Closed Cell Foam for Mash Tun Insulation

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ParanoidAndroid

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The majority of people here seem to use the Reflectix wrap for their mash tun insulation (me included). Since we are only trying to keep a liquid at ~155 degrees for 60 minutes or so, a few wraps with that stuff seems to do the job with just a couple degrees of drop. So, if this works for you (or if you use a sleeping bag), then no need to continue as this post is definitely overkill. But I find this stuff interesting, so I'd like to discuss/learn/investigate it more.



Heat transfer can be categorized in 3 ways: Radiant, Conductive, and Convective. Radiant heat is heat transfer across a space by non-contact. Conductive heat is transferred through materials. Convective heat is the transfer of heat through the movement of air.

The Reflectix wrap is designed for radiant heat, and therefore requires an air gap in between the MT and the insulation to perform the way it was intended. Most people don't do this and just wrap it tight with tape or velcro. What we should be focusing on is conductive heat.

In looking at various insulation I came across Closed Cell Elastomeric Foam. This is the material that some pipes are wrapped in (the long black wrap with a slit in them) and some form of it is readily available at Home Depot or Lowes. Obviously you cant wrap that around your MT so sheets are needed and these aren't available through retail. I did find some various brands online though. There are different materials used in the making of these which include:

-Neoprene
-ECH (Epichlorohydrin)
-EDPM (Ethylene Propylen Dien Monomer)
-Latex/Natural Rubber
-NBR Based (Buta-N or Nitrile)
-PVC
-SBR (Styrene Butadiene Rubber)
-Vinyl Nitrile

Like everything else, each has its strengths and weaknesses. They all seem to have about the same k-factor of 0.25 Btu in/fl² hr °F @ 75 Deg F. Some a little higher, and some a little lower. The k-factor of a material is the thermal conductivity, or the measure of a material's ability to transfer heat. Its related to the more popular R-value by taking the thickness of the material and dividing by k, for flat insulation. For tubular insulation its a different formula where an Equivalent Thickness is used comprising of an inner and outer diameter. I'm not sure how our "closed cylindrical vessel" or "semi-closed rigid tank" R-Value would be calculated, so Ill just go with the flat roll calculations, even though its likely wrong.

These sheets come in thicknesses of anywhere from 1/16 inch to 2+ inches. So a 1 inch sheet would have an R-value of about 4, while a 3/4 inch sheet would have an R-value of about 3.

Reflectix claims to have an R-Value of 6.1. Considering R-Value is based on Conductive heat and not Radiant, this is bogus. There is a message board discussion from a couple of years ago that went into detail about this. The conclusion was that, when installed with the correct air gap (0.75 inches or so) between the Reflectix and the material, the Reflectix provides an R-Value of about 1. Each additional wrap would supply another value of 1. If its right up against the material, then I'm sure the R-Value drops significantly.

In going back to the Closed Cell Foam, I was looking for the following:

-Flexibility
-Not extremely soft
->210 deg F handling
-Non-Toxic
-Microbial agent incorporated since this comes in contact with wort
-Water resistant
-Good price to performance ratio
-Available with non-PSA side (or non adhesive on both sides)

Some brands I found online were:

K-Flex Insul-sheet
-K-Factor of 0.245 @ 75 deg F
-Operating Temperature of -297 to +220
-0% Water Absorption
-2 sided plain face available
-Excellent Flexibility
-$44 for 3' x 4' x 1" sheet

Armacell Armaflex
-K-Factor of 0.25 @ 75 deg F
-Operating Temperature of -297 to +180 (I think they make a higher temp version, but was unable to price it)
-$72 for 3' x 4' x 3/4" sheet

Nomaco Flextherm Sheet
-K-Factor of 0.245 @ 75 deg F
-Operating Temperature of -70 to +200
-0% Water Absorption
-Didn't Price

Nomaco Thermacell Sheet (Polyolefin material)
-K-Factor of 0.25 @ 75 deg F
-Operating Temperature of -330 to +210
-Water Vapor Permeability of 0.0 Perm-Inch
-Didn't Price

Aeroflex (EPDM Material)
-K-Factor of 0.245 @ 75 deg F
-Operating Temperature of -70 to +257 deg F
-Water Vapor Permeability of 0.03 Perm-Inch
-Water Absorption of 5%
-$20 for a 3' x 4' x 1" sheet from local supplier

This is a quick list and there are more out there. I'm picking up a sheet of the Aeroflex today. It has a little higher max temperature, but has a slight water absorption. Its cheap, comparatively speaking, and is available now from a local guy. Ill report on results next time I brew.

