[Travlin]

You're welcome. You do some fine work.

Regardless, there is something different between your and Antoine's photo results.

It could be atmospheric, time of day (later in the morning), light source, oblique angle of the photo, or only that the color of the white van doesn't lend itself to revealing the detail in as clear a fashion as Antoine's dark van does. I couldn't say with any degree of certainty with the many potential variables.

The fact remains how Antoine's van is bleeding heat at the places where those channels are located. When they covered the facing metal with EZ-Cool the issue was mitigated.

Nobody expects the Spanish Inquisition! > Long Live the Pythons!

 

[Hein]

Regardless, there is something different between your and Antoine's photo results.

The difference (based on my experience and opinion) is that I filled the cavities more thoroughly.

But I'm not sure that reason will be accepted by the person who penned the original question posed in this thread:

Filling the small channels with insulation, WHY?

The phrase, followed by 'WHY' in capital letters appears to indicate a predisposition. Not so much an open mind.

All the best,
Hein

 

[Travlin]

You are consistent. I'll give you that. You consistently attempt to move the focus away from the topic at hand by discrediting the source. Attacking the messenger really isn't the most effective method for working out an answer to a query regarding the physical world. For matters involving ego and emotion and even politics this isn't an unusual tactic, most often employed as a last resort. Sticks and stones ...

Filling those cavities with an insulator is unlikely to prevent the transfer of heat around the insulator, nor prevent the heat from going elsewhere without doing something else with that energy. Energy that is naturally drawn from the hot to the cold through the materials present that conduct it. Drawn through the metal at a rate 2000 times greater than it is through the air. Drawn through the air if no faster means is available. The laws of thermodynamics are, to date, immutable. You have not denied this.

Heat can be blocked by an insulator placed between the heat source and the cold, but we know this doesn't apply in this case as the metal extends beyond the insulator toward the cold panel. This is shown clearly in the photo of the dark van. Enough heat made it to the outside of that van to raise the temperature of the panel higher than the dew point.

Even if there is adhesive or air space between the metal tabs that attach the other side of that channel to the panel on the outside, the heat will move toward that cold. It will move through the air and/or the adhesive after briskly passing around anything placed in that cavity. You have not denied this.

I'm quite open to hearing anyone's theory that explains what happens to that energy any better than the photos of the dark van clearly do. It really would not make any difference how thoroughly anyone filled the cavity when the insulation is not placed between the heat source (the metal channel) and the cold, which by nature attracts the heat to that panel in the photo preventing condensation at that point. You have not denied this.

The kind of things that could take that heat elsewhere might be high volumes of cooler moving air, water, or other fluid that the heat transfers to from the metal and is then carried away. But there is nothing to suggest that Thinsulate has any properties as a carrier of heat, or as a heat sink. Quite the opposite. In fact, that is its selling point, isn't it? So this is not a reasonable theory to pursue. I have stated that the only way to prevent heat loss is to place a barrier between the source and the cold. You have not denied this.

Energy can neither be created nor destroyed, only transmuted. You have not denied this.

Despite the absence of any such statement from you, your replies give every appearance of denial. It just isn't clear what it is exactly that you are denying.

Let's make the question "how?" instead of "why?" if that suits you.

How, in any physical sense, would placing Thinsulate inside (beside, in all actuality) a heat sink between the interior and exterior in any way prevent that heat from moving toward the cold, just as the photo of the dark van shows it has done?

 

[Metacenter]

Been lurking for a while, but this discussion finally brought me out of the woodwork.

What seems to be missing here is the big picture. Sure steel is far more conductive than still air by a factor of 2000 or so, but the typical void or channel has steel walls only a fraction of an inch thick sticking into the van separated by several inches of air. I bet that the ratio of air to steel in many channels is well into and even well above the 100 range. This drops the theoretical ratio down to 20 or less. The argument that "steel is a better conductor than air so why insulate" starts to make sense when there is a lot of steel vs the amount of air, say steel spaced every 1/4" or so, but that is starting to look like a radiator not a van interior. Wonder why radiators are built that way.

