New Insulation Solutions for Residential Boilers

Companies seeking practical and cost effective alternatives to traditional Refractory Ceramic Fiber (RCF) insulation are now moving towards alternative materials with low bio-persistence. Among these are Alkaline Earth Silicate (AES) composition fibers, supplied by Morgan Advanced Materials under its Superwool^® brand. Manufacturers of residential boilers in Europe began transitioning over to these new products some years ago for both chamber insulation and joint gaskets. Recently the demand to replace RCF has also been strong in Korea, where Morgan has been able to solve the problem by supplying its Superwool^® HT C insulating board. In making this change the Korean manufacturers gain the advantage of excellent performance characteristics, whilst avoiding the use of materials that may be subject to regulation as carcinogens. By using Superwool^® fibre manufacturers are also are ensuring that models built for export will comply with existing and anticipated regulations in Europe and elsewhere. 

Transition from RCF to AES insulation

Major boiler manufacturers in Korea have reacted to the classification of RCF as a possible carcinogen because their products are intended for residential use and there is a strong desire to use only materials that are not likely to be subject to future regulation. There are many advantages in transitioning to a low bio-persistent alternative, including elimination of regulatory concerns, improving the environmental image of the manufacturer, and fewer concerns and complaints about the insulation from the customer. Perhaps the most important advantage is that models built for export will comply with existing and anticipated regulations or restrictions. 

The search for alternatives to RCF

As a result of the increasing concerns about the classification of RCF as a possible carcinogen, several companies have been developing non-RCF alternatives that meet the high temperature needs for commercial, industrial, and transportation applications.

For example, Morgan Advanced Materials developed a range of special AES fibers engineered to deliver advantages in high temperature insulation applications, while having low bio-persistence. These fibers, sold under the brand name Superwool^®, are exonerated from carcinogen classification in Europe after rigorous testing under Note Q of European Directive 97/69/EC (adapting Council Directive 67/548/EEC).

For residential boiler chamber insulation, the product used is Superwool^®  HT C Board, which is specially designed for applications up to 1000°C that require cycling resistance and high mechanical performance. The fibers are formed into boards, rigid panels made from a mixture of fibers, refractory fillers and organic and inorganic binders. These boards can be cut with a saw blade, allowing precise shapes to be made. The boards have very low thermal conductivity, a low heat storage capacity and good thermal shock resistance and they can also be used in direct contact with flame. 

For joint gasket insulation, Superwool^®  papers offer excellent performance in high-temperature applications and offer an alternative to traditional solutions as a result of their high refractoriness, stability, and resistance to chemical attack.

Implementing the solution

After discussing the increasing movement to regulate RCF in the future, and the advantages of using the new material, several Korean manufacturers of residential boilers decided to consider the use of Superwool^®  HT C Board for new models being designed and for some existing models. Many of the manufacturers had previously had positive experiences with Morgan’s Ceraboard^® RCF product, and technical experts were able to demonstrate that the new Superwool^® board would perform as well. 

Morgan engineers also conducted frequent visits to boiler manufacturers’ research and development facilities as well as their production lines, to discuss the advantages of AES over RCF. Discussions were held with the production team, including assembly line workers, to discuss the benefits of transitioning from RCF to Superwool^® insulation. 

After these discussions, several major boiler manufacturers have either switched to the use of the new board material for new models or are planning on doing so in the coming year. For example, Kiturami Boiler, with a yearly output of between 250,000 to 300,000 units per year, has switched from Ceraboard to Superwool^® HT C Board, Superwool^® Plus blanket, and rigidized Superwool^® board for chamber insulation, and Superwool^® paper for joint gaskets. 

Also using the Superwool board or paper are a number of other major boiler manufacturers, including Kyoung Dong, Daesung Celtic, and Daewoo.