Water treatment of cooling towers in the prevention of legionellosis

1. Cooling Tower
Water Treatment

2. • About H2O Biotech
• About Cooling Towers
• Working principles
• IAQ problems caused by cooling towers
• The old way: chemical disinfection
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Agenda
• H2O Biotech solution
• The new way : Copper + Silver Ionization System
• How it works
• Installation , operation and maintenance
• Benefits
• Sizing
• Pricing

3. Biological technologies
for water treatments
EAUBIOTECH
ENVIRONNEMENTAL
20 years in biological
water treatment
About us: some genealogy
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18 years in energy
engineering consulting
Distribution of ingenious products to
help reduce environmental footprint
16 years in
UV air treatment

4. Our product lines
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Public Pools &
Water Parks
Cooling towers
Sanitary Hot
Water Systems
Copper -
Silver
Ionization
UV
Disinfection
+
sediment &
filtration
Potabilization
Reverse
Osmosis
UV
Ozonation
Spa
Therapeutic Baths
Laundromats
Fountains

5. Cooling towers are the outside
heat sinks that exhaust the heat
carried by the air conditioning
cooling water circuit used in
buildings HVAC systems.
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What is a cooling tower?
Pump
HVAC
Air
conditioning

6. www.h2obiotech.com
What is a cooling tower?

7. Step 1:
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How it works
Step 2:
Magic of evaporation
Liquid water + energy Water vapor (with less energy remaining in the liquid)
Evaporative cooling

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How it works (in a bio-clean world !)
Dry air
Humid air (evaporated water)
+
Water loss (drift)
Dry air
Warm water
from AC
Cool water
to AC
Demister
Water distributor
Fill
Fan
Water make-up
Typically between
85 and 95 °F.

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In the real “dirty” world…
Dry air Dry air
Wind
Building “fresh
air” intake louvers
Building “fresh
air” intake louvers

10. Simple definition:
An ubiquitous aquatic organism that causes Pontiac Fever
and Legionnaires’ disease (lung infection) if inhaled.
Thrives in temperatures between 77 and 122 °F.
Travels from infected water source through aerosolized water
droplets.
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Legionella pneumophila
In the United States…
• 10,000 to 20,000 people get infected by legionella every year.
• Various studies have shown that some 40 to 60% of tested cooling towers contained Legionella.
• Legionnaires’ disease mortality rate: 10 to 15% of those infected.
Cooling tower drift

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Biofilms
• Form on surfaces in aquatic systems.
• Often resistant to biocides.
• Monitoring is difficult.
• Release organisms into bulk fluid.
• Cost the US nation billions of dollars yearly in equipment damage, product
contamination, energy losses and medical infections.
Bacteria

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The old way
Make-up
Warm water
Cool waterBlow-down
CHEMICAL$$$
(transport, storage, handling)

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The H2O Biotech way
Make-up
Warm water
Cool waterBlow-down
Copper - Silver ionization system
Corrosion inhibitor

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The H2O Biotech alternative
Going from this:
Oxidizers
or others
Cu++ + Ag+ Ionization
system
To this:
Scale
inhibitor
Corrosion
inhibitor
pH
regulator
Biocide
Algaecide
Corrosion &
Scale
inhibitor

15. www.h2obiotech.com
Copper - Silver Ionization
Input: 110-240VAC 50/60Hz
Output to electrodes: 0 to 42V

16. Copper
A natural algaecide
Ex: copper cook ware
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Copper - Silver Ionization
Copper + Silver disinfection is a natural proven method for
elimination of water-borne pathogens and algae.
And others approve the use of Copper & Silver Ionization to control and prevent water infections.
Providing adequate dosage of Cu++ and Ag+ ions in water,
results in 99.9999% ( 6 Log ) kill rate.
Silver
A natural bacteria inhibitor
Ex: silver utensils

17. www.h2obiotech.com
Installation
Pump
Cu++ + Ag+ chambers
standard installation
HVAC
Air
conditioning