But wait there is more and it's called convection. Convection loops are very good at moving heat from hot to cold and a lot of those channels will do a fine job of supporting convection. Basically the cold air against the skin sinks and the warmer air near the interior will rise until it gets to the top where the sinking air pulls it against the skin, sucking out its heat until it starts to fall. The reverse goes on at the bottom. Stuffing insulation of any kind in the gap will pretty much stop this. One almost comparable data point is that you can double or triple the R value of a cinder block wall by filling the interior voids with pearlite. That might be a bit messy in a van, but thinsulate, old newspapers, spray foam, dirty kleenex or shredded blue jeans will stop the circulation. Some better than others. Some of these have drawbacks.

When my domestic purchasing agent approves the van purchase, I will fill the voids. I will also cover the interior steel with some insulation if it gets to be a big problem.

Finally, thanks for the great forum. It has been very informative.

Leonard

 

[ranchero]

You know: two beers, one missed football game on TV and $50 or less of Thinsulate to fill cavities and it is done. Most of us waste far more time and money on other trivial things. As a recovering research economist I appreciate mental masturbation as much as anyone, but really, what is lost by just going ahead and insulating the cavities?

 

[JP4]

Well, I insulated my roof with Thinsulate. I pulled it through all the ribs except for one. My van is dark grey and it regularly gets up near 100f here in the summer. I can put my hand on the ribs that have the Thinsulate and it's warm but not uncomfortable. The rib without it is unbearably hot.
Sure, covering the whole ceiling with insulation would probably be more effective, but there is without a doubt some thermal benefit to stuffing those ribs on the roof, at least under the blazing sun.
JP

Sent from my Nexus 6P using Tapatalk

 

[surfvan]

One more quick comment, I'd like to point out that photo that has been shown a few times, of the Faroutvan, if you read the text with that photo, it states that at the time of the photo, there was no insulation in the channels. If you then check out the photos of the young lady filling the channels, you'll see one that has been done and the thinsulate is a small piece floating freely in the channel, nowhere near what I would think adequate for proper insulation. My point here, is that the photograph being used as the evidence is very much flawed. That is not to say that the poster is wrong, obviously thermal bridging is real, but I'd still like to see a photo with the channels stuffed full.

 

[Michael Ophus]

@Michael Ophus - that was a brave reveal of your true self. Thank you for that. Hopefully, others here will better understand some of the comments you make. And may or may not give you some slack.

RE: AC and you may not have been referring to me - I did not complain about inability to keep a huge uninsulated van cool. I complained that the temperature of the air coming out of the vent was warm (like 55 deg on a 70 deg day). It's now December, I have no longer have complaints about the AC.

no it is not you, it is many of the people who populate the AC complaint threads all summer long.

the lack of good insulation practices is a biggest part of it, the transit AC system is deigned to save fuel so it does not work like your old AC did! but i am not going to try to explain that now/again.

 

[Michael Ophus]

I've been following this whole debate, and since I'm about to put in the insulation, I've been wondering why no one mentions that nearly the entire inner structure of the van is separated by about a quarter inch of foam glue which breaks the thermal bridge that is at the core of this discussion. Be civil now, I'm just asking.

this is just my opinion: that foam was not put there as an thermal break only, that foam was also put there because the van skin needs to be able to expand and contract in the heat and cold, so it also acts as a pad the keep the frame work from eventually wearing holes in the skin. (you could also wonder if this was the only reason it was put there)

2 years ago when nobody knew anything about the transit there was a forum member who thought that foam was a low grade glue, so he scraped it all off and replaced it with epoxy, we never did hear back from him how that worked...

 

[Travlin]

You know: two beers, one missed football game on TV and $50 or less of Thinsulate to fill cavities and it is done. Most of us waste far more time and money on other trivial things. As a recovering research economist I appreciate mental masturbation as much as anyone, but really, what is lost by just going ahead and insulating the cavities?

