Cooling down a country?

In 2010 the international football association FIFA picked that Qatar to host the 2022 soccer world cup. This event usually takes place in the summer when the average daily high temperatures in Qatar are around 110F. Playing 2 x 45 minutes under such conditions is not desirable. The presented solution is to cool down entire stadiums using solar energy to cool down entire stadiums. The idea is to use chill water to cool down air before it is blown into the stadium and keep the pitch temperature bellow 80 F. The spectators are also promised “comfortable temperatures”. So the idea is to cool down entire open roof stadiums.

Conceptual stadiums for 2022 World Cup. From http://www.cnn.com.

 

However, the ambitious project does not stop there. The football association FIFA also wants comfortable areas for spectators. FIFA purposed that public areas, walkways and training pitches also were to be cooled down. Represents from the Qatar 2022 World Cup organization have even promised to cool down entire neighborhoods to keep visitors comfortable.

A total of 9 stadiums are to be built for the world cup. Keeping all of them, as well as public areas and training pitches cooled will require an enormous amount of energy. Technology will develop further before the 2022 world cup, but it will be interesting to see more detailed plans on how these areas are supposed to be cooled.

The FIFA president Sepp Blatter recently admitted that awarding Qatar the world cup could have been a mistake. FIFA is currently considering moving the tournament to the winter to reduce the heat problem. A decision is expected in the near future.

 

Sources:

Gibson, O. (2012) Qatar promises fans to take the heat out of 2022 World Cup. Online: http://www.theguardian.com/football/2012/dec/12/qatar-cool-2022-world-cup

Gibson, O. (2013) Sepp Blatter admits Qatar World Cup error and backs winter switch. Online: http://www.theguardian.com/football/2013/sep/09/world-cup-2022-sepp-blatter-qatar

Tutton, M (2010) Qatar promises air-conditioned World Cup. Online: http://www.cnn.com/2010/SPORT/12/03/qatar.world.cup/

Campus project in Building Enclosure design: Alumni Memorial

This project highlights some characteristics of building enclosure performance such as heat transfer, air leakage, and moisture performance, by means of inspection of the Alumni Memorial building on the Illinois Institute of Technology main campus located in Chicago.

 

A visual thermal inspection of the building was conducted using an infrared camera to analyze thermal bridges and possible leaks in the enclosure. Architectural and structural plans and detail drawings were acquired in order to model the building’s envelope in critical areas and develop a deeper understanding of the building components and their performance. A temperature and relative humidity data logger was placed inside the Alumni Memorial at certain locations and data was logged for a 24-hour period at each location. Visual inspection of the exterior was done and the results captured using a professional DSLR camera. We use THERM to analyze the R-value of the building and  WUFI to model the moist performance of the building.

 

From the visual and thermal inspection, modeling and measurement data, we draw some conclusions.First of all, according to the thermal model of the walls, glass, and roof, the thermal resistance of the building is significantly low. The enclosure is not good enough to prevent heat loss.Furthermore, there is no insulation present between the wall and column.The roof does not have any insulation either. Single glass panes with extremely low R-values take up a large part of the building facade. These, combined with eroded sealant and rusted steel frames, result in large heat losses from window and water leakage to the inside. At last, most part of the steel frame structure is visually corroded and damaged, resulting in weak structural and thermal performance. 

We also suggest some recommendations such as use double low-e glass instead of single glass. Add insulation in the wall and between the columns. The sealants around the window frames need to be replaced and then coated with all-weather paint to further extend its lifetime.

Floating Solar PV Systems

In June, a 1.18-MW PV system floating on a water reservoir became operational in Japan. The system called “Solar on the Water Okegawa” in Saitama prefecture is currently the biggest system of its kind in Japan. Having recognized the issues of land shortage and of protecting natural and agricultural lands, the company Ciel el Terre noticed many inland water reservoirs, which are located near grid-connection, but under-utilized.

