pressurizing a misting system...?
Brandon
has decided) that the patio needs a misting system.
I have held off simply because I find the systems that can be bought at HD
and the like are complete trash in my opinion. At least from what I have
seen installed around the area.
I seems to me that one could probably fabricate a decent looking system from
similar diameter copper tubing with the associated fittings. BUT the real
issue I think is the pressure behind the water. The water pressure here is
strong enough to produce an ok mist, I know that pumps can be purchased, but
at over $200, I wondered if there was another method?
Any thoughts? Could I use an electric pressure washer as a pump of sorts?
What I really want is a fog system, rather than a misting(dripping) system.
Any links to misting system parts suppliers?
Thanks
Brandon
m Ransley
water misted to provide cooling. If you start pushing pressure those
heads will wear out fast, Pressure washers have carbide heads that cost
20- 50 $ for good reason. And pressure washer heads wear out. PVC can
be hidden and painted . The HD stuff is cheap enough to experiment
with. Hook a head to a garden hose to experiment. Pump it and you may
get wet with the volume, you dont want to soak yourself, just evaporate
some water . Im sure areas that are large need pumps, so it depends on
sq footage you need to cool and the amount of heads.
There is an Electric fan sold with a mist head built in , you just hook
up a garden hose. Try placing one in front of a fan , I will bet it
cools real nice.
Jim2034204
>up a garden hose.
Recently saw them listed in one of my garden mag on sale. If op interested I
could see if i could find it.
RICARDO AQUINO
and check out a couple of the pages that follow.
Rich
http://www.new-garage-door-parts.com
"Brandon" <bnd...@cox.netthefish> wrote in message
news:JjeBc.66566$%T.21648@okepread05...
wayne
well there are fly spry systems for barns that do a really nice fine mist
the secret is the misting heads they have a spring inside so that they don't
start to mist until the pressure builds up,
Also they have a fine filter so the heads don't clog.
You may be able to find a system used or just purchase a small system.
What makes these systems nice is that they have a timer for how often it
mists and how long it mists.
Wayne
"RICARDO AQUINO" <atre...@verizon.net> wrote in message
news:jKhBc.8425$U.2...@nwrdny02.gnilink.net...
Jeff Cochran
wrote:
>Well, after 5 years in the AZ heat I have decided( rather the better half
>has decided) that the patio needs a misting system.
>I have held off simply because I find the systems that can be bought at HD
>and the like are complete trash in my opinion. At least from what I have
>seen installed around the area.
>I seems to me that one could probably fabricate a decent looking system from
>similar diameter copper tubing with the associated fittings. BUT the real
>issue I think is the pressure behind the water. The water pressure here is
>strong enough to produce an ok mist, I know that pumps can be purchased, but
>at over $200, I wondered if there was another method?
Most commercial misting systems work fine on water pressure, 25-35
PSI.
>Any thoughts? Could I use an electric pressure washer as a pump of sorts?
Bleh! Use a commercial misting system. Most of the drip irrigation
suppliers also have mist emitters for cooling.
>What I really want is a fog system, rather than a misting(dripping) system.
>Any links to misting system parts suppliers?
Google turns up dozens of links:
http://www.littlegreenhouse.com/accessory/mist.shtml
http://www.mrdrip.com/mistingsystems.htm
http://www.berryhilldrip.com/ArizonaMist.htm
And so on...
Jeff
Wayne
news:JjeBc.66566$%T.21648@okepread05:
If you're trying to compare what you may have experienced in commercial
environments like restaurant patios, country clubs, etc., there _is_ no
comparison to the typical equipment sold for home use by Home Depot,
Lowes, etc. Having already been through this, I can tell you from
experience.
The equipment marketed for homes will only produce a so-called "mist"
that is not much finer than a misty rain. The droplets from these
systems not only cool you a bit, but also make you wet.
We installed such a system on our 15 x 35 foot covered patio. We bought
the best system that Home Depot offered, including the pressure pump.
The overall cost was around $450.00. Although we felt cooler, we were
also much wetter, and it was an overall disappointment. Even though we
use filtered water for the feed, the mist continually deposited a mineral
haze on every surface it landed on.
