- Written by Phalguni Mukhopadhyaya, Jean-Francois Masson, Minh-Tan Ton-That, Tri-Dung Ngo & Gordon Sherrer National Research Council, Canada
Growing concerns about climate change, irreversible environmental damage and rapid depletion of non-renewable resources have made a great impact on the global construction industry. This has resulted in a search for renewable next generation construction materials. Could biofoams be a viable possibility?
Bio-based renewable construction materials are not a new concept for the construction industry. Indeed, they have been widely used as various building components all over the world for building construction for many years. However, in modern construction, the ratio of bio-based to non-renewable building materials is very low.
- Written by Jim Young, ITW Insulation Systems
Mechanical insulation systems are used on cold and hot pipes, tanks, ducts, vessels and equipment to conserve energy, prevent surface condensation, prevent contact burns and more. In most outdoor applications and some indoor locations, these systems use an outer protective metal jacketing to provide UV- and damage-resistance and water shedding. Regardless of the type of metal used, this jacketing is susceptible to galvanic and pitting/crevice type corrosion on the interior surface caused by the intrusion of water into the insulation system. Here, the use of a moisture barrier to help prevent this type of corrosion is described and a recommendation on the best type of moisture barrier to use is provided.
Insulation is used on the exterior surface of pipes, tanks, ducts, vessels and equipment for the same reason that insulation is used on building envelopes - to reduce the flow of heat. In this application, the insulation is part of a complex construction generically called a mechanical insulation system, which can include one or more layers of insulation, adhesive at the insulation joints, vapour retarders and metal jacketing.
These systems are often more complicated than building envelope insulation because of their complex geometry, the unidirectional heat/moisture flow, the extreme temperatures of the mechanical equipment being insulated and the often outdoor exposed location of the systems. Table 1 shows some common examples of applications for outdoor mechanical insulation systems, their operating temperatures and a brief description of the insulation system used.
- Written by David Yarbrough, R&D Services, Inc.
Reflective technology that is used to reduce energy use in buildings is represented by three commercially available product types. In all three cases the performance of the reflective product depends on reduction in radiative transport across air spaces due to low thermal emittance surfaces.
Products identified in North America as 'radiant barriers' typically have a low-emittance surface adjacent to a relatively large air space that may be ventilated or unventilated. The performance of radiant barriers is related to reduction in thermal radiation from the low-emittance surface, which is directly proportional to the emittance at a specified surface temperature.
Surfaces with low-emittance coatings perform much like radiant barriers. The coating for the surface, known as interior radiation control coating (IRCC), reduces radiative transport in the same manner as radiant barriers. Radiant barriers and IRCCs are not typically assigned thermal resistance values (R-values).
- Written by Roberto Massini, STM Technologies & Carl Bender, TurboSonic Inc.
STM Technologies' clients are very concerned about environmental issues, wanting the ability to meet the most stringent anti-pollution laws anywhere in the world. In order to satisfy these requests, STM Technologies (STM) made contact with many wet electrofilter producers. After thorough analysis, STM expressed its full confidence in TurboSonic's proposal and together developed what the companies believe to be the most efficient and reliable wet electrofilter to be used in glass-wool manufacturing.
The first application was in a Chilean glass-wool plant, completely designed and supplied by STM Technologies. After the upgrade to increase the capacity of this plant, the air pollution control equipment was also improved by installing a specially designed TurboSonic SonicKleen™ Wet Electrostatic Precipitator (WESP). The goal was to decrease atmospheric emissions as much as possible, while recycling all of the process water used to flush electrodes so that it could be used for binder preparation. These goals were realised and exceeded. The emissions were lower than expected, as presented in this article.
- Written by Tim Swales, Johns Manville
The insulation industry is changing. Savvy consumers and regulatory agencies are adopting more stringent standards in response to health concerns and are forcing the industry to take a hard look at how it manufactures its products. One key ingredient coming under fire is formaldehyde. This begs the question, 'Is formaldehyde in your insulation future?' The short answer is 'no.' But that would make for a rather incomplete and boring article. Let's take a deeper look at the reasons why.
First, let's consider the past. Formaldehyde has played an important role for many years as a binder (or glue) for glassfibre insulation. Unlike paper and some organic fibres, glass-fibres are chemically inert and will not stick together in a familiar rigid batt without bonding the many fibres together.
Years ago, the industry was focused solely on binder performance at the lowest cost. This typically meant choosing phenol-formaldehyde (PF) binder as the glue. PF has an effective and well-understood chemistry and low cost. With most fibreglass insulation, urea was used to extend the PF binder to bring in additional cost savings and help promote more effective curing, the process in which glass-fibres are heated in an oven so that they adhere to each other.
An example of these older products is the traditional bonded fibreglass insulation. In the past and to some extent still today, this type of insulation was colour-coded based on its formaldehyde content. The formerly common yellow batts denote formaldehyde because the PF binder turns yellow in the curing oven. Pink PF insulation is just yellow insulation with pink dye added.