Ciel el Terre began the R&D process for floating PV systems now marketed under “Hydrelio System.”  PV modules are mounted on floats made of high-density polyethylene, which is the same durable material used in marine buoys. The Hydrelio System uses no metal parts and is as easy to assemble as LEGO blocks. Eva Pauly, International Manager at Ciel el Terre International, said that it took three weeks to assemble the floating system and three months to construct the entire Okegawa project, which consists of 4,500 PV modules.

The company conducted several durability tests to prove that the systems can withstand up to 118 mph winds and changes in water levels of up to 20 feet.  In fact, the Okegawa project withstood three typhoons in Japan, according to Pauly. Ciel el Terre claims that due to the cooling effects of water, its floating PV systems generate about 10 percent more electricity than rooftop or ground-mount systems of the same size.

While this practice may seem ideal in Japan, where land is more limited that here in the States, it can still be considered a viable option compared to the popular rooftop trend that is spreading. In the U.S., there is a 190-kW (AC) floating PV system at a winery’s vineyard irrigation pond in northern California. Since March 2007, the system has been generating electricity along with a 250-kW (AC) ground mounted system installed adjacent to the pond.

While this idea is not necessarily innovating for the sustainability project, it does offer a different media to use solar panels. What is not discussed in this article, but should be discussed ethically, is the ecosystem that is disturbed by these panels. Fish and birds alike would be affected dramatically, especially if any toxic deposits somehow manage to leak into the lake. It should also be noted that the maintenance cost would be considerably more costly compared to solar panels on land due to algae removal, corrosion of panel frames, and the fact that the panels are more difficult to access.

References:

http://www.renewableenergyworld.com/rea/news/article/2013/11/running-out-of-precious-land-floating-solar-pv-systems-may-be-a-solution

Green Plumbing

Green Plumbing

We have been discussing green buildings in our building science course with an emphasis on topics such as heating and solar ventilation. We have explored advances in insulation of homes and green HVAC systems. One more facility that I have learned can be modified to be more green is the plumbing system. Reducing bills and adverse effects on the atmosphere, targeting the plumbing system would benefit us greatly. In a course on plumbing that I am taking, I learned a number of important facts and figures on how we can go green more effectively by going green in plumbing department. Below are a few areas in which residential energy use related to water and plumbing is proving costly and a few ways that can be implicated to conserve the energy being used.

Heating water for use by residents of a home accounts for approximately 30% of residential energy use. Moreover, wasted water adds up to thousands of gallons per year which wastes a lot of energy involved in water handling. If we can reduce the heat loss from hot water and conserve water, we can see a drastic reduction in bills and can contribute more effectively to going green.

Some of the things we can do to reduce the use and heating of water are as follows:

• Low-Flow fixtures: Installing this type of over-head shower fixture can reduce the water usage in the residence by up to a staggering 60 percent by reducing the flow of water. Less water being used means less water being heated and this would prove beneficial financially as well as environmentally.
• Faucet Flow Reducers: Similar to the concept of low-flow shower fixtures, installation of such faucet fixtures is easy considering that they can fit on the end of your current faucet fixture where the aerator is screwed on and will reduce water flow by up to a handsome 40 percent.
• Low-Flush Toilets: About 28 gallons of water per person per day are used by the flushing of toilets. Flushing the toilet is the single most water consuming use in a home.
  Installing these types of toilets reduce the amount of water used per flush by anywhere from two to five times less than the standard toilet.
• Home Leak Monitoring Device: This involves installing a device that will alert you when it senses a leak so that you can find and fix the issue sooner than you would without being alerted. Leaking faucets, toilets and pipes account for thousands of gallons of water being wasted monthly so such a device certainly would play a role in energy conservation.
• Energy-Efficient Appliances: You can reduce the amount of water consumption in a residence by as much as half by installing energy-efficient dishwashers and clothes washers.

