This year was the first time that Engineers for a Sustainable World hosted the Alternative Energy Challenge at UT Austin. We are happy to say that the competition was a great success! Three teams spent roughly 6 weeks building their designs and the results were quite impressive. The teams were:
Team Gurlz: The Humble Umbrella. A patio umbrella that can be deployed at restaurants and coffee shops around Austin that utilizes solar and wind power to charge electronics.
The Dream Team: Solar Powered Rooftop Hydroponics System to grow food in urban environments.
Team RAJ: A Peltier thermoelectric generator to capture heat energy released by appliances such as light bulbs and convert the heat energy to electrical energy.
In the final judging round, each team presented their research and prototypes to an audience of roughly 40 UT Austin Engineering students as well as three judges. In the end, the judges selected Team Gurlz as the winner of the competition. We are very proud to present them with a cash prize as well as recognition as the Spring 2014 winners of the Alternative Energy Challenge!
We would like to congratulate all the teams who participated in the Spring 2014 ESW Alternative Energy Challenge. Your hard work and dedication was very apparent and the judges were thoroughly impressed. The Dream Team plans to continue working on the solar powered filtration system for their hydroponic system. Team RAJ is still working through the technical details of their ambitious project. Team Gurlz spoke about implementing their prototype at a local coffee shop in Austin.
A Brief Project Update from smRTsolution: smRTsolutions is finishing up our laboratory testing of HVAC fault detection in mid-July and look forward to finalizing our results and publishing our findings in the next few months.
In the meantime, we’d like to turn our focus to an interesting topic of energy pricing in different countries throughout the world, in light of our recent travel to Germany to the IGSSE student conference with TUM, and interesting discussions and insights we’ve had related to residential building efficiency improvements such as the project we’re working on.
In the United States electricity is on average around $0.10 per kWh, We pay approximately $0.10 for every 1000 Watts we use each hour. On average a household pays a little under 3% of their income towards energy costs. In Germany, arguably on par with the US in terms of energy technologies, pays close to $0.35 per kWh, 3.5 times that of the U.S. In Munich, this amounts to nearly 10% of household income spent just on electricity, more than 3 times that of the U.S, providing much more monetary incentive to reduce inefficiencies in building and their systems. What does this look like, on average, for other countries? We did some quick analysis of other European and Asian countries, particularly those who use residential HVAC systems the most.
Which countries use residential HVAC most?
The Guardian conducted a study in 2012 on HVAC use internationally in residential buildings. The U.S. has the highest penetration, but according to their research, not for long. China, Japan, and South Korea are near the same penetration, with India and Saudi Arabia growing quickly. Particularly with concerns about CFC emissions with high Global Warming Potential, and growing demand for HVAC, and increasing peak loads, the detection of HVAC faults in these regions is extremely important, so that if use increases, at a minimum the systems can be functioning efficiently.
Which countries can benefit most from improving HVAC efficiency?
In China, electricity costs 7.5-10.7 cents/kWh, in Japan 20-24 cents/kWh, in South Korea about 9.3 cents per kWh. In India and Saudi Arabia the prices are 8-12 cents/kWh and below 7 cents/kWh, respectively. These rates are approximately similar to those in the U.S, however when compared to the household incomes, for example, of $10,220 in China, $25,000 in Japan, and $18,000 in South Korea, the U.S.’ household income of approximately $40,000 is about 1-4 times that of these countries. Many of these country’s HVAC systems are also less efficient than the average U.S. air conditioner, even when functioning at optimal design.
U.S. households should have motivation to reduce energy costs, particularly with lower-income levels. However, other countries in which air conditioning is highly used stand to benefit even more from reducing inefficiencies in HVAC use.
SmRTsolutions’ project goal is aimed at increasing the energy efficiency of residential buildings and their systems using Real Time data. We are a group of Architectural Engineering students from the University of Texas at Austin. Our team is made up of, graduate student, Kristen Cetin, undergraduate students Caitlyn Kallus, a sophomore, and Melissa Flores, a freshman. SmRTsolutions’ project goal is aimed at increasing the energy efficiency of residential buildings and their systems using Real Time data.
- Post by Kristen Cetin, Caitlyn Kallus and Melissa Flores
A question we often are asked when we explain that we’re working on understanding the effects of faults on residential air conditioning systems is – “What is a fault?” We dedicated this post to briefly explain what this means.
What can go wrong with your HVAC system (considered a “fault”)?
Have you ever put you hand up to the vent of the AC system in your house on a hot day and the air isn’t very cold? Likely there is a problem with your AC system and it needs to be serviced. This is one of many problems that are common in residential systems. Some of the most common faults in residential HVAC systems are:
- Low and high refrigerant charge: Each HVAC unit has a specified amount of refrigerant needed to make the system function properly. If the system is undercharged, this means there is less refrigerant than needed in the system. You can find how much refrigerant should be in your system by looking on the outdoor unit on the nameplate.