In a post yesterday in another thread Hein quoted the costs of insulating with and without filling the voids using SM600L to a forum member. As I recall, the difference Hein came up with was around $100 saved in Thinsulate costs alone by not filling those voids. That post he made yesterday has since been edited, or, I simply couldn't find it today.

That is a lot of beer and bacon money to me. Especially when I can achieve greater effect with less effort by covering the structural metal with a polyiso layer behind the paneling for about that same cost and provide an additional R-5 or greater to the build.

For example, using SM600L with R-5.2 (?) on every surface except inside the channels, and adding a sheet of 3/4 polyiso at R-5 behind the paneling, the result is in the neighborhood of an R-10 wall without the voids filled for the same cost as an R-5.2 wall with the voids filled.

Win-win.

 

[Travlin]

Well, I insulated my roof with Thinsulate. I pulled it through all the ribs except for one. My van is dark grey and it regularly gets up near 100f here in the summer. I can put my hand on the ribs that have the Thinsulate and it's warm but not uncomfortable. The rib without it is unbearably hot.
Sure, covering the whole ceiling with insulation would probably be more effective, but there is without a doubt some thermal benefit to stuffing those ribs on the roof, at least under the blazing sun.
JP

Thanks. This is exactly the sort of feedback I had wanted from the get-go in this thread.

I'd be interested in such a scenario to cover the unfilled rib with automotive felt or something similar, let it bake for a while and see what that feels like in comparison to the filled channels.

Asking someone to do this with a layer of CS150 over the rib would be too much if they don't have it on hand, though if there were a willing participant I'd be happy to mail a piece to use for comparison testing. Even better if the tester has one of those nifty laser guided temperature guns.

 

[Eiko]

Even better if the tester has one of those nifty laser guided temperature guns.

In this thread I'm feeling the need to start with a disclaimer "I'm not an engineer nor have skills resembling one". Remember that the temperature guns measure a small part of the IR spectrum and process that into a number. Other parts of the IR range and the EM spectrum contribute to heat. So a temp gun may not be reliable for your purpose.

A FLIR camera might be better although I don't know how much of a range of the IR they're capturing either. But they're cheap! I didn't see the price but $200 for the basic model: http://www.flir.com/flirone/android/ After this project, use it plug up heat loss in your house.

 

[Travlin]

Been lurking for a while, but this discussion finally brought me out of the woodwork.

What seems to be missing here is the big picture. Sure steel is far more conductive than still air by a factor of 2000 or so, but the typical void or channel has steel walls only a fraction of an inch thick sticking into the van separated by several inches of air. I bet that the ratio of air to steel in many channels is well into and even well above the 100 range. This drops the theoretical ratio down to 20 or less. The argument that "steel is a better conductor than air so why insulate" starts to make sense when there is a lot of steel vs the amount of air, say steel spaced every 1/4" or so, but that is starting to look like a radiator not a van interior. Wonder why radiators are built that way.

But wait there is more and it's called convection. Convection loops are very good at moving heat from hot to cold and a lot of those channels will do a fine job of supporting convection. Basically the cold air against the skin sinks and the warmer air near the interior will rise until it gets to the top where the sinking air pulls it against the skin, sucking out its heat until it starts to fall. The reverse goes on at the bottom. Stuffing insulation of any kind in the gap will pretty much stop this. One almost comparable data point is that you can double or triple the R value of a cinder block wall by filling the interior voids with pearlite. That might be a bit messy in a van, but thinsulate, old newspapers, spray foam, dirty kleenex or shredded blue jeans will stop the circulation. Some better than others. Some of these have drawbacks.

When my domestic purchasing agent approves the van purchase, I will fill the voids. I will also cover the interior steel with some insulation if it gets to be a big problem.

Finally, thanks for the great forum. It has been very informative.