Making your home green does not just mean making it healthier for the environment but also healthier for the inhabitants of the home. A couple examples of steps to make your home healthier are as follows:

• Installation of Chlorine Filters on Shower heads: Chlorine is readily absorbed through the skin six times faster than through the digestive system and so chlorine sensitivity can be a major issue for many. Installation of a filter would reduce chlorine levels effectively.
• Installation of Activated Carbon Filters: These filters are installed on faucets and showerheads and absorb pollutants. If you are concerned with poor water quality this option would prove beneficial as a purification strategy.

Some of the measures we can take to reduce home energy use regarding plumbing are as follows:

• Remove/Avoid Plumbing from Exterior Walls: Doing this and running the pipes through conditioned spaces instead will reduce the amount of heat loss from being in close proximity to the outside atmosphere and temperature.
• Insulate Pipes: If the above mentioned strategy is not a possibility then insulation of the pipes will allow less heat loss and will definitely make a beneficial impact in your utility bill.

Resources:

http://www.homeadvisor.com/article.show.Green-Plumbing.16396.html

http://www.greenbuilding.com/professionals/green-building-practices-and-technologies/green-building-plumbing

http://www.greenbuildingadvisor.com/green-basics/green-plumbing-systems-save-water-and-energy

Welcome Aboard the Mother[Earth]ship

The concept of the Earthship all started in New Mexico by Michael Reynolds, an architect, whose goal was to bring self-sufficient homes that were everlasting and in harmony with the environment that dealt with the waste that building design often creates. The Earthship movement began in the southeast of the United States but today has grown to be implemented globally.

The typical Earthship home uses tires filled with soil to act as thermal mass for the exterior walls. Oftentimes in the new world of high performance enclosures the utilization of thermal mass is overlooked as a means to lower energy costs on the building. Using a material for its thermal mass is a traditional building method that has been overlooked even though it is an excellent way to keep a room cool during the hot days and allow then give off the daily collected radiation by the evening into the cooler interior space. Often the home is set into a slope or hillside to utilize the insulated mass of the land as well. Other features include systems such as renewable solar and wind energy in addition to natural ventilation and capitalizing on day lighting to keep the space lit. The majority of the building materials are recycled items that would be thrown out anyways. For example, many homes use glass bottles as decorative wall art which also allows in light.

The MEP systems of the Earthship include water harvesting cisterns that are supplied by channels from the roof that filters the water through several steps in order to provide irrigation to indoor and outdoor landscaping, flushing toilets, and regulating the humidity of the house. The Earthship collects and stores solar and wind energy and are usually still connected to the public grid as a backup or as a means to give energy back to the grid.

http://arizonaearthship.com/Earthship_facts.html

 

Photovoltaic windows

Imagine a building envelope with windows creating electricity from the sun light. It could be the future of the building envelopes with windows composed with photovoltaic cells inside the layers of glass.  Nowadays, it is possible to create transparent photovoltaic windows. One such windows can produce to 250 Watts of electricity power.

This kind of windows is conceived with two layers of glass, an insulating layer and transparent photovoltaic cells. One advantage is that they are able to filter 100% of the undesired rays, infrared and ultraviolet radiations, by alloying the entrance of the desirable rays of the sunlight. The new transparent photovoltaic cells have the ability to transform sunlight into electricity at a relatively high-efficiency. This is how photovoltaic cells are turning windows into solar panels.

One challenge of that cells to be commercialized and commonly used deals with their longevity. Indeed, the life span of those cells has to be similar to the life span of windows to be viable. Windows would not be replaced for decades. That is why such cells need to have a quite long life span.

Concerning the cost of such photovoltaic cells, it is really close to the cost of traditional photovoltaic panels. Nevertheless, the price of the whole window remain expensive, almost the price of the highest technological window. It means that the amount of electricity produced should be sufficient in order to justify such an investment.

Hold Your breathe

What started off as a question from the past…

We were looking at comparisons of hospitals in Europe to the U.S. One of the comments that really stuck to me was that health-care facilities (in Europe) let patients open windows to their rooms to bring in fresh air, however in the U.S. they don’t like to do it because of increase contamination and safety reasons depending on the patients case. I asked the professor about it, but he said that the U.S. has tighter rules and that was it. Since now I am re-looking into natural air ventilation, this question popped up in my head again.