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Copper - Silver Ionization
The ionization chamber contains
sets of pairs of electrodes made
from a calibrated copper-silver
alloy.
A safe and low DC voltage is
applied to the electrodes.
Water flows between the
electrodes and picks up the
Copper and Silver ions that are
released everywhere in the water
system.
+ -
Power
Supply

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Copper - Silver Ionization
And it doesn’t stop there…
Less Chemicals = Less added minerals
• Reduced blow-down
• Less make-up water consumption
• Less scale
• Less corrosion
=

20. Measure the copper
concentration in the water
with the tester kit.
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Operation settings
As required, increase or decrease the ion
production rate with the voltage knob.
Silver concentration follows proportionally
Step 1: Step 2:
Only 5 minutes, twice a week!!!
99.9999% disinfection requires:
0.4 ppm of Cu++ ions to control algaes
Traces of Ag+ ions to control bacterias

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Maintenance
H2O Biotech Cu++ + Ag+ System uses a unique polarization inverting
technology that minimizes the scale build-up on the electrodes and
equalizes the electrodes’ wear-out. Nevertheless, it is recommended
that the electrodes be mechanically cleaned every two to four weeks.
Step 1:
15 minutes, every two to four weeks!!!
Step 2: Step 3:
Typical life expectation of a set of electrodes: between 8 and 16 months.
Shut power off.
Isolate unit using the
bypass valves and
open the hinge lock.
Brush and rinse each
electrode plate with fresh
water to remove scale
Reinstall
electrodes
and restart .

22. www.h2obiotech.com
Benefits
• Powerful algaecide and bactericide
• Eliminates the Legionella and other bacterias &
viruses
• Both curative and preventive action
• Penetrates the biofilm and acts directly at the
stump
• Effective throughout the entire water system, not
just on passing water

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Benefits
• Not affected by temperature
• Non-corrosive
• Does not destabilize water pH
• Minimal maintenance
• Compact and easy to install

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Benefits
• Eliminates all chemicals except corrosion inhibitor
• Reduces the build-up of scale and blow-down rate
• Eliminates the algae surface coating resulting in
better heat transfer and lower energy cost
• Extends the lifespan of the cooling tower and coils
system
• Generally pays for itself within 1 or 2 years
maximum
Which means cost saving!

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Benefits
• Less water consumption
• Substantially reduces airborne
toxic chemical drift
• Substantially reduces the risks
of incidents inherent to chemical
transport and handling
• Eligible for Green, LEED and
Toxic release inventory points
And a greener environment

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LEED points
Ionization devices on cooling towers have been shown to providing or contribute
to provide LEED points in these categories:
Water efficiency : Cooling tower water management (1 point) (for existing building only)
Develop and implement a water management plan for the cooling tower that addresses chemical treatment, bleed-off,
biological control and staff training as it relates to cooling tower maintenance.
Develop a water management strategy addressing treatment and bleed-off to ensure proper concentration levels in the
cooling tower. Also, develop a program to avoid biological contamination and the risk of Legionella in the building.
Innovation in design (1 to 2 points)
To provide design teams and projects the opportunity to achieve exceptional performance above the requirements set by
the LEED Green Building Rating System and/or innovative performance in Green Building categories not specifically
addressed.
Credit can be achieved through any combination of the Innovation in Design and Exemplary Performance paths.
Substantially exceed a LEED 2009 for New Construction and Major Renovations performance credit such as energy
performance or water efficiency.
Water Efficiency : Water use reduction (2 to 4 points)
To further increase water efficiency within buildings to reduce the burden on municipal water supply and wastewater
systems. Requirements: employ strategies that in aggregate use less water than the water use baseline calculated for the
building.

