This document discusses an evaporative cooling system that uses water spraying and evaporation to cool hot outside air before it reaches condenser coils. On 100 degree days, this system can lower the air temperature to 79 degrees, reducing energy usage. Case studies show energy savings ranging from 15-30% depending on cooling degree days. In addition to energy savings, the system reduces maintenance needs, increases equipment lifespan, and lowers water usage compared to traditional energy production.

1. A Simple Principle
Hot outside air is cooled as it passes
through the frame, before it reaches the
condenser coils. This is done by spraying
water and using evaporative cooling. This
is same principle as cooling towers.
This allows the system to operate as
though it were cooler outside than it
actually is.
On recent 100 degree days (73 wet
bulb), in a humid Southeastern U.S.
climate, the leaving air temperature of
the system entering the condenser is
79.2 degrees!

2. Using Evaporative Space Cooler
(AKA “Swamp Cooler”)
Standard Air Conditioned Space
81° and
85%
relative
humidity
55°
Dehumidifed
Air

3. Standard Unit Unit with Pre-cooler
Using Evaporative Space Cooler
(AKA “Swamp Cooler”)
Standard Air Conditioned Space
81° and
85%
relative
humidity
55°
Dehumidifed
Air
95° to
100°+
81.5°

4. The Systems:
• Reduce Energy Use. Typically 20%+ of
compressor energy. Typically 2-4 Year
Paybacks
• Reduce Demand Charges
• Reduce Overall Maintenance
• Increase tonnage capability
• Reduce Head Pressure
• Increase system reliability
• Protect Coils from Dust, Debris and
Damage
• Extend the life of HVAC equipment
• Minimal Maintenance.

5. Helps keep building comfortable even when 100
degrees plus outdoors
Modest water usage
Financing available so that the system can “Pay For
Itself”

6. Water is typically NOT sprayed directly on the condenser coils. In addition, the water is usually treated
to remove minerals (calcium and magnesium mainly).
Pressure usually provided by domestic water pressure. Booster pump can be used if needed..
Air pressure drop thru media needs to be minimized.

7. SensorsMicroprocessor

8. Houston, TX
Sample Installations
Air-Cooled Chillers

9. Atlanta, GA
Sample Installations
RTU

10. El Dorado Hills, CA
Sample Installations
RTU - High Efficiency DX-Style

11. Memphis, TN
Sample Installations
Remote Condensing Units
Horizontal EZ-Frame Installation

12. El Dorado Hills, CA
Sample Installations
Refrigeration Units

13. Customer Case Studies
The following case studies demonstrate energy savings.

14. TESTING PROCEDURES
All data is sorted according to the Cooling Degree Days…
Definition: COOLING DEGREE DAY (“CDD”)
A unit used to relate the day's temperature to the energy demands of air conditioning. One cooling
degree day occurs for each degree the daily mean temperature is above 65° Fahrenheit.
Examples:
Day 1 Day 2 Day 3
Min 60° 70° 75°
Max 80° 90° 105°
Mean 70° 80° 90°
- 65° - 65° - 65°
CDD 5 15 25

15. TESTING PROCEDURES
Step 1: Baseline Testing
Prior to installation of the system, a data logger* is installed on the subject HVAC equipment to
collect all applicable real-time energy consumption and unit performance information. The duration
of this test depends upon the weather at the location, but will typically last at least 2-3 weeks.
Step 2: Installation of the system
Step 3: Comparison Testing
After application of the system, real-time energy consumption and unit performance data is
collected. The duration of this test typically mirrors the duration of the baseline testing, but is also
highly dependent on the weather.
Step 4: Data Analysis
Once complete, all data is collected and analyzed by our in-house engineering department. all data is
sorted by Cooling Degree Day, as provided by the National Oceanic and Atmospheric Administration.
The average kWh consumed during the baseline testing period is then compared that consumed
after installation of the system.
*All data was collected using either an Amprobe Data Logger (Model DM-II Pro) or a Satec Event & Data Logger (Model #EDL172XR or EDL174).

16. Unit Description: 40 Ton Packaged Condensing Unit
Location: Cypress, TX (Houston Area)
Date of Testing: Summer of 2008
Customer: Large Telecom Company
CASE STUDY #1

17. Summary of Results
CDD % Savings
14 19.5%
16 29.5%
17 31.1%
19 21.5%
20 19.3%
21 20.3%
22 17.5%
CASE STUDY #1
500
450
400
350
300
250
200
150
100
50
0
339
239
363
250
393
308
395
319
425
338
Cooling Degree Day (CDD)
Without System
16 19 20 21 22
With System
14
352
283
kWh
17
332
402
Percent savings on case study is based on entire unit including condenser fans.

