Class Reflections: Influences of Sustainability in Design

The most influential aspect that I took away from this course is that sustainable and efficient design can be accomplished in many ways. We tended to focus on utilizing the ways that a structure itself can capture and dissipate energy, but there are many other external applications that can be implemented as well. I found it particularly interesting to learn that there are so many ways to maximize the energy efficiency of light, heat and ventilation systems. While they can often be interdependent on each other, using one system by itself can be quite valuable as well. Also it is important to study and understand the specific needs of a site, as changes in region, climate, and season can, for example, drastically change which heating and ventilation systems will be successful in a structure. We discussed the relative difficulties between designing a zero energy house in warm and cool climates, however that does not mean that either is impossible. Strategies to maximize natural lighting and ventilation can be used in various ways to best fit the given situation.

A second topic that I found extremely interesting is the concept of a structures resiliency. Many of the topics that we have covered are based on systems that were developed hundreds or thousands of years earlier. For example, cooling towers were often used in Mesopotamia as early as 2000 years ago, and even today are still being perfected. Also, civilizations have long understood the suns path across the sky and have designed their cities and temples according to its position. This not to say that these technologies have not advanced, as modern materials and building techniques allow us to construct buildings that were unimaginable even 100 years ago. While buildings will most likely continue to improve upon their efficiencies in the future, many of the techniques that develop will have their roots based deep in methods and designs of the past.

The discussion of more general systems is also an integral part of this course. By understanding the larger systems that operate around that of architecture, it helped put the topics we discussed into place in relation to each other. The Bay Game exercise represented an excellent way to illustrate and understand how our decisions relate to larger events that may be causes or effects of our own actions. This helped put the course into perspective that I don’t think could have been provided in any other way. 

Assignment 9: Application and Customization

Double Skin Facades as Architectural Features and HVAC Solutions

As we move closer to the final project, I’ve found myself paying closer attention to the details of the systems we discuss in class as I think about how I might employ them in my studio project. Thus far, the most intriguing to me has been the idea of a double layered facade that. The concept of using two distinct layers of material that can be operated independently presents a level of human interaction that isn’t present in most building skin systems. Their complexity levels can vary drastically, which I believe is what is so intriguing about them. A fairly simply system could be deployed such as the one above, where the inner layer can be operated to exclude or accept warm outside air, in order to combat heating and cooling costs throughout the year. For many cases, this is plenty, as this system adequately reduces the buildings dependence on conventional HVAC systems and therefore lowers its energy consumption drastically. 

However, double skin systems can extend in complexity essentially to the limits of imagination. Above is an image from inside the double skin facade of the Donnelly Center in Toronto, Canada. Created in partnership between Behnisch Architekten and Stuttgart architectsAlliance, the structures southern face consists of a double layered glass and aluminum facade that envelopes a series of walkways, allowing the inhabitant a unique experience of the building and view outside onto the city of Toronto. 

The practicality of applying a system of this sort to my studio project is not yet clear, as WG Clark’s studio sites are quite limited and seem to call for small, contained structures without much of the exterior armature that is exhibited by double skin facade systems. However, I feel that it would be possible to apply it in limited amounts and possibly in conjunction with other non-standard heating and cooling methods in order to reduce the energy consumption of my building and, hopefully, add to the experience and aesthetic of my studio project.

Ventilation Case Study: The Cooper Union for the Advancement of Science and Art

Above: Street front facades of the Cooper Union building, on the corner of 3rd Avenue and East 7th Street in NoHo

Above: Seasonal high and low average temperatures in New York City, with description of seasonal climate conditions.

 

 

Above: Diagram of the stack effect on the building, with high air pressure at the entrance and low pressures inside creating a suction of air through the major spaces.

