swamp coolers
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This will be boring for some.
If you find it interesting, go to that second link and read the rest of it!
The first link has a somewhat-animated diagram.
<< BTW, what is a swamp cooler? >>
http://www.adobeair.com/coolers/evap_cooling.htm
http://www.ci.phoenix.az.us/WATER/evapcool.html
Background
Evaporative cooling is one of the most ancient and one of the most
energy-efficient methods of cooling a home. It long has been regarded as
environmentally "safe," since the process typically uses no ozone-depleting
chemicals, and demands one-fourth as much energy as refrigeration during the
peak cooling months of the year. In dry climates, evaporative cooling, even
the relatively inefficient "swamp box" household cooler, can be used to
inexpensively cool large homes.
Direct evaporative cooling adds moisture to the air. In wet climates, or
during the late summer rainy season in the desert, this results in
uncomfortable and, for many individuals, unacceptable indoor humidity. In
Phoenix, those who have the option to choose between evaporative cooling and
refrigeration usually switch systems during July and do not go back to
evaporative cooling until mid-September. Indirect evaporative cooling,
without added humidity, is less effective, costs more, and if not used
properly, can cause damage to refrigeration systems.
The most common form of residential evaporative cooling uses a vertical pad
of cellulose fiber, a system for delivering water to the top of the pad, and
a fan to draw air through the porous pad as the water runs down the medium
and is absorbed. As dry air moves over the wet pad, water evaporates, and the
air gives up its heat. The air moving from the wet pad into the home is
cooler than the outdoor air. Where water is high in mineral content, a
bleed-off system often is used on the water circulation system, constantly
dumping part of the water and allowing the refill valve to replace it with
fresh water. This decreases the mineral build-up on the pads and on the
inside of the cooler, but at a 25 to 50 percent increase in water use.
The drop in temperature depends on how much water the air can absorb (a
function of the relative humidity), how evenly the pad media is wetted, and
how long the air is exposed to the pad (a factor of turbulence, wetness, and
speed of air movement), the evaporability of the water (both temperature and
hardness of the water affect this), and the ability of the building to "vent"
warmer exhaust air back to the atmosphere.
There is general agreement, even among domestic manufacturers, that U.S.-made
evaporative coolers are not as energy- or water-efficient as they could be.
These products are targeted heavily to middle-, lower-middle-, and low-income
households, and appear to be designed against a one- to two-year capital
payback, rather than optimum operational efficiency. Operating savings in
both water and energy, as well as in maintenance costs, often fall victim to
production of price-competitive units.
Inefficiencies in less expensive units include: under-powered, inexpensive
aluminum-wound fan motors rather than more energy-efficient, larger
copper-wound motors; recirculating pumps that run faster and hotter than
necessary to compensate for a lack of volume capacity; fans that run up to 20
percent over design capacity to move larger volumes of air at increased
velocity to make up in wind movement what is lost in evaporative efficiency.
Slower movement of air through a thicker pad medium, adequately wetted by a
properly sized pump, all contained within a high-reflectivity cabinet, and
with all components operating at voltages higher than the usual household
current, would result in energy and water savings as well as a longer-lived
cooler and a more cost-effective long-term investment.
If you find it interesting, go to that second link and read the rest of it!
The first link has a somewhat-animated diagram.
<< BTW, what is a swamp cooler? >>
http://www.adobeair.com/coolers/evap_cooling.htm
http://www.ci.phoenix.az.us/WATER/evapcool.html
Background
Evaporative cooling is one of the most ancient and one of the most
energy-efficient methods of cooling a home. It long has been regarded as
environmentally "safe," since the process typically uses no ozone-depleting
chemicals, and demands one-fourth as much energy as refrigeration during the
peak cooling months of the year. In dry climates, evaporative cooling, even
the relatively inefficient "swamp box" household cooler, can be used to
inexpensively cool large homes.
Direct evaporative cooling adds moisture to the air. In wet climates, or
during the late summer rainy season in the desert, this results in
uncomfortable and, for many individuals, unacceptable indoor humidity. In
Phoenix, those who have the option to choose between evaporative cooling and
refrigeration usually switch systems during July and do not go back to
evaporative cooling until mid-September. Indirect evaporative cooling,
without added humidity, is less effective, costs more, and if not used
properly, can cause damage to refrigeration systems.
The most common form of residential evaporative cooling uses a vertical pad
of cellulose fiber, a system for delivering water to the top of the pad, and
a fan to draw air through the porous pad as the water runs down the medium
and is absorbed. As dry air moves over the wet pad, water evaporates, and the
air gives up its heat. The air moving from the wet pad into the home is
cooler than the outdoor air. Where water is high in mineral content, a
bleed-off system often is used on the water circulation system, constantly
dumping part of the water and allowing the refill valve to replace it with
fresh water. This decreases the mineral build-up on the pads and on the
inside of the cooler, but at a 25 to 50 percent increase in water use.
