Air cooled heat exchangers are simply 1 of the numerous different types of heat exchanger. Heat exchangers are devices which have been specifically made for aiding the transfer of heat from one fluid to the other. For us to better fully grasp, common samples of appliances that use heat exchangers include the air conditioners, fridges as well as space heaters.

But let's not dwell too much on the general heat exchanger rather let's at this point look at air cooled heat exchangers or ACHEs for short. It rejects heat from a warm fluid straight away to fan-blowing ambient air. ACHEs can be used whenever a procedure or setup generates heat that must be removed and sadly lacks local use. Your car's radiator is actually an example of ACHE equipment. The engine has to be cooled to prevent overheating due to friction and combustion processes by the engine. The surplus heat is carried away by the water or glycol coolant mix. Most of the heat should be taken away, and the easiest way is by supplying ambient air.

There are many uses of air cooled heat exchangers, such as the upstream production, refineries and petrochemical plants. It can also be used on conditions with high temperatures, high pressure, corrosive fluids and environments. In addition, air coolers could be equipped and used in gas and oil refineries; compressor stations used for gas pipelines; subsurface gas storage facilities; plants producing polychlorvinyl, polyethylene, glass fiber, biplastic; caustic soda plants; by-product coke plants and ammonia transportation and handling plants.

Apart from learning the actual purposes of ACHEs, we should have a peek about how it works inside and its components. Normally, air coolers for process use are composed of a finned-tube bundle with rectangular container headers on both ends of the tubes. Headers are boxers that eliminates the fluid from the piping to the tubes. Other parts consist of one or more fans that give cooling air. The fans are generally powered by electric motors and are supported by speed reducers. The fan drive assemblage is sustained by the metal mechanical drive support system. Generally, the air blows up-wards all the way through a horizontal tube bundle. The fans could be either forced or induced draft, determined by if the air is pushed or pulled through the tube bundle. Forced draft unit enables an easy access for maintenance for the fans and also to the bundles. Additionally, the fans remain within the cold ambient air. While the induced draft unit offers a stable and strong thermal performance because of the protection of the finned surface against wind, rain, hail and snow by the plenum chamber. The induced draft also guarantees an improved air distribution, much less hot air recirculation, much less air-side fouling and reduced noise levels at grade. Space in between the fans and the tube bundle is encircled by a plenum chamber, which guides the air. The entire assembly is normally mounted on legs or a pipe rack.

Understanding and knowing the inside and out of ACHEs is quite difficult, particularly if you have no background in mechanical matters. And because of this, let's once more change our concentration on another subject matter, which is the "why" question. With regards to economy, air coolers are preferred due to the lower maintenance expenses. Some other benefits presented by air coolers are as follows: lack of the need for cooling water or other cooling media, no problem shall arise with regards to the thermal as well as chemical pollution of cooling fluids, and it quite fast to install by bolted assembly.

ACHEs are regarded as a "green" alternative simply because no chemical treatment is needed to the water or fluid used by the assembly. And temperature is the only parameter that needs to be considered whenever getting rid of the water used. With no appropriate heat exchanger equipment, overheating can certainly ruin your equipments and appliances, more particularly the heat exposed parts. Out of all of the things that have been mentioned, if we're to consider the trend the world is moving, air cooled heat exchangers are the best choice for industrial plants as well as other plants when the environment is to be considered.

The writer is an active supporter of green technology. He provides information and praise to pro-environment technological advancements, specially in manufacturing industry. To know more, visit the link below:
Air Cooled Heat Exchangers

Article Source: http://EzineArticles.com/?expert=Bryce_Thurman_Q_Steed

A Heat exchanger(H Exchanger) refers to a device built for effective heat transfer from one medium to another. In a heat exchanger, both the mediums are separated by a solid wall so that they never get in direct contact with each other. H exchangers are commonly used for large-scale industrial processes such as refrigeration, air conditioning, petrochemical plants, petroleum refineries, and natural gas processing.

A H Exchanger is in fact a device that facilitates efficient heat transfer from one fluid to another across a solid surface. The convection and conduction principle of heat transfer is mainly employed in the design and manufacturing of a H exchanger. One of the most common examples of a H exchanger is the radiator in a car where the hot fluid in the radiator gets cooled by the flow of air over the radiator surface. A few other examples of H exchangers are pre-heaters, intercoolers, boilers, condensers, etc. that are used in power plants. There are various types of H exchangers. H exchangers could be classified based on their design and construction into the following types i.e. shell and tube H exchanger and plate and frame H exchanger.

With scientific advancement, new technology has been employed in the manufacturing of heat exchangers and they have been put to a wide variety of industrial and commercial uses.

