To keep your cooler newer and in top condition for many years, it’s best to drain all water, allow pads to dry completely, and use a cooler cover to protect your cooler and help keep cold air out of your house during the off- season.

We have Cooler Covers for EVERY SIZE Evaporative Cooler, and any other units you need to protect with a durable, long lasting cover.

Visit our COOLER COVER pages on our website for listed sizes and please give us a call for custom sizes.

Evaporative Swamp Cooler Covers

Choosing Whether or Not To Install Evaporative Cooling

(Also see “Trouble-Shooting” if your cooler is not performing well)

Evaporative Cooling
Refrigerated Air Conditioning??

A common question asked by many is “should I install an Evaporative Cooler or Refrigerated Air Conditioning?”

(Please note: The correct terminology is “Evaporative Cooler” and NOT “Swamp Cooler”)

If you live in a coastal or tropical region, you probably never hear the explanation below because “evap cooling” is not very efficient when your ambient air is full of humidity.
(except for use in greenhouses where high humidity is healthy for the plants)

If your wet bulb temperature is around 60% and higher, then refrigerated cooling is the correct answer.
In lower wet bulb regions a properly sized evaporative cooler can be a very cost- effective and comfortable choice.

Sizing the evaporative cooler is the key

A good “rule of thumb” is to have 1 air change every 3 minutes in northern states, 1 air change every 2 minutes in the mid section and 1 air change every 1-2 minutes in the southern states.

The Rule of Thumb formula for sizing your cooler is very simple;

Multiply the length by the width by the height of the area to be cooled to get the cubic footage for the area. Then divide by your air change factor minutes. The example below reflects a “2” minute air change.


A home that is 30′ wide, 40′ long and 8′ ceiling has a total of 9600 cubic feet of area to be cooled.
30 x 40 x 8 = 9600
Using the factor two (for an air change every two minutes),
divide 9600 by two to give you the CFM required, in this case, 4800 CFM.
9600 / 2 = 4800

In this case, you would want to use a 4800 CFM cooler.
(Note: It never hurts to go one size up. You might consider a 5500 CFM cooler here)
The cooler can be run on low speed, then cranked up to High on severe days.

Another important factor is “Exhaust Air’. A good cooler design is to exhaust slightly more air than your cooler is supplying, this can be done with windows or doors being open slightly or a sized exhaust fan inter-locked with the cooler.

Having enough air exhausted is important so that there is negative air pressure in the conditioned space, positive air will cut down your blower’s capacity. A big advantage to evap coolers is that the capacity can be changed easily by adjustable pulleys to increase or decrease air flow. If you open your front door and the pressure slams it shut then, you need more exhaust openings, such as a window or another door.

(Ample air exhausted also reduces the humidity build up)

Refrigerated air conditioning cools no matter what the humidity is and usually increases your home value (as well as your electric bill) more than an evap cooler, but with a well designed evaporative cooling system installed, cost is less to install and hardly noticeable on your utility bill.

A few notes for evaporative cooler maintenance:

The more frequent aspen cooler pads are changed the better – don’t try to get 2-3 years out of pads. Twice a season is best (although seldom done). Be sure to change aspen pads at the beginning of each season when starting up your cooler.
(An exception to this is using a cooler with a celdek type pad, such as our UltraCool)
The pads can easily be used for five years or more when the cooler is properly installed with a bleed off system.

A properly installed bleed off system can prolong the life of your pads and greatly reduce the corrosion affects on your cooler. Below are two types that can be used.

Bleed Off Kit System
Power Clean Purge Pump System
(Purge Pump Conserves More Water)

Oil the motor and bearings – Most evaporative cooler motors do have oil ports. Use SAE #20 non-detergent oil.
Do not use motor oil. It has detergent content. This will reduce the life of your bearings.

Check for proper belt tension, and amp draw. (Overloading the amp draw will burn the motor out)

(just a few tips – there are many more things to check out)
This should be done by a qualified technician

Cooler undersized
Replace with larger cooler
Clogged or dirty filters
Replace with new pads
Dry pads or lack of water while cooler is operating
Check water distributing system for possible obstruction in tubing. Check pump operation.
Replace Pump if necessary
Insufficient air discharge openings or inadequate exhaust from area being cooled, causing humidity building up and discomfort

Evaporative coolers must have large enough ductwork
Ductwork sized for refrigeration simply will not let the higher cfm from a cooler out.