Two years later we made a much larger investment in a commercial misting
system, professionally installed. The pump operates at more than 10
times the pressure of the old system, pumping through copper lines to
bronze misting heads with orifices fine enough to produce clouds of vapor
rather than "rain". The overall effect is incredible. This system cools
the patio at 15 degrees lower than the surrounding temperature, ofen
more. There is no "wetting" of people or surfaces, and no mineral
deposits left on surfaces.
Consider your choices well.
--
Wayne in Phoenix
If there's a nit to pick, some nitwit will pick it.
nicks...@ece.villanova.edu
>The equipment marketed for homes will only produce a so-called "mist"
>that is not much finer than a misty rain. The droplets from these
>systems not only cool you a bit, but also make you wet.
Tap-water in $5 Mister Misters seems frugal...
>...we made a much larger investment in a commercial misting
>system, professionally installed. The pump operates at more than 10
>times the pressure of the old system, pumping through copper lines to
>bronze misting heads with orifices fine enough to produce clouds of vapor
>rather than "rain".
I think you mean "smaller droplets." If it really produced water vapor,
it wouldn't cool at all.
>...This system cools the patio at 15 degrees lower than the surrounding
>temperature, ofen more. There is no "wetting" of people or surfaces,
>and no mineral deposits left on surfaces.
Do you believe that a gallon per hour evaporating from "clouds of vapor"
produces more coolth than a gallon per hour evaporating from a concrete
patio? Where do your minerals go?
Nick
m Ransley
Wayne
news:cb6ku0$l...@acadia.ece.villanova.edu:
> Wayne <way...@att.net> wrote:
>
>>The equipment marketed for homes will only produce a so-called "mist"
>>that is not much finer than a misty rain. The droplets from these
>>systems not only cool you a bit, but also make you wet.
>
> Tap-water in $5 Mister Misters seems frugal...
Whatever floats your boat. It wouldn't float mine.
>>...we made a much larger investment in a commercial misting
>>system, professionally installed. The pump operates at more than 10
>>times the pressure of the old system, pumping through copper lines to
>>bronze misting heads with orifices fine enough to produce clouds of
>>vapor rather than "rain".
>
> I think you mean "smaller droplets." If it really produced water
> vapor, it wouldn't cool at all.
That's all vapor is...smaller droplets.
>>...This system cools the patio at 15 degrees lower than the
>>surrounding temperature, ofen more. There is no "wetting" of people
>>or surfaces, and no mineral deposits left on surfaces.
>
> Do you believe that a gallon per hour evaporating from "clouds of
> vapor" produces more coolth than a gallon per hour evaporating from a
> concrete patio? Where do your minerals go?
Absolutely! Water evaporating from a patio floor is clearly not going to
have a significant cooling effect 5-6 feet above the surface. While the
net effects of each gallon may be equal technically, the perceived effect
is radically different between the two.
>
> Nick
>
>
Do you have a personal problem with mist?
Wayne
3132.bay.webtv.net:
> Wayne you found your nitpicker
You're so right! :-)
He obviously has no clue what powered misting systems are all about.
nicks...@ece.villanova.edu
>>>...we made a much larger investment in a commercial misting
>>>system, professionally installed. The pump operates at more than 10
>>>times the pressure of the old system, pumping through copper lines to
>>>bronze misting heads with orifices fine enough to produce clouds of
>>>vapor rather than "rain".
>>
>> I think you mean "smaller droplets." If it really produced water
>> vapor, it wouldn't cool at all.
>
>That's all vapor is...smaller droplets.
Common matter comes in solid, liquid, and vapor phases. Vapor contains
no liquid--no droplets and no latent cooling power. You can't see vapor.
Clouds are not vapor. High pressure systems make smaller droplets that
evaporate faster because they have a higher surface to volume ratio and
a higher vapor pressure, so we don't get as much liquid on the floor...
>>>...This system cools the patio at 15 degrees lower than the
>>>surrounding temperature, ofen more. There is no "wetting" of people
>>>or surfaces, and no mineral deposits left on surfaces.
Where do the minerals go?
