This weekend I dissected my boat's refrigeration hatches, removing the old foam insulation so that I could take measurements and order vacuum insulation panels with a much higher R value. Once I was done I went to order the panels from r-parts, only to find out that the production has been "temporarily" suspended. Arghhh!!! I wrote to r-part's sales and here's what I got back:
Clearly this schedule won't do. Does anyone have any other sources for panels? I looked at Glacier Bay, but their prices are too high.
-- Geoff
Here is some info on why r-parts can't supply the VIP anymore.
In marine-refrigeration there are many boats that simply do not have room to apply the insulation thickness guidelines above and still have room for a box of the desired volume. So called super insulation, or vacuum insulation panels (VIPs) can provide the answer. There are two basic types of VIP on the market at present. The first type of panel uses a special one inch thick foam core from Dow Chemical, called Instill™.
Dow has recently discontinued the manufacture of this foam core material and when the existing inventory is gone, these panels will no longer be available. The foam cores for this type of panel are wrapped in a vacuum barrier membrane material. When the panels are pulled down in a vacuum and sealed, they achieve an insulating value close to R 30. This product was originally developed for shipping applications and was reasonable in cost. On the down side, the vacuum membrane around foam core panels punctures easily. Even if the membrane can be maintained intact, the internal pressure rises over time.
The pressure rise occurs because of the slow diffusion of air through the membrane and possibly some outgassing of the foam material comprising the core. The insulation value of these panels goes down to about R 3 per inch when they are no longer holding a vacuum. They still may be a good option if only short term performance life is required or provision can be made in the box design to easily replace the panels. There are some technical options to increase the service life of these panels such as adding packets of a chemical called a getter when the panel is manufactured. Even so, there were no manufacturers of this type of panel that offered a performance life warranty.
A second VIP technology is available that uses aerogel as a core material. Aerogel is a powdery silica based material which has an R value of around 9 per inch at atmospheric pressure.
Glacier Bay, Inc., uses this core material in BARRIER ULTRA-R super insulation panels. BARRIER ULTRA-R panels have an R value of 50 per inch. They come with a 25 year performance warranty against loss in R value. This is possible because the aerogel core chemically adsorbs gas molecules that pass through the vacuum barrier membrane. This getter activity allows the panel to maintain its high vacuum level and R value over an extended time.
Marine-refrigeration ice-boxes built with BARRIER ULTRA-R have a total wall thickness of about two and one quarter inches. Although the initial cost of this material is higher than other insulation options, it is often chosen for new marine-refrigeration construction and marine-refrigeration ice-box retrofit projects because usable space can potentially be doubled or more for a given external volume. When coupled with the long performance life and superior energy performance, it may offer the greatest value.
Both types of VIP panels have to be custom built to fit the application. If they were to be cut or punctured after manufacture, they would lose a high percentage of their performance. Use of these high tech materials is not an either/or option. VIPs can be used in hatches or high heat load areas while the rest of the box is constructed of conventional insulation.
Here is a link to the complete article.
http://www.yacht-sailboat.com/marine-refrigeration.html