Make sure there is adequate provision for exhausting air from area being cooled.
Excessive humidity.
(See also item above re: inadequate exhaust)
In some areas, there may be a few days during the summer when the relative humidity is high, resulting in poor cooling. (60% or higher) These are limitations of an evaporative cooler under conditions of high wet bulb temperature.
Blower turning backwards
Reconnect motor for correct direction.
Blower installed backward
Remove and reinstall blower wheel to turn in correct direction.
Blower running too slow
Check motor amps. If below nameplate amperage, readjust variable pitch motor pulley to increase blower speed. Do not increase amperage above motor rating. This will burn the motor out.

Is an Evaporative Cooler for You?

Model WC 50 Our most popular Window Model

It’s getting warmer and you need a way to keep cool. Want to know if evaporative cooling is for you. Check out our article “What is Evaporative Cooling?” and learn more.

Looking for a cooler? Check out the ones in our cooler section. Call or use the Order Info page to learn more.

Call me to learn more!
Rita Newsom
K&S Sales and Supply
(405) 586-9191

Evaporative Cooler Maintenance

A Breeze For Do-It-Yourselfers

Save money on energy and repair costs, and increase cooling efficiency with this easy Spring cleaning project!

Service Tips for Optimum Cooler Performance

Cooler maintenance is not a difficult task, and can be completed with a minimum of mechanical knowledge and a little assistance. Use this guide and ask for help at your local home improvement center or hardware store where evaporative coolers are sold.

1) Shut off power and water. Essick Air Products, manufacturers of Champion, Ultra Cool, and Tradewinds coolers, cautions that safety is important, so disconnect the power to the cooler and turn off the water supply before attempting any preventative maintenance.

2) Replace pads: Remove side panels and install new evaporative media pads at least twice during the season. Cooler pads become clogged with dust, pollen, mildew and minerals from evaporated water. Dirty media pads reduce cooling efficiency and overwork the motor. Clean debris out of the louvered side panels and water troughs. Call your cooler manufacturer for pad size, or write down the cooler make and model and visit your improvement center for assistance.

3) Clean water reservoir: Remove the cooler overflow/drain tube in the reservoir pan and rinse out standing water, dissolved salts, silt, old pad fibers, etc., with a solution of water and vinegar. If necessary, use a sturdy nylon brush or plastic scraper to loosen deposits. Do not scratch through the protective coating of a metal cooler. A wire brush or metal scraper should only be used on rust spots, and then reseal the pan with spray cooler coating. If you have an easy-care polypropylene cooler, there’s no need to patch and reseal, just rinse out debris.

4) Check water pump: Clean the pump screen of debris and make sure the water pump impeller turns freely. If the pump shaft is stuck, water will not be distributed to pad surfaces, so replace it. Call the cooler manufacturer or visit a retailer for an inexpensive replacement.

5) Check V-belt and oil bearings: Check to see that your V-belt is not cracked or frayed. If so, replace it. Allow about 1-1/2-inch play in belt tension to reduce strain on the motor and blower bearings. To set belt tension, loosen the bolts at the motor cradle, move the motor, then retighten the bolts. Oil the blower wheel bearings on both sides using a 20-weight non-detergent oil. Lift the oil caps and oil slowly until it fills the stem. Don’t overfill! Cooler oil is available in small zoom spout plastic containers to make this easy. Most motors are permanently lubricated but look for oil caps on both ends of the motor, just to be sure.

6) Rotate motor and blower wheel: Turn the blower wheel by hand a few revolutions to spread a thin coat of oil on dry bearing surfaces. If the motor or blower wheel doesn’t turn freely, you may have to replace the motor or call for service.

7) Open dampers: If you have manual slide-in dampers, they are usually located where the cooler is attached to the ductwork and/or at the furnace air handler, or both! Remove any slide-in dampers. If you cannot locate a damper, your cooler probably has a barometric damper that opens automatically. If no air enters the home when the cooler is turned on, call for service, or ask for assistance.

