Water Misting System Questions

[jaideeguy]

In my quest to cool the outside kitchen from this d*mn hot summer, I recently visited a local irrigation shop that had the following 2 options.

1] a low pressure system that I went for that gives a decent mist from my small pressure of 6 meter elevated water tanks with 3 15thb plastic mister outlets…..but not enough to make much cooling effect even with a fan behind it blowing the mist in the desired direction, but only wets the floor. Total cost …..less than 200thb. Water consumption….. 7.5 liter/hr/per emitter

2] a high pressure pump system with expensive HP pump and brass fittings that puts out a much finer mist that doesn’t wet the floor and is noticeably cooler on the demonstration unit. Total cost 15,000thb [including the 11,000thb pump and 25 mtrs with emitters spaced at .5 meters]. Water consumption….1.5 liter/hr/per emitter.

One super cheap and the other super expensive and makes me wonder if there are any cheaper options to the high pressure pump systems.…maybe a smaller HP pump that would push 5 or 6 emitters??

And does anyone have one of these high pressure systems and can say with certainty that it will actually lower the air temp in our outside kitchen without getting everything wet??

A thought came to my mind that maybe a pump from a high pressure cleaner could generate enough pressure to use the high pressure emitters?? But my pressure washer is quite noisy.

Edited April 22, 2012 by lopburi3
correct font

[sirineou]

The high preasure system is the only one that will make any difference. We had this type of system in Florida and it made a significant difference there. The mist has to be fine enough to evaporate, as it evaporates it removes thermal energy from the air, much in the same way that when alcohol evaporates on your arm, it removes heat from your arm an you feel cool. .

[P76]

There is a pub near my place in Australia that has a high pressure misting system in their outdoor area. It works well, noticeably cooler and nobody gets wet. The system is on a timer and it goes off 4 or 5 times a minute for a few seconds each time.

[jaideeguy]

There is a pub near my place in Australia that has a high pressure misting system in their outdoor area. It works well, noticeably cooler and nobody gets wet. The system is on a timer and it goes off 4 or 5 times a minute for a few seconds each time.

yeah, that's the kind that I'm looking for and I have seen these systems both here in LOS and Philippines. It's the high pressure that makes the mist fine enough to not get you wet, but cool you off, but would like to find a smaller unit for home use, as stated in my OP. 15kthb is a bit too much.

[doggie888888]

I always thought that these don't work too well in high humidity (works better in dry heat or lower humidity than these days)? No matter how fine the mist, it adds to the already moisture laden air, so evaporation from your skin (the cooling effect) is limited or slowed right down, so you end up feeling somewhat hot, damp and bothered which is far worse than just a normal high speed fan. I may be wrong?

[necronx99]

TYou could try these, but probably out of your range. http://www.tropicalmistsystems.biz/p&s.htm

Or these

[bankruatsteve]

Yah, I'm guessing you need < 40% rel. humidity for these things to "feel good". Same as the "swamp coolers" commonly used in the desert regions in the states as (good) alternative to A/C.

[jaideeguy]

Yesterday I saw a med large 'Astina' mister fan in Big C in CM for 5,900thb and may take a gamble on that if anyone can give a decent consumers report on it. It had one [or possibly 2] mister and a resevior of approx 10liter

Anyone tried it??

[sirineou]

I always thought that these don't work too well in high humidity (works better in dry heat or lower humidity than these days)? No matter how fine the mist, it adds to the already moisture laden air, so evaporation from your skin (the cooling effect) is limited or slowed right down, so you end up feeling somewhat hot, damp and bothered which is far worse than just a normal high speed fan. I may be wrong?

I have seen these systems in Florida , my home state in the US, places like Disney World, ,and Universal studios use it, I also have seen it at the Daytona flea Market, all high humidity areas, and it worked very well in all these areas, I will certainly consider such a system when I am finished with my place in KKC.

[necronx99]

The systems are not ideal for > 60 or 70 % humidity, the efficientcy drops off but theystill do make a difference. I've seen/felt them at teh races and also in some markets. They are somewhat refreshing.

[dave111223]

If you already have a water pump for your house can't you just hook the misting pipes right into your house water pipes? Or is the pressure not high enough?

Also does the water for these systems need to be cooled, or it can just use standard room temp. water and still works ok?

[jaideeguy]

If you already have a water pump for your house can't you just hook the misting pipes right into your house water pipes? Or is the pressure not high enough?

Also does the water for these systems need to be cooled, or it can just use standard room temp. water and still works ok?

What I learned as stated in my OP is that are basically 2 types [that I know of]....the low pressure that produces smaller droplets that wet the floor and other things that are within range. I have a short run of 4 emitters at low pressure and they are cool to stand under, but it quickly gets you wet.

Then there is the high pressure types that require a much more expensive pump and fittings, but put out a finer mist that doesn't wet surfaces, but cools the surrounding area.

As to the incomming water temp.....no problem with ambient temp water, as it's the evaporation effect that cools you and the air around you.

[bmore99]

Putting it in the Thai kitchen? Be careful with water getting into the cooking oil...

