Field Notes Research Update — May 2016
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!
Spring 2016 Research Updates:
Field study of a moisture and heat transfer furnace retrofit device
Single-family space heating is among the largest end uses of energy in Minnesota and, as few furnaces are replaced before failure, there is immense potential for savings through furnace retrofits. New transport membrane humidifier (TMH) technology can retrofit older, mid-efficiency furnaces to significantly increase their energy efficiency. TMH is a new type of technology that is not directly addressed by existing building code. Thus, the project team has been researching how the technology will integrate with existing codes before it is installed for field testing, and this has delayed the majority of the field testing. However, the project team has completed testing at one site and the preliminary data are promising.
The TMH device boosted furnace efficiency by 15% to a net efficiency of about 91%. About 2/3 of that increased efficiency contributed to the relative humidity of the home, with the remaining 1/3 contributing to heating the home, indicating that houses with either portable or central humidifiers will see a big efficiency gain from TMH. In addition, the humidity gain was reliable and predictable, indicating that it will be easier than expected to determine how TMH can best be incorporated into older homes. Project staff are optimistic about the upcoming installations because the approach performed well at the first site, which was among the most difficult scenarios for the technology due to its high occupancy density and low envelope leakage.
Commercial building plug load energy strategies *
Plug load energy use in commercial buildings is the fastest growing end use in U.S. commercial buildings, in stark contrast to decreases in other end uses such as cooling and lighting. This project characterizes commercial building plug load and evaluates various reduction strategies. This project looks at four plug load reduction strategies: two types of smart power strips, computer power management, and a behavior campaign. The field team has finished monitoring at six of the eight sites and will finish up the final two sites in June. While savings have been highly variable and dependent on the type and amount of loads in a typical workstation for an office, field results showed savings of 23-33%, with smart power strip strategies at the low end of that range and others at the high end. It was also noted that the human element of plug load technology must be addressed with behavioral management strategies to achieve optimal savings.
In conjunction with the monitoring, project partner LHB surveyed site participants toward the end of the monitoring phase to capture more qualitative feedback. The next steps are to analyze the survey responses and the quantitative data collected on site, complete an economic analysis, and write the final report. Once the final report is complete, project staff will shift their focus to presenting the results both to project participants and at numerous conferences including ACEEE Summer Study later this year.
Note: We will profile this project in CEE's blog in coming weeks.
Cold climate air source heat pump assessment
Air source heat pumps (ASHPs) have the potential to improve space heating efficiency and reduce energy costs for houses in cold climates where natural gas is unavailable. This study assesses the efficiency and reliability of new generation ASHPs in Minnesota’s cold climate homes to determine how to best integrate this technology into utility efficiency programs. The project team has installed ASHPs and begun data collection at four of the six locations, and analysis is currently under way. Initial data show that the equipment is capable of high performance as long as the control that activates the backup is adjusted to lock out the backup system when it does not need to run.
This project is also assessing the policy and program implications of reducing delivered fuel consumption. The field results will be used to inform policy recommendations and help accelerate the integration of ASHPs into utility programs. Project staff has compiled initial recommendations and these will be included in the presentation at the ACEEE Summer Study later this year.
Quality installation and retrocommissioning of condensing boilers **
While high-efficiency condensing boilers have been available in the residential market for many years, consumer acceptance and market penetration is low. One contributing factor is the widespread belief that many installed boilers are not achieving their listed efficiency. This project is characterizing existing boilers and determining practical and cost-effective steps to improve performance through both retrocommissioning and improved installation. The project team completed monitoring of the “as is” operating condition of existing boilers and has identified cost-effective ways to improve their efficiency. Preliminary data showed that installed boilers actually perform relatively well at about 90% efficiency, which was unexpected and, while this is good news for existing condensing boilers, it suggests that there may be fewer opportunities for optimization to significantly increase energy efficiency. The team is now monitoring the optimized boilers to determine how much the identified retrofit options boost efficiency, and if that boost is enough to be worth the effort. The next step is to install new systems and monitor performance through the next heating season.
The preliminary data from the existing boilers also indicated that the “as is” high performance is a combination of the equipment being able to modulate with temperature changes and proper installation. Project lead the Neighborhood Energy Connection is using the data to determine best practices for installation, and will work with contractors to gain feedback and disseminate the information for widespread adoption.
Field study of intelligent, network, retrofittable water controller ***
CEE has partnered with Gas Technology Institute and Sunnovations on a yearlong field study of the Sunnovations Aquanta smart water heater controller. The Aquanta is a retrofit device for residential and small commercial storage water heaters that can be installed on existing water heaters to monitor and control hot water energy use from a smart device or home networking platform. This study aims to validate the field performance, cost-effectiveness, direct energy savings, and demand-side management capabilities of the Sunnovations Aquanta smart water heater controller.
The project team is currently recruiting Minnesota residents to participate in this study.
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.
* CEE is subcontractor to Seventhwave on this project.
** CEE is subcontractor to the Neighborhood Energy Connection on this project.
*** CEE is subcontractor to Gas Technology Institute on this project.