The
Future of HVAC
The Perspective of One American
Richard
B. Hayter, Ph.D., P.E.
Kansas State University Manhattan, KS 66506
(Presented
at the 40th anniversary of the Netherlands Technical Association for Building
Services (TVVL), June 11, 1999, Amsterdam, The Netherlands)
|
Summary:
Our technology is constantly changing, sometimes because of new discoveries and sometimes because of influences outside our industry.
As recently as this century,
central, indoor climate control was available to only a privileged few.
Today, even central air-conditioning in homes is common in the U.S.
Our industry has had a profound
effect on population shifts, particularly in hot climates. Occupants in our
buildings are now more comfortable, healthier, and more productive than they
once were, thanks to improvements in our equipment and system designs.
These improvements have been
brought on by a number of factors including technical, market changes, energy
and environmental concerns, and political decisions.
Regardless of the reason for the
changes, they will continue to occur and we have an obligation to direct
those changes for both the benefit of our clients and our future.
Learning from the Past:
Trends indicate that there continues to be an increase in demand for air-conditioning and with that comes a need for new technology. Let us review that trend.
Records show that central heating
existed as long ago as the third century BC. Similarly, various techniques
have been used to enhance ventilation in buildings. An article in the ASHRAE
Journal describes an innovative design to enhance ventilation in the Natural
History Museum, London, constructed in 1873. Cooling for comfort also had
early beginnings. In the eighth century a Baghdad caliph had snow packed
between walls of his villa for summer cooling. These are certainly unique
examples but do not demonstrate the present impact of HVAC on the general
public.
Although central cooling in office
buildings existed as early as 1928 in the U.S., it was too expensive for the
typical homeowner. After World War II, air-conditioning for comfort became
increasingly popular. Whereas in the past, buildings had operable windows
with awnings for shade, high ceilings, and possibly portable fans for
cooling, the entire architecture of buildings began to change as
air-conditioning became more prevalent.
Since 1940, eight of the 10
fastest growing cities in the U.S. are located in the Southeast and Southwest
parts of the country. This is the direct result of air-conditioning.
"Stay Cool! Air Conditioning
America" is an exhibit that opened May 1, 1999, at the National Building
Museum in Washington, DC, USA. The exhibit shows the growth and impact of
air-conditioning in the U.S. The exhibit will remain open through
January 2, 2000.
Today air-conditioning is a way of
life in the U.S. According to the Air-Conditioning and Refrigeration
Institute (ARI), nearly 50% of all U.S. homes have air-conditioning and in
1996, 81% of all new homes constructed were equipped with central
air-conditioning.
Will this exponential growth in
the use of air-conditioning continue? Will other regions of the world see
similar growth? It is the author’s opinion that growth will occur.
However, the rate of that growth will depend on a number of variables.
The HVAC Market:
Trends would indicate that the HVAC industry is responding to a robust market and that the market is significantly influenced by a concern for energy and the environment. Advancements in technology are responding to those concerns.
According to ARI, the value of
shipments by U.S. HVAC manufacturers exceeded $28 billion U.S. in 1996. With
52,000 CFC chillers yet to be replaced in the U.S. alone, there remains a
large market for new chillers, new technology, and new opportunities for the
HVAC industry. In 1998 the U.S. manufactured 7558 non-CFC chillers for use in
the U.S. and abroad. ARI indicates that the new, non-CFC chillers will be 40
percent more efficient than the CFC units installed 20 years ago. With less
energy consumption comes lower CO2 emissions from electrical
generating plants.
The U.S. Environmental Protection
Agency predicts that by the year 2000, 44 percent of the CFC chillers that
existed in the early 90’s will be replaced or converted. As a result, energy
consumption will be reduced by 7 billion-kilowatt hours/year compared to that
before replacement began.
Similar improvements in residential, unitary air-conditioners can be seen in figure 1. Figure 1: Shipment-Weighted Seasonal Energy Efficiency Ratios of Unitary Air-Conditioners (Less than 65,000 BTUH)
Sales in unitary equipment
increased 16 percent in 1998 over the previous year.
Influences on HVAC Applications:
Buildings have a significant impact on our global resources. ARI reports that in the U.S., 5.5 quads of energy are consumed in commercial buildings each year. Comfort cooling and refrigeration account for the largest portion of this (48%). Overall, buildings in the U.S. consume about 35% of the country’s total energy consumption.
As scientists, engineers, and
technicians, we tend to feel that advances in the industry are primarily in
response to advances in technology and a consumer demand for that technology.
Technology is indeed important but much of the change in our industry is in
reaction to other influences. The following is a description of some of these
influences.
Energy: Few doubt that the energy we presently use is finite.
The engineer who designs or operates equipment and systems has a commitment
to minimizing energy use for the long-term benefit of humanity, as well as to
save costs for his or her client or employer. In the U.S. the primary driver
for energy conservation is not necessarily the finality of the source but the
cost savings. Therefore operating costs are major influence in the adoption
of new technology.
