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21. Sep 2007 - Vacuum insulation: Systems or products?
Abstract
The third “VIP-BAU" symposium took place on 20/09/2007 in Würzburg. This event organised by ZAE Bayern was well attended by 140 visitors. Event participants were already familiar with and actively using this new technology: manufacturers of building and insulation materials, construction systems and building components, as well as planners, architects, advisors or research institutes already involved in using vacuum insulation. In addition, planners and decision makers from public institutions and building societies, interested in using innovative thermal insulation technology, were also represented.
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Symposium report
Vacuum insulation is a relatively recent technology in the building trade with the first research projects and prototype building applications starting around 10 years ago. There are now also several institutes and companies specialised in dealing with vacuum insulation for buildings. The first products only recently appeared on the market, however today the third generation of products is available: whereas, initially, the bare vacuum panels were offered for on-site construction, this was later followed by concealed panels. The third generation panels are usually foamed or integrated in facade systems or prefabricated elements. At present, the price of thermal insulation and facade systems with vacuum insulation is roughly double that of conventional systems This does not take into account, however, the gain in usable floor area when compared to bulky thermal insulation or the savings in energy costs as opposed to conventional insulation materials of the same thickness. Furthermore it is expected that significant cost reductions will be achieved.
Solution for problem areas with high requirements
The thermal conductivity of vacuum insulation lies between 0.002 and 0.008 W/mK and provides extremely good thermal insulation when compared to traditional insulating materials. This technology is also suited to specific applications where, due to a lack of space, thick layers of insulation material are not feasible or the usable floor area is intended to be maximised due to high land prices. Vacuum insulation offers suitable thermal insulation for refurbishment projects and also other problematic applications, however there are some special requirements which need to be addressed. For example, the effect of thermal bridging at panel joints is significantly more severe than with conventional insulation materials. Systematically preventing thermal bridges is therefore even more important than in traditional thermal insulation systems.
Systems or products?
It is generally accepted that the handling requirements for vacuum panels are new to the building trade. There are two schools of thought on this matter: one concludes that “you have to be extremely careful”, but that the correct handling of panels on-site should be possible by competent and, if necessary, certified craft businesses. Some companies use an alternative approach by integrating the vacuum panels in facade systems or prefabricated elements. Prefabrication is aimed at reducing the risk of damage.
Correctly dealing with any concerns
Even in conventional insulation applications, building contractors are often sceptical about increasing the level of insulation and air-tight construction methods by claiming that “walls have to breathe”. Vacuum insulation technology faces the same preconceptions; concerns about employing hermetically sealed insulation methods re-surface in this context. It is therefore important to competently address such concerns when communicating with building contractors.
Building regulations approval
The DIBT building regulation approval for two vacuum panel products has now been obtained. This approval is restricted to the indoor use of prefabricated facade panels with a design similar to insulation glass and strictly requires that they are handled by trained personnel. It is anticipated that approvals for other applications will follow shortly. If there is no general building regulations approval, approvals must be gained in individual cases.
Open discussions with industry representatives have made a major contribution to identifying not only the status quo, but also the success criteria and perspectives for this new type of thermal insulation technology.
Conference proceedings
Copies of the conference proceedings containing all presentation papers are now available. These can be obtained from the event organiser for a nominal fee of EUR 25 (incl. VAT and postage). Send an e-mail stating your full address to vip-bau(at)zae.uni-wuerzburg.de.
Background
The “VIP-BAU" symposium is held every two years. The 1st "VIP-BAU" symposium "Vacuum Insulation Panels in the Construction Industry" in Warnemünde, Rostock (2003), focused above all on technical basics and primary applications. The 2nd symposium in Wismar (2005) exhibited the practical experiences which had been gained up to that point. At the 3rd "VIP-BAU" symposium, practical examples and experiences were on the agenda again.
The 3rd "VIP-BAU" symposium follows on immediately from the 8th International Vacuum Insulation Symposium (18th-19th September 2007), which is primarily aimed at participants from the field of research and development.
Link
Additional information on vacuum insulation may be found at www.vip-bau.de