Introduction: How to Fix Your Swamp Cooler ("Overclock" It 50%)

Picture of How to Fix Your Swamp Cooler ("Overclock" It 50%)

Swamp coolers work ok until it reaches 94 degrees. At that point, they stop cooling as well, because the pump can not get enough water on the pads to keep them wet. So by increasing the amount of water going to the pads by 50% the unit cools the house down faster, and the pads don't dry out.

Step 1: Replace the Blue Pads With Good Old Aspen

Picture of Replace the Blue Pads With Good Old Aspen

The blue sponge pads do not really absorb the water very well and do not cool well at all. So pitch them and replace them with the low tech, sustainable aspen pads. the aspen wood actually absorbes water in additon to creating a curtain of water which makes the swamper cool better. It does get messy at the end of the year but it is worth it. These pads are also cheaper.

Step 2: Materials

Picture of Materials

you will need the following: (I purchased everything at Home Depot, but any decent hardware store should stock it) A pump, a supply tube, a distribution array ("spider") a pump basket, a basket filter bag, a grounded 3 prong splitter (not pictured) 7" and 14" zip ties... (10 of each should do) a pair of dykes, a utility knife, a radio or cell phone to have someone turn on and off the pump for you and about 2 gallons of water- to drink while you are cooking on top of the roof because you didn't get started until 1:00 pm in the afternoon.

Step 3: Shut Down the Power and Lock Out the Power

Picture of Shut Down the Power and Lock Out the Power

ok. Go to the power switch and turn off the swamper. Then take some duct tape and tape it off. Then put a little sign that says not to turn on the power. (if someone turns on the fan motor while you are in there you will get hurt.) Also, you can unplug the fan motor up in the swamper for extra safety.
OK.. notice that there are 8 tubes on the distribution assembly, 2 on each side. We are going to add 1 tube to each side taking the total tubes to 12, our 50% overclock.

Step 4: Arrange the Secondary Distribution Array

Picture of Arrange the Secondary Distribution Array

Now take the spider and put 4 of the 8 tubes in it so that they form a cross. Then Put it up under the existing one and loosly zip tie it into place ( you are going to cut it down in a minute). Next you need to cut the distribution tubes to length such that they will empty out into the trough. (I had to offset the center of the second spider slightly so each tube is a different length) Measure the distance you need then pull the tube out of the spider and cut it down. then re- insert it. Repeat this on all 4 sides.

Step 5: Remove Spider, Glue It Up , Install It Again

Picture of Remove Spider, Glue It Up , Install It Again

Cut the zip tie that is holding the spider in place and pull the spider out (keeping track of the orientation) then use the glue that comes with the spider to quickly glue each piece in. Then you will need to glue the plugs in for the other 4 holes that you aren't using. Make sure the tubes are pointing down, because you don't get 2 chances at gluing since it welds the plastic.
Now re-install the spider. I used two zip ties to hold it to the original one. I went around it in an x pattern. You may have better, and cleaner ways to do this but the reality is that the roof was about 105 degrees so zip ties seemed great at the time

Step 6: Install the Pump and Supply Line and the Power Connection

Picture of Install the Pump and Supply Line and the Power Connection

Now put the basket filter on the basket, the basket in the water and the pump in the basket. Take the supply line and run it up to the spider alongside the original supply line. (the tubing I purchased tended to kink so I tried to zip tie it every so often to the original to keep smooth curves.) Cut the tubing to length and fit it onto the spider.

Unplug the pump power from the connection and pull that connection out of its mounting slot. I got a grounding splitter to plug both pumps into the power source. (they are now both controlled by the main switch.) I zip tied it to the mounting area making sure that the cords are attched with zip ties and the whole thing is out of the way of the fan, fan belt and the water. You dont want something migrating into one of those areas.

Step 7: Turn on the Pumps for a Test

Picture of Turn on the Pumps for a Test

Now call down and have somone turn on the pumps only and you can verify that you are getting the water comming out of the pump and that the spider is filling the troughs and there are no leaks. Also check that the pads are aligned correctly and you are getting good distribution of the water. Let the pads soak for about 5 minutes and then let it rip.

Step 8: Improvements and Such

Picture of Improvements and Such

I would be interested in ideas to improve the cooling ability of this project.