Does anyone else have any experience with this type of insulation? The instances where this is discussed in a homebrew application are few and far between and/or old.
 
I plan to make a neoprene sleeve to insulate my stainless steel mash tun after I get my RIMS tube
 
WrQth said:
I plan to make a neoprene sleeve to insulate my stainless steel mash tun after I get my RIMS tube
Click to expand...

From what I can tell, Neoprene and EPDM have about the same k-factor. However, EPDM has a higher max temp (180 vs 220+ ) and is cheaper. Plus neoprene is incredibly soft.
 
I do mechanical insulation for a living and use all mentioned materials, though usually on cold systems. Armaflex sheet is awesome stuff, but will become hard and brittle over a fairly short period of time being exposed to temps above the temp rating. It meets most your requirements, more then the others, except that it is soft. It is however zero perm, anti microbial, very flexible and stretchy and non adhesive. The biggest down side the adhesive used to adhere it is kind of nasty stuff, it is called 520 adhesive if you want to look it up.
 
nettekdl said:
I do mechanical insulation for a living...
Click to expand...

Small world, me too. Great response and I would add that I usually don't recommend closed cell insulation on anything over 180 degrees because it will eventually get hard and brittle. I've done work for several commercial breweries and closed cell insulation was only used on glycol systems and cold water lines. I would not recommend it for a direct fired mash tun.
All that being said, my cooler mash tun has a nice layer of 1" Armaflex on it.
 
Picker said:
Small world, me too. Great response and I would add that I usually don't recommend closed cell insulation on anything over 180 degrees because it will eventually get hard and brittle. I've done work for several commercial breweries and closed cell insulation was only used on glycol systems and cold water lines. I would not recommend it for a direct fired mash tun.
All that being said, my cooler mash tun has a nice layer of 1" Armaflex on it.
Click to expand...

Nice to have a couple people with real world experience.

My mash tun isn't direct fired. Im BIAB, but still wanted the highest temp rating possible within that category.

I ended up with 3/4 inch aeroflex. He had armaflex and they felt the same.
 
ParanoidAndroid said:
The majority of people here seem to use the Reflectix wrap for their mash tun insulation (me included). Since we are only trying to keep a liquid at ~155 degrees for 60 minutes or so, a few wraps with that stuff seems to do the job with just a couple degrees of drop. So, if this works for you (or if you use a sleeping bag), then no need to continue as this post is definitely overkill. But I find this stuff interesting, so I'd like to discuss/learn/investigate it more.



Heat transfer can be categorized in 3 ways: Radiant, Conductive, and Convective. Radiant heat is heat transfer across a space by non-contact. Conductive heat is transferred through materials. Convective heat is the transfer of heat through the movement of air.

The Reflectix wrap is designed for radiant heat, and therefore requires an air gap in between the MT and the insulation to perform the way it was intended. Most people don't do this and just wrap it tight with tape or velcro. What we should be focusing on is conductive heat.

In looking at various insulation I came across Closed Cell Elastomeric Foam. This is the material that some pipes are wrapped in (the long black wrap with a slit in them) and some form of it is readily available at Home Depot or Lowes. Obviously you cant wrap that around your MT so sheets are needed and these aren't available through retail. I did find some various brands online though. There are different materials used in the making of these which include:

-Neoprene
-ECH (Epichlorohydrin)
-EDPM (Ethylene Propylen Dien Monomer)
-Latex/Natural Rubber
-NBR Based (Buta-N or Nitrile)
-PVC
-SBR (Styrene Butadiene Rubber)
-Vinyl Nitrile

Like everything else, each has its strengths and weaknesses. They all seem to have about the same k-factor of 0.25 Btu in/fl² hr °F @ 75 Deg F. Some a little higher, and some a little lower. The k-factor of a material is the thermal conductivity, or the measure of a material's ability to transfer heat. Its related to the more popular R-value by taking the thickness of the material and dividing by k, for flat insulation. For tubular insulation its a different formula where an Equivalent Thickness is used comprising of an inner and outer diameter. I'm not sure how our "closed cylindrical vessel" or "semi-closed rigid tank" R-Value would be calculated, so Ill just go with the flat roll calculations, even though its likely wrong.