Energy supplies also have a strong
political influence, not only between producing and consuming countries but
also within countries where distribution inequities, taxing authority, and other
political issues can influence policies that have little or no technical
basis. The national security of a country may be dependent on a reliable flow
of energy and therefore decisions regarding its use and availability may or
may not directly impact equipment and system design.
We can anticipate that energy
efficiency will continue to play a dominant role in our designs. We should
not assume that we must sacrifice comfort for the sake of energy. Our
challenge is to provide comfort while at the same time conserving energy.
Environment: The environment has possibly had more influence on HVAC
technology than has energy. The environment will continue to impact our
industry into the foreseeable future.
Ozone depletion is a global issue
that is still being resolved. Developing countries are still permitted to
produce CFC’s and are doing so in record volume. Illegal imports of CFC’s to
the U.S. and other countries are a continuing concern. Much of the illegal
imports are virgin CFC’s.
Likewise, local governments or
groups of governments that attempt to ignore the Montreal Protocol cause
major disruptions in the planned phaseout of refrigerants. For example
attempts to accelerate the phaseout of HCFC’s will ultimately have damaging
effects on our environment. As Ted Rees, President of ARI explains, early
phaseout of HCFC’s will encourage use of CFC’s, particularly in developing
countries, because HCFC alternatives are threatened with premature phaseout.
In addition, trade barriers will negatively effect our industry,globally,
without a benefit to society.
Policies regarding climate change
have also directly impacted our industry. As we design and operate more
energy-efficient equipment and systems, we use less energy, energy that, in
many cases, comes from burning CO2-producing fossil fuels.
An interesting anomaly resulting
from climate change is the new design conditions that are evolving for
buildings as climate zones shift.
Like energy, the environment will
continue to impact our industry. Fortunately our industry has proven that it
can respond in a timely way. As we developed new, environmentally friendly
products, those products are also more energy efficient. Each of us has an
obligation to adopt these new technologies and support research that will help
our industry meet the challenges of the future.
Human Factors: Worker productivity will become a significant factor in
the way we design, install and operate our environmental control systems.
Annual energy costs for an office building in the U.S. is approximately 45 to
90 Nlg/m2/year. Maintenance and other building and operating costs are
similar. The cost to rent or own the property is approximately 225 to 900
Nlg/m2/yr. The total cost of personnel who occupy that building ranges from
4500 to 9000 Nlg/m2/yr. The point here is that although the cost of energy
can and should be minimized, it should not be done at the expense of the
productivity of the worker. Safety, health, comfort, and productivity are
certainly influenced by the HVAC system. Air quality, noise, temperature,
humidity control, and, in some cases, radiant heat transfer are all
controllable variables. As important as good design is, it is equally
important that the system be operated to assure a quality environment.
Beyond the immediate impact on the
occupant, the level of control of the environment is also somewhat governed
by occupant expectations. For example, in the U.S. occupants dress for indoor
conditions that will be somewhat uniform regardless of exterior conditions.
Whereas in some countries, this level of control may not be expected,
particularly with regards to air-conditioning, in the U.S. temperature
control has a major impact on occupant satisfaction.
As we better understand the impact
of the environment on worker productivity, we will see an increased use of
individual environmental control systems. Here each occupant will be able to
select his or her preferred dry bulb temperature, air velocity, and possibly
radiant and wet bulb temperature. Some systems will even provide a white
noise generator that is under the control of the occupant.
Political: Adoption of building standards will increase. Whereas
standards based on sound technical information and decisions are usually of
benefit to a global society, those that have political overtones,
particularly those that create a protectionism of local commerce, have a
negative effect on those outside as well as inside the country.
The dialogue between ISO, CEN, and
other multinational standard writing bodies is both commendable and productive.
As engineers, we must continue to support the creation of standards based on
a consensus of the industry and help avoid undue political influence. The
sharing of knowledge through conferences such as this, scholarly
publications, and cooperative activities of technical societies will
contribute to technical rather than political-based standards.
We can anticipate that global
standards for design of equipment and systems will increase. This should not
necessarily be interpreted as negative or restrictive to our designs because,
if the standards are based on sound technical information, they will provide
the collective knowledge of engineers from throughout the world.
Societal: The engineer, scientist, and technician can make a major
contribution toward satisfying the goal to conserve energy and to minimize
the impact of our industry on the environment. He or she also has an
obligation to assure that an interest in sustainability continues.
A growing societal ethic exists
for protecting our environment and extending the availability of our natural
resources. "Green Buildings" and sustainability are in-vogue terms
at the moment. It is the author’s observation that this ethic is particularly
strong in northern European countries. Although countries that have only
limited or no domestic sources of energy have reasons of national security to
be energy conscious, the commitment of the general public in many of those
countries goes well beyond national security issues.
Communication: As engineers, we have an obligation to verify that the
information we use whether received verbally, in print or on the Web is sound
in principle and applicable to our client’s need.
Instant global communication has
become commonplace, particularly in developed countries. As the author
prepared for this conference, virtually all of the communication with TVVL
was via the Internet. Similarly, engineers are regularly transmitting plans
and specifications for new equipment and systems. We can now be interactive
in real-time with engineers in multiple locations throughout the globe, while
we work simultaneously on the same drawing, set of plans, or document. Visual
communication via computer desktop video allows us to converse face to face.
