Last week, I explained how tracking make-up water levels could help you diagnose various problems in a closed-loop system like steam heat. This week, I’ll show you why you should pay attention to your stack temperature and how it can help you save thousands on fuel each year while extending your boiler’s life by decades.
Monitor peak stack temperatures, and when they rise, clean your boiler. Schedule cleanings based on insights, not a calendar.
High stack temperatures almost always indicate dirty boiler tubes. Inefficient heat transfer due to either soot (on the fire side) or mineral build-up (on the water side) will cause you to waste huge amounts of money on fuel and it causes unnecessary wear on your equipment.
Normally, you should expect stack temperatures around 350 to 450 degrees Fahrenheit. Every 100 degrees above that equates to a 2.5% efficiency loss.
Most buildings schedule boiler cleanings at regular intervals throughout the year, but if you notice those numbers jump above that range, it’s time for a cleaning.
Have someone punch the tubes and see if that brings temperatures back down to normal. If it doesn’t, you may have scaling on the water side, which will require a more intensive cleaning process and is indicative of a poor chemical composition of your boiler water.
Last year, one of our clients moved up their scheduled cleaning by three months after noticing their stack temperature rise. If they hadn’t, they would have used an additional 1,092 gallons of oil, which represents $3,824* in fuel savings over that three-month period.
Their cleaning took place on February 3rd. Stack temperature, as well as fuel use, dropped off sharply.
Not only does proper and strategic cleaning save money in the short term, it reduces capital expenses as well. A boiler kept clean and properly maintained should last as much as 30 years or more. If you don’t take care of yours, however, it could wear out in as few as 10.
If you don’t already have a gauge measuring stack temperature, installing one is quick, easy, and inexpensive(be sure to get one that measures both peak and current temperature). Install it, monitor it, and use it to track performance and schedule maintenance. It will save you time and money, and your building will be healthier because of it.
*(based on $3.50/gal oil prices and a 2.5% efficiency loss per 100 deg. rise)