 

Climate Control Through Evaporative Cooling

^Image source: Kwok, The Green Studio Handbook, page 151

To me, the most interesting new method introduced by the Kwok reading was the evaporative cooling tower. This is the first time I have heard of such a system, and the idea is immediately attention-grabbing while still being functional on an important level. Operating in nearly the polar opposite way of a chimney, evaporative cooling towers expose hot dry air to water at the top of the tower, causing its temperature to drop and its moisture content to increase. This dense air is consequently drawn down the tower and through an opening in the base. Constant suction of air downward through the tower ensures than air continues moving as long as the humidification process continues. 

The benefits of utilizing an evaporative cooling tower are tremendous in terms of reducing money spent on mechanical cooling systems. However, they are suited almost exclusively to hot, arid climates such as the southwestern United States. Such a climate is ideal in regards to the need for a large supply of dry air, but the large amount of water that is often required by these towers could be a problem in areas where water is scarce or rationed. Also, Kwok notes that performance of the tower is often dependent on the difference in wet and dry bulb temperature. The greater the difference, the greater the air flow through the tower will be and the more effective its cooling performance will be. This characteristic requires that the towers height and amount of water consumption must be tailored to the specific climate of each usage.

Above is an example of an evaporative cooling tower that is incorporated into a small home on a Navajo Indian reservation in Arizona. The structure uses the tower in conjunction with the cool nature of its adobe structure and the surrounding ground to keep the home insulated against the hot desert climate. The tower itself is coupled with a wood stove at its base to which it provides ventilation in the winter when the desert nights can become very cold.

Chimneys and Related Heating Systems

This past week in systems, we have looked more in-depth into heating mechanisms. Often passive heating and cooling techniques are not enough to create comfortable climates. In these cases, mechanical systems like furnaces, HVAC, fireplaces and refrigerators are necessary to create a suitable living environment. I first wanted to understand the chimney as it is the most historically used method of heating. I wanted to take a more specific look at my own fireplace. In the fireplace of my living room, the inside has a bent shape which Professor Sherman explained allows for better heat dispersion through the room. The radiant heat from the fire reflects off the back wall and enters the room. Heat from the chimney dissipates across the room through radiant heat. Because the chimney opening is near the ground, the fireplace will primarily heat the air near the ground and rise upward.

At UVA I live in an older house, so we rely on radiators to heat our other rooms. Like a fireplace, radiators provide a heat source near the floor. Because of this origin of heat, the heat will warm the air near my feet and rise upward in the nature of hot air. The radiator functions similar to the fireplace in that it provides radiant heat to the air in my room. In contrast to the fireplace that uses combustion to administer heat, the radiator uses a boiler and steam. The boiler heats the water, the hot water runs through pipes, the pipes heat the room and then the water returns to the boiler to be reheated.

In other methods of heating like the modern HVAC system, the heating passes through vents and can be released from the ceiling. This practice of ceiling vents is one that I have in my house back home and can be found in many constructions. Because of the nature of hot air rising, this method of heating seems to be less effective. When the heat is released from the ceiling height, the hot air has no place to move and stays stagnant near the ceiling. Since hot air rises, any warmth near the floor would also move upward. In this situation, much of the heat energy is wasted on warming a space uninhabited by people (the air near the ceiling).

Harnessing Water as a Heating Element

Throughout last weeks lessons and readings I found it interesting that the idea of using water to heat and cool a building has only recently become widely popular. Moe discussed at length in “Thermally Active Surfaces” how air is a much less efficient medium for the transfer of heat and would be more effective as an insulator. His idea of a better system is an HVAC system that uses water as its tool for distributing heat throughout the structure. Water is much denser and would require much less energy and space than air in order to adequately heat a building. Also, using water would reduce many problems associated with traditional climate control such as air leaking in and out of the building. Air would still be able to move in and out of the building, but since it is no longer the primary source of thermal comfort this would not be as much of a problem. Using water allows the heating of surfaces in the room, which then radiate heat throughout the living space. Moe said that comfort is best achieved when heat is being radiated from all sides of a space, and circulating water instead of air would allow a closer approximation of this perfect system as all surfaces would be potential sources of heat.