There is many open ended questions whether increasing the demand of natural ventilation is the best solution as you can see in Table 2.1 mentioned from Natural Ventilation for Infection Control in Health-Care Settings, each type of system has their own advantages or disadvantages. HVAC filtration is one of the best systems to be used in hospital because depending on the size of the filtration can remove certain size aerosols particles. A quote from Azrimi and Stephens (2013), shows some of the key about implementing this system as the best, “(i) the effectives of particle filtration for controlling airborne infectious aerosols, (ii) the associated risk reductions achievable with HVAC filtration, and (iii) the relative costs of risk reduction by HVAC filtration versus other control mechanisms such as increased outdoor air ventilation rates.”

 

v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
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One of the ways for the estimating risks dealing with airborne contamination is the Wells-Riley model stated in Azrimi and Stephens (2013):

 Pinfection= (cases/susceptible)=1-e^(-I*q*p*t/Qoa)

Notes for the equation: Pinfection=probability of infection, cases=number of infected cases, susceptible=number of susceptible individuals, I=number of infector individuals, p=pulmonary ventilation rate of a person (m³/hr), q=quanta generation rate (1/hr), t=exposure time (hr), and Qoa=room ventilation rate with pathogen-free air (m³/hr).

When you cough or sneeze, you send little particles or “droplet nuclei” into that air that can carry a small viral bug or something more serious like SARS. The Wells-Riley formula is used to calculate the rate of the virus infecting people in respiratory scenarios, however due to different forms of transportation (long-range or close-contact) of the droplet nuclei. Additional back research is needed to help support the findings for the Wells-Riley model which long-range transportation was a major factor. In newer hospitals, mechanisms removing aerosols with HVAC particles filtrations help reduce the transportation of contaminates, as well as, reducing pollutants from outside that might hurt patients more. However, there is not straight answer on what is the best solution; either system is acceptable for health-care facilities.

 

Sources:

Atkinson, J., Chartier, Y., Pessoa-Silva, C.L., Jensen, P., Li, Y., and Seto, Wing-Hong (2009) Natural Ventilation for Infection Control in Health-Care Settings. WHO Publication/Guidelines, 1-133.

Azimi, P., and B. Stephens (2013) HVAC filtration for controlling infectious airborne disease transmission in indoor environments: Predicting risk reductions and operational costs. Building and Environment, 70:150-160.

Chao, Julie (2013) Berkeley Lab Indoor Air Roundup: Natural Ventilation Comes with Health Risks, and More. Berkeley Lab: Lawrence Berkeley National Laboratory. http://newscenter.lbl.gov/feature-stories/2013/09/26/indoor-air-roundup-natural-ventilation-comes-with-health-risks-and-more/

Escombe, Rod Dr., MD, DTM&H, Ph.D., (2008) Natural Ventilation of Health Care Facilities, Engineering Methods for the Control of Airborne Infections: An International Perspective. Harvard School of Public Health, presentation.

Sze To, G.N. and C.Y.H. Chao (2009) Review and comparison between the Wells-Riley and dose-response approaches to risk assessment of infectious respiratory diseases. John Wiley & Sons: Indoor Air, 20:2-16.

Working with Multizone Heating and Cooling

Office high-rise buildings have many zones by their nature.  Often individual tenant’s inhabit entire floors or even a part of the floor.  Each of these tenant spaces must be designed separately and as a unique zone in the building.  Within each tenant space, you also face the design program of private offices, conference rooms, open office areas, IDF computer/network rooms, elevator lobbies, and corridors.  All of these rooms have different heating and cooling needs just as the tenant space as a whole has unique needs from adjacent tenants.

