Zeta Rod Blog

US Army Corps of Engineers Publishes Report on Cooling Tower Water Conservation Using Zeta Rod

The US Army Corps of Engineers Engineer Research & Development Center (USACE-ERDC) has been evaluating the Zeta Rod for over four years at four different military bases. 

The main purpose of the evaluation was to be able to determine whether the Zeta Rod could help reduce the amount of water used by evaporative cooling systems in order to meet the water conservation requirements set by Executive Order 13423 while maintaing proper levels of protection against scaling, corrosion and biofouling. 

The first phase to the project was done at Davis Monthan AFB and Fort Huachuca in AZ. The full report has been published by the USACE. 

The results encouraged the USACE to expand the project and include two more bases: Warner Robins AFB in Georgia, and Ft Irwin in California. These two bases were selected given the quality of their water. W-Robins water is extremely soft and corrosive by nature whereas Ft. Irwin's water is extremely hard and with a very high potential for scaling. Davis Monthan and Ft Huachuca's water fall in between these two and remained as part of the project.

The 2-year second phase is scheduled to end in August of 2011 and a final report will be available by December 2011 or January 2012. 

In the meantime, the USACE-ERDC has already been publishing the results from this project. In their website they have published a paper titled: "Electronic treatment reduces water, chemical use in evaporative cooling systems." 

The USACE-ERDC also gave a presentation in the 2011 USACE Infrastructure Systems Conference in Atlanta, GA. Download Non-Chemical Treatment of Cooling Water - Beitelman .

For more information on how can the Zeta Rod help meet water conservation targets in Federal Buildings or help with LEED credits, contact Zeta Corporation at (888) 785-9660.

 

 

US Army Corps of Engineers' Engineer Research & Development Center Reports 20% Water Savings in Cooling Towers with Zeta Rod

From July 2007 to September 2008 the US Army Corps of Engineers' Engineer Research and Development Center (ERDC)conducted an independent and thorough comparative study between the Zeta Rod and a conventional chemical water treatment program for cooling towers. Two sites were chosen for the study, Davis Monthan AFB in Tucson, and Fort Huachuca in Sierra Vista, AZ.

The study looked at corrosion, scale and biofouling control as the parameters to be used as the metric to evaluate both programs, however, the ERDC had a special interest in water saving capabilities in order to meet requirements set by Executive Order 13423 regarding water conservation. 

This study was also the launching platform for the Zeta Water Management System, which allows remote control, data logging and monitoring of a cooling tower.

The Abstract of the report reads:

 The United States Department of Defense (DoD) has a specific legislative mandate to increase its conservation of water and energy. It also is interested in improving the effectiveness of open-loop, cooling water treatment processes at its installations worldwide, for purposes of extending the useful life of evaporative cooling equipment and reducing energy use/costs. A Cooperative Research and Development Agreement (CRADA) was approved to demonstrate that, without using chemical additives, a capacitor-based water treatment system is capable of (1)providing equivalent protection to a chemical treatment program in preventing scale, corrosion, and bio-fouling; (2) allowing cooling systems to be operated in an enhanced water conservation mode; (3) delivering measurable reductions in water usage over conventional methods; and (4)providing control, monitoring, and wireless data transfer via the Internet.

Results documented in the subsequent demonstration and evaluation project showed the technology was able to meet every objective and also was able to deliver a 20% reduction in cooling water use over standard chemical treatment methods.

Application of this technology would allow the DoD to (1) reduce chemical usage, exposure, and disposal expenses; (2) conserve water and energy; (3) facilitate water re-use; and (4) meet new goals for conservation of resources.

The complete report can be read and downloaded by going to the following link.