27. www.h2obiotech.com
Sizing
Cooling tower tonnage, flow-rate, total water volume,
system operating pressure.
Function of…
Capacity
Daily blow-down, daily make-up, days in operation per year,
use of other chemicals.
Operation
Location, feed water analysis, environmental conditions.
Others
Questions such as system operating pressure, piping material and diameter, filling material,
etc., are also asked to the customer to make sure our product is fully compatible.
Always maintain 0.4 ppm Cu++

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Sizing
Questionnaire Biological Technologies
For Water Treatments
www.h2obiotech.com
144, Barr St., St-Laurent, QC, Canada, H4T 1Y4 Tel. : (514) 739-1001 Fax : (514) 382-8488
Evaporative Cooling Tower Information:
Owner Contact Person
Location of the Cooling Tower (Full Address) Telephone Fax
Email
Cooling Tower Manufacturer Model
Serial Year of Built Year of Commissioning
Fill material (plastic, aluminum, etc.) Basin heater
○ Yes ○ No
De-Scaling Device
○ Yes ○ No
Cooling Tower Tonnage (ton or BTU/hr) Cooling Tower Flow-rate (gal/min)
Inlet Water Temperature (o
F) Outlet Water Temperature (o
F) Total Water Volume (in the evaporation circuit, gal)
Wet Bulb Temperature (o
F) Number of Cell System Operating Pressure (psi)
Daily Blow-Down Volume (gal) Blow-Down TDS (ppm) Chemical Products Used (type, annual consumption, by hand or by
dosing pump)
Daily Make-Up Volume (gal) Make-Up TDS (ppm)
Concentration cycle Make-Up Water Temperature (o
F)
Days of Operation Per Year Average Loading (%)
Please use the back to make a sketch of the water circulation pipes of the evaporative circuit.
Indicate the diameter and material of the pipes.

29. www.h2obiotech.com
Sizing approximation
Systems for Cooling Tower
Tower Size* Model
300 tons IOCH-1P
up to 600 tons IOCH-2P
up to 900 tons IOCH-3P
up to 1,200 tons IOCH-4P
up to 1,800 tons IOCH-6P
up to 3,600 tons IOCH-12P
* For reference only (based on a typical cooling tower in operation for 150 days per
year at a load of 80% on average – electrodes will last for a year)
Options and parts
Pair of electrodes
Teflon electrode support
Copper tester kit
Control box cooling system
(If the ambient room temperature exceeds 104 oF)
1 Cooling Tower ton
= 1.25 HVAC ton

30. www.h2obiotech.com
Pay off
Copper - Silver Ionization benefits
As an example, a 400-ton cooling
tower will typically use $8,000
worth of chemical products. The
same tower equipped with our
Copper - Silver Ionization water
treatment system will only use
$2,000 worth of consumables
while providing water, sewage
and energy savings of $6,000*.
400-ton cooling tower
ROI = 21 months
* Varies with municipality regulations and climate.

31. www.h2obiotech.com
Publications
“Copper-Silver Ionization distorts the permeability of the Legionella cell, denatures proteins, and leads
to lysis and cell death. A commercial system can be easily installed to perform this ionization. Copper-
silver ionization is less expensive than hyperchlorination and provides residual protection throughout
the water distribution system.”
Legionella: Human Health Criteria Document, Environmental Protection Agency (EPA)
“Legionella are known to enter cooling tower systems in the make-up water. (...) Stagnant areas or dead
legs may be difficult to clean or penetrate with biocides. (...) Cooling towers have been implicated in
numerous outbreaks of Legionnaires' disease, and studies have shown that detectable levels of
Legionella are present in many, if not most, such devices. (...) Metallic ions, namely copper and silver,
effectively control microbial populations.”
Minimizing the Risk of Legionellosis Associated with Building Water Systems, ASHRAE
“Copper-silver ionization can eradicate L. pneumofila (most virulent form of Legionella) in a water
distribution system. The advantages of copper-silver ionization include relatively low cost,
straightforward installation, easy maintenance, nontoxic by-products, and the presence of a disinfecting
residual. (…) When the ionization unit was inactivated, water fixtures continued to be free of Legionella
species for two additional months.”
Departments of Medicine and Engineering, University of Pittsburgh

32. Thank you!