My business parnter said that the second pump should only come on when it is over 95 degrees outside (to save electricity) and that I should install a second switch for the second pump.. But I don't want to do the wiring.

so, possibly a wireless switch in the swamper with the other switch downstairs. It would be really cool if you could just get the second pump to kick in when necessary, but that is beyond my techability.

Other ideas might involve adding a unit for spraying the inside or outside of the pads with a sprinkler head. to get better distribution of the water on the pads.

Anyway, hope it works for you .

Comments

KaseB (author)2017-04-13

So I'm not looking to bash the guy that made this instructable but this isn't going to to do much at all as long as you have a properly sized pump. I'll tell you why, the pump pumps water to trays that sit over top of the pads. These trays have slots in them every inch or so to let water drip onto the pads and on the end are open to let excess water fall directly into the pan at the bottom of the cooler. If your cooler pumps enough water to make it to the end of the trays then the maximum amount of water is already reaching the pads. Pumping more water into the trays is not going to do anything in this scenario.
Now you can open up these slots a bit more and let more water through but if the bottom of your pads stay wet already then this isn't going to help much.
In my opinion your best bet is to check the temperature of the incoming air right at the cooler vent and if the further reaches of your house are significantly hotter than this, say 10-15 degrees then you need more air movement.
If so make sure you have a window partially open in the room/rooms you want to be cooler. I'm surprised how often I have to explain this to my tenants. An evaporative cool is not a closed loop system like an AC unit. You gotta let the hot air a way to escape to let cooler air in.
Now if you are already doing that and you still need more air movement your best bet is to change out the little pulley on the motor to a larger size. This will cause the squirrel cage to spin faster and move more air. If you cannot get the pulley off you can always buy a new motor with a little more hp and put the new pulley on that. Just make sure to check your temperatures to see if it is going to be worth the effort.
Now I'm sure you are asking yourself why you should believe me and not the guy who wrote the article. I service 300+ evaporative coolers on a yearly basis and I have a lot of experience fixing/replacing them.
A final note don't expect an evaporative cooler to be more than 20 to 25 degrees cooler than the outside air temperature. If you are already in that range and you want to be cooler your best bet is to go with an AC unit. This is the reason why you don't see many evaporative coolers in places like Phoenix Arizona, it's just too hot for em. If you have any questions, feel free to message me.

Itlleprcn (author)KaseB2017-08-13

So whenever I turn on my swamp cooler sand and debris blow through the front grill. I live in the high desert and was wondering if it's possible to take off the face plate of the cooler (It's coming in through the window) and put in a thin filter of some sort?

Thanks in advance!

Melissa

KaseB (author)Itlleprcn2017-08-13

You can do that though it's not commonly done. Just make sure you use a low density filter like the fiberglass media ones. Evaporative coolers only work well with a lot of air flow so you don't want to restrict it very much. I would also check your cooler pads and make sure they are in good condition and fully cover the louvers on the sides. The pads usually do a good job of filtering out debris themselves and if they are in bad condition, I would replace those first.

BryantI (author)KaseB2017-05-02

Hello have you ever had a condition where the blower is sucking water out of the pads as its going down the face of them which in turn the water spins around the blower for a little bit but eventually spits out into the house... i have the blue pads and im wondering if it has to do with them not absorbing the water and its just going on the face of them which allows the fan/blower to pull the water. the other thing i thought about was possibly the blower is spinning too fast? your help is appreciated

KaseB (author)BryantI2017-05-02

I have seen that a few times before and it could be a couple different things or a combination of them. First off I have seen where the water isn't soaking into the pad and is getting pulled in. I would go ahead and replace those blue pads with some Aspen ones, they cool better anyway. I have also seen where the pulley ratio was too high and it was just pulling in too much air and sucking the water in with it. Once you replace those pads turn on the cooler on high and put the last side on. If you can see the pads flex in as if they are being pulled towards the squirrel cage, if so then it's moving too much air. (a little flex is normal) One last possibility is that your distribution tray at the top of your cooler pads has a larger hole rusted in it that is letting too much water onto the pad in one spot. One last note, I am assuming that this is a side draft unit and that's why it's pudding water in the squirrel cage housing. If that is the case you should drill a few weep holes so that water can drain back into the pan. Good luck with it.

TinaF54 (author)KaseB2017-05-27

I would like you to work on my swap cooler in phoenix. How do i contact you?