H exchangers such as sanitary heat exchangers used in product processing play a significant role in dairy processing facilities. They help a good deal in heating, cooling and pasteurizing dairy beverages and foods. Equipment manufacturers are always coming up with highly innovative methods and designs to enhance the overall efficiency of heat exchangers, save resources and customize them for various product types. New features have been incorporated for different types of H exchangers such as plate H exchangers, tubular heat and scraped-surface exchangers and for gasketed and welded units.

Quite recently, Radicon, a leading manufacturer of H exchangers in Southeast Asia, developed a new generation of efficient heat exchangers intended for heavy-duty applications. Headquartered in Bangkok, Thailand, Radicon is a well-known supplier of radiators, oil coolers and charge-air coolers.

The author is associated with IPFonline. http://www.ipfonline.com allows you to efficiently and quickly search through product profiles of engineering and industrial products from Indian manufacturers.

Article Source: http://EzineArticles.com/?expert=Rakesh_Kumar_S

Heat exchangers are a staple in today's devices. They are not only present in the simplest of devices; exchangers have also found their use in big industries and machineries in the world today. They are basically devices found in some machines that enable it to transfer heat from one medium to another. They facilitate the efficient transfer of heat from one object to another.

Use of Heat Exchangers

One example of this is the radiators found in cars or air conditioners. What usually happens is that a heat source transfers water that will cool the engine through the exchanger. The exchanger will transfer heat from the water to air leaving the engine cooler.

Heat exchangers are widely used for the purposes of space heating air conditioning and even refrigeration. Heavy industries that also use this technology include power plants, chemical and petrochemical plants, oil and petroleum refineries, natural gas processors and sewage treatment facilities.

Types of Heat Exchange Flow

Heat exchangers can be classified into two types, mainly according to their flow arrangements. These are the parallel-flow and the counter-flow exchangers.

The parallel-flow exchange involves the two mediums going in the exchanger through the same side of the device. For example, two fluids will enter the exchanger at the same side and travel parallel each other for the whole process.

The counter-flow exchange, on the other hand, is the opposite of the first process. Here, fluids will enter the device from different ends and meet each other for the process of heat exchange. Many exchangers use this flow since it has been proven to be the more effective of the two processes because it can transfer more heat from the heating medium to the other. In this set-up, the mediums travel to one another and are then processed by the exchanger.

Traditionally, exchangers are designed in a way that the surface area between the two exchanging fluids is maximised whilst minimising the resistance to the exchange flow at the same time. Additional fins installed in either direction where the fluids enter can also enhance exchangers. These fins can add to the surface area of the exchangers whilst also helping control the flow of fluids during the exchange process.

Temperature during the Heat Exchange Process

Depending on the size of the exchanger, temperature will vary during the exchange process. The temperature will also vary according to the position of the device. But many industries that use exchangers almost always have their own defined mean temperature.

This temperature is usually defined in terms of the Log Mean Temperature Difference or the LMTD. Sometimes though the temperature is still hard to determine through the LMTD method, in this case, the NTU method is then used.

Types of Heat Exchangers

There are several types of heat exchangers used today. These include shell tube exchangers, plate exchangers, adiabatic wheel, plate fin, fluid exchangers, dynamic scraped surface, phase-change exchangers, HVAC air coils, spiral exchangers and the direct contact exchangers.

For more information about heat exchangers and its different types, you can visit plate heat exchangers.

Article Source: http://EzineArticles.com/?expert=Luke_Wildman

October 21, 2009 (FPRC) -- San Antonio, TX – MFGmatch.net, a division of ILG announced today the launch of its new Heat Exchanger and Heat Processing Equipment marketplace at http://www.industrialleaders.com/listings/heat_processing.html The company reported today during its annual meeting the site includes offerings for plate heat exchangers, air, water, tube, flat plate, oil fired and water-to-air heat exchanger systems as well as electric boilers, central heating boiler, portable commercial heaters and allied equipment for industrial applications.

According to Mark Hamilton, an MFGmatch.net spokesman, the site also provides registered users the opportunity to buy and sell new and used heat exchangers and heat processing equipment on its new marketplace at http://www.industrialsaver.com/classifieds/index.php/cat/193 The site allows users to post and view offerings for condensing, peerless, gas fired and industrial boilers as well as various HVAC equipment such as filters, ducting, large space heaters, hot air blowers and related products.

“MFGmatch.net's latest marketplace was created because the company realized a need to help manufacturing companies, foundries, machine shops and industrial plants with their heating needs,” said Hamilton. He concluded, “Those sourcing locally, national or even worldwide for heat processing systems and equipment can use the site to locate suitable suppliers of new, pre-owned and re-manufactured heating systems, accessories and solutions designed and developed specifically for the manufacturing community.”