- Air flow rate reduction to the condenser: In the fall when leaves fall off the trees they may fall onto or into your condenser, or over time, dust and other debris may collect on the outside of your condenser unit. This restricts air flow to the condenser and reduce performance.
- Air flow rate reduction to the evaporator/air handling unit: Air from inside your home is pulled into the air handling unit either in a closet or in your attic, and is pulled across a cooling coil to reduce the temperature of the air, then is returned to your home (colder than before). The less air that can flow through the AHU, the less air is cooled in your home. This may be caused by a dirty filter if the filter is not changed regularly.
- Non-condensibles in the refrigerant: If there is air or other gasses in the refrigerant this will decrease the efficiency of the system. Since the system functions at a higher pressure, the compressor needs to work harder to achieve the same performance
- Refrigerant flow restrictions: If there are flow restrictions in the refrigerant this translates to reduced refrigerant flowing to the cooling coil of the indoor air, which means the air inside your home coming from the ducts/vents will be warmer and provide less cooling.
How does this affect HVAC performance?
The short answer is – that what we are working on understanding. Faults will affect the energy use of the system, the cooling capacity, how often the system cycles on and off, and the efficiency (EER, SEER, and COP). In short, if there are problems (faults) in your HVAC system, this will decrease the performance. We are now running tests and will have results within the next month or two to better quantify these values.
- Kristen Cetin, Caitlyn Kallus, and Melissa Flores
SmRTsolutions’ project goal is aimed at increasing the energy efficiency of residential buildings and their systems using Real Time data. We are a group of Architectural Engineering students from the University of Texas at Austin. Our team is made up of, graduate student, Kristen Cetin, undergraduate students Caitlyn Kallus, a junior, and Melissa Flores, a sophomore. SmRTsolutions’ project goal is aimed at increasing the energy efficiency of residential buildings and their systems using Real Time data.
Longhorn Lights Out held its final event of the semester on April 25th. We had a team of over 33 volunteers representing seven colleges at the university, to assist in reducing electricity, we turned off over 4080 lights, 6 projectors, and 36 computer monitors in 28 buildings. We had an amazing turn out considering it was the end of the semester. To take a break from studying for final students also enjoyed short massages and pizza. Thank you to all who came out!
We are also excited to announce the start of, in the month of May, faculty and staff pledges as a part of Longhorn Lights Out. Faculty and Staff will submit an electronic pledge form committing to turning off lights, electronics, and other energy-using equipment!
The University of Texas at Austin, through partnership between the UT Energy & Water Conservation Program, Engineers for a Sustainable World, and ASHRAE , have developed an energy conservation program called Longhorn Lights Out. This program’s purpose is to engage students, faculty, and staff in reducing energy use. Once a month students meet on Friday’s at 6:30 pm, and split up to survey all the campus buildings to reduce energy use by turning off lights, and electronics.
- post by Kristen Cetin
This month we have begun setting up the UTest House. The UTest House is a 1300 square feet manufactured home at the University of Texas’s Pickle Research Campus. This test house is equipped with materials needed to monitor power use (W) and energy consumption (kWh), and understand how varying amounts of refrigerant in the HVAC unit, and air flow restrictions of the condenser HVAC unit change the performance of the system.
X10s are plugged into outlets, and are controlled through commands sent through electrical wiring. The X10s allow us to turn lamps and other electronics on and off through a remotely accessible computer. This allows us to control these amount of heat and moisture generated during different times of the day so that we can accurately recreate the amount of heat (sensible loads) created at different time of the day from people and other heat generating sources (e.g. appliances and electronics) . For instance, during the night, the amount of heat increases because occupants return from their jobs. Now that we understand these patterns, we are programming the test house to reflect this.
In addition to producing heat, occupants also produce moisture. To recreate this in the test house, humidifiers will beused. The amount of water evaporated was measured to determine how much moisture was released into the air. In our initial attempts, too much moisture was being released. The amount of heat and moisture we want to create is based on an algorithm, which determined the number of occupants in a home based on the number of bedroom in a home; the UTest House has three.
According to the Building Simulation Protocol by National Renewable Energy Laboratory, we should expect to see 220 Btu/person/h produced in sensible loads. Sensible Loads refers to temperature and can be detected using a typical thermometer. We should also expect to see 164 Btu/person/h in latent loads. Latent heat cannot be detected using a typical thermometer. Latent heat refers to changes in the moisture in the building, but does not result in changes in temperature.
Setting up the UTest House is in progress. Repairs to the weather station, which will measure wind speed and direction, temperature, humidity, and sunlight, will be needed before we can start testing. We will begin testing and measuring the power used by the HVAC unit shortly. Using CT collars, the current and voltage of the HVAC unit will be measured. This will be used to calculate the power required to run the unit.
Once testing is successful and complete, we will compare our experimental results with the results predicted by energy modeling software. The goal is to create an algorithm that will show if there is a fault in the HVAC system.