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GEA's Global HVAC Technology Blog

GEA's Global HVAC Technology Blog covers a range of topics including:

  • Core HVAC Technologies
  • Technology & Patent Evaluation
  • Manufacturing Technologies
  • Product Quality Improvement
  • Materials/Failures/Corrosion
  • Product/Technology Commercialization
  • Business Strategy Development
  • New Factory Design & Equipment

We'll draw upon our range of experts to provide comments, insights, technical articles and a little humor from time to time

We encourage your participation and feedback!

Trane Introduces HFO1233zd in Series E Centrifugal Chillers

Posted October 22, 2014 9:23 AM by larhere

Trane introduced the first chiller using R1233zd at the Chillventa Expo last week in Italy. Air conditioning manufacturers are scrambling to comply with the revised EU F-gas Regulation going into effect 1/1/2015 limiting and banning "F Gases" in the EU.

HFO 1233zd is described as a single component refrigerant, both low toxicity and non-flammable. It was originally developed for use as a blowing agent but has also been found to be a high efficiency alternative to R123. It has been submitted for ASHRAE designation and classification and is expected to be classified as A1. Its GWP is low, listed under the F-gas regulations as 4.5 but variously described as 6, by UNEP, or 1, by Honeywell.

According to the announcement...

The Trane Series E CenTraVac is a large-capacity chiller (capacities from 2600kW to 14,000kW) for applications like comfort cooling of large commercial buildings including district cooling. It is available in Europe, the Middle East and other 50Hz markets, and received Air-Conditioning, Heating and Refrigeration Institute (AHRI) Certification.

Honeywell markets the new refrigerant under the tradename Solstice zd, a US SNAP-approved alternative to R123 and 245fa. It has a GWP of 1. It will have applications in large centrifugal chillers, organic Rankine cycles and high temperature heat pumps.

Also Read:

U.S. EPA Moves to Phase-out Familiar HFCs

Editor's Note: CR4 would like to thank Larry Butz, President, GEA Consulting Associate, for contributing this blog entry, which originally appeared here.

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Manufacturing Cost Competitiveness is Changing Worldwide

Posted October 10, 2014 2:00 PM by larhere

Boston Consulting Group, BCG, just released a "must read" report "The Shifting Economics of Global Manufacturing" if your company manufactures in multiple international locations. What is so great about this report is that it presents, analyzes and summarizes a 2014 study on the cost competitiveness of the top 25 exporting nations, an update of the previous study done in 2004. It is

  • available online at the BCG Perspectives website (no cost)
  • contains an interactive Cost competitiveness Index tool
  • a readable 12 to 15 pages in length
  • has great illustrative graphics

(Disclaimer: GEA receives no compensation and does not have a business relationship with BCG. We are excited about good work on a critical topic for manufacturers around the world. This includes the global HVAC industry. Our compliments and thanks to BCG for this fine work and the sponsors who paid for the study.)

The study analyzed manufacturing costs for the world's 25 leading exporting economies along four key dimensions: manufacturing wages, labor productivity, energy costs, and exchange rates.

What BCG found was a lot of change...Who would have thought a decade ago that Brazil would now be one of the highest-­cost countries for manufacturing-or that Mexico could be cheaper than China?...or that China's estimated manufacturing-cost advantage over the U.S. has shrunk to less than 5 percent. Brazil is now estimated to be more expensive than much of Western Europe.

Cost structures in Mexico and the U.S. improved more than in all of the other 25 largest exporting economies. Because of

  • low wage growth,
  • sustained productivity gains,
  • stable exchange rates, and
  • a big energy-cost advantage,

these two nations are the current rising stars of global manufacturing. BCG estimates that Mexico now has lower average manufacturing costs than China on a unit-cost basis.

The authors conclude "These dramatic changes in relative costs could drive a large shift in the global economy as companies are prompted to reassess their manufacturing footprints. (See Exhibit 3.)

One implication is that global manufacturing could become increasingly regional. Because relatively low-cost manufacturing centers exist in all regions of the world, more goods consumed in Asia, Europe, and the Americas will be made closer to home."

