Claire Desser Nicholas Piucci Louis Lubow ESP 167 Energy Policy Joan Ogden June 6, 2016 Energy Engineers: Earth and Physical Sciences Building

Transcription

1 1 Claire Desser Nicholas Piucci Louis Lubow ESP 167 Energy Policy Joan Ogden June 6, 2016 Energy Engineers: Earth and Physical Sciences Building Introduction: The Energy Conservation Office (ECO) of UC Davis seeks to improve the energy use intensity of buildings campus wide. UC President Janet Napolitano implemented the Carbon Neutrality Initiative (CNI) in 2013, with the goal of zero net greenhouse emissions from buildings and vehicle fleet by 2025 (UCOP, 2016). There are 1,200 buildings on campus, which account for 70% of the campuses greenhouse gas emissions, mostly from energy used to heat and cool the buildings (CEED, 2016). Thus there is a significant opportunity to decrease campus greenhouse gas emissions by improving the energy efficiency of the buildings on campus. Under ECO s guidance, we will utilize the Campus Energy Education Dashboard (CEED) to explore the baseline energy usage of the 92,350 gross square foot Earth and Physical Science (EPS) Building, ultimately looking for opportunities to save energy. We will also see how the EPS compares to other buildings on campus. A combination of building level data, zone level mechanical data, and thermal comfort data information will help with this overall goal. CEED contains the building level data and zone level mechanical data, which provide information on steam usage for heating and chilled water usage for cooling. With the results of this analysis we will create a plan to improve the comprehensive efficient energy use and optimize the thermal comfort of the building. Room type information suggests which parts of the building require more energy than others. For example, laboratories use more energy than typical

2 2 classrooms. The EPS Building contains an interesting mixture of rooms, so we will investigate how to manage the energy allocation in the most efficient manner. Furthermore, we will utilize TherMOOstat to establish greater energy efficiencies within the EPS building. TherMOOstat is an app that allows individuals to record their thermal comfort at a given time and place. Long term trends in TherMOOstat data will allow us to find ways in which to optimize thermal comfort and energy efficiency. Both in website and app form, TherMOOstat shows the total number of votes and the average voted temperature in most buildings on campus. Problem Statement: We will investigate how to enhance the energy use in the Earth and Physical Sciences (EPS) building by: 1. Increasing energy efficiency through data analyses 2. Decreasing overall energy demand and designing strategies to offset peak energy use 3. Assessing specific room type needs 4. Promoting the use of TherMOOstat to improve thermal comfort 5. Comparing the EPS building to other campus buildings Background: Our unit of analysis, the Earth and Physical Science Building, was completed on November 5th, This three-story building was constructed for the Department of Geology. The EPS building was a $65.5 million project, which primarily received state funding. The building is comprised of 12 room type categories. This includes research studios and laboratories, administrative and academic offices, as well as classrooms, bathrooms, conference

3 3 rooms, and scholarly activity rooms. Collectively, the laboratory area makes up 33.7% of the total room type area, which is the largest of any room type. Laboratories require more energy for lights, storage facilities, plug loads, burners, and centrifuges, amongst other things. We will consider this while analyzing energy use in the EPS building compared to other buildings. The EPS building is also Leadership in Energy and Environmental Design (LEED) Silver certified. This program aims to increase overall efficiency and sustainability of building design and operation (USGBC, 2016). LEED is ranked from Certified, Silver, Gold, or Platinum. To meet the minimum levels of sustainable practice required by the Silver standard, a building must obtain 60/136 points. The points can be gained through credit categories such as Innovation and Design, Materials and Resources, and Energy and Atmosphere. The Energy and Atmosphere section contains the largest amount of points to earn. It calls for optimization of energy efficiency through well insulated and tight building envelope, as well as efficient cooling and heating systems (USGBC, 2016). The EPS gained many of its points under these criteria. Hypothesis: We expect to see less energy use on weekends than school days, and a decrease in energy use during the hours that the building is closed (10:00 PM - 7:30 AM). Additionally, we predict that campus buildings use more chilled water during summer and more steam in winter months due to the associated climate during these times. Due to Davis moderate winters and very hot summers, we think that overall there will be higher chilled water use than steam or electricity. Furthermore, electricity should remain relatively constant throughout the year as its usage depends on activity within the building as opposed to weather. In addition, we expect an increase in electricity use only during the time the building is occupies. Our building is Silver LEED