Although it is relatively new to building, water cooling has evolved as a natural system of many animals. An excellent example is the system of countercurrent heat exchange that is found in aquatic animals. The concept behind this process is that the animal can maintain its body temperature through the circulation of its blood. As blood passes by the exterior of the fish it is cooled by the lower water temperature outside of its body. By the time the blood makes it to the center of the body near the vital organs it has reached its highest temperature and can transfer some of the heat to maintain a high internal temperature. This heat is lost as the blood circulates back to the surface, where the process restarts. 

Above: This diagram shows the flow of blood throughout the body of a cold water aquatic animal regulates its own temperature as well as the temperature of the entire body.

This idea of an enclosed circulation system is what many modern HVAC units strive to replicate. Some water-based systems utilize a similar effect by running cold water along a hot roof where it is heated by the sun, allowing the same water to take the heat it receives from the sun and transfer it to the surfaces inside the building. As the system grows more popular it will radically change the common conception of air conditioning. The ability to heat a house simply by running water through the walls would change not only the way buildings are designed and build but also how people experience them.

Assignment 6: The Thermal Environment and the Human Experience

Above: My position on the southern plinth of Fayerweather Hall.

It’s Sunday morning at approximately 10:00 AM, and I’m perched on one of the concrete ledges that borders Fayerweather Halls southern stairs. The dry bulb temperature is 65° Fahrenheit and the wet bulb is 51°. A slight breeze of 3 miles per hour makes the air feel a bit cooler still, but not uncomfortable as I feel content in a t-shirt and khaki pants. As I sit down, the first sensation that I feel is the cold concrete slab on which I am sitting, as well as the concrete column that I am resting my back against. Their material temperatures are 55° and 52°, respectively. Their massive forms are still storing the cool air temperatures of the night before and now conducting that temperature onto my legs and back, providing a cold but not uncomfortable balance to the morning sunlight radiating heat onto my face.

While I sit calmly and pay attention to the small inconsistencies in the current weather condition, it is suddenly much busier and more elaborate than what is typically noticeable. Air currents swirl around the corner of the building behind me and to my right as well as between the columns to my left, resulting in a whirlpool of air around me that is constantly shifting speed and direction. These winds primarily chill my arms and the back of my neck, but occasionally slip up the leg opening of my pants or down the back of my shirt and give unexpected but not unpleasant rushes of cool air to my body.

As time passes I’m becoming acclimated to the once noticeably cold surfaces of the concrete that I am resting on. Reaching down to touch it with my hand still results in similar sensations of cold to when I first sat down almost 30 minutes ago, but my back and legs are now hardly registering the cold material as a noticeable difference in temperature. It is still drawing a small amount of heat conduction from my body, but it has diminished to a low and comfortable level.

During my time sitting here, I feel that taking notice of the specific conditions of the climate and materials around me has provided an extremely complete and immersive experience of what would otherwise be just another cool Autumn morning. Combining the feelings of touch I have been experiencing with the sounds of rustling leaves and the colors of Autumn foliage around me, I feel foolish for not stopping to experience such things more often. Typically, brushing my hand against concrete or stonework as i walk by results in a truncated feeling of coolness that I do no stop to fully experience, and the swirling breezes around me are just forces to push the leaves in front of my path. Having completed this experience, I feel that I will go out of my way to find such conditions much more often and take the time to really feel what is occurring around me.

In “Thermally Active Surfaces In Architecture,” Moe discusses at length the different methods that are available to heat and cool a living space with varying levels of energy efficiency. A perfect system, he believes, would be a room in which all six surrounding surfaces were equipped with hydronic climate control systems so that the space is managed evenly and optimal comfort levels are reached for the inhabitants. However, as these systems rely on the usage of massive materials such as concrete, they are often impossible to create perfectly with the popularity of large windows, multi-story spaces, and other programatic elements that make efficient heating and cooling difficult. Consequentially, all of the excellent arguments that Moe makes in favor of thermally active surfaces are only optimally effective in regular, rectilinear spaces. Beyond that, Moe makes no mention of how this change in efficiency would compare to traditional HVAC systems. Thermally active material systems would assumedly still require less energy and be more effective due to their usage of water instead of air, but there are few specifics in this text that point to Moes conclusions.