8) Fill cooler, adjust float: Turn on water supply and make sure the float shuts the water off about 1/2-inch below the top of the overflow/drain tube. If the float valve is not working, replace it by purchasing an inexpensive repair kit. If the overflow tube leaks around the gasket, tighten the nut or replace the tube gaskets. If water runs over the tube, adjust the float arm. Check to make sure the cooler is level and there are no leaks.

9) Turn on cooler: Replace side panels, turn cooler on and examine water distribution to make sure water fills the troughs and flows down all pads evenly. If water flow is restricted, remove the panel(s) and clear the blockage by snaking a flexible wire into the tube-end orifice.

10) Control corrosion: The best way to minimize corrosion is to install an inexpensive “bleed-off kit” that continually flushes minerals out of the cooler as it operates. Or add a mineralizing agent neutralizer, or replace the water manually two times a month by draining and refilling the reservoir.

Essick Air Products manufactures both the Tradewinds polypropylene line of UL Approved polypropylene evaporative coolers, as well as the Champion and Essick line of metal coolers that are marketed throughout the Western US. For additional information on evaporative cooler maintenance, refer to Essick Air’s Web site at or call 1-800-643-8341.

About Essick Air Products

Essick Air Products/Champion Cooler Corporation was founded in 1943 in Little Rock, Arkansas, and today is one of the largest and leading evaporative cooler manufacturers in the country. The company has been owned by Walton Enterprises since 1978 and operates manufacturing facilities in Arkansas and Texas. Essick is the only company that manufactures both metal and polypropylene coolers due to varying customer needs and interest.

Greenhouse Cooling

Evaporative cooling (Sometimes referred to as “Swamp Coolers”) is probably the best way to reduce greenhouse temperature. The principle is simple. As the exhaust fans blow air out of one end of the greenhouse, they draw in moist air from the other end. As the moist air moves through the greenhouse, some of the water vaporizes, absorbing heat in the process. Moisture is supplied at the end opposite the fans with an evaporative cooler that drips water through an absorbent material such as aspen pads, cellulose or a synthetic fiber media (commonly called “cooler pads” or “wet pads”).

All incoming air passes through this wet media. Any water that drips through the pad media is collected into the water pan at the bottom. Water is recirculated by a small water pump through a plastic line from the pump in the water pan back to the top of the cooler pads.

There needs to be a provision for replacing water that is evaporated by the air passing through the cooler pads. This is usually done with a 1/4″ copper or plastic water line to the float valve that is mounted in the cooler. This line can be installed from a garden hose bibb or sillcock located near the greenhouse to the cooler float valve.

Evaporative cooling is more effective when the air outside the greenhouse has a low relative humidity. As the relative humidity of the outside air increases, this technique becomes less effective. But so long as the relative humidity is less than 100 percent, this method will have some cooling effect on the air.

Model WC 50 Our most popular Window Model
Model WC 50
Our most popular Window Model

Champion Window Model Coolers
Phoenix Window Model Coolers

Are An Excellent Choice For Cooling Your Greenhouse
They Are Completely Factory Assembled
With A Two Speed Motor, Supply Grill, Switch
And Pump Kit

They Have An Electrical Cord And Plug And Use 115 Volt Electricity
Installation Instructions Are Shipped With The Coolers

Evaporative Cooler Service Tips

Evaporative Cooler FAQ

What types of evaporative coolers are there?

Evaporative coolers range in size from small portable models to large ducted models for residential and commercial/industrial applications. Go to What is Evaporative Cooling to learn more about evaporative cooling and its benefits.

Can evaporative coolers be used in different climates?

Evaporative cooling is best suited for climates where the air is hot, and humidity is low. They may be a cost-effective option in some higher humidity areas. Use for spot cooling, garages, workshops, garden centers, auto shops, dog kennels, outdoor tents, horse stables, exercise areas, industrial plants, commercial kitchens, farming (i.e. poultry, hog, and dairy buildings), laundries, dry cleaners, and greenhouses.

Which is better – an evaporative cooler or an air conditioner?

That all depends on you. Evaporative coolers provide continuous fresh, cool air and are energy efficient to operate. Use an evaporative cooler for whole house cooling or combine an evaporative cooler with an air conditioning system.