About MFGmatch.net

MFGmatch.net is a free custom manufacturing online marketplace for machine shops, product designers, engineers, foundries and other companies looking to buy and sell machines parts, precision components and other custom manufacturing services in local, national and international markets.

Heat exchangers are pieces of equipment that are used for the transfer of heat from one fluid to another. When a heat exchanger goes bad, chances are, important things stop working. When your automobile engine is overheating, it's likely that the heat exchanger is the problem. You probably call it a radiator, but it's one type of heat exchanger. In your radiator, antifreeze cools air that flows past it. This air is then blown by a fan onto the engine to keep it cool. If the radiator doesn't work properly, you won't be driving very far until the situation is fixed.

Your home heating system also has a heat exchanger. In fact, nearly every piece of mechanical equipment that has a need to intentionally heat or cool part of a system does. Inside your furnace there is a combustion chamber. There is a metal wall that separates the internal combustion from the air that flows past the heat exchanger and on through the ductwork to heat your home. You need this separation because you don't want the toxic gases inside mixing with the air that is distributed throughout your home. In the previous example, a faulty heat exchanger could lead to a broken down automobile, but in your home you could be gambling with your life.

Carbon Monoxide can be present in the combustion gases. It's supposed to be contained inside, but as time goes on, it becomes possible for the heat exchanger in your furnace to crack or warp. Each time your furnace turns on, the metal wall heats up and expands. During the off cycles, the metal of the heat exchanger cools and contracts. Over time this repeated process of expansion and contraction of the metal takes it's toll. The metal can become fatigued, and eventually warp out of shape, or just plain break.

As I noted before, these metal walls were designed to keep the toxic combustion gases inside the heat exchanger chamber. Guess what happens if there is a crack? That's right, the toxic gases inside can mix with the forced air that is being blown through the ductwork and into your home. Having a reliable Carbon Monoxide detector is an inexpensive measure to protect yourself and your family from the danger of Carbon Monoxide poisoning, but you can also take some proactive measures to protect against any potential danger.

Give your furnace an annual checkup, just before the heating season, to check the condition of the burners, the heat exchanger, the furnace filter, and other components that can affect the performance of your furnace. I recommend have a certified HVAC specialist do this. Only a certified specialist will have the knowledge and experience needed to know exactly what to look for, and where to look for it, as well as knowing what the operating specifications for your unit should be.

If your furnace is over 10 years old, it is even more important to keep that annual checkup. This is the time period where the years of wear and tear on your heat exchanger make a failure of the heat exchanger wall significantly more likely. Keeping your furnace in good health can also help keep you and your family in good health.

Find out more about heat exchanger safety at my heat exchanger cleaning equipment site.

Article Source: http://EzineArticles.com/?expert=Alex_Parry

A heat exchanger is a device designed to efficiently transfer the heat from one medium to another. In the case of an outdoor corn boiler, these media would be air and water.

A typical domestic setup would include a water-to-water heat exchanger for hot water and a water-to-air heat exchanger for forced air home heat. Water-to-water heat exchangers are also used to heat hot tubs, swimming pools and the water for radiant baseboard or radiant in floor
heating systems.

Water-to-Water Heat Exchangers

The three most common types of water-to-water heat exchangers used with outdoor
corn boilers are: Sidearm, Shell and Tube, and Brazed Plate. What differentiates these heat exchangers, besides the cost, is the way they're designed to transfer heat from one medium to another and the method used to create turbulence.

A key component in the efficient transfer of heat between liquids is turbulence. The
more turbulent the flow of water through a heat exchanger, the more efficiently heat
is transferred.

Sidearm Heat Exchanger

The sidearm heat exchanger is a popular and inexpensive choice for heating
domestic hot water. It incorporates a pipe within a pipe design where the
water in the inner pipe (your hot water) is heated by hot water from the
boiler circulating through the outside pipe.

Turbulence is created by scrolling on the outer surface of the inside pipe.

This straightforward design prevents clogging by sediment and resists
scaling. One drawback of the sidearm heat exchanger is reported slow
recovery under heavy use. Cost: $130-$150.

Shell and Tube Heat Exchanger

Shell and tube heat exchangers are available in dozens of tube configurations and
sizes ranging from a few feet long to 50 feet or more for power plant steam
generation.

A variation on the shell and tube design is shell and coil where a helical (spiralling) coil
replaces the tubes.

No matter what the design or application, the basic principle is the same. The water to
be heated flows through tubes, and the heated boiler water, encased by the shell,
flows around the tubes.

Turbulence is created by the baffles holding the tubes together in what is called a tube bundle.