BryantI (author)KaseB2017-05-18

KaseB. The water cooler I have is on a mobile home and its a straight shot into a hallway ceiling register. I removed the register to look at the metal inside and find that it is very rusted. I have scraped off the rust and figured I should paint it. what kind of paint would you recommend?

vatosupreme (author)BryantI2017-05-18

A couple ideas. The easiest is to get some

Rust-Oleum Rust Reformer. It converts the rust to a paintable surface that is supposed to keep the rust from coming through. It is a cheap solution. If you want to go pro - get some POR 15 (it is alot more expensive but works better.) Don't just rattle can it, unless you sand all the rust out, and prime it first. If you don't get rid of the rust it will just come back.

KaseB (author)BryantI2017-05-18

I would use an acrylic paint like rustoleum to paint it with. Acrylic has good moisture resistance and the rustoleum brand is designed to bond well to rusted metal.

BryantI (author)KaseB2017-05-03

Believe it or not the issue was resolved just by replacing the blue pads with aspen.. is it that those absorb the water better and don't allow the water to be sucked out?

BryantI (author)KaseB2017-05-02

Cool thanks! i will try that later today!!

vatosupreme (author)BryantI2017-05-18

The best thing to do is to take a look at what is happening inside. Take one of the panels off and see. Sometimes the fan is spinning too fast, but lots of times, the hoses aren't filling the troughs correctly and water is spilling or splashing. Try that and see how it goes.

vatosupreme (author)2017-05-18

Interesting take on it. I have been able to solve many of these problems by fixing the troughs too. This instructable is for when that doesn't work; which is fairly often. Lots of times, I run into a unit where the flow rate is fine, the troughs are open but the pads are still dry. In these situations, this fix has done the trick. I had to do it on 10 units on a commercial building after trying to open up the slots. We had great flow on the units from about 10 am until noon, and then after that, it was so hot, that the water wouldn't make it to the bottom of the pads, even though it was flowing correctly. So I agree, that the first pass is to check your flow, your slots and make sure everything is running correctly. This will solve it 80-90% of the time. When/if that doesn't work then you can try this one. If you set everything up correctly, this is a great fix in these situations.

jeremysheikh (author)2016-06-15

I live in Utah and I am looking at installing a cooler in my garage shop. I am looking at the traditional types like the one pictured in the mod instructions and also the MasterCool units which seem to be more expensive and designed different. Does anyone know if the MasterCool units are any good and if they can still be moded like the one in the instructions? I have not been able to find good information on the differences.

There are two types of coolers sold.

1. Centrifugal fan.

2. Axial fan.

Centrifugal systems: Champion, Phoenix Mfg, Master Cool.

Axial fan systems: Bon Air, Master Cool.

Let's talk about the Axial fan system's first. The Bon Air ( Durango ) is manufactured in Australia from domestic and imported parts. The Bon Air uses a Axial fan motor, a single circulation pump, a 3 piece rigid media pad (celdek). and a analog controller. I have installed more than 40 of these units in the past four years and only one unit had a detective pump. The master cool unit, although similar in construction, is manufactured almost entirely in China and is assembled in the united States. This cooler has proved less than satisfactory, I have replaced over a dozen of the units digital control modules over the past two years at a cost to my customers of approximately $100.00 per each cooler, it seems that the control modules fail about six months after the coolers warranty expires.

The Champion unit uses Aspen pad's. Some models of the Phoenix use Aspen pad's and some models use rigid media. The master cool units ( aero, trophy, ll, etc.) uses rigid media. Replacement rigid media pads range in price from $75-125, depending on the particular cooler.

JLynne44 (author)jeremysheikh2016-07-17

vatosupreme is correct about the MasterCool units. They are way more expensive. I got ripped off on a used one.

They used to be made by AdobeAir and are discontinued. I needed parts for mine and the parts were either not available or more expensive than just replacing the unit with a traditional type. I needed new pads too. The total would have been more than $350.00.

The traditional type are very easy to service and some maintenance folk don't know how to work on them. I can't remember exactly but the pads for mine were in the $150 to $200 range.

The difference in cooling wasn't worth the cost for me personally.

vatosupreme (author)jeremysheikh2016-06-16

I have had both, (here in Utah) The Master cool works a little bit better, but they are expensive and you have to replace the cardboard insert things every couple years and they are also expensive. I modded the master cool to spray more water also, but I did it a little differently, but same basic idea.