How do I size a cooler?

Evaporative coolers are sized based on the amount of airflow needed or CFM (cubic feet per minute). There are two ways to size a cooler. See an example here.

One, you can calculate the cubic feet of an area by multiplying the length by the width by the height (L x W x H). Once you’ve determined cubic feet, multiply that number by an evaporative cooling climate factor for your area. Referring to a specification chart for a particular type of cooler, you can determine which model meets your needs. See Sizing a Cooler.

Two, determine the total square footage of your home referring to a square foot sizing guide. Please note, however, square foot ranges shown in any guide are based on ceiling heights of 8′ and other assumptions (i.e. desired room temperature and heat loads, etc.). Square footage sizing guides are approximations only. Since conditions vary from house to house, contact a salesperson or contractor for additional information.

How do evaporative coolers rid my house of indoor pollutants?

Evaporative cooling constantly exchanges the air instead of re-circulating it so stale, polluted inside air is replaced with fresh, filtered outside air that has been cooled.

Do evaporative coolers save energy?

An evaporative cooler uses 70% less power than air conditioning. The annualized energy savings make evaporative cooling a cost effective alternative to air conditioning.

How often should my cooler be serviced?

Regular maintenance will extend the life of your cooler and help avoid unnecessary problems associated with parts replacement. We recommend servicing your cooler three times throughout the year – at start-up, mid-season, and shutdown. Refer to your Owners Manual for the recommended maintenance schedule for your cooler. Check out this page for more information on how to maintain your unit.

Is it okay if I use soft water with my evaporative cooler?

Soft water may cause corrosion decreasing the effective life of your cooler.

I see scratches on my cooler. How can I get rid of them?

Should a scratch or any bare metal appear on your cooler, sand the area with steel wool to prepare the finish. Paint with standard spray paint or touch up paint available from a dealer.

What is a BLEED OFF KIT ?

The bleed-off helps your cooler function at its optimum. By continuously eliminating a small quantity of water from re-circulation, it reduces scale build-up and dilutes mineral concentrations. Consult your Owners Manual to determine the correct flow rate for your model.

You can also use a POWER-CLEAN® kit. This can reduce the amount of water used.

Is it important for my evaporative cooler to be level to operate properly?

Yes. When an evaporative cooler is mounted level, then the water within the pan is set at the appropriate level for the pump to operate efficiently. If the pump doesn’t have enough water to circulate, it will prevent the right amount of water from reaching the pads and will possibly create dry streaks. This would allow warm air to enter the evaporative cooler.

When I turn the fan on, no air is discharged. Why?

It’s possible the electrical power to the unit has been disconnected. Check fuses and/or circuit breaker. On portable or window coolers, make sure the cord is plugged in.

My evaporative cooler produces an unpleasant odor. What can I do?

Drain, flush and clean the reservoir. Make sure the cooler has a bleed-off. Clean or replace pads, if needed.

The cooler doesn’t seem to be cooling.

You could have inadequate exhaust. For every 1,000 CFM of air delivery, 2 square feet of unrestricted air relief is needed. Check the water distribution system to ensure there is adequate water reaching the pads. Clean and/or replace the distribution system if needed. Also, check the pads to make sure they aren’t clogged. If they are, clean and/or replace as needed.

I’ve heard about relief air. What is it?

As an evaporative cooler draws fresh outside air through the cooler into the home, hot stale inside air is exhausted out of the home. This is referred to as relief air. Generally speaking, a good relief design exhausts slightly more air out of the home than your cooler supplies.

How many windows and doors must I leave open?

It’s all based on the unrestricted exhaust air openings your home requires. For every 1,000 CFM of air delivery, allow 2 square feet of unrestricted air relief through windows or doors.

Are there other ways to exhaust air in my home?


VENTMATIC™ vents can be installed to exhaust air through your attic and out the roof vents. Remember to provide 2 square feet of relief for every 1,000 CFM of air delivery.

What is VENTMATIC™ ?

VENTMATIC™ is a brand name of ceiling vents that allows for air exhaust through an attic. This also cools down the attic temperature. When the cooler comes on, the air pressure automatically opens the barometric dampers. When the cooler turns off, the damper automatically closes.

How many VENTMATIC™ vents should I install?