>> Do you believe that a gallon per hour evaporating from "clouds of
>> vapor" produces more coolth than a gallon per hour evaporating from
>> a concrete patio? Where do your minerals go?
>Absolutely! Water evaporating from a patio floor is clearly not going to
>have a significant cooling effect 5-6 feet above the surface.
"Clearly," eh? :-) I disagree, altho some of the floor water may be
wasted, if misting isn't continuous, even for shaded floors.
>While the net effects of each gallon may be equal technically,
>the perceived effect is radically different between the two.
Water on the floor makes cool air that is less easily blown away in
a wind. And radiant temperature is more important to comfort than
air temp. Misting people (making wet clothing) cools even better.
Low-pressure systems are simpler and cheaper, altho it's nice to
see all the water that falls on a floor evaporate, with no runoff.
>Do you have a personal problem with mist?
No. Seems like a good idea, altho less wasteful if done indoors, with
a vent fan to provide outdoor air. This works like a swamp cooler,
when 4500(wi-wo) > To-Ti. The left-hand side is the amount of latent
cooling per cfm of vent air. The right is the amount of sensible
heating per cfm of vent air. As they become equal, swamp cooling and
misting no longer work.
The ASHRAE comfort chart has an efficient corner at Ti = 78.5 F and
wi = 0.0126 pounds of water per pound of dry air, which makes the
equation above To < 135.2-4500wo. NREL says Phoenix has an average
wo = 0.0056 in June, so indoor misting should help until the outdoor
temp rises to 135.2-4500(0.0056) = 110 F, on an average day.
For optimal ventilation, a house with a 200 Btu/h-F conductance that's
78.5 F indoors with wi = 0.0126 when it's 100 F and wo = 0.0056 outdoors
needs about 1000x60C0.075(0.0126-0.0056) = (100-78.5)(200+C) Btu/h of
cooling, including cooling C cfm of outdoor air from 100 to to 78.5 F.
So C = 430 cfm, with 60C0.075(0.0126-0.0056) = 13.5 pounds or 1.6 gallons
per hour (or "1.1 tons" :-) of water... from 4 $5 0.5 gph Mister Mister
nozzles and a solenoid valve scrounged from an old washing machine in
series with a 78.5 F room temp thermostat and a $5 humidistat that turns
on a $12 window box fan when the RH rises to 60%.
Pw = 0.996 "Hg at 78.5 F and 100% RH, and Pi = 0.594 "Hg with wi = 0.0126.
ASHRAE says a square foot of pool evaporates 100(Pw-Pi) = 40 Btu/h, so we
can evaporate 13.5 pounds of water per hour with 13.5/40 = 336 ft^2 of
interior surface, not counting droplets in air. Masonry floors and walls
or indoor cylindrical rock gabions with fountain pumps have high thermal
conductance and mass that can allow more efficient cooling at night and
keep the house cool with the fan off during the heat of the day.
Nick
Need an answer or a method for figuring which window, insulation, heating
system, etc to use? Ask us.
Join solar guru Steve Baer and PE Drew Gillett and PhD Rich Komp and
me for an all-day workshop on solar house heating and natural cooling
strategies ("HVAC Nonsense") on July 9 in Portland, OR--see page 25 of
http://www.ases.org/conferences/2004_call_for_papers/SOLAR2004_prelim_program.pdf
Jeff Cochran
>> vapor, it wouldn't cool at all.
>
>That's all vapor is...smaller droplets.
Water vapor is the gaseous form of what you normally see liquid. Ice
would be the solid. The "cooling" effect comes from the transference
of heat into the energy required to evaporate the liquid, transforming
the liquid to a gaseous state.
No, vapor doesn't cool.
>> Do you believe that a gallon per hour evaporating from "clouds of
>> vapor" produces more coolth than a gallon per hour evaporating from a
>> concrete patio? Where do your minerals go?
>
>Absolutely! Water evaporating from a patio floor is clearly not going to
>have a significant cooling effect 5-6 feet above the surface. While the
>net effects of each gallon may be equal technically, the perceived effect
>is radically different between the two.
Actually, the effect of water evaporating off concrete is identical.