There are profound implications for manufacturers with operations in all countries. They must (continue to):

Enhance productivity. As once-enormous gaps between wages in developed and developing economies continue to shrink, improving the value added by each worker is becoming an increasingly important factor in manufacturing competitiveness across the globe

Account for the full costs. While direct costs such as labor and energy will continue to have a strong influence on decisions about where to manufacture, logistics, obstacles to efficiently conducting business, and the hidden costs and risks of managing extended global supply chains, for example, can offset much of the savings from labor or favorable exchange rates. It is also crucial to take into account hidden cost advantages of operating shorter supply chains, such as speed to market, greater flexibility, and a better ability to customize products for specific markets.

Consider the implications for the broader supply chain. Reliable local suppliers may not yet be available to provide important inputs. In other cases, deconstructing the value chain could involve added logistics costs or unanticipated tariffs, duties, or other penalties.

Promote better business environments. Maintain a dialogue with relevant regulators and policy makers in countries in which you manufacture.

Reevaluate your business model. To take full advantage of production in an economy, a one-size-fits-all model that uses the same processes and materials is unlikely to be optimal. Many companies should consider adjustments in their products or business models to better meet the needs of that manufacturing environment. It may make sense to use different materials that are locally available.

The shifting economics of global manufacturing requires approaching the world with a fresh mind-set. Rather than seeing the globe in terms of low cost versus high cost, manufacturing investment and sourcing decisions should increasingly be based on a more current and sophisticated understanding of competitiveness within regions.

Read the complete report here

Editor's Note: CR4 would like to thank Larry Butz, President, GEA Consulting Associate, for contributing this blog entry, which originally appeared here.

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Corrosion Diagnosis - Understanding the Environment

Posted October 01, 2014 3:16 PM by psikorsky

In my previous blog post I said we would take a more detailed look at each of the elements in the 6 step process I suggested for addressing corrosion issues in HVAC equipment.

1. Identify the corrosion mechanism.

2. Understand the environment, both external and internal.

3. Understand the equipment - materials of construction, operating cycles, hours.....

4. Identify alternatives - materials, coatings, limiting operating envelope, changing the environment (water treatment, alternative lubricants/refrigerants, filter the air, etc.), redesign the machine (better drainage, eliminate contact of dissimilar metals, .....)

5. Implement change.

6. Monitor results.

In that last post I went on to address step 1, so now the time has come to look at step 2:

2. Understand the environment, both external and internal.

If we consider that the purpose of step 1 in this process was to determine how things are failing, the purpose of the next couple of steps is to determine why things are failing. Understanding the environment an air conditioner or heat pump operates in is usually pretty straightforward, but there are pitfalls, particularly as that environment relates to corrosion failures. Particularly with outdoor equipment, the operating environment often is not constant. The temperature, prevailing winds, pollution levels, chemical discharge from surrounding buildings, etc., etc. vary over time.

Since many corrosion failures take a significant length of time to occur, the operating environment at the time of failure may not be the same as the operating environment that caused the failure to initiate. Even with indoor equipment the operating environment changes with time. Take the example of an indoor coil in a heat pump; in the cooling mode, the coil is wet and that is when corrosion initiates. When the heat pump switches over to heating, the coil dries out, corrosion stops or at least slows down, but the operating pressure in the coil increases and often that is when damage that occurred during the cooling season causes refrigerant leaks to occur.

The process I like to use in assessing the environment that HVAC equipment operates in is the following:

  1. Be observant. Look at the condition of other equipment in the vicinity of the HVAC, is it corroded? Are there chemicals stored nearby? Do you smell anything strange? Are there residues on the equipment?
  2. Ask questions. Ask the service personnel about what they have observed in the environment. Ask about other failures. Ask about cleaning/maintenance practices and chemicals that are used. Ask about neighboring businesses, what they produce and what they discharge into the environment.
  3. Gather historical data, not just a one time snapshot. If you obtain water quality data, for example, get a years worth, not just from the time of the failure. If you gather air quality samples, do it over time, not just once. If you are assessing a work environment, talk with employees about what chemicals they use in doing their jobs.