What impact will this have on our industry? It will be significant and
totally positive. We can now instantly share information regardless of our
location. We can draw on the knowledge of individuals throughout the globe as
we design and operate systems for the comfort and health of our building occupants.
In addition, the Internet gives us
access to a vast array of current technology that was previously unavailable.
Geographic location is no longer an issue as we access the World Wide Web.
Looking Ahead:
Conferences such as this one sponsored by TVVL will help disseminate new technology. All of us have an obligation to our profession and a global society to share our knowledge by contributing to the literature, supporting research, writing standards, and encouraging students to pursue our field of engineering.
It is impossible to predict the
impact of technologies presently under development. For example, systems that
do not rely on vapor compression such as desiccant cooling, thermoacoustic
and magnetic refrigeration, and even older technologies like thermoelectric
or vortex cooling may all have significant effects on our designs in the
future, particularly as there becomes an increased emphasis on personal
climate control.
It may be easier to accurately
predict the effect of improvements in more traditional technologies, such as
advances with natural and flammable refrigerants. Both Europe and North
America are experiencing exponential growth in the use of natural
refrigerants, particularly ammonia. The rate of growth in the use of
flammable refrigerants is somewhat more difficult to predict. Adoption of ISO
5149, "Mechanical Refrigerating Systems Used for Cooling and
Heating-Safety Requirements," will likely help increase the use of
flammable refrigerants once thought to be unsafe.
Whereas in the recent past we
experienced significant changes in air handling system designs ranging from
variable air volume to displacement ventilation, it is the author’s
prediction that innovations in computer-based control systems will have an
equally dramatic effect on new designs. For example, the advent of fuzzy
logic controllers which control a system to maintain a comfort zone or
envelope rather than a single point or dead-band will have a significant
impact on the equipment we select and the systems that deliver the
conditioning fluid such as water or air.
Regardless of the equipment or
controls used, it is the author’s opinion that we will definitely see an
increase in the integration of the environmental control systems and the
building structure. An increasingly popular terminology in our industry is
"the building is a system." The communication between the
architectural profession and the engineering profession will increase with
division of responsibility becoming more integrated.
I also anticipate that we will see
a renewed emphasis on our knowledge of human factors. A wealth of information
exists on how we respond to the thermal environment, yet humans are the most
complex part of the HVAC system. As we better understand the cause and effect
of indoor air quality, the interaction with noise, light, air velocity and
other environmental variables on humans, the better our design will be for
environmental control systems.
Specialty environments will also
take on increased importance. For example, special needs in a variety of
medical facilities, facilities for the aging, manufacturing, and confinement
housing for food animals will all present new challenges for our profession.
Preparing for the Future:
Your value as an engineer is in what you know and your ability to apply that knowledge. As soon as your knowledge is less than state-of-the-art, your value to your client and employer declines.
We are in a dynamic profession. It
is virtually impossible to keep current by merely continuing to use the same
solutions to problems or to depend totally on our own innovative ability. We
must be proactive in learning about new technologies throughout our entire
career. In addition, we have an obligation to our profession to share our
knowledge with others.
Again, electronic communication
gives us the tool needed to share information globally. I predict that the
future of our industry will be as dependent on lifelong learning as it is on
the development of new technology.
Virtual electronic classrooms are
here today. We need not wait for the future. ASHRAE President George Jackins
set the establishment of the ASHRAE Learning Institute as one of his goals.
His vision for this institute is to provide an opportunity for engineers
around the globe to share knowledge regardless of their locations, time
differences, and political boundaries.
ASHRAE will be making a
considerable investment in the institute in order to serve our members, as
well as share opportunities with other societies and individuals in our
field.
It has long been the author’s
position that virtually everyone in our industry has some knowledge from
which the rest of us could benefit. The ASHRAE Learning Institute will help
us share that knowledge.
Beyond ASHRAE, every technical
society affiliated with the HVAC industry such as TVVL, will be increasing
its emphasis on the transfer of knowledge. Only you, the engineering
practitioner, will determine what knowledge is transferred and the method by
which it is shared.
Conclusion:
The rate of change in our industry will be exponential. Some changes will be caused by improvements in technology whereas others will be the result of influences outside our immediate control. As engineers, we have an obligation to be proactive in encouraging changes that are of benefit to the society we serve. This in turn will have direct benefit to our industry and to each of us individually.
You can be part of that positive
change by sharing your knowledge with other engineers through publications,
serving with standard writing organizations and participating in technical
societies.
We are a
"people-oriented" profession. Our designs have a direct impact on
the people who occupy our buildings. We will continue to discover ways to
assure their comfort and health, while reducing our impact on the environment
and natural resources.
Changes will occur and for the
better. Our vision for our industry can be fulfilled as we take action
through our contributions to the technology of HVAC.
Richard B. Hayter was the 1995/96 president of ASHRAE. He is the Associate Dean of Engineering for External Affairs at Kansas State University, 133 Ward Hall, Manhattan, KS 66506, rhayter@ksu.edu . |
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