4 4 certified so we also expect its energy use intensity to be lower than that of other buildings on campus with Gold or Platinum certifications. Methods: In order to begin our analysis on energy usage within the Earth and Physical Science Building, we were given data collected by the CEED office at UC Davis. The Energy Conservation Office collected this data on energy use from a number of monitors throughout the building. The monitors record the energy use in kbtu for steam, chilled water, and electricity. A Btu is the amount of heat required to raise the temperature of 1 pound of water 1 F (cite). Steam use was recorded in 5 minute demand, daily usage, and monthly usage. Electricity and chilled water were only measured in hourly demand. Steam data was collected from May 2012 to May Electricity and chilled water data was recorded from January 2013 to December For continuity, comparison, and relevance, we only examined data from January 2015 to December 2015 for each type of energy. Our first goal was to look into potential inefficiencies in energy usage. To do so we compressed our data into a variety of pivot tables. One series of pivot tables looks at the average monthly energy usage per hour of the day for chilled water, steam, and electricity use. These tables allow us to see if there are certain hours in the day that energy is being used inefficiently. For example, these graphs would allow us to determine if too much steam is being used during the night when the building is unoccupied. We then created another series of pivot tables that show the average daily energy use of steam, chilled water, and electricity across the full year. These graphs allow us to look into trends in inefficiencies over time, such as overuse of steam in the summer months.

5 5 We were also able to use the graphs of daily average energy use over the course of the year to test our next set of hypotheses, that steam use will be greater in the winter and fall, and chilled water use will be greater in spring and summer. We looked to see if there were changes in electricity over the course of the year to match when classes were in session. If these hypotheses do not hold true, then there are likely some energy use inefficiencies occurring. To do a more direct comparison of how the energy usage of chilled water, steam, and electricity varied relative to one another at different times/seasons of the year, we examined the total energy usage of these sectors during each season of the year. Once we understood the general trends in our buildings energy usage, we then wanted to see how our building compared to other buildings on campus. In order to do so we first needed a metric to standardize energy usage between buildings, as a large building clearly would use more energy, although it may be using that energy more efficiently. To standardize energy use we used the energy use intensity metric (EUI): EUI = (Annual Energy Use in kbtu) / (Gross Square Footage of Building) This metric then gives us the average energy use per square foot of the building, allowing comparison of one building s average to that of another. We examined our building s annual EUI to that of Meyer Hall, the Student Community Center, ARC, the Science Laboratory Building, and the Plant and Environmental Science building. Lastly, we used TherMOO stat to identify thermal comfort and energy issues on campus. With this app students, staff, and faculty can use their UC Davis logins to rate their comfort level of each building as cold, chilly, perfect, warm or hot. We have access to data of the date, room, building, and comfort rating. The data on specific rooms, rated as too hot or cold, serves as a valuable source of information; occupant ratings may be more accurate than a thermometer.

6 6 Additionally, TherMOOstat users can respond with how satisfied they are with the room temperatures on campus, overall. To increase the use of the app we advertised it in the EPS with postings and quick announcements in individual classrooms. Results: Relative Energy Use per Quarter: Figure 1 shows the total energy use in kbtu for chilled water, steam, and electricity for each quarter of The relative trends shown are good indicators of long term average efficiency in the Earth and Physical Sciences building. In fall, energy use by the three sectors are about equal, which is to be expected with the temperate weather that is experienced in Davis at this time. Steam then spikes as temperatures drop in Davis during the winter months. Energy usage again is about equal during spring. During summer steam use drops and chilled water use spikes in conjecture with the rising temperatures in Davis. These trends are signs that the long term average of energy use is moderately efficient. Next we look at daily and hourly trends in order to get a closer look at where inefficiencies may be occurring. Figure 1

7 7 Chilled Water: Figure 2 below shows the average hourly chilled water usage per month in The hourly usage shows the trends of chilled water usage throughout the day. Its use tends to pick up around 7 AM before classes start in the building at 7:30 AM. Moreover, peak energy use in all months occurs around 4:00 PM, generally the hottest time of the day. Both graphs show an increasing trend in chilled water use starting in the early spring and going on through the summer. As illustrated in Figure 2, there is a large spike in energy usage in August around 12:00 PM, which may highlight an accidental energy misuse. It is possible that this spike represents an error in our available data. Other potential inefficiencies include how energy demand never drops below 500 kbtu, even in the night when we would expect no occupancy in the building. Figure 3 shows the average daily chilled water energy usage for The spikes show daily variation in energy use. There are relatively high peaks seen in the end of April and beginning of May. Figure 2