Just like all the other steps in this process, the better job you do in understanding the operating environment for the equipment, the better prepared you will be to find a robust, cost effective solution to the corrosion problems you are experiencing.

Editor's Note: CR4 would like to thank PJ Sikorsky, PE for contributing this blog entry, which originally appeared here.

1 comments; last comment on 10/03/2014
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HVACR Industry Sees Global Warming as Business Opportunity

Posted September 24, 2014 1:00 AM by larhere

Despite the huge costs the HVACR industry has incurred over the last few decades in response to the growing environmental threats industry is optimistic about the business opportunities presented by the threat of global warming.

Last week CDP (formerly the Carbon Disclosure Project) released the results of the worldwide survey on the question of carbon taxes as a response to global warming. Among the wide range of questions asked the following one received the most responses.

More than 600 companies around the world view global warming as an opportunity and are setting their business goals and strategies to respond to this opportunity. As the report summarized "Companies are Leading the Way to Climate Readiness....Companies reporting to CDP are showing clearly that major corporations not only recognize climate-related regulatory risks and opportunities, but are proactively planning for them and are outpacing their governments in thinking ahead."

This was underscored at a White House meeting last week by AHRI President Stephen Yurek stating...

"Close to $2 billion has been spent by the industry since 2009 researching energy-efficient equipment and the utilisation of low-GWP refrigerants," Yurek stated, "and over the next 10 years, the HVACR industry will invest an additional $5 billion for R&D and capital expenditures to develop and commercialize low-GWP technologies."

What's Different Now?

In the past, major OEMs lead the way in deciding which refrigerants were chosen for industry use, preferring to limit the number of different refrigerants to achieve low refrigerant costs with the high volumes and minimizing confusion in the service industry.

This strategy carried through the ozone depletion era with R-12 being largely replaced by R-134a, R-11 replaced by R-123 and R-22 largely replaced by R-410A in global HVACR markets and applications.

Because the "discovery" and "proof" of global warming has been a slowly evolving topic industry has had more time to evaluate the characteristics and trade-offs between refrigerant alternatives. New refrigerants such as HFOs have been developed. New and modified cycles have been developed and are being tested. Mixtures have become more common opening the door to an endless range of new refrigerant possibilities. New technologies in heat transfer surfaces, compressors and controls are being introduced to take advantage of newfound flexibilities in refrigerants. The industry has recognized the value of customized refrigerants and is far more willing to pay more for refrigerants and use less of it to get improved performance.

Opportunities

The opportunities now are abundant, and they are available to a far broader range of companies including many small and medium size companies. Chemical manufacturers are introducing a plethora of new medium and low GWP refrigerants to help solve the global warming problem. It appears our industry will end up with a higher number of new refrigerant (molecules) as well as the endless possibilities of mixing together a number of these individual components. The end result may not be "dial-a-refrigerant" for each job but unless you are thinking of such possibilities you will miss the opportunity of a lifetime.

Editor's Note: CR4 would like to thank Larry Butz, President, GEA Consulting Associate, for contributing this blog entry, which originally appeared here.

10 comments; last comment on 09/26/2014
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Six Steps To Solving Your Corrosion Problems

Posted September 10, 2014 1:00 AM by larhere

Quite a while ago, I wrote a blog post about dealing with corrosion problems in HVAC equipment. In that post I outlined a six step process to resolve corrosion issues:

"Though solving corrosion problems is often viewed more as a black art than as an engineering discipline, there are excellent tools and techniques available to address corrosion issues and to solve corrosion problems. Step wise the process is clear cut:

1. Identify the corrosion mechanism.

2. Understand the environment, both external and internal.

3. Understand the equipment - materials of construction, operating cycles, hours.....

4. Identify alternatives - materials, coatings, limiting operating envelope, changing the environment (water treatment, alternative lubricants/refrigerants, filter the air, etc.), redesign the machine (better drainage, eliminate contact of dissimilar metals, .....)