MikeKulka (author)2016-08-23

We installed a swamp cooler about a year ago and it was working fine up until recently. There is no actual leakage but it seems as though the fan is pulling the water out of the air in the cooler and throwing it down to the register and onto the wall of the house. We changed the pads, to no avail. Everything else is working ok with the swamp cooler. We can't figure out why it's doing this. Has anyone heard of this happening?

Here is a list of possible issues with your cooler:

1. The pads are worn out and need to be replaced.

2. The pump is putting too much water into the troughs.

3. The blower fan is running faster than it was designed to.

4. The float could be defective or improperly adjusted and too much water is in the cooler pan.

In order to determine what change has happened since the unit was new and operating normally, you need to be a detective.

1. If the pads are worn out or were installed incorrectly, the flow of water could be drawn directly into the coolers blower rather than being drawn out of the pads first.

2. If the pump was recently replaced, a larger pump may have been installed than the pump that was replaced. If your cooler was originally equipped with a 5000 series pump, then another 5000 series pump should be used. If a larger size pump is used in a cooler then what it designed for, there will be too much water put into the water troughs and water droplets can be drawn into the house. A restrictor can be installed on the pump water supply hose to reduce the amount of water that is delivered to the water troughs.

3. If the blower pulley has been changed or the motor pulley has been changed or misadjusted, the blower may be turning faster than it was designed to. An increase in air pressure can draw water droplets from the pads and or liquid water directly from the coolers pan. Also if any baffles have been removed from inside of the cooler, splash water can be drawn into the blower.

4. If the float has malfunctioned, too much water may be in the cooler pan and water may be leaking from the pan directly into the coolers ducting under vacuum pressure.

SusanG108 (author)2016-07-30

Simple solution: I have always double padded my swamp coolers - aspen pad on the bottom, blue on the inside, installed both a more powerful pump and motor than came with the cooler (as these parts wore out), kept the pan clean by draining the water and refilling it several times during the summer months and been very happy with the results - the coolers have always worked very well here in the CA high desert. The newer Mastercool is a bigger problem - there's way too much humidity in the air and another problem to figure out.

WilliamW21 (author)2016-06-23

Mostly true. Most evaporative coolers in dry/arid climes can get expect a 25° F cooling given sufficient water supply to the pads, relative humidity, condition of the pads and scale build up. It was 98° here yesterday with a relative humidity of 17% and the temp indoors was 73° F. A common problem with spiders is that they become clogged or air enters the system if the connections aren't tight. The pic at the top of this post shows a typical spider/octopus. To the poster's point, it is go idea to slightly oversize the pump somewhat to ensure sufficient water flow gets to the pads. Newer evaporative coolers (and more expensive can achieve ~ 29° F differential under optimal conditions. They draw the air through a larger water bed thus increasing the evaporative rate.

horrorhallh (author)2016-06-22

i was looking for an easier way to keep water on the pads during the hottest part of the days . I normally go out by noon or 1 pm and add extra water from the cool hose . I thought the cooler water could equal cooler air . . ive been told that is not so . Now i will learn how to incease the volume of water to pads to prevent the 'drying' out of the pads during our triple digit days. thanks for your article .

vatosupreme (author)horrorhallh2016-06-22

I hope you have success, let me know how it works.

shunkawea1. (author)2016-06-20

"Swamp coolers work ok until it reaches 94 degrees"----simply not true: its 106 today here in Acton, Ca, and my cooler is putting out 70 degree air-always has and always will if maintained properly. Also, it's a myth that they don't work in humidity: they do, as long as you don't live on the equator.

vatosupreme (author)shunkawea1.2016-06-22

At somewhere between 94 and 97 degrees, most coolers can't keep the pads wet enough to provide cooling. As a result, they stop working well. It is a problem for thousands and thousands of swamp coolers. It is a well documented fact supported here by the many successful
implementations of this idea, as well as other ideas aimed at keeping
the pads wet at high temperatures.

Some coolers and owners are able to do a better job of keeping the pads wet, but most lose effectiveness over time. The loss of performance may simply be due to incorrect pads, scaling of pads, undersized pump, or lack of maintenance. However, many of these units also suffer from design flaws and manufacturing defects such as: poorly placed or aligned output tubes, undersized pumps, water distribution channels that don't allow for good water flow, etc. It is for these problems that I wrote this instructable.