 

Another Satisfied Customer

We received the following unsolicited email from a residential customer in Scottsdale, AZ:

Dear Zeta,

I wanted to write to you and thank you for your wonderful product!  After using it for several months now, I noticed that my pipes were beginning to clear out.  I discovered this because the screens in my faucets started collecting debris and had to be cleaned out repeatedly for a short period of time.  I’ve also noticed that I’m not getting the hard water buildup in my showers like before.  The water here in Scottsdale is extremely hard, and I struggled with it for years.  Now, while I still get some white spotting, none of it sticks!  I’m able to clean the glass and faucets right off with no trouble at all.  Also, it’s nice to be saving the considerable amount of time and money I was spending for the lease and maintenance of my old salt water softener.    

I would highly recommend this product for anyone’s home.  Thank you Zeta!

Regards,

Heidi Bryant

Scottsdale, AZ

The internet has many web forums in which people ask for opinions on several topics. The Zeta Rod has been questioned in several of these forum. Usually negative opinions are given by "trade experts" who have not used, or tested a Zeta Rod. Their opinions are based on their "previous experiences". However, those who have used the Zeta Rod have positive comments about the technology, such as the following entry that was made in one of those forums:

• Posted by dtrimmer (My Page) on

  Tue, Jul 14, 09 at 20:27

I think a lot of the criticism of the Zeta Rod system on this forum has been a bit unfair. First, I have no association of any kind with Zeta Rod. I don't sell or install water conditioning equipment. I do have a degree in chemistry. First, Zeta Rod DOES NOT claim to remove calcium and other dissolved minerals from your water. In fact, they have been very clear that they DO NOT remove anything. Therefore, and chemical test of water that has been conditioned with a Zeta Rod system will have exactly the same chemical composition as the water prior to the test. If you collect some Zeta Rod conditioned water and let it dry, you will get a deposit -- again, exactly what Zeta Rod states. What Zeta Rod DOES claim to do is to keep minerals dissolved in the water, so that they do not precipitate on (coat for the non-chemists) pipes, dishes, sinks, etc. (at least prior to the water evaporating). Zeta Rod also claims that any scale present due to evaporation will be easier to remove than normal scale. I have been using a Zeta Rod system for almost two years and my experience is that both of Zeta Rod's claims are true. Here are the trade-offs between a Zeta Rod and a traditional water softener; at least as I see them: 1. A Zeta Rod system may have a higher installation cost, but a lower operating cost. 2. In municipalities where traditional water softeners are not allowed, the Zeta Rod is a LOT better than nothing. 3. A traditional water softener will remove metals from your water -- the Zeta Rod will not. However, the Zeta Rod does appear to prevent the metals from depositing on pipes and other surfaces (as long as the water is not allowed to evaporate). During the first few months of use, the Zeta Rod also appears to remove any existing scale that has built up on pipes. Based on my personal experience, the Zeta Rod appears to be MORE effective than a salt based water softener at preventing scale buildup on pipes. 4. While the Zeta Rod does not remove anything from the water, it also does not add anything to the water. A traditional water softener replaces metals (usually calcium and magnesium) with sodium and/or potassium, depending on the kind of salt used with the water softener. 5. A traditional water softener should prevent water spots. A Zeta Rod will not prevent water spots. 6. The Zeta Rod system is MUCH smaller than a salt based water softener. If I had to install a new system and salt based water softeners were legal in my area, it would be a pretty close call for me. I would probably opt for the Zeta Rod system because of lower operating costs, smaller size and not lower maintenance (don't have to mess with bags of salt). Cheers, Don

 

Zeta Rod and Tankless Water Heaters

One of the most frequently asked questions we receive from potential residential Zeta Rod customers is whether the Zeta Rod will help protect their Tankless Water Heater from scaling. The answer is: "Yes, the Zeta Rod will prevent scale deposits from forming on the tankless water heater pipes".

The following is a brief description on how tankless water heaters work and why are they susceptible to scale deposits forming on their pipes.

Tankless water heaters are gaining popularity over the older tank water heater model. Some of the advantages that tankless water heaters offer over the older tank design include: reduced floor space, lower energy consumption and endless hot water available on demand .