8 8 Figure 3 Steam: Figure 4 below shows the average hourly steam usage per month in Generally there is an efficient trend in steam energy usage throughout the day. Peak usage occurs around 6 AM to warm the building before classes start at 7:30 AM. There is then a downward trend in energy usage as the day warms. An interesting spike around 2PM occurs which we believe is potentially an inefficient usage of steam. Steam use picks back up around 5PM when it starts to cool outside. The building is in use until 10 PM but in the winter months steam use continues all through the night. We believe this to be an inefficient usage of energy. Looking at both graphs you can see a rise in steam use during the winter months and a sharp drop off during the summer. Steam use remains at around 500 kbtu, even in the summer, which is also likely an inefficient use of energy because steam would seemingly not be necessary at that time of year.

9 9 Figure 4 Figure 5 Electricity: Figure 6 below shows the average monthly energy usage for electricity. There are some immediate concerns about the efficiency of electricity use. There is relatively little fluctuation in energy use throughout the day. There is a slight increase from 800 kbtu to 1200kBtu during the time the building is in use, but usage never falls below 800 kbtu. This signifies energy use

10 10 inefficiencies during the evening hours when the building is closed. The daily average in figure 6 shows that this fluctuation is fairly consistent throughout the entire year. This also seems like incorrect electricity usage as there are periods of time over summer when the building is not in use but the energy use is unchanged. Both graphs also indicated an extreme spike in energy use in August. As this surge varies so greatly from the rest of the trend we expect a large energy use inefficiency to be occurring. Figure 6 Figure 7

11 11 Building Comparisons: Figure 8 below shows the energy use efficiency of a number of different buildings on campus. The Earth and Physical Science building had an EUI of 256. This is close to that of the Science Lab Building (EUI 170) and the Plant and Environmental Science Building (207). The SCC (EUI 140) and the ARC (EUI 130) were much lower than the EPS. Meyer Hall (EUI 434) has a much higher energy demand than any of the other buildings. Figure 9 II. TherMOOstat As stated before TherMOOstat is a program created by UC Davis that allows the user to rate the comfort level of the room as cold, chilly, perfect, warm, or hot. We changed these temperatures to a scale of 1-5, cold being 1, chilly being 2, etc. in order to better analyze and manipulate the data. We originally began to look for trends among the results that we received. For example, one of the first things we found was that from January 2016 through February 2016, the average response was a 2.25 and respondents rated the mode temperature as cold.

12 12 These are the winter months which tend to be cold in Davis, therefore we expected users to rate their classrooms as being colder. Unfortunately, this conclusion was drawn from less than 8 users, in a building that had thousands of students passing through it every day. Our data does not allow us to make stringent conclusions. Looking at figure 8 below, one would see that the EPS building did not crack the top ten buildings that received TherMOOstat data. In fact, it did not even crack the top twenty buildings, despite it being one of the more highly used buildings on campus. Nevertheless, we begun our energy investigation and attempted to analyze the 91 points of data received since Even though we lacked TherMOOstat data, oneof the main trends we identified was that the number of entries decreased over time, since the beginning of the program in We looked at the data from other buildings and we found that for the most part, the same was also true. We also found was that there would be a huge spike in the number of entries in fall quarter, respective to each school year. However, then the number of entries would drop again. This held true for other buildings we looked at as well. Despite being able to find trends within the data, we felt as if the sample size was simply too low. Subsequently, we came to the conclusion that there was simply not enough data to conduct any substantial analysis to present any reasonable findings to the Energy Conservation Office. Figure 9. Top ten buildings that received TherMOOstat input from students (From Fall 14-April 16)