In addition, it is a verifiable fact that the effectiveness of a swamp cooler decreases as the relative humidity increases, not a myth. It is just one of those pesky laws of physics that we haven't been able to overturn yet.

At a 106 degree outside to get 70 degree air, you will need to be less then 5% humidity. On the day of your post, you had a low of 7% humidity in Acton, so it seems probable that you would be blowing approximately 72-74 degree air with an outside temp of 106. If, for example, you were at 35% humidity on that day, you would only be blowing 88 degree air.

This is why you don't see swamp coolers in the southeast US very often. It becomes more economic to just use a normal air conditioner when the humidity is up over 25% during the heat of the day.

Hopefully this explanation will be helpful to people. You can google how swamp coolers work for some good articles on the subject.


PaulG220 (author)2016-06-01

Would it not be better to simply install a pump that will move more water?

vatosupreme (author)PaulG2202016-06-22

Also, On this one, I put the biggest one they had at home depot. It was the 110,000 one and It couldn't really keep up. If you could get a bigger one, you probably will still want to increase the number of distribution tubes.

vatosupreme (author)PaulG2202016-06-16

You can do that. The other part of the trick is to get better distribution of the water at the top of the pads with more output hoses. Two pumps allows you to add the thermostat on #2, that is addressed in the comments early on.

jimswamp (author)2016-05-30

My swamp cooler is spraying water into the house. WHY??

kris256 (author)jimswamp2016-06-22

Another possibility is if the water tubes on the top are not dripping into the rail on the top of the cooler pad. If they miss they can point inwards and the water can get sucked into the house. This happened on my friends pretty bad and all it was, was one of the tubes spraying water away from the pads.

JH51 (author)jimswamp2016-06-03

The water level in your swamp cooler is too high. Adjust the float to lower the water level.

Styluss (author)2016-06-15

Excellent write up! I wish I would have thought about this as it seems my old (I just moved) swamp cooler was the damn same as yours. I was always grabbing the hose and spraying that pads to get a boost of cool.

heroay (author)2016-06-11

Please pass on this information. My mailman recommended I add a floating (it does) IVORY soap bar to my swamp cooler. I did, then I disconnected the second drain pump (worked every 8 or 12 hrs), and let the system run on its own. NO drain at all from then on.

The Aspen pads were clean of crust at the end of the season; the usual heavy calcium scale on the pads and the pan was absent (only the accumulated dust on the bottom); and cleaning the unit for winter was a charm. The soap, however, was an ugly looking thing, swollen out of proportion, with black, gray, and rust colored spots, and would disintegrate after letting it dry outside the pan. All the damaging chemicals or minerals in water are acid, the soap is alkaline. They attract each other neatly, and the water, pads, and unit remain clean from all those chemicals and minerals.

Now, these pads were already 3 years old (!) before the Ivory soap, and I maintained these before without scale by adding a gallon of white vinegar to the tank at the start of the season, and a half a gallon again every two months. The drain pump would empty all the calcium filthy water every 8 or 12 hours, and start all over again. But with the addition of the Ivory soap (alkaline, and there are several other brands) I stopped adding vinegar to the tank. Besides, these pads were ready to be discarded after the first 3 months of use, but the vinegar cleaned them out and the entire unit off the calcium deposits after a 4 hour run, then continued using the same pads for the following 3 years. Until Ivory soap.

I had to discard the pads after another year because they developed a black fungus-like deposit on the outside, sunny side of the pads. Rotten wood? Fungus? Just replaced them; they paid for themselves many many times over. And YES, both the vinegar or the Ivory soap will keep the air smelling CLEAN. Both kill the fungi that grows in the internal 'swamp' that releases the sewer pipe smell gas into the house.

JH51 (author)2016-06-03

Aspen pads are way way WAY better than anything else

Pure GENIUS my friend. After I swapped the expensive blue pads with Aspens, installed the new water dispensers, and replaced the puny bare minimum water pump with a max capacity one the cooler's been running like a champ. Thanks for all the great advice.

Charlotteg2 (author)2015-07-08

can something b added to swamp cooler water to make it over corroded with salt ,I think my manger may have added something to the water an now its not working properly,plus its full of salt inside out everywhere

BrentV2 (author)Charlotteg22015-08-15

That "salt" is probably Hard water build up. Salt will actually cut down on this left over residue. Suggestions on how to fix this, is to buy a more expensive pump that filters the water before it hits the pads. Look at pumps over $40, and read the description about them. It will usually say if it filters the water or not.

