Here is a video animation I made of how refrigeration works in system.  All of the diagrams shown are my own, unless noted otherwise. Simply click on the images to enlarge.

Refrigeration is the process of achieving and maintaining a temperature below that of the surroundings, making a certain product or space cooler than its natural climate. I want this study to help foster better ways of using refrigeration systems.  I will discuss history of refrigeration along with the new strategies and technologies that are being developed to make refrigeration more efficient.  Many new alternative energy sources are being developed as a result to high electric bills.  These new energy efficient systems could lead to a different set of possibilities for public life.  This study has helped me understand the concept of refrigeration and its impact on architecture.  Additionally, through my research I have been able to understand different methods of refrigeration as well as more sustainable uses of energy to reduce costs, make the system more efficient and protect the environment.  Refrigeration can create a very stimulating effect displacing itself from the natural environment.  Through different research I have found that this does not have to be a harmful experience, and can in fact, be an enlightening one that helps to better understand how systems work and how to utilize the environment as much or as little as you want for a structure. Through this study I have gained a better understanding of refrigeration in its relationship to air conditioning and larger structures such an ice rink.

Refrigeration was first applied to preserve perishable food products by storing them at low temperature. Humans have been finding ways to refrigerate since 1000 BC when the Chinese cut ice in the winter and stored it for the summer.  This kind of seasonal harvesting of ice and snow became very common through ancient cultures.  The Chinese, Hebrews, Greeks and Romans would store ice and snow in caves or storage pits dug out of the ground and insulate them with wood and straw.   Today, the refrigeration we think of is produced artificially.  In the mid 1700’s in Scotland, the first refrigerating machine was demonstrated when William Cullen boiled ethyl ether into a partial vacuum and produced a small amount of ice in the laboratory.  In 1820, Michael Faraday liquefied ammonia and other gases by using high and low pressures, which would later be used in 1834 by Jacob Perkins in the first vapor-compression refrigerating system.  In 1841 Dr. John Gorrie designed the first system to refrigerate water to produce ice.  He also conceived the idea of using his refrigeration system to cool the air for comforting his patients with yellow fever in the hospital.  Through time, refrigeration systems have become a means of thermal comfort for humans through air conditioning.  There have been constant improvements of the refrigeration system and many different iterations continue to be developed.

In 1992, the EPA made it against the law to intentionally vent CFC and HCFC refrigerants into the atmosphere because it was found to be depleting the ozone layer. The late twentieth century phenomenon of climate displacement has great significance towards sustainable design and energy use.  This manipulation of the environment, constructing entirely artificial climates outside of the domain of their natural occurrence, has not been around for very long in terms of refrigeration. Using refrigeration to create an artificial climate has only been around for the last 70 years. The refrigeration is much simpler than one would think.  Here are the basic steps of a refrigeration system:

  1. The compressor a machine that increases the pressure of a gas or vapor (typically air), or mixture of gases and vapors compresses the ammonia gas. It is located on the outside of the refrigerator or system. The compressed gas heats up as it is pressurized.
  2. The coils on the back of the refrigerator let the hot ammonia gas dissipate its heat. The ammonia gas condenses into ammonia liquid at high pressure.
  3. The high-pressure ammonia liquid flows through the expansion valve. The expansion valve regulates the flow and meters the systems. On one side of the valve is high-pressure ammonia liquid. On the other side of the hole is a low-pressure area (because the compressor is sucking gas out of that side).
  4. The liquid ammonia immediately boils and vaporizes. This makes the inside of the refrigerator cold.
  5. The cold ammonia gas is sucked up by the compressor, and the cycle repeats.

The air conditioner system works just like refrigeration system. Here is a window air conditioner.  You can see that the evaporator is located on the inside and works just the same with the compressor on the inside, turning hot air into cool. At a larger scale, HVAC systems in homes work the same as well with the main air conditioning unit on the exterior of the home with the evaporator, and the compressor above the furnace in the interior. This process can then be brought at an even larger scale with a mechanically-refrigerated ice rink.  The first ice rink was opened in 1876 in Longdon.  The ice was made through an expensive process of sending a mixture of glycerin and water through copper pipes. The main difference in an ice rink is that the refrigerant doesn’t cool the ice directly. Instead, the refrigerant cools Brinewater, a calcium-chloride solution.  The Brinewater is then pumped through underground pipes that go under the ice and are rooted in a sand base, as shown in the diagram. As I had mentioned in recent posts, ice rinks are a large produced of energy and waste a large amount.  Ice rinks typically use energy through refrigeration, lighting, pumps, fans and heating.

There are also many mechanically-refrigerated heat leakages in ice rinks from ceiling radiation, brine pump work, rink humidity, rink air temperature, ice resurfacing, light radiation, ground heat, skaters and header heat.