Shell and tube heat exchangers for non-chlorinated water
applications, such as domestic hot water and hydronic
heating, are usually constructed with a brass shell and
copper tubes.

For swimming pools and spas the shell should be PVC or stainless steel with stainless
steel tubes. 316L grade stainless steel is commonly used for this application.

Cost: $200-$600 depending on copper or stainless construction and the overall size based on the volume of water to be heated.

Brazed Plate Heat Exchanger

The brazed plate heat exchanger combines compact size with a highly efficient design to produce a device for heat transfer that is up to six times smaller than a shell and tube heat exchanger of similar capacity.

The key to this efficiency lies in their unique construction. Corrugated stainless
steel plates are brazed together (eliminates gaskets) with every
second plate turned 180 degrees. This design creates two highly
turbulent fluid channels that flow in opposite directions (counter flow)
over a massive surface area.

Cost: $100-$500 depending on capacity.

Get better outdoor corn boiler information at Alternative-Heating-Info.com

Article Source: http://EzineArticles.com/?expert=Sam_Streubel

If you are interested in harnessing solar power for solar heat in your home, but are not quite in the position to be installing solar panels and a large solar heating system, you should consider using a solar heat exchanger. Solar heat exchangers are great for heating your home in many different capacities. They are also usually quite affordable.

Did you know that heat exchangers are used throughout your home already? They are commonly found in cars, refrigerators, and air conditioners and they regulate the heat that is generated and used in these items. They prevent over-heating and transfer the right amounts of heat to the right places. Solar heat exchangers are essentially the same, but they transfer the sun’s heat instead of heat generated by an appliance or engine. They usually use liquid and air to transfer heat to another area, such as your swimming pool or your hot water tank.

One of the most popular types of solar heat exchangers is a swimming pool heater. These are great for any swimming pool owner. As you may know, heating a swimming pool can be expensive and consumes quite a bit of energy. If you don’t want to give up your heated pool, but still want to be environmentally friendly, you should look into installing a solar heat exchanger.

Another type of solar heat exchanger is one that works to heat smaller areas, such as hot water heaters and sheds. These heat exchangers are great for those individuals that want to use solar heat, but do not want to spend a lot of money. These come in a variety of styles and sizes, so you can choose one that suits your needs.

Learn the pros and cons of solar power - Solar Energy Advantages is your source for information on solar panels, fountain pumps, home solar plans and information on how solar power works and can benefit your home and family. One of the ways that you can use solar heat without spending too much or converting your entire home to solar heating is with a solar heat exchanger. These are available for a wide variety of uses including heating swimming pools, sheds and solar water heaters.

Article Source: http://EzineArticles.com/?expert=Christine_Douglas

RESEARCH TRIANGLE PARK, N.C.--(BUSINESS WIRE)--Feb. 1, 2000

BuildNet, Inc., a leading e-business, technology and project management systems provider for the home building industry, announced today that it has acquired the assets and certain operations of Atlanta-based UniLink Group LLC, which has established an information delivery exchange that automates manufacturer, distributor and contractor/dealer (&uot;three-tier&uot;) business-to-business transactions in the &uot;hard goods&uot; industry. UniLink focuses on four mechanical service vertical markets: heating, ventilating and air conditioning (HVAC) via the brand name hvaconline.com(R); plumbing via plumbingonline.com(R); electrical via electricalonline.com(R) and appliances via appliancepartner.com(R). Founded in 1996, UniLink automates the sending and receiving of purchase orders, warranty claims, advance shipping notices and invoices through a &uot;universal link&uot; application that allows seamless 24/7 connectivity and messaging to all the companies involved in buying and selling within an industry vertical. Using UniLink, manufacturer and distributor systems can exchange transactions seamlessly using any type of document or file format, or through EDI. The system can significantly enhance efficiency because most manufacturers have over 1,000 distributors, and building traditional links to each individual one is costly. With UniLink, manufacturers need to build only one link, to UniLink, in order to have access to all the distributors linked to UniLink's integrated e-business network. Manufacturers, including recent additions to the UniLink system like Johnson Controls, and divisions of Masco and Emerson Electric, have joined existing UniLink customers York, Lennox, Honeywell and others who daily process transactions through UniLink's system. Learn more about UniLink by visiting www.unilinkgroup.com.
Also included in the acquisition was UniLink's Cypress, Calif-based subsidiary, KeyPrestige, Inc., a leading electronic warranty claims management, administration and systems-development company. KeyPrestige operates customized warranty claims processes for leading appliance and consumer electronics brands; the data runs through proprietary software links or through Web-based applications. The KeyPrestige system seamlessly links the parts distributor, manufacturer, factory and authorized repair centers in a paperless warranty claims transaction system that can cut the traditional 90-day cycle down to under 24 hours. Clients include Bosch, CAMCO, Fedders, Frigidaire, GE, Jacuzzi, Thermador, Whirlpool and others.