Above: Architectural plan of Peter Zumthors Bregenz Kunsthaus in Bregenz, Austria. The structures usage of massive concrete walls and pools of water provide excellent usage of thermally active materials that can adequately control the buildings temperature and humidity levels.

In the example of Zumthors Kunsthaus, the thermally active material system is implemented to perfection as the pools of water necessary for a bath house behave just as the hydronic systems running throughout the structures concrete walls. Heating both the water and the concrete, coupled with the buildings fairly open floor plan, essentially turns the entire interior into a single space that is heated and cooled by the same system of radiantly transferring energy through materials to the human body. In addition to these systems, the buildings position in the mountainside and structural support system extending into the cool earth provides it with an inherently stable climate condition, as the enormous heat sink of the surrounding ground prevents the interior of the building from major fluctuations in temperature. However, this condition also presents the necessity of insulating the warm baths from the cold earth that is piled against the interior walls just meters away. Again the massive concrete wall structures provide much of the needed insulation, and the usage of multiple climate zones in the building would allow some thermally active materials to heat where needed, and others to cool at the same time.

Assignment 5: Surviving Disaster and Harnessing its Environment

1) Scenario: During the rainy Spring season, a small riverside village in Costa Rica is ravaged by a tropical storm leaving much of the villages structures in disrepair and most of the area submerged in feet of water. The climate is very hot and humid during this time of the year, although the village is surrounded by forests that provide shade from the sun. However, there is no way to prevent the constant wind and rain that affect this area of the world, only to harness it. The system that is put in place will be able to serve the village from Spring into Autumn, a time of approximately six months.

2) Solution: In order to solve the needs of both energy and transportation, a survival system will be deployed based around a fan boat that can be propelled by both wind and rain, and stores this power in deep cycle batteries that are then used to charge cellular phones and provide limited electricity for lighting and other needs.

3)

Above: Section view of the proposed energy collecting craft, showing overall form and layout. The craft measures 6′ in length, 4′ wide and 1.5′ deep, adequately transporting up to six people at once. At the stern is a 5′ shaft with a 6′ diameter fan mounted to catch wind or, with the blades rotated 90 degrees, to catch rain. This fan powers both the crafts propeller as well as a 12 volt electric motor that charges a series of deep cycle batteries to be used in supplying the village with small amounts of electricity.

Above: Detail of the crafts electrical system that converts rotational energy of the fan blades into electrical energy to be stored in the deep cycle batteries carried on board. The drive shaft turns a 12 Volt electric motor, whose energy is led through a blocking diode that prevents any kind of resurgence through the system, into a charge controller. This controller limits the rate at which current is added to the batteries, preventing overcharging and over voltage. In the event that the charge controller fails, in-line switches are in place between the controller and each battery as a secondary safety measure.

Above: This diagram shows how the fan blades can rotate to catch the force of either wind or rain.

4)

Above: This diagram shows the flow and change of energy as it moves through the energy collection system, beginning as kinetic energy from the wind and converted into rotational kinetic energy in the drive shafts. The electric motor converts this into electromagnetic energy that passes into the batteries, where it is then chemical potential energy ready to be used to charge electronics or provide electricity to flooded villagers.

5) This method of energy collection could be used to extend hybrid gas/electric technology to fan-propelled boats often used for transportation through rivers and marshes throughout Central America and the Gulf Coast of the United States. This would decrease the amount of gasoline consumed by these boats, saving money for fishermen and tour guides as well as decreasing the pollution their engines produce.

This system would be suitable for disaster relief in any area that receives large amounts of rain or wind storms. The fan and its shaft could even feasibly be removed from the boat and used simply as a wind turbine when the boat was not needed for transportation, or when another location could gather more wind or rain energy than on the water. This would make this system even more versatile and applicable to even more situations, in both disaster relief and everyday life.