5. Implement change.

6. Monitor results."

In an ongoing series of posts, I'm going to review each of the steps in this process in a little more detail. Today we will start with:

1. Identify the corrosion mechanism.

It seems fairly obvious that we can't solve a problem, if we don't know what the problem is, unfortunately, to paraphrase Steven Covey, common sense is not necessarily common practice. It's not unusual for people dealing with corrosion problems to implement corrective actions (or what they think are corrective actions) before knowing or understanding what the corrosion mechanisms are. The potential problems with this approach are many, but a few of the key ones are:

  1. The corrective action can be ineffective.
  2. The corrective action can make the situation worse.
  3. The corrective action can be unnecessarily expensive.

So, how do we go about identifying the corrosion mechanism?

  1. Get a professional involved early.
  2. Obtain as much documentation as possible about failures - where the failures occur, how much time to failure, environment, etc., etc.
  3. Obtain failed components for examination. Make sure they aren't 'cleaned up'. The professional will want to examine the corrosion products on the failed parts, so it's important you don't wash them away.
  4. Give the professional time and resources to evaluate the application and the failed parts - don't just ask for an 'off the cuff' opinion.

If the goal is to solve the corrosion problem as thoroughly and cost effectively as possible it's crucial to get this step right.

Editor's Note: CR4 would like to thank P. J. Sikorsky, GEA Consulting Associate, for contributing this blog entry, which originally appeared here.

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Water Side Pressure Drop in Shell and Tube Heat Exchangers

Posted August 26, 2014 1:00 AM by larhere

In previous posts I have presented the methods and equations used to design flooded evaporator and water cooled condenser tube bundles for specific heat transfer conditions. These water chiller heat exchangers operate with water on the tube side and refrigerant on the shell side. They are designed for water velocities in the range of 3 to 10 FPS. The water flow rate is usually one of the design inputs.

Both heat transfer performance and water pressure drop increase with increased water velocity. It is important to design for the highest water velocity that will have an acceptable pressure drop in the application. The method for calculation of pressure drop is shown below.

For the tube bundle, determine the water flow area.

Af=Nt*(π*Di2/4)/Np

Where

Nt=number of tubes

Di=inside tube diameter, ft

L=length of tube, ft

Np=number of passes

For internally enhanced tubes, a good approximation of L is the length of the enhanced surface, as that will be the majority of the friction.

Water side pressure drop (ref ASHRAE Handbook-HVAC Systems & Equipment, Chapter 35):

∆P=Np*(KH+f*L/Di)*ρ*V2/2*g

And

V=GPM/(448.8*Af)

Where

∆P=pressure drop, psi

Np=number of tube passes

KH=entrance & exit flow resistance & flow reversal coefficient, number of velocity heads (V2/2*g)

f =friction factor

ρ =fluid density, lb/ft3

V=fluid velocity, fps

g=gravitational constant=32.17 lbm*ft/(lbf*s2)

For smooth tubes the friction factor, f, can be obtained from the Moody Diagram.

For internally enhanced tube and Reynolds Numbers greater than 20,000 the friction factor is usually in the form

f=C* ReD

where

Re= V* Di* ρ/µ

and

µ=viscosity, lbf*sec/ft2

The coefficients C and D can be provided by the enhanced tube manufacturer.

Flooded evaporators and water cooled condensers are major components of water chillers. As such they represent a large part of the chiller cost. The tube bundle design determines the length of the chiller and is a major factor in its width.

Using the heat transfer and water side pressure drop calculation methods, designers can perform iterative analyses to vary the tube bundle lengths, number of tubes and number of passes. This will result in the heat exchangers with the desired performance, lowest cost and chiller dimensions that best meet the requirements of the market.

Want to learn more about HVAC Technologies?

Editor's Note: CR4 would like to thank Jim Larson, GEA Consulting Associate, for contributing this blog entry, which originally appeared here.

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