13 13 Figure 10. All TherMOOstat data received for the Earth and Physical Science Building Discussion: I. EPS vs other Campus Buildings When comparing the different buildings on campus, we looked at the energy use intensities(eui) in order to compare energy use efficiency between buildings. A low EUI constitutes good energy performance. When looking at each type of energy use, the EPS building had an EUI at least 50 points higher than the Science Lab Building, Plant and Environmental Science Building, SCC, and the ARC. For example, the SCC is Platinum LEED certified, compared to the EPS s lower Silver ranking. We would expect greater energy efficiencies within the SCC, and thus a lower EUI. Also, the EPS building is comprised of a larger area of laboratories than the other buildings, which require more energy throughout the entire day. On the other hand, Meyer Hall s EUI was nearly double the EPS building s EUI. Meyer Hall is composed primarily of laboratories (63%), which most likely accounts for its elevated energy use (CEED, 2016). Furthermore, it was constructed in 1987, when energy use techniques were not as efficient as today. As noted earlier, the EPS building was constructed in 2009, when climate change and environmental issues were more of a concern.

14 14 II. CEED As stated before, we first looked at the long term trends of the the building data, and compared it to our hypotheses. First, we believed that during the fall and spring we would see a fairly even use of steam and chilled water. The quarter begins in September, while Davis is still relatively hot and ends during December when Davis begins to get colder. The results of Figure 1 add support to this hypothesis and therefore signal efficient energy usage during this time. Next we hypothesized that there would be an increase in steam use and a decrease in chilled water use during the winter season. Our results again validated this hypothesis. The first deviation from our hypothesis that we noted was the fact that in the spring, steam usage was greater than chilled water. We did not expect this as Davis is usually hotter in the spring months and we believed that the building would be heated naturally, rather than through steam. We believe that lab activities may be the reason for these higher than expected values. Alternatively, this could highlight an energy use inefficiency, signaling that steam use in spring should be decreased. We looked at how chilled water, steam, and electricity fluctuated throughout the day to look for more specific inefficiencies that may be occurring. We first broke down average hourly steam use per month. As expected, chilled water use increased in the hotter summer months, such as June, July and August. We can also see that the least amount of chilled water is used in the winter months; but there was a baseline use of roughly 500 kbtu regardless of month or time of day. We came to the conclusion that certain lab rooms needed to have the temperature maintained during all times of the day, which is why there was a baseline use for chilled water, and as we found out later, steam. Additionally, one can see that the amount of chilled water used increases in relation to the hottest hours of the day. One thing we did not account for in our hypotheses was building s energy use in preparation of occupancy before it opens. Chilled water

15 15 use begins a half hour before the building opens, compared to steam use, which starts an hour and a half before. We originally presumed that heating and cooling would begin when the students arrived, but according to the data, maintenance turns these on before to allow the building to cool or warm before the students arrive. This contributes to a higher energy load per day, overall. One possible inefficiency we found was that chilled water would begin being used around 7:00AM or 8:00AM. It is still very cool most mornings in Davis and we therefore believe chilled water could be turned on later in the day. Next, we examined steam trends based on the month and time of the day. We saw trends opposite of usage in the chilled water graph, with there being an increase in use during the cooler months like December and January and less use during the summer months. Similar to chilled water, steam use began early in the day. This makes sense as it is coolest in the mornings and it takes time for the building to warm, which is why it usually turned on around 6:00AM to 7:00AM. The Earth and Physical Science building has a lot of windows allowing it to bring in a significant amount of natural sunlight to warm the building. As the day progresses, steam use decreases because the building uses the more sunlight to warm the EPS. We also saw in the data that there was a baseline use of 500 kbtu no matter what time of the day or year it was. We attributed this, like we did to chilled water, on the fact that some lab rooms had to have the temperature regulated within a specific range. The only other possible inefficiency that we could identify was that in the summer months there appeared to be a slight spike around 2:00PM to 3:00PM. As this spike drops occurs during the warmer part of the day, we believe this to be an accidental misuse of energy that can be corrected. Next we analyzed the long term trend for electricity usage and found usage to be relatively constant throughput the year. As we hypothesized, there were no fluctuations in use