...Or do what Chad said (Below).

ChadD3 (author)2015-07-01

Another great addition to your swamp cooler basin is a Zinc anode ( about $8.50 at home depot ). If you arent familiar, it is a zinc pole about 8 inches long that rests in a plastic bed with a grounding wire. This zinc anode keeps your water nice and clear by attracting all of the hard water deposits and storing them in the plastic container. The zinc anodes last for 1-2 seasons and are self sacrificing... once they are gone simply replace. Not only will it filter the hard water but it will keep your tank from smelling like a mossy swamp.

JeffreyM12 (author)2015-06-28

GlobalFlex (author)2014-07-06

Just made a couple gallon jugs of ice and am going to put inside the box and see what happens.

vatosupreme (author)GlobalFlex2014-07-15

How did it work?

DBCooperIsMe (author)vatosupreme2015-06-23

I would assume well with temporary results. Evaporation works best when the water is room temp or hotter. Chilling the water will make it more difficult for the water to evaporate. Great if you are standing in front of the unit but not affective long term.

jrand1 (author)2015-03-27

I live in Palm springs and rebuilt a unit on the house that hadn't been used in 15 years and was installed back when the house and as built in the early 60's. I tried the blue pads but could never get the house cool at all. Then went to Home Depot and bought the new waffle wax coated see through pads 6.39 each only 3 needed and already cut to size I only use two water spouts per side for a total of 6 spouts. Now the unit which is actually ducted into the a/c system is like a freezer. I put a thermostat at the vent and it was blowing at 71 degrees when it was 100 outside. I figure the system is so effective now with the new non messy style pads (that do not become mush at the end of the season. The swamp cooler keeps the house cool 25 degrees from the outside. Only one humid days will I use the a/c. I also keep the dial anti algee bacteria bars in the water all year and never drain the system. The water is bacteria free as I put anew cake in every 6 months. No need to over clock just use the right pads and make sure you use the right size pump and motor. I only use a 1/2 hp motor and my daily use of cost is about 1.30 verses 6.00 with the a/c. The key is to crack each window and door just enough to cause a string draw. I think you have a little over kill going. Use the new waffle pads and you will see s massive and cleaner difference). Right now the sun went down its 95 degrees outside and the cooler is keeping the house at 68 degrees. Nones for overkill just make sure the drain holes are cleaned out and the pads soak completely within 40 seconds

jjchavez123 (author)jrand12015-06-22

do you know what the brand of these cooler pads are. I went to lowes but they only had aspens, those blue ones, and these others that reminded me of a honey comb that were made of what looked like cardboard.

JunardiA (author)2015-03-18

I was told my the people who set up my cooler for the year that I didn't need new pads. I always replace my aspen pads. They told me you don't have to if they're still good/clean. True or false?

joseph.dennis.joe (author)2015-03-14

is there any alternatives materials that i can use instead of evaporating cooling pads?

Pwag (author)2013-07-07

The heat from the roof aids in evaporation.

If you put it under ground it'd be cool, but it'd not be an evaporative set up. It'd be something closer to a geothermal exchange, which is ALSO VERY COOL.

turncoat (author)Pwag2013-10-17

My cooler is a side vent under a porch facing east, I use the aspen pads on the outside (inside facing out) and the blue sponge pads on the inside right up against the aspen pads. This combo seems to work best and it helps keep out the dust. I also drain and clean the bottom every week to prevent mold. I also installed a new tube overflow drain, the tube comes out easy for draining.
Next year I'm going to cut a round hole and use a bathtub drain plug for faster water draining and install the extra pump and spider for better pad saturation. Last year I installed a 5000 watt solar system and with the new swamp cooler I only use 10% of the electricity I used last year in August!

Pwag (author)turncoat2013-10-17

How cool does your place stay with this and how hot does it get where you're at?

turncoat (author)Pwag2013-10-19

So far with the two pads I'm good to the high 90s. Here is a chart that will help you more, it's all about humidity...
http://s7.photobucket.com/user/picsri/media/Greenhouse/evap_chart3.gif.html
Just right click highlight, copy and paste in your address window...