Summer 2016 Field Notes
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.
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. This month’s ACEEE Summer Study on Energy Efficiency in Buildings provides an outstanding opportunity to share some of our most compelling studies.
With a focus on technology and practical implementation, Summer Study attendees will discuss climate impacts associated with energy use in buildings and innovative ways to tackle energy efficiency challenges. Multiple CEE staff will present, representing several projects detailed in this newsletter:
Dave Bohac, Director of Research, co-presenting with Curtis Harrington of UC Davis Western Cooling Efficiency Center: “Using an Aerosol Sealant to Reduce Multifamily Envelope Leakage”
Megan Hoye, Engagement Manager: “Pilot Program with Two Focused Approaches to Enhance Energy Code Compliance”
Nicole Kessler, Research Analyst: “Field Assessment of Cold-Climate Air Source Heat Pumps”
Carl Nelson, Director of Program Development, co-presenting with Nick Mark of CenterPoint Energy: “Bridging the Gap Between Direct Install and Whole House Programs: Minneapolis Home Energy Squad Residential Engagement Pilot”
Chris Plum, Operations and Contracts Manager, co-presenting with Scott Hackel of Seventhwave: “Advancing the Last Frontier: Reduction of Commercial Plug Loads”
Jenny Edwards, Director of the Innovation Exchange: “Human-Building Interaction (HBI): A User-Centered Approach to Energy Efficiency Innovations”
ACEEE Summer Study on Energy Efficiency in Buildings runs August 21 through 26. Visit the ACEEE website for more details and specific presentation times.
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 close to completing the field portion of this project. All phase two sites have implemented recommendations and the researchers will continue data collection at these sites through early fall. Based on data already collected, the project team has developed a strong understanding of common ERV operational issues and what it takes for an ERV to operate efficiently. The team is now working to generalize lessons learned and develop recommendations.
The majority of ERV issues stem from incomplete specifications, communication, and expectations, rather than technical problems with the system itself. By providing information and clearing up some common misconceptions, there is an opportunity to broadly impact ERV performance across the state. To do this the project team is developing two items that they plan to disseminate in 2017: the first is a basic guide to help the individuals responsible for ERV operation identify and assess potential issues; and the second is a longer paper that will condense project findings to explain how ERVs work and how various roles can work together to ensure efficient operation.
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, construction, and code enforcement professionals to help improve compliance with the most commonly neglected and highest-impact energy code requirements. The project includes pilots for both small building design support and large building plan review. To date, eight small building projects have received design team support and seven large building projects have received permit stage plan review assistance. The majority of buildings are located in the Twin Cities metro area, with some buildings in northern Minnesota. So far the project team has seen tremendous value in both pilots — many large building projects are able to make important improvements before permitting, while the small building project provides numerous teachable moments. The team has identified more issues with energy code compliance than anticipated, which also indicates a higher potential energy impact than predicted.
In April 2016 the project team held a focus group with nine code officials to learn more about common challenges and enforcement issues with the new energy code, as well as potential educational opportunities. The team will use this information along with preliminary analysis from the two pilots to provide feedback on the new energy code and potential energy impacts in an interim report due out this winter.
Recruitment for both pilots is ongoing. 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. Members of the project team are also presenting at several upcoming events. Check out the events section below for more information.
Note: We will profile this project in CEE's blog in coming weeks.
While tight exterior envelopes have become standard for single-family homes, these construction practices are just starting to be applied to the multifamily sector. This research is designed to determine whether the aerosol sealant method developed by project partner UC Davis Western Cooling Efficiency Center is a cost-effective way to reduce envelope air leakage in Minnesota multifamily buildings. The project team completed air sealing work on nine units in three existing multifamily buildings. This was much more of a challenge than sealing new construction, as the existing buildings were around two to five times leakier than new construction. However, the aerosol method still resulted in leakage reductions of 39% to 89% with an average of 68%, a much greater reduction than is possible with current conventional methods that typically average a 25% reduction. The results from both new construction and existing buildings demonstrated that the aerosol process can be used to reliably and cost-effectively produce extremely tight building envelopes that can even meet passive house standards in some instances. The team will now make recommendations for how to incorporate aerosol sealing into current utility programs for existing multifamily buildings and design assistance for new construction. In addition, Aeroseal® is continuing its development of commercially available aerosol sealing equipment, and will work with CEE on the upcoming Department of Energy project assessing sealing on new construction single-family homes.
