To the Western Cooling Connection Update Newsletter! This month's newsletter includes updates from the Aerosol Envelope Sealing project and the latest downloadable reports from the Demonstrations program. Also included is a formal congratulations to Zhijun Liu, WCEC's first Ph.D graduate. A new WCEC webinar is available to view online on climate appropriate technologies.
Aerosol Sealing Update: New Injection System Seals Apartments in less than 2 Hours
One of the three New York apartments sealed by WCEC's automated aerosolized sealing process.
Sealing leaks with aerosols is an effective way to simultaneously measure, locate and seal leaks in a building. Though far more successful than manual methods, most of the previous field tests took roughly 8 hours from set-up to breakdown and sealed just over 50% of the available leaks. Armed with a new injection system, WCEC set out to break these time and efficacy barriers.
WCEC Field Test at the Norman Apartments in Queens, New York
A sealed electrical outlet from one of the Norman Apartments in Queens, New York
WCEC set out to New York to seal 3 new one-bedroom apartments, each roughly 600 square feet in size. The goal: to seal each of these apartments more effectively and with a quicker turnaround than previous efforts. The previous design was entirely airless, which allowed for the system to be relatively compact while being able to serve multiple nozzles. The one disadvantage of the previous system design was the relatively low amount of effective aerosols reaching their intended destination due to a lower exit velocity from the nozzles. This led to larger deposits of aerosolized adhesive on the floor and increased the overall sealing time. To fix this issue while maintaining the flexibility of using multiple nozzles simultaneously, WCEC developed a new injector system technology that allows for the use of multiple air-based nozzles that discharge at a much higher velocity than the previous system. This was the first field test for WCEC’s latest injector technology.
Results from the field
New air-based nozzles used for the New York field test
Utilizing the new air-based nozzles showed significant improvement in all aspects of sealing over the older method of airless nozzles. Of particular note, WCEC reached its most thorough sealing of a building ever, clocking in at over 90% sealing of available leaks in one of the apartments. This success also came at a much faster rate than ever recorded in the field. The sealing time for these apartments took an expeditious 1.5 hours, significantly shorter than any other previous field test using the previous airless nozzle system. So the new system sealed more comprehensively and in less time than any previous field test, was there a drawback? Did it reach these milestones by just spraying more sealant? No, in fact the new system also used sealant more judiciously than the previous one, roughly half as much as the previous system.
OTHER BENEFITS OF ENVELOPE SEALING IN MULTI-FAMILY SETTINGS
Apartments and other attached wall spaces also have potential sound transference issues. Hard shoes on hardwood floors, the clanking of dishes, or any other variety of noises can transfer between the leaks within walls and add to the overall decibel level noticed by other tenants. WCEC is currently analyzing sound data taken pre- and post-sealing from the New York field test to determine just how useful sealing leaks can be for sound attenuation. Initial results look promising, showing roughly between a 3-6dB difference in mid- to high-level sound frequencies. Further research will need to be conducted to fully realize this potential benefit, but at this point, it looks to be another tangible benefit from sealing leaks in building envelopes.
Demonstrations Program Update
Ongoing Demonstration for adaptive thermostats at Segundo Housing Complex in Davis, California
WCEC has recently completed 3 new demonstration research reports for the State Partnership for Energy Efficient Demonstrations (SPEED). These reports include field research from the past few years on climate appropriate technologies, behavioral change program to increase laboratory energy efficiency and rooftop unit (RTU) optimizers.
Coolerado H80 Field Test at UC Davis
Field test results for the Coolerado H80 hybrid indirect evaporative air conditioner at the University House, at UC Davis.
Download PDF »
Shut the Sash: Fume Hood Ventilation in Laboratories
One of the simplest ways to reduce the energy required by operating laboratory fume hoods is to ensure that the sash—the moveable pane in front of the fume hood that controls the exhaust flow from an experiment—is always in the lowest possible operating position. This simple action can in some circumstances lower the amount of energy used substantially and will in all cases provide for the safest working environment, even in cases where energy use is not reduced. Behavioral change programs to promote being mindful of sash heights have been dubbed “Shut-the-sash” (STS). WCEC observed the effect of such behavioral programs at two university campuses. Download PDF »
RTU Efficiency Optimizers
Several new retrofit controllers are now available for single-zone rooftop-unit (RTU) air conditioners that take advantage of energy saving techniques not previously economically possible. These retrofits work by replacing the simplistic stock control unit with new digital controls, new sensors, and often upgrade the single speed supply fan motor to take advantage of variable frequency drive (VFD) motor controllers. WCEC observed the performance of the CATALYST RTU Optimizer system at two university campuses.
Download PDF »
Congratulations to WCEC's first Ph. D Graduate
Ph. D graduate Zhijun Liu with WCEC Director and Ph. D advisor Mark Modera
June 12, 2014 -- Zhijun Liu became WCEC's first Ph. D graduate, successfully completing his Ph. D in Civil and Environmental Engineering. Dr. Liu's thesis, Analysis of Indirect Evaporative Cooling Systems: Modeling and Experimentation, will aid in the future development of more effective Indirect Evaporative heat exchangers.
From all of us at WCEC, we sincerely congratulate Zhijun on his success. He has been an integral part of WCEC's team for over 4 years and, though we will miss him, we can take comfort knowing he will continue to make valuable contributions in energy efficiency.
Latest Recorded Webinar
WCECs' previous webinars can now be viewed online! This month's featured webinar recording is: Climate Appropriate Technologies... Where are We? Significant progress has been made in both laboratory and field testing of climate appropriate air conditioners. Jonathan Woolley, lead engineer for the Western Cooling Challenge, will discuss his findings from the field on a variety of climate appropriate technologies including: full packaged units, indirect evaporative add-on retrofits and dedicated outdoor air units. Also in this presentation, Jonathan looks to the future of the Challenge and how it can grow to encompass even more technologies and explore new avenues for testing, benchmarking and disseminating the results to the greater public.
Watch the webinar now »
WCEC brings to you a monthly webinar with relevant discussion topics from industry leaders in building energy efficiency. This live webinar service is available only to WCEC Affiliates. An archive of the webinar will be made publicly available 1 month after the webinar date. Please contact email@example.com if you are an Affiliate and would like to attend the Webinars, or if you would like to learn how to join our distinguished group of Affiliates.