16 16 based on the temperature. Electricity is only used for lighting and to power appliances therefore these results were expected. We discovered that there is a base level of electricity needed in the building regardless of season. We then broke down the building's electricity use by its average hourly trend per month. Electricity use again is seen not to vary by month. There is a baseline use of roughly 800 kbtu which rises to 1200 kbtu during peak hours. This means that even when the building is unoccupied there is still a substantial amount of electricity being used. Therefore, there are many appliances, such as computers and televisions, that are using electricity even though they are not powered on. We understand that some lab equipment must be kept running at all times but we believe a significant amount of electricity is being wasted on other appliances. Overall, we found a number of inefficiencies both in daily trends and in long term average use. There are a number of things we believe can be done to help correct these inefficiencies. The first issues that should be addressed are the apparent spikes in energy use. These spikes allude to energy being used at the wrong time, as opposed to a technological inefficiency. We believe that steam use can be decreased during the afternoon hours to better correlate with the outdoor temperature at this time. We also think that energy usage during August needs to be further examined to determine if there was a gross misuse of energy or an error in the data. In either case, this error needs to be corrected to improve energy efficiency. In order to address long term trends in inefficiencies, technological change will be required. The greatest inefficient trend we came across was the extremely high electricity usage when the building was not in use. One potential way to correct this is through the implementation of smart power strips for electronics (Energy Star, 2014). These strips cut all power to anything connected to them and can be programmed to shut on and off at certain times. This would stop computers and other such devices from sucking power at night. This would also

17 17 lower the plug load intensity as this is the equivalent of manually unplugging each of these items every night. In addition, occupancy sensors could be installed which ensure lights are only turned on when rooms are in use. Finally, switching light bulbs to LED s will lower the overall energy needed for lighting. There are also many opportunities to improve the overall energy use of heating and cooling in the building. To help keep the building cool during the warmer months, reflective films can be added to all windows in the building (Energy Star, 2014). These films help reflect sunlight away from the building thereby keeping it cooler. Similarly, reflective roofing could be added to the top of the building to reflect unwanted sunlight. Alternatively, solar panels could be added to the roof so that some of this energy could be used to power the building and thus lower the overall energy demand for the building. We believe it is also important for all air ducts to be inspected for any leaks, this would prevent chilled water or steam from being wasted. Improving the insulation around doors and windows will keep warm and cold air in at the appropriate times. Finally, the most important thing that an be done is educating the buildings occupants. Once they understand how energy is used and lost, they will be able to do their part to help conserve. Personal conservation can be done through closing doors, sealing windows, and installing the technologies stated above. III. TherMOOstat The data that was provided to us on the Earth and Physical Science building was clearly not expansive enough to do an appropriate analysis of the program. In the end we felt that, unlike other Energy Engineers in ESP 167, there was not enough data to bring any conclusive results to the Energy Conservation Office. In the beginning of the quarter we sought to find any possible connections or correlations within the data, while still noting that our sample size was too small

18 18 to make any stringent conclusions. As time passed we began to realize that we would probably not have enough data to do a substantial analysis. We eventually came to conclusion that the most beneficial thing to do was promote the program so that the ECO would have enough data to conduct a proper analysis in the future. In order to provide the Energy Conservation office with a more detailed and thorough conclusion we attempted to promote TherMOOstat in a multitude of ways in order to gain enough data to do an appropriate analysis of the TherMOOstat system. We began by posting flyers throughout the building in order to increase awareness of the program. When we went back to EPS building, we noticed that our flyers had been relatively untouched and we then concluded that in order to increase awareness, we would have to promote the program in person. We went into the classrooms as a group and attempt to promote the app. Unfortunately, we only gained only a few more respondents in time for us to do an appropriate analysis. We speculated why TherMOOstat, and our building in particular, might have received so few entries from students and staff. First off, the data from most buildings that use TherMOOstat all peaked in the fall of 2014 when the program begun. We believe this most likely occurred because the Energy Conservation Office had a very strong education campaign to promote its use when TherMOOstat was first implemented. Following fall quarter s 38 entries, the program only obtained 11 entries in winter quarter. In the subsequent year, fall quarter had 13 entries into TherMOOstat, which was followed up by 4 the next quarter. No substantial analysis can be drawn without students knowing about program and using it more frequently. Cite: Campus Energy Education Dashboard. UC Davis, Web. May Energy Star No and Low Cost Efficiency Measures. Web. May 2016.

19 19 LEED U.S. Green Building Council. LEED U.S. Green Building Council. N.p., Web. May Presidential Initiatives. Carbon Neutrality Initiative. UCOP, Web. May TherMOOstat. UC Davis, Web. May 2016.