1. BACKGROUND

Having traveled to or having been associated with colleagues who have traveled to most continents, I continue to hear the statement: Don’t tell us about air conditioning, no one here uses air conditioning. It’s too expensive. However, is important for all of us in the energy community to realize that there is very little air conditioning in 3rd world countries because THEY ARE 3rd WORLD COUNTRIES. But there are considerable structural changes occurring which are finding international sources of financing supporting projects in any country. Already there is becoming a gray area between 3rd world countries and "modern" countries and societies. At the same time, global warming trends are becoming more and more evident.

All of this points towards local professionals who know their countries but who also understand the choices for air conditioning. Local professionals need to be able to offer technical expertise to the new generation of business people and developers who will DEFINITELY require air conditioning in modern buildings in the 21st century. Otherwise, the local professional will be trapped in a 3rd world mentality while all of the young, aggressive businessmen and engineers will be moving towards modern (air conditioned) buildings and facilities. The simple reality is that no 21st century office with computers and hubs and routers can exist without air conditioning; no 21st century factory, with sophisticated robotics and highly trained and motivated people can exist without air conditioning!

In considering the above, it is important to note that the United States government was a "part time" government until the mid 1930’s. It was just too hot and humid in Washington D.C. to carry out the business of government except for 6 months out of the year. With reliable and reasonably priced air conditioning systems fully commercialized in the 1930’s the U.S. congress was able to convene on a full time basis. Of course, there are many people who may argue that this wasn’t necessarily beneficial. But air conditioning, especially in a modern society and certainly in the 221st century, is going to be a way of life.

WORLD ISSUES:
Agreements and ongoing changes to the Montreal Protocol and, in the United States, the Clean Air Act place the professional in a difficult situation as regards electric cooling. New restrictions and new equipment seem to appear every day; and some make obsolete or diminish the most educated plans of even the best managers or engineers.

What follows is a discussion of the strengths and weaknesses of Gas Cooling as it can be framed against electric cooling, current CFC rules, anticipated CFC limitations and the alternative options presented by electric cooling technologies.

2. HISTORY and PERSPECTIVE
Although absorption cooling has been used on a widespread commercial basis since the 1800's and early 1900's, there has been a general reluctance by commercial and industrial planners to apply gas cooling technologies. Until recently, a simple comparison of gas vs. electric cooling technologies looked like this:

Before gas cooling advantages are discussed, the recent complications regarding electric cooling must be fully exposed. The best place to start is with the Montreal Protocol.

3. THE MONTREAL PROTOCOL
Most facility managers and facility planners know that the Montreal Protocol exists. In fact, the Montreal Protocol has forever changed the selection of refrigerants (both in the US, and throughout the world). However, most of us are not aware of the evolution of this historic agreement as evidenced by the following table:

Table 2

Bear in mind that CFC's and HCFC's as "ozone depleting compounds" had left HFC's reasonably free of environmental controversy. However, this changed with the Rio De Janeiro Global Environmental Summit in 1990 and, more recently, with the Kyoto Summit in 1997. At these conferences, global warming issues took center stage.

Because HFC's such as R-134a are said to have significant "Global Warming Potential", and because world agreements for phase out of CFC's and HCFC's have now been formalized, HFC's continue to come under significant environmental analysis.

At the 1995 International Conference on CFC's and Halon Alternatives, for instance, a vocal European contingent pointed out that many European nations do not use HFC-134a as the refrigerant of choice even in their refrigerators because of their concern for global warming.

More recently, specific targets were agreed to by the U.S. and other countries (U.S. global warming targets follows):

4. THE CLEAN AIR ACT
Title VI of the U.S. Clean Air Act is the part of the Clean Air Act that brings the U.S. in compliance with the World agreements made in the Montreal Protocol. Even these, requirements, however, are in continuous change. Likewise the paperwork associated with compliance is significant.

A thorough understanding of Title VI, Sections 608 and 609 of the Clean Air Act involves hundreds of pages of reading and thousands of pages of interpretations. Yet the simple decision to use gas absorption cooling in place of electric cooling results in the ability to completely ignore the Clean Air Act as it relates to refrigerants and ozone depletion.

Until November of 1995, HFC's were exempt from compliance to the Clean Air Act. For this reason, many planners and facility managers chose HFC-134a as the refrigerant of choice for their electric cooling needs (i.e. instead of HCFC-22 or HCFC-123). However, in November of 1995, HFC-134a was no longer exempted from the many rules and issues surrounding refrigerants and the Clean Air Act. Hence, of the only three refrigerants currently available for electric cooling over 150 tons, ALL are under the jurisdiction of Title VI of the Clean Air Act.

Just a few of the significant issues associated with electric cooling as impacted by Title VI of the Clean Air Act include:

All mechanical rooms defined and described in ASHRAE 15, 1994 now require mechanical ventilation, refrigerant sensors, at least two Self Contained Breath Apparatus, differing types of multiple sensors, and a plethora of other issues or requirements. Just the analysis relating to ASHRAE 15 requires significant time and promulgates significant confusion relating to the question: "Exactly what IS required based on the type and quantity of CFC, HCFC or HFC refrigerants and the layout of the mechanical room?".

6. PERIPHERAL EQUIPMENT REQUIREMENTS
Because CFC, HCFC and HFC based refrigerants are complex, environmentally hazards and relatively expensive, there are now many types of peripherals typical offered by each of the major manufacturers of electric cooling. Of course, the types of peripherals can and do vary significantly between manufactures and change periodically.

The most important piece of peripheral equipment required for Low Pressure chillers is a purge unit. As with other peripheral equipment discussed above, purge units vary significantly from manufacturer to manufacture.

7. SOME ADVANTAGES OF ABSORPTION COOLING
In addition to the many issues surrounding electric cooling as cited above, the advantages of absorption cooling also include:

Yes, absorption cooling has some disadvantages of size and first cost. However, when compared to this updated Table 2, these problems are relatively simple to resolve. Compare this with the unpredictability of laws, international environmental pressure, peripheral equipment requirements, unstable refrigerants, changing safety and mechanical room issues and the sheer number of emergent refrigerants.

As a result, we find the rather simple and predictable disadvantages of gas cooling compared to complex and unpredictable disadvantages of electric cooling may be summarized like this:

It is a small wonder that Japan, with it's focus on long term solutions, total quality management and profitability has more than half of it's total installed tonnage in absorption cooling. Air conditioning is definitely in your future... no matter what country you work in. But as you are familiarizing yourself with issues of the more conventional electric cooling systems and refrigerants, it will be important to also familiarize yourself with gas cooling technologies.