Leonard

I'm not certain I understood some of that first paragraph. The steel is a heat sink. Air is circulating like you say, and where air contacts the steel, if there is a difference in temperature, that energy will migrate from the hotter of the two to the cooler of the two at that point of contact.

We are only dealing with the air that is in contact with the steel at any given moment, rather than the entire volume of air. Reducing steel's thermal conductivity to 20% with that math might need to be reconsidered with this in mind. The energy transfer happens at a molecular level at that point where the air meets the steel. The ratio of contact is 1 to 1. The conductivity doesn't change simply because there is more air volume. Heat energy in air will conduct through to other air molecules (hotter to colder) at a rate that is 0.06% as efficient as the steel's conductance of the same heat energy.

The convection aspect is true enough and should be addressed in the build. In my description it would be dealt with by covering the hole in the channel where the heat in the channel air would contact the air in the living space. By placing a thermal (and acoustic) barrier between the two. This blocks the flow of convective air currents in the channel from leaving the channel.

This is pretty much standard building practice. Tried and true. Place a barrier between the zones you want to separate. This is the standard because it is easier, just as cost effective if not more so, requires less effort, and leaves little to guesswork.

Sure, you can fill the entire cavity to reduce or prevent convective airflow, but if closing the holes at the ends and along the length of the column does the same job, and, is easier to do, what advantage would be gained by filling?

Thanks for offering some good points for consideration.

 

[Travlin]

One more quick comment, I'd like to point out that photo that has been shown a few times, of the Faroutvan, if you read the text with that photo, it states that at the time of the photo, there was no insulation in the channels. If you then check out the photos of the young lady filling the channels, you'll see one that has been done and the thinsulate is a small piece floating freely in the channel, nowhere near what I would think adequate for proper insulation. My point here, is that the photograph being used as the evidence is very much flawed. That is not to say that the poster is wrong, obviously thermal bridging is real, but I'd still like to see a photo with the channels stuffed full.

Scrolling up on that page I see the photo is captioned "We filled the van cavities where possible." I have no further data to determine to what degree the job was performed. I don't think it will make much difference whether a little or a lot was used. This isolation from the thermal bridge can be better accomplished with less effort by doing what they eventually chose to do after finding that filling had not accomplished the goal.

I quote: "To minimize the thermal bridges, we will apply Low-E EZ-Cool to the “bare” frames (the wood finish will helps as well). The EZ-Cool is a closed-cell foam sandwiched between two aluminum sheets."

I take this reference to "bare frames" to mean those metal structural frames that were still exposed to the living space air. These bare frames (filled, but uncovered) are thermal bridges conducting heat from the interior to the exterior as shown in the photo.

This information, along with what you have stated, all add up to two choices.

1. You can fill the cavities to overflowing AND then cover the exposed metal to block the thermal bridge, or,
2. You can just block the thermal bridge and be done.

Builder's choice. Same result.

 

[Hein]

1. You can fill the cavities to overflowing AND then cover the exposed metal to block the thermal bridge, or,
2. You can just block the thermal bridge and be done.

Builder's choice. Same result.

That summary is incorrect and doesn't address the loss in acoustic performance. Filling the enclosed areas is what you want to do. There is no doubt about it.

But it is very clear that Travlin will never be convinced of that. That's fine. To each his own. Thank you for raising awareness to the awesome performance of the Thinsulate(TM) and encouraging us to increase our offerings with the TAI1547.

All the best,
Hein
DIYvan.com

 

[Travlin]

That summary is incorrect and doesn't address the loss in acoustic performance. Filling the enclosed areas is what you want to do. There is no doubt about it.

Well, actually, we're 8 pages into a thread because there is doubt about it.

If you feel this would still leave a discernible level of acoustic performance loss I'd be interested to hear more about how you have determined this beyond use of the generalized "salesman speak" terms you employ. Perhaps an estimate referenced to percent, db, or other measurement might give us some idea of just how much performance loss you feel may be expected overall.

