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"Pet" Subject: vacuum Panel Insulation cut n paste

Does Vacuum Insulation Make Sense? To insulate refrigerators, perhaps — but to insulate buildings, probably not Posted on Nov 14 2013 by Alex Wilson Image 1 of 3 Microtherm's vacuum insulation panel has a microporous substrate covered with an airtight aluminum skin. I’ve recently worked on revising the BuildingGreen Guide to Insulation Products and Practices (available as part of a webcast), so I’ve been steeped in all sort of insulation materials, including some oddball products. One of those is vacuum insulation — the principle of a Thermos bottle. In theory, vacuum insulation is a great idea. To understand why, it helps to know a bit about heat flow. How a vacuum slows down heat transfer There are three modes of heat transfer: conduction, convection, and radiation, and if we remove most of the air molecules from a space — as occurs when we draw a vacuum — we largely eliminate the first two of those heat transfer mechanisms. Conduction is the flow of heat from molecule to molecule. It’s the reason a cast-iron skillet handle heats up. But thermal conduction also occurs across a layer of air, as kinetic is transferred from one air molecule to the one next to it. If we remove most of those air molecules by creating a vacuum, there will far less conductive heat flow. RELATED ARTICLES A Few Product Highlights from GreenBuild GBA Product Guide: Dow Corning Vacuum Insulation Panels Vacuum Insulation Panel Convection is the transfer of heat by moving molecules from one place to another. Warm air rises, and these convection currents carry heat — for example, this is the primary means that heat is delivered to a room from baseboard convectors (often called radiators). In a vacuum there are far fewer air molecules, so convection of heat nearly stops. Only radiant heat flow occurs to a significant extent in a vacuum, because radiation is not dependent on air molecules. That’s why low-emissivity surfaces are so important in vacuum panels. The Stanley Thermos bottle has a very shiny, low-emissivity (low-e), inner surface that helps to control radiant heat transfer; the same sort of low-e surface is included in various vacuum insulation panels. The net result is that an inch-thick vacuum insulation panel can provide a center-of-panel insulating value of R-25 or even more — compared with R-6 to R-7 for standard rigid foam insulation. The “hardness” of a vacuum The key property of a vacuum is its pressure, or how “hard” it is. We often measure that with Torr units. One Torr is exactly 1/760th of a standard atmosphere (1.3 x 10-3 atm), or approximately 1 mm of mercury. With a very hard vacuum, more of the air molecules are sucked out, resulting a greater negative pressure. The walls of a typical Stanley Thermos bottle contain a relatively hard vacuum of 10-6 Torr. With such a hard vacuum, that Thermos bottle can keep coffee hot all day. By comparison, the vacuum in a flat vacuum insulation panel is typically no more than 1/1000th as strong (10-3 Torr). The harder the vacuum, the more difficult it is to maintain it. Thermos bottles are made with a cylindrical design for optimal strength. With flat panels, it’s very hard to achieve comparable strength and maintain such a hard vacuum, particularly at the edges. Using a vacuum to insulate more than our coffee If a vacuum works so well to keep our coffee hot all day, why not use one to insulate our houses? Vacuum insulation panels have been used to insulate some high-tech demonstration homes, such as entrants in the Solar Decathlon student design competition in recent years, but high cost makes them impractical for real buildings. There’s also the problem that puncturing that vacuum insulation panel will significantly reduce its insulating performance. (I can imagine how bummed one would be after spending thousands to insulate a home with vacuum insulation panels and then hearing a hiss while hanging a painting!) However, these vacuum insulation panels (sometimes called VIPs) could make a great deal of sense in certain value-added products like refrigerators, freezers, water heaters, and entry doors. Whirlpool actually used a VIP that Owens Corning produced for a while (the Aura panel) in a high-efficiency refrigerator in the mid-1990s, but then dropped both the refrigerator and the use of VIPs. But I believe the benefits of R-25 or more in a one-inch-thick panel are significant enough — especially as we try to get more usable volume in refrigerators without growing the exterior dimensions — to warrant the embrace of vacuum insulation. These could also be a great solution for exterior doors that are notoriously poorly insulated — as I’ve written about in this blog. There are at least a half-dozen manufacturers of vacuum insulation panels today. Most, including Microtherm and Nanopore, produce panels that have a rigid, porous substrate surrounded by an impermeable metal skin. A new VIP on the market The latest VIP to come along is made by Dow Corning (no relation to Owens Corning). This panel, not yet widely available, is one inch thick and has a center-of-panel insulating value of R-39 and a “unit R-value” (accounting for the edges) of R-30, according to the company. The Dow Corning product has a core made of fumed silica cake, a remarkable “microporous” material that provides R-8 per inch even without a vacuum. This material allows a very high insulating value even with a softer vacuum. The core is reinforced with silicon carbide and polyester fibers for structural support, and it is encased in an inner layer of polyethylene and an outer layer of polyethylene, polyester, and aluminum. The panels are vacuum-sealed, and the edges are heat-sealed. According to an Environmental Building News article, these Dow Corning panels should cost $10-12 per square foot. At that cost, I believe VIPs can be very practical for those appliance and exterior door applications noted above. Alex is founder of BuildingGreen, Inc. and executive editor of Environmental Building News. In 2012 he founded the Resilient Design Institute. To keep up with Alex’s latest articles and musings, you can sign up for his Twitter feed. Read more: http://www.greenbuildingadvisor.com/blogs/dept/energy-solutions/does-vacuum-insulation-make-sense#ixzz4vnfONKc5 Follow us: @gbadvisor on Twitter | GreenBuildingAdvisor on Facebook
MEXICOWANDERER 10/17/17 02:42pm Tech Issues
Black Tank Flush vacuum Breaker

