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Example #1 : "Under-Slab Insulation the industries' number one selling under-slab insulation. Why Brand-X Works... Traditional mass insulation such as foam board addresses mainly Conduction and Convection and has been
shown to be only 30% effective when dealing with Radiant heat flow. Unlike conventional insulations, Brand-X reflects up to 97% of the Radiant heat transfer back into the living areas. There is no need to use other insulating products in conjunction with Brand-X for it to achieve its
superior performance... Brand-X stands alone."
Example #2: "With Brand-X under-slab installation, the response time of the heating system is quicker and more consistent due to the insulation's superior reflective properties"
HH Response: These claims appear to have come from this
document. A few other sites also state, "In a heated slab, Radiation is responsible for 93% of the heat traveling downward." Since the claim is made under the heading of 'Under-Slab Insulation the industries' number one selling under-slab
insulation. Why Brand-X Works.', a consumer could easily be misled to believe this to be true given the contents of the article when in fact downward heat loss in an underslab system is 100% conduction and radiation plays no role.
We consider this text from the distributors web site, "In a heated slab, Radiation is responsible for 93% of the heat traveling downward", as inaccurate and misleading as is, "...underslab
heating...the response time of the heating system is quicker and more consistent due to the insulation's superior reflective properties" since reflection plays no role under the slab.
Interestingly, the manufacturers website (referenced below) is somewhat careful and makes no such specific claims so you can tell in this case others are taking some liberty with information.
Example #3: "In a heated slab, Brand-X improves the performance of the radiant heating system and provides higher slab temperature output."
HH Response: The performance of the radiant panel is a function of the surface temperature, it's emissivity and the temperatures of the other surfaces in the room. No insulating product not even Brand-X is going to change the physics of radiant transfer. What insulation does in an
underslab application, is slow down
the conductive rate of downward heat loss, which means in part, there can be less heat input to the slab which means the design will be for a lower slab temperature not a higher slab temperature.
In fact higher slab temperatures are not necessarily a good thing. Most humans generally prefer surface
temperatures between 74 deg F and 84 deg F with the lower value being preferable. You can learn more about this here.
We know the intent of the manufacturers wording but the general population has little understanding of heat transfer so in our opinion we consider this claim misleading. If they change the wording to state "Brand -X as an underslab
insulation, has an R value Y according to test report Z by ABC Testing Agency, which reduces the conductive
heat transfer to the grade below" ...it would serve them better.
Here's the real grit...In company literature an "Effective R-10" is claimed and associated to ASTM C518 test; this despite company representatives stating that they do not publish values since it changes with application. We have asked to see the original test supporting this
claim but have yet to receive them.
Furthermore, at least one U.S. State has explicitly stated "Brand X under-slab reflective insulation shall not be installed as a stand alone product" when the product web site content says,
"there is no need to use other insulating products
in conjunction with Brand-X for it to achieve its superior performance"
This is a great big warning flag to consumers!
Claim of the month ** New as of November 1st, 2007**
Past Claim of the Month
Example #4 and #5
From Brand Y, "A HIGH-STRENGTH Insulating Moisture Barrier
for Use Below Heated Concrete Floors"
So here's their claim....
"Absolute Moisture Barrier
Keeps heat-robbing ground moisture away from the concrete."
Our comments:
It may prevent migration of moisture but it won't prevent heat transfer. Heat via conduction doesn't need moisture to occur - just a temperature differential...sorry brand y but that doesn't hold water in our science books (pun intended).
So here's their claim....
Reduces Downward Heat Loss By Over 50%
Exceeds the requirements of most HVAC load calculation programs.
More smoke and mirrors (pun intended again)...this is another bad case of prescription before diagnosis - first it can't reduce anything until there is something to reduce. Two surfaces of equal temperature in contact with each other exchanger ZERO heat plus
what they don't tell you is that even with the insulation the R value is still well below minimum standards such as those in the MNEC or OBC. In our opinion, it is irresponsible to make consumers think that a reduction of 50% is better when it is grossly inadequate. Furthermore,
exceeding, "...the requirements of most HVAC load calculation programs.", is a plate full of cow manure. There is no software requirement. None. Zero. Zip. The software just crunches numbers - think MS Excel (r) but with pretty colors.
It (the software) has no requirements to exceed - period - end of story. Let's just say these are more claims which are a bad reflection on the insulation industry (more pun intended).
This is exactly why the U.S. Federal Trade Commission and Canada's NRC/IRC are concerned about these products.
More to come... |