Together, UniLink and KeyPrestige process over five million transactions a year for over 50 manufacturers in 25,000 locations in the U.S., Canada and Latin America.

&uot;When you combine the e-business system BuildNet will begin rolling out in 2000 with the technology and services UniLink and KeyPrestige already have in place, you should be able to achieve a synergy that `completes the circle' of e-business connectivity in certain verticals for the residential home building industry,&uot; said Mike Atwood, BuildNet president and COO. &uot;BuildNet has already gathered an impressive community of builders, distributors and manufacturers, but when they are linked with the contractor-wholesaler-manufacturer community gathered by UniLink and KeyPrestige, you should have one of the most robust, customer-focused e-business systems in the nation.&uot;

&uot;Our manufacturer and wholesaler partners have frequently asked for help in extending their e-business reach to builders,&uot; said David Dunn-Rankin, UniLink chairman. &uot;With this new e-business relationship, we have the power to reach retailers and repair centers linked by UniLink to the builders building approximately one-third of all new U.S. residential homes, and the manufacturers and distributors now BuildNet-enabling their systems to supply their material needs.&uot;

About BuildNet, Inc.

BuildNet, a privately held company based in Research Triangle Park, N.C., is one of the $240 billion home building industry's largest e-business, technology and project management system providers. In January 2000, BuildNet announced that it had raised $104.7 million in private placement venture capital, to add to a May 1999 round that raised $35.7 million. These investments make BuildNet one of the best capitalized companies in the residential construction industry's business-to-business and project management system arena.

BuildNet's Internet-based e-business platform is being developed to provide home builders and their subcontractors access to an integrated on-line network designed to change the residential construction market by availing every aspect of a building project to real-time, on-line, integrated e-business links, from the builder's back offices to the back offices of a wide range of product suppliers. (This is commonly called &uot;business-to-business e-commerce.&uot;) Through its six project management systems, BuildNet products currently manage the construction of around one in three homes built in the U.S.

Business Editors

WOODBURY, N.Y. & COURBEVOIE, France--(BUSINESS WIRE)--June 25, 2003

Saint-Gobain Glass France SA, a subsidiary of Europe's largest glass company, Compagnie de Saint-Gobain (Paris Stock Exchange:SGOB.PA) has been granted a worldwide (except Korea) non-exclusive license by Research Frontiers Incorporated (Nasdaq: REFR) to make various SPD-Smart(TM) glass products.

In an SPD-Smart window, sunroof, or other product, the user can manually or automatically "tune" the amount of light, glare and heat coming into a home, office, or vehicle. SPD-Smart film technology was recently awarded a Best of What's New Award from Popular Science magazine for home technology. Additional information about SPD-Smart windows and other products can be found at www.SmartGlass.com. About SPD Technology and Research Frontiers Incorporated

Research Frontiers Incorporated (RFI) develops and licenses suspended particle device (SPD) technology used in SPD-Smart(TM) light-control glass and plastic products. SPD technology, made possible by a flexible light-control film invented by RFI, allows the user to instantly and precisely control the shading of glass/plastic manually or automatically. SPD technology has numerous product applications, including: SPD-Smart(TM) windows, sunshades, skylights and interior partitions for homes and buildings; automotive windows, sunroofs, sun-visors, sunshades, rear-view mirrors, instrument panels and navigation systems; aircraft windows; eyewear products; and flat panel displays for electronic products. SPD technology is covered by approximately 365 patents and patent applications held by RFI worldwide. Currently 26 companies are licensed to use RFI's patented SPD light-control technology in emulsions, film, or end products. Additional information about RFI and its licensees can be found at http://www.SmartGlass.com.Note: From time to time Research Frontiers Incorporated may issue forward-looking statements which involve risks and uncertainties. This press release contains forward looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Actual results could differ and are not guaranteed. Any forward-looking statements should be considered accordingly. SPD-Smart(TM), Powered by SPD(TM), The View of the Future - Everywhere You Look(TM) and Visit SmartGlass.com - to change your view of the world(TM) are trademarks of Research Frontiers Incorporated.

