### Va

- Q

- tec VIP Lifetime Analysis
Performance test of panels 7 years after production

This report presents va

- Q

- tec’s VIP lifetime analysis . The panels used for this analysis were
produced according to va

- Q

- tec quality standards. Specifically, va

- Q

- tec uses three main quality
aspects which are necessary to guarantee the VIP function shown in the results :

1. Test of the thermal conductivity of each core material lot (tested in a va c uum panel)

2. T est of the diffusion rate of the film and the sealing for each p roduction lot of film (tested

in a va c uum panel)

3. T est of the inside gas pressure for every single vacuum panel within three days of
production

.

### Lifetime Analysis

Performance test of panels 7 years after production

ISO Dok. Nr.:
Version: va-Q-tec AG

Erstellt von: Jochen Hiemeyer Karl-Ferdinand-Braun-Str. 7 Erstellt am: 09.09.2010 12:14 97080 Würzburg/ Deut schland

Druckdatum: 09.09.2010 12:15 info@va-Q-tec.com

Seite: 1 von 1 www.va-Q-tec.com

1. Intention: Vacuum insulation panels show an increase in gas pr essure over time as gas molecules diffuse through the high barrier film. Depending on the po re size of the core material this leads to an increase in thermal conductivity and thus a perform ance degradation of the vacuum panel. To predict this aging properties the diffusion prop erties of the high barrier film need to be

characterised. The diffusion rates for these films are extremely low, so that common test methods cannot be used to quantify this rate. Va-Q-tec use s a sophisticated test method to qualify each batch of high barrier films before releasing them f or production ( cf: proceedings of the 7 th
International Vacuum Insulation Sympossium, Duebend orf, 2005, Dr Roland Caps ). From these tests an increase in gas pressure of les s than 1 mbar per year is predicted for the highest quality metallized films which are used for va-Q-tec panels (for a 20 mm thick panel at ambient temperatures and normal humidity).

To validate these values and show the lifetime stab ility of the film composite 116 panels which had been produced in December 2003 were analysed.

2. Proceedings: The 116 panels which are regarded had been produced in December 2003. The panels are made up of a silica core and a metallized film and were drawn from a normal production run. The panel size is 346 x 263 x 20 mm3. The 116 panels were pro duced in two production lots (#03067708: 66 pcs; #03067008: 50 pcs). Internal gas pressure of the panels had been measured with the va-Qcheck system ( cf: Quality control of vacuum insulation panels: Me thods of measuring gas pressure, Vacuum 82 (2008), Dr. Roland Caps et al ). The panels were stored on a pallet at ambient tempe rature. In March 2010 all panels were controlled for internal gas pressure with va-Q-chec k. To control the long term reliability of the va-Q-ch eck measurement, for several panels the inside gas pressure was controlled with other means yieldi ng good consistency. Also the thermal conductivity of some panels was me asured to control that the measured gas pressure is consistent with the expected thermal va lues.

3. Results: The following table shows the results of the gas pr essure measurements for the two production

lots: Lot 1 (#03067708) Lot 2 (#03067008) Number of panels 66 50 Mean gas pressure December 2003 1,5 +/- 0,2 mbar 0, 8 +/- 0,2 mbar Mean gas pressure March 2010 4,0 +/- 0,6 mbar 8,8 + /- 2,3 mbar Total increase in gas pressure 2,5 +/- 0,5 mbar 8,0 +/- 2,2 mbar Increase in gas pressure per year 0,4 mbar / year 1 ,3 mbar / year

4. Discussion: None of the panels is showing an increase in gas pr essure that exceeds 2 mbar / year. Also within one production lot the increase in gas press ure for different panels is similar. No unexpected discrepancies to lifetime expectance based on our diffusion rate tests or accelerated aging were discovered. Also the high influence of production parameters (c omparison between lot 1 and 2) can be seen. Only an accurate control of these parameters can gu arantee sufficient quality.

For refrigeration applications the expected diffusi on rates are reduced by the lower temperatures. An increase rate of 1 mbar / year would mean a 15% increase in thermal conductivity during a refrigerator lifetime of 15 years.