Often a medium-pressure system is put into place for the base-building’s HVAC system.  Large roof top units, chillers, cooling towers, etc are put into place.  On each floor of a typical office tower, you have a core consisting of elevators, stairs, restrooms, and storage.  It is here that you also find the medium pressure loop.  This is a large duct that brings primary air to the floor usually at 55F for further conditioning.  This large duct loop can be tapped into as needed as long as you are staying in the base-building’s system limits.

Each tenant on the floor taps into this medium pressure loop and ties into a VAV or FPB box to further condition the air.  A Variale Air Volume box will use the thermostat input from the user to module a damper and let different volumes of air into the space.  A Fan Powered Box will bring in a given amount of primary air that the fan can handle.  Often on each of these (but mostly on the FPB’s), we see reheat coils.  Water is fed to and taken from these coils to then feed the base-building’s exhaust to a heat sink (outdoor air).  These boxes feed diffusers which let the air go into the space.  Often the return air is not ducted and goes straight into the above-ceiling plenum.  In a FPB situation, this return air can reenter the box and mix with primary air.  Other systems may include a base-building boiler which serves water-based radiators or induction units on each floor (at the perimeter).      All inputs come from the zone’s thermostat.  A zone may be a series of rooms or one open office area.  There will be one box per zone.

http://www.bdcnetwork.com/high-performance-building-systems-mechanical-electrical-and-controls-systems-0

Concentrating Solar Power (CSP)

Alternative energy has always been on the rise in the times we live in. More specifically green energy has been on the rise and this is due to the shortage of fuels. In particular, the most well known alternative energy would have to be solar power.

How does a concentrated solar power system work though? They work by utilizing the “…sun’s heat-rather than fossil fuels-to boil water and create steam that spoons the large turbines that drive electricity generators” (ASME). This is very important since, well, the sun is always going to be around.

Solar power is also on the rise because some places cannot utilize the other ways of alternative energies such as hydro power and electric power. Places in the West deal with this problem of being unable to utilize these alternative sources so having solar power is perfect for their case.

The usage of CSP systems has spread around the United States with up to forty-one projects in the Southwest with nine gigawatts of energy generated just from the machines alone. The number of CSP is continuing to rise due to its benefits and will continue to rise throughout the years.

Solar power is important because fossil fuels are being diminished and an alternative energy will be needed once we consume these fuels completely. Not only solar power in general but green and alternative energy is important nowadays because of our decreasing supply.

Building energy reduction based on economic model predictive control

A team of chemical engineering researchers worked together to design a new software that would demonstrate the effectiveness of an economic energy model prior to its use. To do this they designed a model predictive control (MPC) simulator; such simulator would be used to predict the performance outcome, optimize the energy use, and reduce the cost of the building heating, ventilating, and conditioning (HVAC) systems.

The Model Predictive Control works as follow: A simulated multi-zone commercial building equipped with of variable air volume (VAV) cooling system is built in Energyplus. Building Controls Virtual Test Bed (BCVTB) is the middleware needed to produce the real-time data exchange between Energyplus and Matlab. The controller is then obtained from sending and receiving sockets. To adjust the MPC framework, zone temperature and power models are introduced through a performed System identification.

The economic objective function in Model Predictive Control accounts for the daily electricity costs, which include time-of-use (TOU) energy charge and demand charge. In each time step, a min–max optimization is formulated and converted into a linear programming problem and solved. In a weekly simulation, a pre-cooling effect during off-peak period and a cooling discharge from the building thermal mass during on-peak period can be observed.

Cost savings by MPC are estimated by comparing with the baseline and other open-loop control strategies. The effect of several experimental factors in the MPC configuration is investigated and the best scenario is selected for future practical tests.

If this new Model Predictive Control system’s efficacy was proven, this would become ground breaking software for the building energy reduction industry, allowing for the prediction of energy efficiency with a minimal error yield.

 

Jingran Ma, Joe Qin, Timothy Salsbury, Peng Xu, Demand reduction in building energy systems based on economic model predictive control, Chemical Engineering Science, Volume 67, Issue 1, 1 January 2012, Pages 92-100; http://www.sciencedirect.com/science/article/pii/S0009250911005240)