"I'm extremely disappointed say Mansie Booker Jr. of the steady stream of corporate misdeeds that have rocked the stock market. Booker, a 58-year-old television production coordinator for the city of san Bernardino, California, says his wife, Mary, 60, is almost ready to pull out of stocks. "You don't know which company is going to be next in terms of scandal." A few years ago, the heat of the tech sector was firing up the market. Now it appear the only thing cooking in corporate America is the books. The Bookers' sentiments echo that of most investors who, after witnessing a slew of reports and allegations of corrupt accounting practices, are reluctant to pour any more money into the stock market, no longer accepting Securities-and-Exchange-Commission--required financial information as gospel. Corporations ranging from Adelphia Communications to Xerox Corp. are finding themselves under scrutiny, as skeleton after skeleton is uncovered in corporate closets.

And all the while, the market continues to free-fall (see chart). The Dow Jones industrial average index opened at 9,379.20 on Oct. 23, 2001--the day after Enron announced that the SEC was investigating its accounting practices with its partnerships. By July 11, 2002, the Dow would shed 6%, to open at 8,800 amid a steady stream of accounting scandals from corporate America.

Desperate to repair investors' shattered trust in the battered equity markets, President George W. Bush proposed a series of actions that include: * Longer, harder jail time for executives convicted of mail and wire fraud, document shredding, and other transgressions

* Steps by the SEC to freeze questionable payments to executives from companies under investigation

* An end to executives receiving personal loans from corporate boards

* The creation of a "financial crimes SWAT team" at the Justice Department headed by Deputy Attorney General Larry Thompson, an African American

* Requirements that most corporate directors be independent

At the root of it all is greed. The overuse of stock options has been a "root cause" of corporate excess, according to B. Kenneth West, senior consultant of corporate governance for TIAA-CREF in New York City. "When executives have a carload of options; they may do anything to get the public to think the company's stock price should go up" he says.

Now that stricter oversight of public companies is in the headlines, what's likely to come to pass? "One is that [the U.S. government] is clearly going to call for more corporate governance measures," says Shawn Baldwin, chairman and CEO of Capital Management Group Investments L.L.C. (No. 9 on the BE ASSET MANAGERS list with $1.8 billion in assets under management). He says that although individual investors may fear the market at this point, asset managers and other institutional investors will continue to play the stock market. "Institutional money has to be placed somewhere, so the fiduciary stewards of these plans are going to start looking for strong governance measures at the companies before investing in its stock."

Baldwin says that although he hasn't lost any clients as a result of investor distrust in the equity markets, he and other asset managers have been reassuring clients, "making sure they know we're looking at the books, looking for anomalies, and delving into more intrinsic analysis"

Dennis Kroner, president of Pitt, Ryan & Linnear, an accounting firm in Chicago, says that a recently-passed law requiring CEOS and CFOs to personally sign off on corporate financial statements will have a major impact. "Most CEOs don't have an accounting background. They'll want some assurance that these statements aren't misleading."

That assurance, according to Kroner, may come from independent directors--but only if the process is revised dramatically "Today," he says, "some directors sit on many boards, in addition to holding a full-time job. A week or so before each board meeting, a director might get a 200-page packet of materials describing what's on the agenda."

Kroner believes government measures will help to restore investors' confidence, "but it will take awhile. It will probably be a year or so before professional directors are sitting on many boards and another couple of years before investors realize what a difference [the directors] make, in terms of corporate reporting This issue is not going to go away quickly," he says. Capital Management Group's Baldwin, on the other hand, says the public will need an example made of a corporate executive before trust is restored--a CEO like Enron's Kenneth Lay; Tyco's Dennis Kozlowski; or World, Com's Bernard Ebbers sentenced to hard time if found guilty of criminal activity,

Rex Jackson, a money manager with Integrity Planning, a subsidiary of a credit union in Redlands, California, agrees that these issues will bedevil investors for some time to come. "Companies are still doing things the old way," he says. "Any improprieties that are under way now won't come out until 2003."

CAMBRIDGE, Mass.--(BUSINESS WIRE)--Oct. 8, 1996--Aspen Technology, Inc. (NASDAQ:AZPN), today announced it has completed the acquisition of B-JAC International, Inc., a leading supplier of detailed heat exchanger modeling software, based in Richmond, Virginia.

AspenTech is a leading supplier of computer-aided chemical engineering, on-line automation, and process information management software and services to help process manufacturers operate closer to potential through the entire manufacturing lifecycle. AspenTech chairman and CEO Lawrence B. Evans said, "The addition of the B-JAC software to our modeling family allows AspenTech to tightly link the B-JAC tools with our powerful ASPEN PLUS(r) software to provide our customers a common model, from design through to the specifications with their equipment manufacturers. Since virtually every process plant requires heat exchangers, the B-JAC acquisition allows us to build upon our leadership in process modeling."