An energy efficient ice rink could reuse that heat in order to reduce refrigeration use.  For example, by adjusting the air temperature at different times so that it is warmer during games and colder when the ice is less used.  Or, installing heaters above the bleachers would reduce having to heat the entire space.  Another possibility is to add heat recovery. According to Touch Stone Energy, “on average, as much as 7.2 million Btu,  or more than 2,000 kilowatt-hours, of heat are generated each  day by [a Canadian] ice plant—more than enough to satisfy the entire daily heating load of the ice rink while having excess thermal energy left over for other purposes. By implementing heat recovery systems, ice rinks can realize overall heating savings of over 75 percent.” By recovering the wasted heat energy that I mentioned in the diagram earlier, heat can applied in other ways such as domestic water heating, subfloor heating, flood water heating, ice melt and preheating cold outdoor air for ventilation.

Additionally, by adding low-emissivity ceilings ice rinks can better hold in the cold air and reject the hot air from the outside.

There are many new modern refrigeration technologies that can also help to reduce energy:

  • Magnetic Cooling (diagram from Talbott, NIST)
  • Closed-Cycle Air Refrigeration
  • Thermo-Acoustic Refrigeration

There are many different forms of climate displacement  that can be found in restaurants, botanical gardens, theme parks and other forms of architecture.  In Dubai, a indoor ski resort was recently built in the middle of the Arabian desert.

For more information on Ski Dubai: http://science.discovery.com/videos/how-do-they-do-it-6-indoor-ski-resort.html

diagrams from philip rahm architects

Philip Rahm represents how the manipulation of the environment does not have to be a harmful process, but a very psychologically stimulating one that creates a contrast to the natural environment and plays with different kinds of systems. The new forms of technology seem very promising for the future of refrigeration. I am very interested to see how the thermo-acoustic refrigeration and magnetic cooling efforts play out.  Before this study, I had no idea there were so many possible ways of refrigerating a space or product.  Through time, however, there have been many different variations of cooling systems that have built upon one another in order to produce the more efficient and environmentally sound system.  This study of the evolution of refrigeration is itself a system, developing mechanically refrigerated buildings and air conditioned space.  Today, refrigeration is looking to work with the environment rather than fighting against.  However, it is still generating high amount of energy waste in structures that are not acting upon the new advancements in refrigeration.  Simple tasks of just managing pumps or adjusting the air temperature can save drastic amounts of money on electric bills and energy.  This study has helped me  better understand how refrigeration is working with the environment and space to develop a more sustainable system.  I have developed a deep understanding of the methods and am eager to see where it goes to next.

Bibliography:

“Advanced Refrigeration Technology.” Refrigeration-Engineer.com Forums – The Front Page. Web. 08 Nov. 2011. <http://www.refrigeration-engineer.com/forums/showthread.php?4531-advanced-refrigeration-technology&gt;.
“Hormonorium – Philippe Rahm Architectes.” Philippe Rahm, Architectes. Web. 08 Nov. 2011. <http://www.philipperahm.com/data/projects/hormonorium/index.html&gt;.
“How Do They Do It?: Indoor Ski Resort : Video : Science Channel.” Science Channel: Space, Technology, Engineering, Earth Science. Web. 08 Nov. 2011. <http://science.discovery.com/videos/how-do-they-do-it-6-indoor-ski-resort.html&gt;.
“HowStuffWorks “How Ice Rinks Work”” HowStuffWorks “Learn How Everything Works!” Web. 08 Nov. 2011. <http://www.howstuffworks.com/ice-rink.htm&gt;.
“Managing Energy Costs in Ice Rinks.” Touch Stone Energy. E Source Company LLC, 2010. Web. 4 Nov. 2011. <http://www.touchstoneenergy.com/efficiency/bea/Documents/Ice_Rinks.pdf&gt;.
“New Refrigeration System Based On Magnetics More Economical And Quieter Than Current Technology.” Science Daily: News & Articles in Science, Health, Environment & Technology. 4 Nov. 2011. Web. 08 Nov. 2011. <http://www.sciencedaily.com/releases/2009/02/090211111013.htm&gt;.
“Refrigeration, Naturally – Archives.” Food Engineering. 4 Nov. 2011. Web. 08 Nov. 2011. <http://www.foodengineeringmag.com/Archives/318ed4f4472f8010VgnVCM100000f932a8c0____&gt;.
“Refrigeration: Some Cool Ideas | The Economist.” The Economist – World News, Politics, Economics, Business & Finance. 4 Nov. 2011. Web. 08 Nov. 2011. <http://www.economist.com/node/1648576&gt;.
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