These sheets come in thicknesses of anywhere from 1/16 inch to 2+ inches. So a 1 inch sheet would have an R-value of about 4, while a 3/4 inch sheet would have an R-value of about 3.

Reflectix claims to have an R-Value of 6.1. Considering R-Value is based on Conductive heat and not Radiant, this is bogus. There is a message board discussion from a couple of years ago that went into detail about this. The conclusion was that, when installed with the correct air gap (0.75 inches or so) between the Reflectix and the material, the Reflectix provides an R-Value of about 1. Each additional wrap would supply another value of 1. If its right up against the material, then I'm sure the R-Value drops significantly.

In going back to the Closed Cell Foam, I was looking for the following:

-Flexibility
-Not extremely soft
->210 deg F handling
-Non-Toxic
-Microbial agent incorporated since this comes in contact with wort
-Water resistant
-Good price to performance ratio
-Available with non-PSA side (or non adhesive on both sides)

Some brands I found online were:

K-Flex Insul-sheet
-K-Factor of 0.245 @ 75 deg F
-Operating Temperature of -297 to +220
-0% Water Absorption
-2 sided plain face available
-Excellent Flexibility
-$44 for 3' x 4' x 1" sheet

Armacell Armaflex
-K-Factor of 0.25 @ 75 deg F
-Operating Temperature of -297 to +180 (I think they make a higher temp version, but was unable to price it)
-$72 for 3' x 4' x 3/4" sheet

Nomaco Flextherm Sheet
-K-Factor of 0.245 @ 75 deg F
-Operating Temperature of -70 to +200
-0% Water Absorption
-Didn't Price

Nomaco Thermacell Sheet (Polyolefin material)
-K-Factor of 0.25 @ 75 deg F
-Operating Temperature of -330 to +210
-Water Vapor Permeability of 0.0 Perm-Inch
-Didn't Price

Aeroflex (EPDM Material)
-K-Factor of 0.245 @ 75 deg F
-Operating Temperature of -70 to +257 deg F
-Water Vapor Permeability of 0.03 Perm-Inch
-Water Absorption of 5%
-$20 for a 3' x 4' x 1" sheet from local supplier

This is a quick list and there are more out there. I'm picking up a sheet of the Aeroflex today. It has a little higher max temperature, but has a slight water absorption. Its cheap, comparatively speaking, and is available now from a local guy. Ill report on results next time I brew.

Does anyone else have any experience with this type of insulation? The instances where this is discussed in a homebrew application are few and far between and/or old.
Click to expand...
Thanks for this information. I've been thinking about making a foam cozy for my BIAB kettle to get away from the towels and winter jacket I use for insulation now. Sounds like Aeroflex is a good candidate for both temp resistance and cost effectiveness.

I am planning to make a three layer cozy from either 1/4" or 3/8" sheet material. By gluing the layers together while they are wrapped around the kettle, cozy will hold its cylindrical shape and be easier to keep wrapped around the kettle. The offset ends will also provide significant insulation of the gaps.

3 Layer MLT Insulation.jpg

Brew on :mug:
 
doug293cz said:
Thanks for this information. I've been thinking about making a foam cozy for my BIAB kettle to get away from the towels and winter jacket I use for insulation now. Sounds like Aeroflex is a good candidate for both temp resistance and cost effectiveness.

I am planning to make a three layer cozy from either 1/4" or 3/8" sheet material. By gluing the layers together while they are wrapped around the kettle, cozy will hold its cylindrical shape and be easier to keep wrapped around the kettle. The offset ends will also provide significant insulation of the gaps.

View attachment 340424

Brew on :mug:
Click to expand...

Looks good, but not sure if the staggering is necessary. The gap shouldn't let too much heat out since we are only looking at an hour. Now, if this was some piping that was insulated permanently, then id see the advantage of closing the gaps. Just try one sheet to see how it works, and it might save some you some time.
 