The comfort and convenience is far from it. Water evaporating off
your body (called sweat) also cools, but is even less convenient or
comfortable.
Jeff
nicks...@ece.villanova.edu
when 4500(wi-wo)>To-Ti. The left side is the amount of latent cooling per
cfm of vent air. The right is the amount of sensible heating per cfm of
vent air. As they become equal, swamp cooling and misting no longer work.
The ASHRAE comfort zone has an efficient corner at Ti = 78.5 F and
wi = 0.0126 (about 60% RH), which makes To < 135.2-4500wo. NREL says
Phoenix has an 88.2 F average temp in June, with an average daily min
and max of 72.9 and 103.5 and average humidity ratio wo = 0.0056 pounds
of water per pound of dry air in June, so misting should help until
the outdoor temp rises to To = 135.2-4500(0.0056) = 110 F.
Evaporating a pound of water takes about 1000 Btu, and air weighs about
0.075 lb/ft^3, so a house with no internal heat gain or unshaded windows
and a 200 Btu/h-F conductance that's 78.5 F indoors with wi = 0.0126 when
it's 88.2 F and wo = 0.0056 outdoors needs about 1000x60C0.075(0.0126-0.0056)
= 31.5C = (88.2-78.5)(200+C) Btu/h of cooling, including cooling C cfm of
air from 88.2 to 78.5, so C = 89 cfm (not much), with 4.5C(0.0126-0.0056)
= 2.8 pounds or 0.34 gallons of water per hour, which might come from a $5
0.5 gph Mister Mister nozzle and a solenoid valve scrounged from an old
washing machine in series with a 78.5 F room temp thermostat and a $5
humidistat that turns on a $12 window box fan when the RH rises to 60%.
Herbach and Rademan (800) 848-8001 http://www.herbach.com sell a nice
brass $4.95 Navy surplus humidistat, item number TM89HVC5203, with a
20-80% range, a 3-6% differential, and a 7.5A 125V switch that can be
wired to open or close on humidity rise.
Pw = 0.996 "Hg at 78.5 F and 100% RH, and Pi = 0.594 "Hg with wi = 0.0126.
ASHRAE says a square foot of pool evaporates 100(Pw-Pi) = 40 Btu/h, so we
can evaporate 2.8 pounds of water per hour with 2800/40 = 70 ft^2 of wet
surface, counting droplets in air. Masonry floors and walls or an indoor
cylindrical rock gabion with a fountain pump (in a toilet tank?) with high
thermal conductance and mass might allow more efficient cooling with cooler
night air and keep the mass of the house cool with the fan off during
the heat of the day.
Nick
Tired of Iraq? Do something about it. Learn to halve your energy use
while having fun with math and science.
Join solar guru Steve Baer and PE Drew Gillett and PhD Rich Komp and me
for an all-day workshop on new solar house heating and natural cooling
Wayne
news:cb8lrl$m...@acadia.ece.villanova.edu:
> Wayne <way...@att.net> wrote:
>
>>>>...we made a much larger investment in a commercial misting
>>>>system, professionally installed. The pump operates at more than 10
>>>>times the pressure of the old system, pumping through copper lines
>>>>to bronze misting heads with orifices fine enough to produce clouds
>>>>of vapor rather than "rain".
>>>
>>> I think you mean "smaller droplets." If it really produced water
>>> vapor, it wouldn't cool at all.
>>
>>That's all vapor is...smaller droplets.
>
> Common matter comes in solid, liquid, and vapor phases. Vapor contains
> no liquid--no droplets and no latent cooling power. You can't see
> vapor. Clouds are not vapor. High pressure systems make smaller
> droplets that evaporate faster because they have a higher surface to
> volume ratio and a higher vapor pressure, so we don't get as much
> liquid on the floor...
Funny, most of the commercial "mist" companies refer to producing "clouds
of water vapor". I am not a scientist, nor do I play one when I post to
Newsgroups. However, I do know what has worked in our situation and what
has not.
>>>>...This system cools the patio at 15 degrees lower than the
>>>>surrounding temperature, ofen more. There is no "wetting" of people
>>>>or surfaces, and no mineral deposits left on surfaces.
>
> Where do the minerals go?