At a minimum, install VENTMATIC™ vents in every major room. For maximum cooling comfort, install one VENTMATIC™ vent for every 500 CFM of air delivery.

How can I direct cooled air into various rooms?

Direct the air exhaust by changing the direction of the vents or opening windows or doors in different rooms. Remember to allow a total unrestricted area of relief of 2 square feet for every 1,000 CFMs.

Are thermostats available for evaporative coolers?


Thermostats are available for whole house coolers.

What can I expect the discharge air temperature to be from my evaporative cooler?

That depends on a number of factors. The discharge temperature is determined by the temperature and relative humidity of the incoming air. To determine the temperature of the air leaving the cooler, you will need to know the outside dry bulb temperature, the current outside wet bulb temperature, and the evaporative efficiency of the evaporative cooler (typically provided in product brochures under Performance Data). This should provide a guide to approximate discharge air temperatures.

What should I do if I won’t be using my evaporative cooler for a period of time?

Always drain the water from the cooler and start with fresh water if it has not been in operation for a week. If you are shutting down the cooler for an extended amount of time or the season, drain the water and clean the cooler. Cover cooler after cleaning.

What is a portable evaporative cooler?

A portable evaporative cooler requires no installation or wiring and can be used anywhere spot cooling is needed. Suited for residential and commercial applications, use portable coolers to cool rooms, offices, garages, workshops, garden centers, auto shops, dog kennels, outdoor tents, horse stables, exercise areas, industrial plants, commercial kitchens, farming (i.e. poultry, hog, and dairy buildings), laundries, dry cleaners, and greenhouses.

Where should I place a portable cooler?

The most important thing is to place a portable evaporative cooler where there is plenty of fresh air. The best position is adjacent to an open window or external door with additional openings on the opposite side of the room for relief air. This placement will provide the most cooling comfort.

How often should I clean a portable evaporative cooler?

Empty and replace the water reservoir at least once a week with fresh, clean water to reduce scale or mineral deposits from building up on the pad. At a minimum, clean your cooler (water system and filters) at least once during the season or more periodically depending on usage. This will help maintain the high performance of your cooler. Refer to your Owners Manual for required maintenance and scheduling.

Sizing Your Cooler

Chart below is a “Rule of Thumb” Guide Only Not a Substitute For an Engineered Calculation
When in doubt, always choose one size larger


  1. Consult zone map to find correct zone
  2. Consult table to find correct “minutes per air change” for your zone
  3. Determine area to be cooled in cubic feet (building length x width x height)
  4. Divide cubic feet (step 3) by minutes per air change (step 2) to determine CFM
  5. Select correct Champion Cooler model according to CFM and expected static pressure


If CFM falls between models, choose the larger model

Interior Heat Load:

High means places with unusual heat sources from hot equipment or processes, crowded conditions, etc.

Normal means no unusual heat sources – typical home or office.

Exterior Heat Load:

Exposed means walls, roof exposed to the sun, poor insulation, etc.

Insulated means walls and roof well insulated and/or shaded.


A house in Phoenix AZ, 40 feet long by 30 feet wide with an 8-foot ceiling. Insulated, no unusual heat sources.

30 x 40 x 8 = 9,600 cubic feet
Zone: 2
Minutes per Air Change: 2
9,600 / 2 = 4,800 CFM

A 4800 CFM Cooler model is indicated.

Select An UltraCool Unit for Your Area

See the map and chart below to help you select
a proper sized UltraCool Unit for your home

Select area A, B or C where you live from the map
See the approximate square footage you’d like to cool on the chart
Select the UltraCool Model that best matches your square footage
Note: Aspen pad type coolers must be a larger cfm size to do the same areaCalculations based on approximately 80º F room temperature with 8′ ceilings
Always choose the next larger size up when in doubt

Note: Beginning with the gray area and Eastward,
evaporative cooling efficiency decreases tremendously.
Evaporative cooling can still be used,
especially for greenhouse cooling & humidification.

Map for cooler selections
Approximate Square Footage To Be Cooled
UltraCool Model Number
Zone A
Zone B
Zone C
Side Draft
Down Draft
ASA 50
ADA 50
ASA 50
ADA 50
ASA 70
ADA 70
ASA 70
ADA 70

What is Evaporative Cooling?