Tankless water heaters work by rapidly heating the water in a heat exchanger to the desired temperature as the water flows through the heater. The burner of the unit only turns on when there is demand for hot water, this is how it is able to use less energy while providing endless hot water. Older model hot water heaters store water in a tank and heat it up with a burner (or electric heating elements) when the water drops below a certain temperature. This has the inconvenience that the burner may turn on even when there is no demand for hot water.  The following diagram shows a simplified version of a tankless water heater.

Because of the design of the tankless heaters, the water is heated at a very fast rate, forcing the water to come in contact with very hot surfaces on the pipes as it goes through the heat exchanger. This provides conditions that favor minerals in the water to precipitate and form scale deposits on the tube  walls. In places with hard water the problem is exacerbated and precautions must be taken to prevent scaling of the heat exchanger tubes.

Mineral scale is primarily composed of calcium carbonate (hardness in the water) which precipitates from the water under certain conditions (such as high temperature, high pH or high concentrations). Scale has a very low heat transfer coefficient, or thermal conductivity. The thermal conductivity of copper is 384 W/(m*K) and the thermal conductivity of scale is 2.6 W/(m*K). This means that scale is about 140 times less efficient in transferring heat than the copper which is used in the tankless heater pipes. The following graph shows the amount of energy increase that would be required to overcome a layer of scale.

The lower thermal conductivity  of scale has a direct negative effect on the performance of the tankless water heater. Since the amount of heat transfered to the water is reduced, the unit would have to operate at a higher rate in order to try to get the water to the design temperature, which in turn would result in higher energy consumption. If the scale is thick enough, the unit may not be able to heat the water to the desired temperature at all. And if scaling is very aggressive, water flow can be restricted through the unit and it eventually could lead to tube failure.

The Zeta Rod is an ideal low cost and environmentally friendly option to prevent scale formation in tankless water heaters. A Zeta Rod installed in the main water line entering a home will protect the tankless water heater as well as all the fixtures in the house. The following pictures are courtesy of R&G Sales and show a Zeta Rod displayed with a Noritz Tankless Water Heater at Central Arizona Supply. At this show room's display the Zeta Rod protects the tankless heater and the shower fixtures. This picture shows the small floor space that both the tankless heater and the Zeta Rod take.

Scale Control in Potable Hot Water Heaters at Houston Airport.

We have received from many potential customers the question:

-"Will the Zeta Rod work for my hot water heater?".

Apparently many have heard from some "Internet self proclaimed water experts" that the Zeta Rod does not work in hot water applications.

The short answer to the question is: YES.

As an example, we have the Houston Intercontinental Airport. Back in 2000 it was going through a major expansion project involving all terminals.

One of the problems that the engineering firm in charge of the project was facing was a severe calcium precipitate fouling problem with the domestic hot water generators. The heat exchangers (HX) had historically been plagued by persistent fouling on the domestic water (shell) side due to the high temperature of the heat source on the tube side. HX tube bundles would become clogged with fouling annually before we installed the Zeta Rod.

The Airport did not want to consider a water softener as an option because of the inconveniences and costs associated with the operation and maintenance of these systems.

The Zeta Rod was then considered and a trial was set for one of the older units in one of the airport terminals. The HX bundle used in the test was already partially fouled when the pilot program was began but replacement of the bundle was postponed.  About 6 months after the Zeta Rod was installed, the HX bundle was pulled for scheduled replacement but the fouling was found to be reversing from the prior inspection!!  The client was so impressed with the results that Zeta rods were installed on all domestic hot water generator applications. Picture on the right shows two Zeta Rod electrodes installed in the return line to one of the potable hot water heaters in one of the terminals.

Following the success of the hot water systems, the Zeta Rod was then implemented in the Central Cooling Plant to help with fouling problems in the Condensers.

The same principle that allowed the Zeta Rod to protect these large hot water heaters is the principle that applies to your home unit.