The Power of Insulation
By Gerard Hillenbrand, P.E.
That was the subject of the May 16th, 2006 Technical Meeting at Con Edison Headquarters in Manhattan. The speaker for this presentation was Ronald L. King who now acts as a consultant for the National Insulation Association. For years Mr. King worked in Industry as a specialist in the manufacturing of insulation materials and also served as President of the National Insulation Manufacturers Association, an organization representing upwards of 4000 insulation contractors in the USA, and upwards of 80% of the union and non-union labor in the insulation industry, a $9 Billion annual business.
First of all, Mr. King defined his terms. His subject is Mechanical Insulation, not Electrical. Mechanical Insulation is the material that insulates buildings, boilers, furnaces, piping of all types, HVAC units, etc. It is a non-structural material that is frequently overlooked by engineers and architects and has become somewhat of a forgotten technology. In spite of this mindset, a 1998 study documented that existing insulation saved 1.51 Trillion BTU’s in annual energy consumption. This huge quantity is equivalent to 3.7 days of national gasoline consumption (enough to power 8.5 million coast to coast automobile trips), equivalent to 5% of U.S. electric energy usage, and equivalent to savings of 211 Billion tons of carbon dioxide (CO2) vented into the atmosphere each year. But we can do much better. Some of our states do not have energy codes. It is estimated that if suitable insulation is installed at 100% effectiveness in the USA, 2.58 Trillion BTU’s can be saved annually, thus providing 6 more days of national gas usage (equivalent to 14.5 million more coast to coast auto trips).
The condition of existing insulation on industrial facilities across the nation is largely unknown. One recent study revealed that 21% of existing insulation was damaged or missing on 1.87 million feet of 8 inch diameter standard piping conveying fluid at 600oF. Heat loss from this piping with missing insulation was estimated as the equivalent of approximately 6000 barrels of energy per day. One barrel is equal to 42 U.S. gallons. One gallon of oil has 140,000 BTU of energy content which equates into approximately 6 million BTU per barrel. At a price of $70 per barrel, this heat loss comes to $420,000 per day. Interestingly, if the piping in question were 100% insulated, the heat loss would be equivalent to 600 barrels per day, reducing the financial loss by a factor of ten.
So priority attention to insulation is good for business, good for the economy, and good for the environment. Largely, up until now, engineering consideration of insulation has been marginal at best, since it appears technically simple, is relatively easy to mount, and involves no complex equipment such as gauges or computers. Insulation’s benefits are mostly invisible even though they are capable of providing maximum savings, and maximum capacity operations. Sophisticated engineering analysis of insulation is not emphasized during design since detailed data covering costs versus savings payback periods, material corrosion and repair, and environmental effects is not widely available. However, it would seem obvious that more design discipline could yield substantial benefits in the brewing and distillation industries, in power plant operations, in petrochemical and refining operations, in pumping, refrigeration, air conditioning and ventilation applications, as well as in the textile and pharmaceutical industries.
Responding to these technological deficiencies, such organizations as the National Insulation Association and the North American Insulation Manufacturers Association have initiated major educational efforts promoting insulation technology in cooperation with ASME, The American Institute of Architects, The Society of American Facility Engineers, and the National Association of Energy Engineers. Included in these efforts are the publication of “Insulation Outlook”; a technical magazine, conducting insulation training seminars, addressing technical meetings, and developing computer programs that define insulation energy applications, economic implications, environmental calculations, material usage and thickness details. These educational efforts have the objectives of designating the correct product in view of the regulations established by the U. S. Department of Agriculture, the Food and Drug Administration and the Environmental Protection Agency. This correct product will have the required thickness, finish and operating life as well as providing the required insulation for the ambient conditions, the necessary heat balance the condensation and leak detection parameters, and the correct location in the industrial design scheme.
The correct insulation must reduce energy costs, improve process and temperature control, increase the plant life cycle, minimize condensation, corrosion and pollution, as well as provide personal protection to workers in a safe, comfortable and productive working environment with reduced emissions wherever possible. Reduced energy costs are essential in yielding the required return on investment (ROI) during the life cycle of the facility. Minimizing condensation is very important since the resulting mold is very destructive to plant efficiency. Generally speaking, facility heat losses are 70% via the ceiling, 10% through the walls, and 20% through windows; doors and other openings and insulation must be designed to permanently minimize these losses.
Mr. King next described the results of 39 case studies in which these educational efforts caused the desired payback on the ROI criteria consistent with all requirements stated previously. Among these cases Mr. King summarized several typical results:
- A line of fluid flow piping (150 psi steam at 350oF, 7 million cubic feet flow) suffered $447 of heat loss per day when left bare. This loss was reduced to $35 per day, a factor of 12.5 to 1 when the correct insulation was installed.
- An ethylene plant (C2H4) design saved $125,000 in heat losses by including $15,000 of insulation in the design.
- An office building design reduced heat losses by 40% and reduced the size of the HVAC Unit required for year-round climate control. This building design included sustainable energy parameters and “Green Building” designation by correct use of insulation.
- An uncovered 90o pipe bend (8″ Dia.) was insulated with 2 inch thick material and $1,100 was saved in yearly operating costs.
- A heat exchanger operating at 450oF saved $117 million per year in operating costs when the correct insulation was added.
- An Ethylene Glycol line reduced energy costs by $3,600 per year when insulation was added.
The total annual savings resulting from these 39 case studies was estimated at $100.6 million. One chemical plant design was calculated as having 61 miles of piping subject to insulation improvements. Damaged and missing insulation was estimated as reducing operating efficiency from 10 to 30%.
Mr. King concluded his presentation by thanking ASME for cooperating in his organization’s educational efforts, and urging all mechanical engineers to give insulation the high priority it deserves in their design and maintenance practices.