Field Notes Research Update - February 2016
Center for Energy and Environment conducts technology and market assessments to identify tomorrow’s best clean energy strategies. Our research staff produces studies on building science, mechanical system performance, and program and policy design. This blog post is taken from our Field Notes newsletter which features updates on CEE's research projects. Sign up for Field Notes to get this information in your inbox!
Winter 2016 Research Updates:
Duluth Energy Design Conference & Expo
Sharing knowledge is critical to CEE’s mission. Our researchers are driven to transform research into resources for practitioners and leaders to advance the energy efficiency field. And this month’s Duluth Energy Design Conference & Expo provides an outstanding opportunity to share some of our most compelling studies. With a focus on the core principles of energy-efficient building and responsible design, expo attendees will learn about the latest in energy-efficient building and technologies, renewable energy, and best practices. Multiple CEE staff will present, representing several projects detailed in this newsletter:
- Corrie Bastian, Multi-Family Project Coordinator: “Saving Energy in Existing Multifamily Buildings”
- Dave Bohac, Director of Research, “Using Aerosol Sealant to Reduce Multifamily Envelope Leakage”; “Energy Savings from Air Sealing Commercial Buildings”; and “Combustion Safety: Data vs. Dogma and the Evolution of New Standards”
- Jim Hasnik, Lending Manager Paying for Energy Improvements — Wednesday 10:00 AM
- Russ Landry, Senior Mechanical Engineer, and Megan Hoye, Engagement Coordinator, “Commercial Energy Codes Support Program”
- Josh Quinnell, Senior Research Engineer, “Panel Discussion: Opportunities for Improving the Efficiency and Operation of Building Ventilation,” “Duct Leakage and Retrofit Duct Sealing in Minnesota Commercial and Institutional Buildings; and with Nicole Kessler, “Emerging Technologies for Cold Weather Residential Heating”
- Rebecca Olson, from project partner Neighborhood Energy Connection, “Research Update: Residential Condensing Boiler Optimization”
The Energy Design Conference & Expo runs February 22 through 24. Visit DuluthEnergyDesign.com for expo details and specific presentation times.
Reducing the energy cost of effective ventilation in multifamily buildings
Nearly 18% of Minnesota’s occupied housing units are in multifamily buildings. This field research assessed multifamily ventilation systems with the potential to impact both building energy performance and indoor air quality, and developed standardized screening, diagnostic, and retrofits protocols. In 2015 the project team completed a multifamily ventilation manual, which included screening and diagnostic protocols for contractors.
As a follow-up, the team recently hosted a training session on the subject for individuals who assess and retrofit multifamily ventilation systems. The project team prepared by gathering feedback at an earlier training session for Department of Energy Resources project managers and contractors who provide multifamily energy efficiency programs for Minnesota utilities. Based on feedback from this initial session, the training was expanded to include more detailed information on multifamily ventilation and more hands-on training, including stations on ventilation measurements, commission of ventilation exhaust system, and ventilation system design work. A final report will be completed in 2016.
Pilot program for small embedded data centers
Small embedded data centers (SEDCs) are among the fastest growing users of electrical energy in commercial buildings. Through field studies and stakeholder engagement, this project gathers information to improve the operational efficiency of SEDCs in commercial and industrial settings. The project team has selected 10 sites for monitoring — two small manufacturing firms, a nonprofit, a healthcare clinic, two public school districts, a law firm, a municipality, and two architectural design firms. The team is looking into recruiting additional sites, including some academic data centers. Data collection has begun at five of the selected sites using both Packet Power and another monitoring system developed specifically to take measurements at the panel. The project is currently in a baseline measurement phase, and monitoring will likely continue through the summer as the team implements measures and determines savings.
Most sites should be able to implement operational or scheduling measures on the server side, and there may be additional opportunities in some sites to implement measures related to HVAC systems, specifically around cooling. There has been a lot of interest and support from IT staff to implement the operational savings opportunities. While many sites are already doing more than the project team initially realized, there are measures that are not being implemented currently, indicating additional potential to capture some low-hanging fruit and capitalize on some educational opportunities.
Note: We profiled this project in CEE's blog.
Improving the effectiveness of commercial energy recovery ventilation systems
Energy recovery ventilation (ERV) systems have the ability to reduce the heating and cooling energy associated with outside air conditioning by over 65%. This field research identifies common issues affecting the performance of ERV systems in Minnesota buildings and develops protocols to optimize their performance. The project team is now working on phase two, monitoring and formulating recommendations for four sites. Monitoring began in August 2015 and will continue through this winter to gather data on ERV performance in a range of temperatures. While no drastic problems have been discovered with ERVs in this phase, several nuanced and site specific issues have been identified, and these issues, in contrast to a broken ERV, can be difficult to identify and address.
The team is working to generalize the lessons learned throughout the project, and developing general strategies to avoid ERV issues as well as guidelines to identify and fix issues as they happen. While most ERVs are generally operating at a level that is saving enough energy to justify installation, it is possible to make changes to increase energy recovery and increase their benefit to the building. Education of and improved communication among different stakeholders — including building staff, contractors, and recommissioning engineers — will be essential to maximizing the benefit of ERVs.