Beat the s#$@ out of me! All I know is that I don't see it with the high
pressure mist system whereas everything on our patio was covered with it
from the low-pressure system.
>
>>> Do you believe that a gallon per hour evaporating from "clouds of
>>> vapor" produces more coolth than a gallon per hour evaporating from
>>> a concrete patio? Where do your minerals go?
>
>>Absolutely! Water evaporating from a patio floor is clearly not going
>>to have a significant cooling effect 5-6 feet above the surface.
>
> "Clearly," eh? :-) I disagree, altho some of the floor water may be
> wasted, if misting isn't continuous, even for shaded floors.
The only positive effect a wet floor has is cooling my bare feet, which
definitely has its advantages. The air at body and head level never
feels cooler to me from a wet floor. Certainly a misting system has to
be continuous to perform its function.
The bottom line is that comfort is a perception. If it doesn't feel
good, it isn't of any comfort value.
>>While the net effects of each gallon may be equal technically,
>>the perceived effect is radically different between the two.
>
> Water on the floor makes cool air that is less easily blown away in
> a wind. And radiant temperature is more important to comfort than
> air temp. Misting people (making wet clothing) cools even better.
> Low-pressure systems are simpler and cheaper, altho it's nice to
> see all the water that falls on a floor evaporate, with no runoff.
What you say may be true, but it doesn't satisfy my need and I don't like
the effect. Copious amounts of mist/vapor produced by a high-pressure
system is far more satisfying to me and to most people I know who live
here (AZ).
>
>>Do you have a personal problem with mist?
>
> No. Seems like a good idea, altho less wasteful if done indoors, with
> a vent fan to provide outdoor air. This works like a swamp cooler,
> when 4500(wi-wo) > To-Ti. The left-hand side is the amount of latent
> cooling per cfm of vent air. The right is the amount of sensible
> heating per cfm of vent air. As they become equal, swamp cooling and
> misting no longer work.
To me, this is an entirely different area and of no interest. I won't
and can't argue the point about the effectiveness of swamp coolers.
However, regardless of cost, I would never choose one over a properly-
sized and installed central air conditioner. I want and need the air in
my house to be both cooler an drier than a swamp cooler is capable of.
The few times I've wandered into a store using a swamp cooler, my
immediate reaction is...ugh, sticky!
> The ASHRAE comfort chart has an efficient corner at Ti = 78.5 F and
> wi = 0.0126 pounds of water per pound of dry air, which makes the
> equation above To < 135.2-4500wo. NREL says Phoenix has an average
> wo = 0.0056 in June, so indoor misting should help until the outdoor
> temp rises to 135.2-4500(0.0056) = 110 F, on an average day.
>
> For optimal ventilation, a house with a 200 Btu/h-F conductance that's
> 78.5 F indoors with wi = 0.0126 when it's 100 F and wo = 0.0056
> outdoors needs about 1000x60C0.075(0.0126-0.0056) = (100-78.5)(200+C)
> Btu/h of cooling, including cooling C cfm of outdoor air from 100 to
> to 78.5 F. So C = 430 cfm, with 60C0.075(0.0126-0.0056) = 13.5 pounds
> or 1.6 gallons per hour (or "1.1 tons" :-) of water... from 4 $5 0.5
> gph Mister Mister nozzles and a solenoid valve scrounged from an old
> washing machine in series with a 78.5 F room temp thermostat and a $5
> humidistat that turns on a $12 window box fan when the RH rises to
> 60%.
>
> Pw = 0.996 "Hg at 78.5 F and 100% RH, and Pi = 0.594 "Hg with wi =
> 0.0126. ASHRAE says a square foot of pool evaporates 100(Pw-Pi) = 40
> Btu/h, so we can evaporate 13.5 pounds of water per hour with 13.5/40
> = 336 ft^2 of interior surface, not counting droplets in air. Masonry
> floors and walls or indoor cylindrical rock gabions with fountain
> pumps have high thermal conductance and mass that can allow more
> efficient cooling at night and keep the house cool with the fan off
> during the heat of the day.
>
> Nick
Perhaps I should send you some more nits to pick! :-))