Had a major water leak today while operating the black tank flush on our 2017 Outback 325BH. After turning the water off and cleaning up the majority of the mess I went in search of the source. Turns out it was the vacuum breaker under the bathroom sink. Checked the fitting for tightness and had D/W turn the water back on, still leaked. I decided to remove the vacuum breaker to get a better look at it. Seemed fine but I was suspicious of something clogging the breaker. Forget to mention when the leak was discovered we had a super strong odor of stink bugs in the bathroom. Well after shaking the vacuum breaker and flushing water through it in the kitchen sink low and behold a drowned stink bug emerged. Ok so tonight I’m doing my research and found this is common. The vacuum break still has a slight leak so tomorrow I’m calling the dealer and asking for a replacement. My biggest question is how did this stink bug get into the vacuum breaker? Could have it damaged the seat or internal seal of the breaker ? Should I replace with a brass vacuum breaker ? Thanks for any suggestions.
Mikesr 10/01/17 06:18pm Travel Trailers
Black Water Tank San-T- Flush vacuum Braker Leak

I have a occasional leak under the bathroom sink. It takes me a while to figure out it's from the San-T-Flush Vacuum Breaker. It works Ok when flushing. However, it starts to leak as soon as faucet is turned off and won't stop until the inlet hose is detached. I have it taken out to check for debris and lubricated with WD40 without success. I checked on the manufacturer's (Swan Industries in Oregon)web site, it says: "Back-seepage upon shutting off the flow of water is normal." My original thought was to give them a call for a replacement part. I now have a second thought after reading this. Am I suppose to permanently wrap a towel around it? I read on other forum and found a suggestion to replace the plastic part with a brass one. Since I am not experience with these plastic fitting. Can anyone tell me if this plastic fitting is compatible with brass vacuum breaker? Or do I have to change the fitting as well? http://i.imgur.com/HyotDx3l.jpg "border=0" http://bit.ly/1jtQSidClick For Full-Size Image. http://i.imgur.com/KzieO7Dl.jpg "border=0" http://bit.ly/1jtQSidClick For Full-Size Image.
TKW 08/26/17 11:29pm Travel Trailers
Htr / Air controls do not shift the vents - vacuum issue?

