May 13, 2010: Data Loggers to Assess A/C Efficiency Gains in California Pilot Program
“After a system’s compressor shuts down in hot-dry environments such as the western U.S., water that has condensed on the evaporator coil can be re-evaporated into the conditioned space to boost the sensible efficiency of the unit,” said Adrian Hairrell, an engineer with Proctor Engineering Group (PEG), the San Rafael, Calif.-based engineering consulting firm developing the devices.
“The purpose of this study is to compare the energy use of a standard system to that of the same system with the enhanced fan delay control added. Our goal for the project is to realize at least 7 percent energy use savings in each California climate zone we monitor.”
The monitoring period for each participating home will run for approximately nine weeks beginning in May 2010. All participating homes are located within the San Joaquin Valley region, where summertime temperatures can reach 115°F, leading to heavy air conditioning use among residents.
The Onset data loggers, which are compact, battery-powered devices, will be installed on the air conditioning units to measure supply and return air temperatures, fan and compressor runtime patterns, and compressor amperage. The recorded data will be offloaded onto a PC using accompanying HOBOware® graphing and analysis software, and then exported into a spreadsheet program for detailed analysis.
“In the past, we’ve used data logging devices that could take up to eight hours to install at each site, which can be very imposing on the homeowner,” said Hairrell. “One of the benefits of the Onset loggers is that they can be installed very quickly - minutes vs. hours - so the homeowner doesn’t have to spend a lot of time waiting around.”
The results of the study are expected to be published in a report in early 2011.
For more information, visit www.onsetcomp.com.
Publication date: 05/10/2010