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 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 from over-circulation of hot water in hospitality and commercial venues.
The project team has installed the demand control system and begun monitoring at three sites, with two more installations planned for August 2016. The team will continue monitoring over the next six months to obtain data during both hot and cold weather months. While the device has been shown to be extremely effective in multifamily buildings, the installation process has proven to be slightly more challenging in commercial and hospitality buildings where there are typically more complex water heating systems. Installation is particularly easy and inexpensive for simple systems, but the controller can also work well for more complicated systems. Preliminary data indicates the device is capable of significantly reducing the run time of recirculation pumps and achieving savings without jeopardizing hot water availability. The next step will be to determine the types of buildings that are a good fit for this technology and develop clear guidelines for installation.
The Minnesota Youth Tobacco and Asthma Survey (2011) found that 25.8% of middle school students and 37.3% of high school students surveyed had ridden in a car with someone who was smoking cigarettes in the preceding week. Previous research has demonstrated that secondhand smoke levels in cars can be extremely high due to the restricted area. This project furthered that research by measuring passenger exposure to smoke in vehicles under a wide range of variables including window positioning, ventilation settings, speed, smoking behavior, and type of vehicle.
The project team conducted 138 trials to gather secondhand smoke exposure data in vehicles in Minnesota. The most striking results came from trials that involved vehicles with windows closed. The team found that if vehicle windows are closed, a person’s exposure with just one cigarette smoked is similar to spending three hours in a smoky bar. And in some of the trials where vehicle windows were closed, it took 25 minutes or more for secondhand smoke to dissipate and for particulates to return to background levels.
Dissemination of findings is an important part of this project and its goal to educate the public and inform policymakers. CEE will soon complete the final report and will present results at the ASHRAE Indoor Air Quality 2016 Conference in September and at the Society for Nicotine and Tobacco Annual Meeting in March 2017. Project partner Association for Nonsmokers — Minnesota (ANSR) is producing materials for tobacco control advocates, public health communities, and policymakers including a fact sheet, an infographic, a drop-in newsletter article, and a presentation slide deck. CEE and ANSR will also present a webinar later this year on project results and implications for education campaigns and regulations.
While attached garages are a popular home feature, they can pose a threat to a home’s indoor air quality as contaminants from vehicles and other items commonly stored in garages can migrate to the house through numerous potential pathways. This project assessed the movements of contaminants from attached garages and different insulation and air sealing measures that could be applied to reduce movement. ASHRAE sponsored the project — led by the University of Illinois — to gather information to help inform guidelines for attached garage ventilation and air-tightness compartmentalization standards.
The project included five houses in central Illinois with an assortment of attached garage arrangements, with measurements taken over heating and cooling seasons. CEE modified tracer gas and carbon monoxide monitoring equipment to be able to look at the buildup of the tracer gas concentration in a garage and how it spread in to the attached house. CEE then analyzed the collected data to better understand the relationship between peak concentrations in the garage versus peak concentration in the attached house and how that varied for different retrofit measures. Preliminary results indicate that while air sealing can reduce the movement of contaminants and pollutants from some attached garages, it is not always an effective solution.
The project team is working on a final report and will present results at the ASHRAE Indoor Air Quality 2016 Conference in September.
The Department of Energy (DOE) recently announced CEE among 14 awardees nationally to receive a total of $14 million to increase efficiency in our nation’s homes and buildings. CEE’s grant comes through the DOE’s Building America program which funds projects that are piloting new approaches to create healthier, more comfortable homes that will save homeowners money on their utility bills.
The funding will support CEE's research to evaluate the integration of aerosol envelope sealing into the home building process. The project team will work with builders to characterize the cost, performance, and seamless integration into the construction process, and to determine the best options and protocols to share with the industry on the best use of this technology. The new research will focus on single-family homes, building on CEE's prior testing in multifamily buildings.
These projects are 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.
* This project is funded with support from ClearWay Minnesota
, with co-funding by CEE in support of its nonprofit mission.
** University of Illinois
is the lead for this project.