Compressed Air Best Practices - March 2009 - (Page 30)

® | 03/09 Focus Industry ENERGY MANAGEMENT | SEVEN SUSTAINABILITY PROJECTS FOR INDUSTRIAL ENERGY SAVINGS Step #1: Calculate Gas Costs for Winter Heating To begin this project you will need some basic information about the costs related to winter heat and the amount of air exchange happening on the manufacturing floor. A quick check for winter heating costs is to take the monthly gas bills and make a table of the amount of gas used each month as in the table below. Does the amount of gas used increase during the winter months? If so, estimate the amount of gas used during a typical non-heating month such as August. Multiply this amount by 12 months to get an estimate of the amount of gas used for production that is not related to the weather. Now add the total amount of gas used for the year and subtract the amount used for production. This will give you an average amount of gas that is related to the cold weather. 1. 2. 3. 4. 4,657 mmbtus (gas used in August) x 12 months = 55,884 mmbtu (gas for production) Total gas used in 1 year = 67,632 mmbtus 67,632 (total gas used) – 55,884 (gas used for production) = 11,748 mmbtus (gas used for winter heat) At an average cost for gas of $9.80/mmbtu the cost for winter heating is $115,130 per year. “Reducing the exhaust air by 30,000 cfm at $1.00/cfm will save $30,000 per year.” The next step is to estimate the approximate number of hours winter heat is required per year. Adding up the hours during the winter months from November through March provides a rough estimate. A more accurate number can be derived by adding up all the days where the average temperature is < 56 °F. This number can be found by using the free data available on the website: www.weatherunderground.com/history. Enter your zip code and choose the selection “history.” From this data you can also determine what the average temperature was during the heating season. In our sample factory from central Ohio, we found there were 3,960 hours per year that the temperature was below 56 °F, and the average temperature was 42 °F. The differential temperature is 56 °F – 42 °F = 14 °F. 30 www.airbestpractices.com http://www.weatherunderground.com/history http://www.airbestpractices.com

Table of Contents Feed for the Digital Edition of Compressed Air Best Practices - March 2009

Compressed Air Best Practices - March 2009 Contents From the Editor Utility-Air News Compressed Air Audit of the Month Air Standards Assessment Improves Electroplater Production and Saves Energy Demand-Side System Optimization Seven Sustainability Projects for Industrial Energy Savings Personal Productivity Resources for Energy Engineers Wall Street Watch Advertiser Index Classifieds

Compressed Air Best Practices - March 2009

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