The fantastic acoustic reduction achieved by installation of Thinsulate CS150, R-Max Polyiso and 1/4" paneling, without filling those channels, is documented in my build thread with db measurements taken before and after.

Considering the comparably small surface area involved, against the large surface area covered by Thinsulate, I suspect any such loss would not be easily measured.

Whatever small amount of overall "acoustic performance loss" remains by leaving those voids unfilled will be mitigated by installation of the materials I have suggested for covering those channels to address the thermal bridge issue. Which will need to be done anyway whether the channels are filled or not.

 

[surfvan]

About thermal bridge:

This photo was taken during the conversion without ez-cool installed; it means all the frames inside the van had no insulation on them:

ford-transit-camper-van-thinsulate-installation-19

It was a cold and damp morning (37F) and we were heating the van with the Webasto heater (55F). Note that there was condensation everywhere outside (on the van, on the ground, etc).

We observe that condensation remains where Thinsulate is installed, but this condensation is “evaporated” at the frame locations where there is no Thinsulate. This is because the frames are forming a thermal bridge for the heat to be conducted from the inside to the outside of the vehicle, thus providing enough heat for the water to evaporate. In other words, there is heat loss where there is no condensation.

This is the quote I'm referring to about the photo that is being used to illustrate the use of thinsulate in the channels. Read the entire text.

 

[Travlin]

Thank you for raising awareness to the awesome performance of the Thinsulate(TM) and encouraging us to increase our offerings with the TAI1547.

All the best,
Hein
DIYvan.com

You are quite welcome. I think this addition to your offerings is a win for folks to have more choices to meet the wide variety of designs builders come up with. It was my pleasure to be a part of that change.

Sincerely.

 

[Travlin]

About thermal bridge:

This photo was taken during the conversion without ez-cool installed; it means all the frames inside the van had no insulation on them:

ford-transit-camper-van-thinsulate-installation-19

It was a cold and damp morning (37F) and we were heating the van with the Webasto heater (55F). Note that there was condensation everywhere outside (on the van, on the ground, etc).

We observe that condensation remains where Thinsulate is installed, but this condensation is “evaporated” at the frame locations where there is no Thinsulate. This is because the frames are forming a thermal bridge for the heat to be conducted from the inside to the outside of the vehicle, thus providing enough heat for the water to evaporate. In other words, there is heat loss where there is no condensation.

This is the quote I'm referring to about the photo that is being used to illustrate the use of thinsulate in the channels. Read the entire text.

Yes, that is what I understood as well. The way they addressed the thermal bridge problem was to put EZ-Cool on those exposed metal structures.

To be clear, it isn't that the heat evaporated the condensation on those places, it is that the temperature of those parts of the panels were not cold enough to condense water vapor from the air. Their temperature was above the Dew Point. The places where there is condensation were at or below the Dew Point, so water formed on the panel.

Farther up on that page is where they were installing the Thinsulate and made the comment, along with a photo, regarding filling the voids with that product.

Either we are in agreement or I am not understanding the point being made.

 

[orton]

I think the result of this discussion is Hein would fill the ribs and Travlin would not. Next question?

It is interesting that the discussion is mainly about the use of Thinsulate and rigid polyiso. I was in Anchor Brewing one day and saw the insulation contractor using closed cell foam to insulate the beer tanks and piping. Looked like easy to install insulation to use in a van. Bought 1" and 1/2" Aerocel to insulate my van. I also used polyiso for the window indents and the flat portion of the high roof van. Used closed cell on the sloped roof, above the cab and in the deep compartments above and below the window indents. Believe the closed cell R value is slightly lower than the rigid polyiso and higher than Thinsulate. Since I have Tinnitus the noise reduction was not as important as the insulation value. Do not know the noise reduction value of the closed cell but suspect it is adequate. Do know the closed cell was easy to install as is Thinsulate.