The B-JAC acquisition will be accounted for as a stock-for-stock pooling transaction, with AspenTech acquiring all of B-JAC's stock for $3.4 million. "We anticipate that the earnings per share impact of the acquisition will be non-dilutive for the current fiscal year, ending June 30, 1997," stated AspenTech executive vice president and chief financial officer Mary A. Palermo.

In a separate release, AspenTech also announced today the acquisition of Cambridge Control's process control division, a consulting group based in the UK specializing in process manufacturing control application for the refining, petrochemical and pulp and paper industries.
B-JAC information

B-JAC International, based in Midlothian (Richmond) Virginia, is a major supplier of detailed heat exchanger equipment modeling software tools. These allow exchanger design and analysis at both the thermal and mechanical levels.

Founded in 1970, B-JAC is known for its fast, reliable and easy-to-use software that could evaluate heat exchange equipment in detail. B-JAC's software conforms with industry standards, and is the leading supplier of this software in the Microsoft Windows(tm) environment. Prior to the acquisition B-JAC was privately held with more than 700 companies using their products worldwide. Sales in the fiscal year ended April 30, 1996 were $2.5 million.

About AspenTech

Aspen Technology, Inc. is a leading supplier of software and services for the analysis, design and automation of process manufacturing plants in industries such as chemical, petroleum, pharmaceuticals, electric power, pulp and paper, and metals. Process manufacturers use AspenTech's solutions to improve the way they design, operate and manage their plants. These solutions enable customers to reduce their raw material, energy and capital expenses, meet environmental and safety regulations, improve product quality and shorten the time required to get new production processes on stream. Headquartered in Cambridge, MA, AspenTech employs more than 1,000 people with offices in 12 countries worldwide. Revenues for fiscal 1996 increased 80 percent to $103.6 million, compared with $57.5 million in fiscal year 1995.

AC sizing is a long topic, and hence I have broke the articles into two parts.

Part II of air conditioner sizing will talk about the integration of three different charts, and Manual J, in AC sizing. We'll begin now.

Comfort, Psychrometric and Duct Sizing Charts' Use in AC Sizing

This method of air conditioner sizing is more extensive than using Manual J alone, and it is especially useful in sizing for central air conditioning units - where you'll have multiple rooms to cool, with fresh air intake from outside.

Here's the checklist for AC sizing using this method:

1. use comfort chart, to set the desired indoor conditions.

Comfort chart is formulated by ASHRAE, and shows a range of comfort levels for human being.

The comfort levels are provided in terms of humidity, and temperature

2. next, Manual J is used to find out the sensible, and latent heat gain and loss in each room within a desired building.

Room slope will be assigned for all rooms, individually.

It is carried out by dividing sensible heat, to total heat (sensible, plus latent heat)

3. now, psychrometric chart is to be used. This chart, will eventually determine the minimum air conditioner size for your building.

The size is determined by finding out the following values,

* mass flow rate of air into each room,

* fresh air to recirculated air ratio,

* and finally, the air conditioner size from cooling load value

Data that you will need include, the volumetric air requirement per person, of 5 litres/person/compartment/second, outside, and inside temperature and humidity, and room slope values

4. ducts will be the final item to be sized, as it needs information of air mass flow rate.

Duct sizing charts need to be used for this, with prior information of maximum air draft at design condition, and duct resistance values

The checklist above will help you in performing air conditioner sizing, using psychrometric, duct sizing, and comfort charts.

Saunas are fast becoming popular. And there are sure lots of different types created these days. But infrared saunas must be the ones that are making real waves in the market.

What are infrared saunas?

Infrared saunas, which is most commonly referred to as IRS, is a type of radiation having a wavelength that is longer than visible light, but is shorter than radio waves. IRS are saunas that heat its occupants with the use of far emitted radiant heat. These saunas don't produce steam. The infrared radiation is what causes heat inside the person's body, without actually changing the air inside the room.

What do they look like?

IRS usually look like a box made of wood. It is also possible to make a sauna room that is made of wood with some infrared heaters installed in and around it. The heat comes from the heaters inside the box. Basically, infrared saunas follow the same principle for heating bodies as the sun. But Far infrared saunas are a notch better because it doesn't produce ultraviolet rays that can be harmful to the body.

How are they different from traditional saunas?

Traditional saunas use heated rocks. They use different types of heat sources to generate warm air. Stones are positioned over the main heating source for it to achieve high temperature levels. It is the stones that maintain heat and temperature inside the room. Stones are usually used because they produce stable heat. The room is usually enclosed to trap heat in.

IRS's are somehow different. For one thing, the room doesn't need to be enclosed at all. This is because the IR heaters are directed towards the person's body, causing it to sweat as it cools down. It doesn't rely on the air circulating around the room to produce and maintain heat.

