6ft stretch and was >>> getting at least 30 degree F cooling throughout the whole yurt. >>> >>> On Tue, Sep 3, 2013 at 10:19 PM, Jason Adams >>> <jasonadamspriv...@gmail.com> wrote: >>> > So I setup an H12, with two swamp coolers, with insulated ducts into >>> > opposite ends of my Yurt. Just cut a hole for the ducts. >>> > >>> > Its going to be hard to describe, but I still felt like the swamp >>> > coolers or >>> > the yurt wasn't really cooling much. I felt like being out in the sun, >>> > but >>> > in the breeze was way more cooling that in a h12 with two swamp coolers >>> > running. The airflow really close to the duct holes was nice, but once >>> > you >>> > got more than a foot away from duct, you didn't really feel it. >>> > >>> > It also felt hot inside, maybe thats just the moisture or sticky icky >>> > feeling you get from releasing that much moisture in the air. >>> > >>> > It's definitely nice not having the intense light on you, the yurt >>> > certainly >>> > kept alot of that sun off the ground , probably getting a cooling >>> > ground >>> > effect, but I feel like I was missing some comfort. >>> > >>> > I feel like my options are to basically vent the yurt, or do a fan >>> > exiting >>> > air at the top of the yurt. Which would ideally get more airflow in the >>> > yurt >>> > -- however I feel like that would lose some of the effect of the swamp >>> > cooling (after all I'm sealing the bottom to keep the cool air in >>> > right?). >>> > >>> > Maybe what I really needed was some type of airflow in the yurt, either >>> > up >>> > the power of the swamp cooling fans -- or hang a big fan from the top >>> > of the >>> > yurt. >>> > >>> > Just trying to figure out how to make this thing more comfortable, >>> > because I >>> > honestly felt cooler under a shade structure, with some pillows and the >>> > breeze coming through. >>> > >>> > Thoughts? >>> > >>> > -- >>> > You received this message because you are subscribed to the Google >>> > Groups >>> > "hexayurt" group. >>> > To unsubscribe from this group and stop receiving emails from it, send >>> > an >>> > email to hexayurt+unsubscr...@googlegroups.com. >>> > To post to this group, send email to hexayurt@googlegroups.com. >>> > Visit this group at http://groups.google.com/group/hexayurt. >>> > For more options, visit https://groups.google.com/groups/opt_out. >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "hexayurt" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to hexayurt+unsubscr...@googlegroups.com. >>> To post to this group, send email to hexayurt@googlegroups.com. >>> Visit this group at http://groups.google.com/group/hexayurt. >>> For more options, visit https://groups.google.com/groups/opt_out. >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "hexayurt" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to hexayurt+unsubscr...@googlegroups.com. >> To post to this group, send email to hexayurt@googlegroups.com. >> Visit this group at http://groups.google.com/group/hexayurt. >> For more options, visit https://groups.google.com/groups/opt_out. > > -- > You received this message because you are subscribed to the Google Groups > "hexayurt" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to hexayurt+unsubscr...@googlegroups.com. > To post to this group, send email to hexayurt@googlegroups.com. > Visit this group at http://groups.google.com/group/hexayurt. > For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups "hexayurt" group. 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