The drop in temperature depends on how much water the air can absorb (a
function of the relative humidity), how evenly the pad media is wetted, and
how long the air is exposed to the pad (a factor of turbulence, wetness, and
speed of air movement), the evaporability of the water (both temperature and
hardness of the water affect this), and the ability of the building to "vent"
warmer exhaust air back to the atmosphere.
There is general agreement, even among domestic manufacturers, that U.S.-made
evaporative coolers are not as energy- or water-efficient as they could be.
These products are targeted heavily to middle-, lower-middle-, and low-income
households, and appear to be designed against a one- to two-year capital
payback, rather than optimum operational efficiency. Operating savings in
both water and energy, as well as in maintenance costs, often fall victim to
production of price-competitive units.
Inefficiencies in less expensive units include: under-powered, inexpensive
aluminum-wound fan motors rather than more energy-efficient, larger
copper-wound motors; recirculating pumps that run faster and hotter than
necessary to compensate for a lack of volume capacity; fans that run up to 20
percent over design capacity to move larger volumes of air at increased
velocity to make up in wind movement what is lost in evaporative efficiency.
Slower movement of air through a thicker pad medium, adequately wetted by a
properly sized pump, all contained within a high-reflectivity cabinet, and
with all components operating at voltages higher than the usual household
current, would result in energy and water savings as well as a longer-lived
cooler and a more cost-effective long-term investment.
Karin
We have a swamp/evaporative cooler.
We turn it on somewhere around mid-April when the temps start getting warm.
Then we switch to A/C usually around July when the monsoon season starts and
the dewpoint goes up.
The advantage over using a swamp cooler vs. A/C for cooling is cost.
It's much less expensive to run a cooler, and the only working parts
involved are a fan and a pump.
When the dewpoint goes above 55 degrees, that's when the cooler is no longer
effective, and it's just blowing hot, moist air in the house.
Right now in Phoenix, it's still dry and yesterdays dewpoint was 14 degrees!
Our cooler is still working great and even though it's been around 110+
degrees lately, it's still fairly comfortable in the house even in the heat
of the day.
I'm so glad we have the option of using a cooler.
Many of the newer houses these days (especially those red-tiled roof houses)
are strictly A/C.
Some people view having and using a cooler as something the "lower class" of
people use because even if poor people here don't have an A/C unit,
practically EVERYBODY has a cooler to use, even if they live in a shack.
I don't care, though, I love our cooler and use it proudly!
Karin in hot AZ
We turn it on somewhere around mid-April when the temps start getting warm.
Then we switch to A/C usually around July when the monsoon season starts and
the dewpoint goes up.
The advantage over using a swamp cooler vs. A/C for cooling is cost.
It's much less expensive to run a cooler, and the only working parts
involved are a fan and a pump.
When the dewpoint goes above 55 degrees, that's when the cooler is no longer
effective, and it's just blowing hot, moist air in the house.
Right now in Phoenix, it's still dry and yesterdays dewpoint was 14 degrees!
Our cooler is still working great and even though it's been around 110+
degrees lately, it's still fairly comfortable in the house even in the heat
of the day.
I'm so glad we have the option of using a cooler.
Many of the newer houses these days (especially those red-tiled roof houses)
are strictly A/C.
Some people view having and using a cooler as something the "lower class" of
people use because even if poor people here don't have an A/C unit,
practically EVERYBODY has a cooler to use, even if they live in a shack.
I don't care, though, I love our cooler and use it proudly!
Karin in hot AZ
>box
> << BTW, what is a swamp cooler? >>
>
> Evaporative cooler.
>
> A box with a cage-fan (? a drum fan about 2 feet across) in a box. The
> has pads with cellulose fibers that air can pass through. There's a pumpin
> the base of it that pumps water up onto those pads. The fan turns, drawsair
> in through the wet pads and that cools the air which blows into the house.further
>
> In New Mexico, they're usually mounted on the roof.
> In West Texas, they're in a window, and they plant vines on them to
> cool the whole situation.blowing
>
> We have two at our house.
>
> It seems stupid to people in humid places, I know, but it's truly dry here
> and just blowing hot dry air into the house would be worse than not
> at all.can
>
> Probably what's on the ceiling, now that I think about it, is smoke/soot.
> Maybe not, but maybe. Slight.
>
> It's hazy here today. It looks kind of wintery. I can't see a mile, and
> usually see ten. But straight up, the sky is blue. It's gunk from forest
> fires, and they're not even nearby here.
>
> Sandra