Optimized operation of indoor public pool facilities
Energy use intensity for indoor pool areas is three times higher than most other areas within a building. Indoor pool facilities are prime candidates for energy savings through improved recommissioning and operator training, and this project sets the stage to realize this potential. The project team is currently monitoring and collecting data at five sites. Since monitoring began in spring 2015, three sites have made recommended operational changes. Project staff will work with all five sites to identify additional retrofit opportunities, and continue monitoring to determine additional savings potential.
One potential energy saving measure this project will look at is liquid pool cover, a chemical that spreads out on the top of the water and decreases the pool evaporation rate. The majority of energy use in public pools is the result of evaporation, so this has potential to make a big difference in reducing energy use. While many facilities have used a liquid pool cover without reporting any water quality issues, the researchers will be going beyond energy saving estimates to see if the theoretical potential to impact the off-gassing of chlorine has any measurable impact. At sites where it is used, the project team will closely monitor “combined chlorine” (chlorine that is weakened by combining with nitrogen-containing contaminants) both before and after the liquid pool cover is put in to place to determine its impact.
Hot water recirculation controls in hospitality buildings
Commercial and hospitality buildings typically have periods of both heavy hot water use and low or no hot water use, and building owners and managers typically need to ensure that hot water is immediately available at all times. This project assesses the effectiveness of new demand control systems to reduce water heating and pumping costs in hospitality and commercial venues. While past research has shown that reducing the run time of recirculation pumps does achieve savings, systems have failed to achieve these savings and also maintain hot water availability.
The project team completed the first phase of monitoring on a total of 14 systems at five hotels and six commercial buildings (two sites had multiple systems), and this provided a better idea of the savings potential. From this initial monitoring, the project staff identified important takeaways about the run time of the hot water pumps: in hotels all water pumps ran continuously, while only three of the eight commercial buildings ran the pumps continuously. The remaining commercial building pumps had some time of day control, but none were turned off for more than six hours a day. With this information in hand, the next step is to install a controller and begin more intensive data collection. This phase will include six to eight systems in a mix of both hotels and commercial buildings, and will collect data on flow rates, hot water usage, pump run times, and thermal loss reduction. If the controls allow for a quick enough reaction to maintain performance — delivering hot water when needed — this application could be a good, cost-effective option for both hotels and commercial buildings.
Enhancing commercial energy code compliance
Commercial energy codes specify design requirements that achieve a minimum level of energy efficiency in new buildings, additions, and renovations. This project provides tools and technical assistance to design, development, and code enforcement professionals to help improve compliance with the most commonly neglected and highest-impact energy code requirements. The project has launched both the small building design support and the large building plan review pilots. The team has completed its first review of the large building pilot, and has a second review lined up for February. Over the course of the project, the team plans to complete 10 reviews of large buildings in the partner cities of Blane, Minnetonka, and Saint Louis Park. The team also plans to conduct field work to evaluate the pilot and determine energy impacts. From the initial review, it appears that the large building plan review will provide a lot of value to city code officials in assisting them with energy code review. Earlier in the project, the team identified 22 energy code items to include in the review process; the first building reviewed had issues with about half the list.
Project staff are actively recruiting for the small building pilot and have strong leads on four projects that are tentatively slotted for review in the spring of 2016. The small buildings pilot provides support directly to design teams during the design process to help them avoid surprises when the plans are submitted to a city for code review. Recruitment for this pilot has been a challenge, particularly connecting with building project teams at the right time to allow them to take advantage of the project. If you are an architect, a design engineer, or a building developer with a project in the early design phase and are interested in free technical assistance services around the new commercial energy code, visit the project page for more information on participating.
Market and performance characterization of commercial rooftop units*
Packaged rooftop units (RTUs) serve the heating, ventilation, and air conditioning needs of a large proportion of commercial building space in the U.S. This project characterizes the Minnesota market for RTUs and monitors energy use to better understand indicators of high and low performance issues. Project lead Seventhwave did much of the early characterization work for this project, conducting phone surveys and using Google Maps to determine the distribution of RTUs across Minnesota. Seventhwave followed up its phone survey with a detailed interview of 100 sites to determine which sites would be good fits for field monitoring. CEE is responsible for the project’s field monitoring phase. The project team conducted detailed visits to 20 sites, gathering information on site characteristics and selecting a subset to target for detailed monitoring. CEE is now monitoring 50 RTUs at 10 sites, collecting data on energy consumption of specific businesses, as well as RTU details as to whether they are correctly sized and properly maintained, and how well all components work. Monitoring began in December 2015 and will last through the summer to capture data for the full range of outdoor temperature typical of Minnesota.
These projects supported in part by a grant from the Minnesota Department of Commerce, Division of Energy Resources through the Conservation Applied Research and Development (CARD) program. And with co-funding by CEE in support of its nonprofit mission to advance research, knowledge dissemination, and program design in the field of energy efficiency.
* CEE is subcontractor on this project.