18. Unit Description: 20 Ton Rooftop Unit
Location: Sylmar, CA
Date of Testing: Summer of 2012
Customer: Verizon Wired
CASE STUDY #2

19. Summary of Results
CASE STUDY #2
Savings = 16585.5834 kWh
% Savings = 22.54% kWh
Demand Savings = 5.634 kW
Saving/ Ton = 0.28 kWh/ton
% Demand Savings = 20.28%

20. Unit Description: 70 Ton Chiller
Location: Prattville, AL
Date of Testing: Summer of 2009
Customer: State Retirement System
CASE STUDY #3

21. P
Summary of Results
Kwh
1700
1600
1500
1400
1300
1200
1100
1000
900
800
1,061
Cooling Degree Day (CDD)
Without system With system
16 18 19 22
1,249
1,315
1,074
1,429
1,098
1,579
1,213 16 15.1%
18 18.3%
19 23.2%
22 23.2%
CDD % Savings
CASE STUDY #3
Percent savings on case study is based on entire unit including condenser fans.

22. Additional Savings
Additional financial benefits include:
1. Peak Demand Reduction;
2. Maintenance Savings;
3. Reduced Equipment Failure;
4. Increased Equipment Life;
5. Available Tax Benefits; or
6. Potential for Utility Rebates.
The previous case studies only demonstrate savings from kWh reduction

23. “A … dirty condenser coil can
increase compressor energy
consumption by 30%.”
- Federal Emergency Management Program Fact Sheet
REDUCED MAINTENANCE
“If the coil is dirty …. [t]his raises
your electricity cost for air
conditioning and may shorten the
life of the outdoor condensing
unit.”
- Saturn Research Management
Cleaner coils means more efficient operation.

24. REDUCED MAINTENANCE
Properly cleaning condenser coils requires:
• Hours of labor spent taking equipment apart and pressure washing coils.
• Taking the unit “off-line” for this period.
• Using caustic chemicals on your facilities and handling chemical runoff.
• Immediately after cleaning, the unit begins to collect dirt once again.
• Coils are professionally cleaned upon installation, and immediately sealed
off from outside air.
• Dirt and debris are prevented from entering the system.
• Projects can go years without cleaning coils.

25. Water Conservation
• The National Renewable Energy Lab (NREL) reports: “U.S. electricity production
consumes over 20 gallons of water per KWH created.
• Other studies confirm this water usage and state that depending upon the power
plant type, the water usage can range from 10 gallons to 25 gallons of water
consumed per KWH created.
• The system uses approximately 1.9 gallons of water for each KWH saved. This
saves approximately 90% of water usage while saving electricity
• Based on national averages, on a 75 ton hvac unit, the system will use $78 of
water in a year, while saving over $7,000 annually in electricity.
• By reducing electricity demand and consumption, evaporative cooling actually
SAVES water on a global scale!”

26. Weather Underground Memphis 2012
45 Days at 95 degrees and above, 11 Days at 100 degrees and
above. Temperature on roof is even higher.
2012 Temp. (°F) Dew Point (°F) Humidity (%)
Sea Level Press.
(in)
Visibility (mi) Wind (mph)
Preci
p. (in)
Event
s
Jan high avg low high avg low high avg low high avg low high avg low high avg high sum
1 65 54 42 57 36 19 84 60 35 30.43 30.22 29.94 10 10 10 29 14 39 0.00
2 43 38 32 20 12 4 47 35 22 30.50 30.45 30.40 10 10 10 28 15 38 0.00
3 41 32 23 16 10 5 55 40 25 30.61 30.48 30.32 10 10 10 15 5 20 0.00
4 54 43 31 36 27 13 79 60 41 30.34 30.24 30.16 10 10 9 18 8 26 0.00
5 63 48 32 33 30 24 89 57 25 30.29 30.19 30.06 10 10 10 14 5 23 0.00
6 69 54 39 56 46 32 93 71 48 30.08 30.00 29.94 10 10 10 20 10 30 0.00
7 61 57 52 55 47 28 93 66 38 30.13 30.04 29.95 10 8 0 16 7 26 T Rain
8 57 53 48 41 36 28 68 53 38 30.18 30.13 30.10 10 10 10 16 7 21 T Rain
9 57 52 47 45 41 38 86 74 61 30.19 30.14 30.08 10 10 8 12 7 15 T
10 59 55 51 54 49 37 93 76 59 30.08 29.82 29.64 10 7 0 16 10 22 0.36
Rain ,
Thun
derst
orm

27. Some details of the system include:
1. Dramatically reduces the entering condenser air temperature. These systems have had a U.L. testing analysis and
thousands of systems operating successfully. On a humid, 95db/78wb outside design day, the system will cool this
air to approximately 82 degrees db. Depending upon unit type, this reduces the energy usage by 20-22% or more.
2. KW demand is reduced
3. Due to the filter media, dirt in the air is prevented from reaching the condenser coil. This saves on annual
condenser coil cleaning labor. It also increases efficiency.
4. Since the units run at a lower condensing temperature, repairs are minimized. The reason air cooled units
typically require considerably more repairs in the heat of the summer is because of the high condensing
temperatures and pressures that normally are experienced. Prevents high condenser pressure “tripping” problems
5. With the reduced condensing temperatures and pressures of the system, equipment life can be extended.
6. Typical payback periods, only counting the energy savings, are approximately 2 to 4 years. Rebates and
incentives are available in many locations.
7. This is one of the few technologies that increases energy efficiency but at the same time does not negatively
affect the room temperature.
8. Cooling capacity increased approx. 8-12 percent.
9. Large potential impact on our country’s energy usage. Comparable to the entire solar market that currently
does not have good financial paybacks.