I use EPDM every day to insulate refrigeration lines (new code) but have never seen sheets of the Aeroflex at Johnstones. Do you have any links to supply houses or wholesalers? I came up blank.
 
Firewalker11 said:
I use EPDM every day to insulate refrigeration lines (new code) but have never seen sheets of the Aeroflex at Johnstones. Do you have any links to supply houses or wholesalers? I came up blank.
Click to expand...

http://www.aeroflexusa.net/purchase/

I called up the corporate office and asked if they could ship it to me bc there wasn't one nearby. They got me in touch with a local guy who wasn't listed.
 
They have sheets of closed cell but not Areoflex. A 1" sheet (4x3) can set you back $50 or more.
 
I use reflectix now, but originally I used armaflex. It didnt do as well as a job as the armaflex, especially in the winter. Granted this could have been from only using a single layer. I'd be interested in seeing how it performs with several layers. The only downfall is that it is about 1/2" thick.
 
Firewalker11 said:
They have sheets of closed cell but not Areoflex. A 1" sheet (4x3) can set you back $50 or more.
Click to expand...

That seems to be the going rate online for 1" from what I can tell.

This stuff comes in large rolls. These companies are making more by cutting it into individual sheets and selling singles. It looks like the cheapest route is going to be finding a local supplier, or HVAC company, who buys it in bulk, then get them to cut you whatever you need.
 
doug293cz said:
Thanks for this information. I've been thinking about making a foam cozy for my BIAB kettle to get away from the towels and winter jacket I use for insulation now. Sounds like Aeroflex is a good candidate for both temp resistance and cost effectiveness.
Click to expand...

I did the staggering technique with several layers Reflectix, it does hold shape nicely, but it doesn't hold temperature as well as I'd hoped.

If you're interested, swing by Tacoma some time and we can brew a batch.

-B
 
An update......

I was finally was able to brew with this stuff. I have a 1 year old now, so brewing is more rare than it used to be.

I use a 6 gallon stainless steel pot for 2-3.25 gallon batches. I did a 2.25 gallon batch yesterday and lost 0.5 degrees over the course of the mash. I went from 155 to 154.5.

I only mashed in 2.75 gallons of water (BIAB). I cold brewed some chocolate malts and gathered about 0.4 gallons of wort from that. It went in towards the end of the boil. So there was a decent amount of headspace in the tun.

Due to slight variations in different areas in the mash tun, and the precise measurements of my Thermapen, you could make a case that my temp stayed the same.

My cutout for the lid wasn't as nice as I wanted it to be. It was a rush job and had about 1/2 inch all the way around that wasn't covered.

I'm pleased.
 
nettekdl said:
I do mechanical insulation for a living and use all mentioned materials, though usually on cold systems. Armaflex sheet is awesome stuff, but will become hard and brittle over a fairly short period of time being exposed to temps above the temp rating. It meets most your requirements, more then the others, except that it is soft. It is however zero perm, anti microbial, very flexible and stretchy and non adhesive. The biggest down side the adhesive used to adhere it is kind of nasty stuff, it is called 520 adhesive if you want to look it up.
Click to expand...


How does K-Flex hold up to mash and HLT temps?
 
Islandboy85 said:
Bump?
Click to expand...

Still using it. Still working great. I started using a layer of reflectix on the outside just to keep the foam looking good. Impressions in the foam are pretty easy to make.

Only thing I don't like about it is that anything adhesive sticks to it and ruins it. I was using it on the side of my fermenter to keep my probe insulated. I used painters tape to keep it attached and the foam bonds with the adhesive on the tape. The tape will ruin any piece of foam.
 
ParanoidAndroid said:
Still using it. Still working great. I started using a layer of reflectix on the outside just to keep the foam looking good. Impressions in the foam are pretty easy to make.



Only thing I don't like about it is that anything adhesive sticks to it and ruins it. I was using it on the side of my fermenter to keep my probe insulated. I used painters tape to keep it attached and the foam bonds with the adhesive on the tape. The tape will ruin any piece of foam.
Click to expand...


Good to know. I guess wrapping it with some duck tape or flashing would be a good idea then. Or, mane make a Velcro wrap to secure it to the kegs so it can be removed for cleaning. Did you get the PSA backed sheets?
 

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