[sirineou]

If you already have a water pump for your house can't you just hook the misting pipes right into your house water pipes? Or is the pressure not high enough?

Also does the water for these systems need to be cooled, or it can just use standard room temp. water and still works ok?

The way I understand it from what I read ( http://www.coolingline.com/evaporative-cooling.html ) the water has to be pressurized to a minimum of 100 psi and as much as 1,000 psl and forced trough a special nozzle that produces a water droplet no larger then 50 microns. This produces a fine smoke like fog that evaporates almost immediately.

[thunder30101]

Coming from arizona and using misters and evaporative home cooling systems (no ac bills) all of my time there once the humidity level goes above 3-5% they are worthless. Your mind seeing the water mist just makes you think you are cooler. But hey if spending 6k B on getting sprayed with water makes you feel good go for it.

[Naam]

Coming from arizona and using misters and evaporative home cooling systems (no ac bills) all of my time there once the humidity level goes above 3-5% they are worthless. Your mind seeing the water mist just makes you think you are cooler. But hey if spending 6k B on getting sprayed with water makes you feel good go for it.

basically you are right except that humidity levels of 3-5% can only be achieved in laboratories with high-tech equipment. even in Arizona and Nevada relative humidity hardly ever drops below 35%.

[bankruatsteve]

Coming from arizona and using misters and evaporative home cooling systems (no ac bills) all of my time there once the humidity level goes above 3-5% they are worthless. Your mind seeing the water mist just makes you think you are cooler. But hey if spending 6k B on getting sprayed with water makes you feel good go for it.

basically you are right except that humidity levels of 3-5% can only be achieved in laboratories with high-tech equipment. even in Arizona and Nevada relative humidity hardly ever drops below 35%.

Not sure where you got that but a normal summer afternoon in Palm Springs is usually below 20% rel. humidity and would think most of the dersert areas the same.

[thunder30101]

Somewhere like this, You are not thinking in real terms. http://en.wikipedia.org/wiki/Relative_humidity

[bankruatsteve]

Somewhere like this, You are not thinking in real terms. http://en.wikipedia....lative_humidity

Huh? In what real terms am I not thinking?

[Naam]

Somewhere like this, You are not thinking in real terms. http://en.wikipedia....lative_humidity

Huh? In what real terms am I not thinking?

the calculation of relative humidity is not only based on actual humidity but also dependent on temperature and "vapour" pressure. that's why "relative" as opposed to "absolute" humidity is used. i lived in extremely dry places (Riyadh and Baghdad) where instruments showed 20-25% sometimes and one did not need a towel when stepping out of the shower or the pool.

[jaideeguy]

My 'instrument' here reads 60% humidity and we haven't had a rain in over a month.

[bankruatsteve]

Somewhere like this, You are not thinking in real terms. http://en.wikipedia....lative_humidity

Huh? In what real terms am I not thinking?

the calculation of relative humidity is not only based on actual humidity but also dependent on temperature and "vapour" pressure. that's why "relative" as opposed to "absolute" humidity is used. i lived in extremely dry places (Riyadh and Baghdad) where instruments showed 20-25% sometimes and one did not need a towel when stepping out of the shower or the pool.

So, what's the science lesson for? I was simply commenting that the local news/weather media in Palm Springs report "relative humidity" < 20% on a typical day in June/July.

[KarstenBoAndersen]

Any one interested in Misting systems ?

I have a stock of parts for misting systems and would like to sell it all, as i have no time for this anymore.

It is nearly 100 Kg. of high grade brass fittings, hose connectors, stainless steel valves, dampers, nozzle adapters. tools.

I can provide contact details for suppliers of all parts as well (Taiwan, China) !

[email protected]

[Morakot]

I always thought that these don't work too well in high humidity (works better in dry heat or lower humidity than these days)? No matter how fine the mist, it adds to the already moisture laden air, so evaporation from your skin (the cooling effect) is limited or slowed right down, so you end up feeling somewhat hot, damp and bothered which is far worse than just a normal high speed fan. I may be wrong?

I thought so too. Although the OP said it's for an outdoor kitchen, it's still an enclosed space somehow. It will needless increase the humidity and might make you feel even hotter.

I think, the way forward is one or two large fans. Possibly one celling fan combined with another wall mounted oscillating fan.

[Morakot]

My 'instrument' here reads 60% humidity and we haven't had a rain in over a month.

60%, actual humidity? Do you live in a jungle?

Edited August 27, 2012 by Morakot

[overherebc]

Somewhere like this, You are not thinking in real terms. http://en.wikipedia....lative_humidity

Huh? In what real terms am I not thinking?

the calculation of relative humidity is not only based on actual humidity but also dependent on temperature and "vapour" pressure. that's why "relative" as opposed to "absolute" humidity is used. i lived in extremely dry places (Riyadh and Baghdad) where instruments showed 20-25% sometimes and one did not need a towel when stepping out of the shower or the pool.

Relative humidity is the amount of water vapour present in the air expressed as a percentage of the water vapour that air could hold at that temperature and pressure without condensation taking place.