Snowmelt system controls adjusted to save energy
At this large office campus, the sidewalk snowmelt system had never been reviewed or commissioned.
During a recent retro-commissioning investigation for a large office complex, exp U.S. Services learned that the boiler-heated glycol system used for snow melting ran continually whenever the outdoor air temperature was below 38 F. NOAA weather records revealed that while the temperature is below 38 F for about 2250 hours/year, the actual amount of time of snowfall is only 580 hours/year. This difference of about 1700 hours represents the time the snowmelt system is on when it doesn’t need to be.
Because large areas were covered by eight different snowmelt systems, the calculated annual savings was 43,000 therms of natural gas and $21,000. This system was installed many years before the popularity of commissioning, but this speaks to the need for retro-commissioning, and/or at least a periodic review of control sequences and operations.
Terrence Malloy is project manager for the energy solutions group at exp US Services Inc. He focuses on energy conservation, retro-commissioning, and renewable energy systems.
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After almost a decade of uncertainty, the confidence of plant floor managers is soaring. Even with a number of challenges and while implementing new technologies, there is a renewed sense of optimism among plant managers about their business and their future.
The respondents to the 2014 Plant Engineering Salary Survey come from throughout the U.S. and serve a variety of industries, but they are uniform in their optimism about manufacturing. This year’s survey found 79% consider manufacturing a secure career. That’s up from 75% in 2013 and significantly higher than the 63% figure when Plant Engineering first started asking that question a decade ago.