The heater / air conditioning vents seem to be stuck in the defrost setting even when I turn the control knob to Vent or air conditioning, etc.... I do not hear the normal vacuum sound when I move the dial like I normally do. Is there a vacuum hose somewhere that may have gotten disconnected? I opened the hood of my 1999 Ford V10 engine but I do not see any hoses that look like they are for the heater. I did not remove the air cleaner pieces to look under/behind them. Are there any hoses under the dash itself or in the dog house area? If not a loose hose is there some other thing to suspect or check out. The blower and everything else seems to be working. Would appreciate any and all suggestions. Thanks, John S.
John S 07/06/17 01:48pm Tech Issues
Solved: How to find vacuum leak in water supply line?

Hi all, this week we picked up our new camper, a Northstar Arrow. The camper is fantastic and we are very happy with it - except for one problem with the water supply that has us all stumped: The water pump does not provide constant pressure, sputters, and frequently loses prime. It seems to suck in air somewhere. Especially when we take just a little bit of water, it tends to lose the vacuum and runs dry until we take a lot of water again. Then it primes and works, but sputters frequently. The issue is a bit better when the tank is full, and gets worse as the tank empties. What we have done so far: - Checked the tank vent hose - it is free, no kinks or obstructions - There are no water leaks, anywhere. It holds pressure fine on the pressure side - All fittings are firm to the touch and dry from tank to pump - We have switched the winterizing valve and sucked water through the winterizing hose. The effect remains the same. This would put the problem somewhere between the winterizing valve and the pump (including both), right? Anyone have an idea how to find the vacuum leak short of disassembling the whole water line from tank to pump? It is made up of around 8 or 10 short sections of solid plastic pipe. And a number of elbows and the one winterizing valve. You can not see if and where any bubbles are introduced. The strainer is installed with the clear lid facing away from us... To make matters more interesting, we are still on our shakedown trip and have no useful tools with us. What would you do to find the leak?
joerg68 06/10/17 12:20pm Truck Campers
Dyson DC59 battery powered vacuum

After less than 10 uses the battery on my DC59 will not hold a charge. Of course it is out of warranty and a new battery is about 100 bucks. I wonder if I got a defective unit or this is just a fluke.....I have contacted Dyson and they keep telling me to clean the unit....Duh......after charging over night it will only run a couple of minutes and I have cleaned every inch of it....
Bob Vaughn 06/03/17 07:07am General RVing Issues
Dometic toilet vacuum breaker

Pulling my 2015 Keystone Energy 300 FBS out for the first time after a long Alaskan winter and have found my winterization skills to be lacking. I had a leak in my Dometic series 310 toilet and replaced the water valve thinking that would solve the problem. Replacing the water valve fixed one problem but now after flushing, I have water streaming out of the top/back of the toilet at the vacuum breaker. Can I repair thos part? If not, can someone he'll me with the post number?
rangerheave 05/20/17 09:25pm General RVing Issues
12 volt or low wattage vacuum cleaner

Hi All - Can anyone recommend a good 12 volt or low wattage vacuum cleaner. We will be doing some dry camping this year, obviously without hookups. Most everything we need we can do with 12 volts, except TV and vacuum cleaner. I plan on buying an inexpensive 300 watt pure sine wave inverter for the TV. Hopefully I could find a decent 12 volt vac, or find one that will work with the inverter. Thanks for any help.
GaryS1953 05/16/17 10:07am General RVing Issues
vacuum Cleaner

We are looking for a battery operated portable vacuum for our motor home. It has mixed carpet and linoleum. Anyone have a favorite they would recommend? Thanks.
vjstangelo 05/07/17 07:52am Class A Motorhomes
Black Tank vacuum Breaker

A few days ago y'all gave me ideas about why my black tank won't flush. One of the ideas was a vacuum breaker problem. Does the thing in this photo look like a vacuum breaker? http://i66.tinypic.com/24eudxu.jpg How does one test and/or reset it? Thanks much.
beaubeau 04/29/17 05:03pm Class A Motorhomes
vacuum cleaners

Most of us don't have a central vacuum system in our rigs. What make/model vacuum cleaner do you use? We have a dog. Our Grand Design has vinyl flooring in most of it, the bedroom and slide is carpeted. Thanks
Showme 5vr 04/17/17 08:51pm General RVing Issues
Shark vacuum

Anyone have thoughts or experience with the Shark NV-360 Vacuum? Good or Bad?
DD716TED 11/24/16 11:10am Around the Campfire
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