The temperature inside an IRS room is at 120 degrees Fahrenheit, on the average. In a traditional Finnish sauna, it can go as high as 200 degrees. But research shows that the sweat and effects produced between the two saunas are comparably the same. And if you really think about it, you are likely to spend more time inside an IRS than in a regular one, giving you more health benefits in the process.

If you haven't been inside a IR saunas, you might as well try them now. See how different the experience is going to be. Maybe you would reconsider and build one for yourself!

Many older homes were built pre-central heat and air. This is a luxury that many of us have to enjoy and when moving into an older we find that this luxury is also a necessity. We tend to lose tolerance for heat as we grow older and those old window air conditioning units just look tacky. However, the whole idea of having to add ducts to a home can sound difficult and expensive, but it is easier than you might think.

Central heat and air uses a primary heating appliance such as a furnace that is often located in an area such as a small closet, basement or garage. These systems deliver heat throughout the house through pumped warm air through a system of air ducts or by sending hot water or steam through pipes to room radiators. In newer homes, the system is usually built in with the home. The duct system may be set up with an air conditioner, heat pump, or furnace. There are also two types of systems including a forced air system and a gravity system. Gravity systems, however, do not provide air conditioning and can only provide heat. If your system includes an air conditioner, then the system is a forced-air system.

Air conditioners and heat pumps are forced air systems that share ductwork. The air conditioner runs on electricity and removes heat from air through refrigeration. The heat pump is capable of providing both heating and cooling. In the winter, the heat pump extracts the heat from outside air and delivers it into the home. In the summer it does the opposite. It extracts the cool air and pumps it into the home. These systems tend to be very economical and use only one duct system.

Many central air conditioners are split systems with a condenser outside and the fan and coil unit mounted in the attic. This means that the ducts will originate in the attics. The challenge here is if the home is two stories. It can be difficult to get the supply and return ducts to the first floor. The second floor will generally have ducts that run through the attic floor, while the first floor will need to have ducts run through closets. This takes up less space than some may think and the mess can be minimal. The contractor will need to cut holes in the first and second floor ceilings and some second floor closets will need to be used for running ducts.

This work will be well worth it in the long run when your home is kept cool in the summer and warm in the winter. If you have an older home, especially one with two stories, it can be difficult to spend anytime upstairs during the summer. The upstairs rooms will hold a large amount of heat and will definitely benefit from central heat and air. In the winter it is often difficult to keep first floors warm because the heat rises. Central heat will make your first floor rooms much more comfortable.

Water can be present in lubricating oil in three different forms, dissolved water, emulsified water and free water. Dissolved water refers to water that has been chemically absorbed into the oil. Emulsified water is water that maintains its chemical integrity, but is held in suspension in the oil by additives and contaminants. Free water describes water that is present in the oil, but not held in suspension.

Effects on Lubrication
In general, water is a poor lubricant. Proper lubrication is dependant on the formation of an oil film to separate opposing friction surfaces. When pressure is applied to an oil film, the oil’s viscosity will increase proportionally to maintain protection. Water does not exhibit this tendency and will cause boundary lubrication to occur where full fluid film lubrication would otherwise be present.

Alarm Limits
Water is considered to be among the most detrimental of possible contaminants. Studies have shown that water present at any level can reduce bearing life from 10 to 100 times. While the overall tolerance for water varies from machine to machine, a good general alarm limit for water contamination is 0.05% (500 ppm). Systems may be more tolerant to water, while others may be more sensitive. Some manufacturers have set limits as low as 30 ppm. Best practice would tend to indicate that it is beneficial to keep water contamination at the lowest level possible.

Controlling Water Contamination
Controlling water contamination requires two individual considerations. First, we must address the issues of keeping water out of the system. Water can contaminate a system by condensation when moist air enters the component and a change in temperature causes the water to condense and drop into the oil. Water can also enter a system through non-drying breathers, faulty hatches and seals, and internally from leaking heat exchangers.

Second, steps must be taken to remove water once it has entered a system. This can be accomplished with physical filtration, vacuum dehydration or centrifuge. For systems prone to contamination, these types of purification can be installed in the system to remove water continuously or on demand.

Systems that are prone to water contamination should use an oil that rapidly separates from water. An oil’s ability to separate from water is known as its demulsibility. High detergent oils tend to be poor demulsifiers, while turbine oils and many industrial lubricants have better demulsibility. Circulating systems prone to water influx, such as those found in rolling mills and power generation plants, can simply drain the water from the reservoir to control contamination, provided the oil exhibits good demulsibility. In these situations, the oil’s demulsibility should be monitored to ensure that water contamination does not reach the lubricated components