Below Slab Insulation Comparison (ME)

[Deleted User] · December 2005

Help yourself Jerry!

Best bet is to use spread sheet labled Data loogers 1-4.

Merry Christmas and Happy Holidays.

ME

[Deleted User] · December 2005

Take 2....

Heres a screen shot of some data. Looks to be relatively stable, and no one coloring outside the lines:-)

I'll generate some more data tomorrow. Going out to celebrate the season with friends and family.

ME

[Deleted User] · December 2005

Additional graphics...

It boils down to this. The less dead air you have, the less resistance you have. The thicker the insulation, regardless of makeup, the higher the resistance to the flow of heat. That pretty much echos what we've been saying all along.

I looked at the heat flow in two different frames. One from the slab into the earth with the system running, and one from the earth into the slab with the system off. Your analysis is as good as mine.

It would appear that those insulations with metal components have a lower resistance to heat transmission "emmiting" from the earth back to the slab, but thats just my take.

Spend money wisely...

Merry Christmas and Happy Holidays!

Questions gladly taken.

ME

Cosmo_3 · December 2005

Thanks Mark

Now with all the sensors working we seem to reinforce all of our earlier suspicions. Thanks for your hard work, and this generous donation towards our education. Merry Christmas!

Cosmo Valavanis

Dependable P.H.C. Inc.

jerry scharf_3 · December 2005

can you produce a different cut

Mark,

Could you cut a differnt graph for me?

I would like to see the below ground differential from the start of the run to each 8 hour interval as a stacked set of bar charts for each insulation. The reason I am intersted in this is it looks like a steady increase for each sample and should have some direct correlation to the energy lost to the earth. The top side is more prone to microclimate variations.

If you are too busy to get to this, I would be happy to produce it given a copy of the data.

thanks,
jerry

Weezbo · December 2005

NICE *~/:)

This one wont get lost in the system thanks to Mike

this is so over the top Mark:) mana this experiment puts to shame my offer at the wholesalers before they opened their doors. i offered to put three slabs with expansion joints and two with different insulation and one without to let the guys get the drift of snow/icemelt every day on the run by the supply house. sheesh

now i am glad that i didnt ....this lash up of yours would have made it seem absolutely Pathetic

)

Mike T., Swampeast MO · December 2005

Thank you Mark for your time and effort!

The Insultarp continues to be unusual...

The greater the temperature differential on the sides, the greater the insulation value [seems] to be.

Can it be blocking radiation in what we consider to be a conductive environment? Could this be related to my anomolies where my measured temperature is only equal to radiant burner boiler temperature when such temps are nearly perfectly suited to the heat loss at the moment?

[Deleted User] · December 2005

Good questions...

All of them. And to be honest, my experience is limited to the XPS, but I will be interviewing other installers of other products and producing a comparison chart showing costs, and benefits of all sampled.

I do know from personal experience, that I can (have) insulated 3,000 square feet of snowmelt by myself in less than 3 hours.

As for the insultarp, your guess is as good as mine, or even the next guys. Maybe there is something to reflective surfaces when encompassed between other dead air.

ME

Cosmo_3 · December 2005

My problem

Has always been the uneven grading every stinkin builder leaves me with. Next one I figure on renting a tamper, and going over the gravel, adding gravel here and there to get it level. I just wonder what to expect as far as time. I have one builder that did this anyway, because he knew that it was just good building practice. Every other guy (builder) just wants to limit having to hire labor to do this and just don't bother tamping/leveling the stone.

Arrgh!

Cosmo Valavanis

Dependable P.H.C. Inc.

[Deleted User] · December 2005

More graphics...

The interesting thing about graphs and charts is that they present things in different points of view.

Attached are bar charts and line graphs of the Above insulation temperatures as well as Below insulation temperatures.

Taken for face value in the bar charts, it would appear the BFB has the lowest soil temperature, which to me would indicate the highest R value to back loss. Insultarp is right there as well. However, when you don't look at the averages, and you look at the real time line charts, XPS has a better profile.

On the other hand, it could be interepreted that the BFB, and insultarp were such good conductors of heat that their back losses prior to system start caused them to be much lower on average, and slower to heat up, hence less R Value.

Must be a million ways to look at this stuff, and makes some look better than others.

Proceed with caution and an open mind!

Enjoy!

ME

Unknown · December 2005

well, maybe I'm missing something here.. but why would the temps above the insulation be so different between methods?

Is this an automatically controlled (slab sensed) system modulating temperatures, or is each slab running at a setpoint water temperature?

This Bar graph does not seem to reflect the other graph you posted. The barrier is showing an average temp that it never got down to during the storm in the first graph? The time plot shows it over 40 degrees below the insulation the entire time except the very beginning. Either I'm missing something or I suspect a user/program error here in graph making

[Deleted User] · December 2005

Back loss...

All samples are in the core of the diveways center. All are within a few feet of each other, 4 square foot per sample, 6 samples = 24 feet from beginning to end of test array sample.

System is on a tekmar 600 series control.

For all intents and purposes, the samples are not seeing that big of a different tube temperature from beginning of tube circuits to the end of the test bed.

These particular tube circuits are run in parallel from the top of the hil to the bottom. No zig zag patterns, just 13 tubes, 9" OC, parallel, straight up the pike...

I don't think its a maker error, just thermal values averaged over time with no smoothing. You too have access to the raw data if you care to play with the numbers yourself. Feel free.:-)

ME

jerry scharf_3 · December 2005

my graph from ME's data

Mark,

Your generosity with the data as well as the energy invested to collect this data is greatly appreciated.

I took a slice at your data and came up with something that gave me a pretty good sense of what is going on. I thought that if I looked at the difference in temperature below the insulation from the start of the run to now. I make the assumption that the earth's R value is consistent and the neighbors are less important than the common loss to the uninsulated side.

The graphs in general look like what I would expect. If I assume that the XPS is the reference, it shows both the lower temperature and the lag in temperature change against lower value insulations. The big surprise for me was the poor performace of the fanfold EPS. It's one of the poorest performers by this measure.

jerry

[Deleted User] · December 2005

The fan fold...

is EPS, and may have broken up during the pour...

It's also one of the thinnest at 1/2" thick.

See, size (thickness) DOES matter:-)

Thanks Jer

PS, could you also add that last graphic as an excel spreadsheet attachment?

THanks!

ME

ME

jerry scharf_3 · December 2005

here you go

Mark,

I am no excel wizard. I created a new sheet at the end with the graph and the calcs on it. I'm attaching the whole thing.

jerry

Below Slab Insulation Comparison (ME)

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