Evaporative cooling is a method of converting hot air into a cool breeze using the process of evaporating water. It is similar to the cool refreshing effect you feel when you immediately step out of a pool.

Evaporative coolers utilize the natural process of water evaporation along with an air-moving system to create effective cooling. Fresh outside air is pulled through wetted filters that cool the air through water evaporation. A blower wheel then circulates the cool air throughout a room, home, or business.

Cooler Temperatures – More Comfort!

Evaporative air cooling creates cooler temperatures a number of ways:

  • It lowers actual temperature and will nearly always deliver cooler air under a wide variety of typical summertime climatic conditions.
  • It lowers effective temperature – the temperature you feel – by at least an additional 4º to 6º. In some cases, the temperature will be lowered more, depending on relative humidity. The rapid motion of cool air increases skin surface evaporation resulting in body heat loss.
  • It reduces radiated heat. The constant flow of cool air absorbs heat from all exposed surfaces and results in a reduction of the heat radiated by the human body.

Environmental Benefits

Evaporative cooling provides 100% fresh, cool air continuously while traditional refrigerated air conditioning utilizes a closed system that recirculates the same stale, dry air over and over. Constant air movement of the evaporative cooler pushes hot air out removing dust, pollen, smoke, odor, and pollution and replaces it with cool fresh air.

Unlike air conditioning, evaporative cooling does not require an airtight structure to operate at maximum efficiency. In fact, you need to allow your home to “breathe.”

Opening doors and windows or installing VENTMATIC™ vents to let air escape to the attic properly ventilates your home.

Evaporative cooling is also an environmentally-friendly alternative to air conditioning since it has no CFC’s or HCFC’s.

Energy Savings
Evaporative coolers use 70% less power than air conditioning.

A 1500 square foot home is located in Phoenix, Arizona where the dry bulb temperature is 107, the wet bulb temperature is 71, and the wet bulb depression is 36.

Air Conditioner

Assuming air conditioning supplies 500 square feet of cooling per ton, 3 tons of air conditioning would be required to cool a 1500 square foot home. Since an air conditioner would probably run most of the time in this climate, its electric usage would be approximately 3.6 kW per hour depending on your utility.

Evaporative Cooler

Using a Champion or Tradewinds cooler with a minimum of 5000 CFM and ¾ horsepower motor, total power consumption (motor and pump combined) would be approximately 0.991 kW per hour.


If the air conditioner and the evaporative cooler ran for a comparable period of time, the ratio of energy for the evaporative cooler to the air conditioner would be 0.991 kW per hour to 3.6 kW per hour, or 0.275. This means the evaporative cooler would use 72 ½% less power than an air conditioner to cool the same area in the same environment.

Energy Cost Savings

Assuming a new energy cost of .14¢ per kWh, this comparison would result in a possible net savings of ($362.88 – $99.89) = $262.99 each month! With this type of savings, evaporative coolers are a significant cost effective alternative to air conditioning.

Why Is There An Odor From My Newly Installed Cooler Pad?

When a new Rigid Cooling Media pad is installed in evaporative coolers, there is usually a slight odor emitted.
This slight odor will dissipate and be gone after a short period of time.

When these pads are first wet out a slight odor may occur from the dust created when the pad is manufactured and cut to size.


The operation of this type cooling pad requires a wet out period (typically several hours without airflow) followed by draining and refilling the sump water pan. This will remove the small amount of residue in the media that would be the source of the odor. This operation may have to be repeated on larger systems that do not drain completely.

All evaporative cooling systems have odor problems related to the system cleanliness. This is how ‘swamp coolers’ first got its name. When left UN-cleaned, they would start to smell like a swamp. All cooling media require cleaning, both initially, and ongoing. All cooling pads of this type are manufactured using the same base resin materials and have the same odor associated with them. All new cooler pads have a ‘new pad’ odor that dissipates with use. Once the pads are ‘broken in’, this odor will disappear. The once active ingredients in the paper of the cooling pad are rendered inert during the manufacturing processing, however, the odor from these materials lingers until the pads are washed clean by the wetting process after installation.

Click Here For:
Installation Instructions