In-Door Air Quality

Airborne fibres from some insulation are considered carcinogenic and can seriously damage health.

Low-E® Insulation has no fibres and is In-Door Air Quality Approved.

Does your insulation absorb heat and moisture?

Low-E® Insulation works differently to traditional insulation.

Local Authority Building Control Accepted

EN 16012 Tested and Compliant. 25 years of experience, testing and approvals have kept Low-E® Insulation at the forefront of the industry.

Fire Lab Tested

Low-E® Insulation is Class A/Class 1 Fire Rated and is suitable where other reflective insulation is not.

This is Low-E® Reflective Foil Insulation.

It’s reflective because it’s aluminium. Only aluminium has an emissivity value of 0.03 and reflects 97% radiant heat

How Reflective Foil Insulation Works

Why Aluminium is Best

Emissivity Values

The amount of  heat which passes through a material.
How Reflective Foil Insulation Works

Everything has an emissivity value, your clothes, a table. For example cast iron has an Emissivity of .85 This mean that 85% of heat that comes in contact with its surface to pass through it, which is why radiators are made from cast iron.

Aluminum has a natural low emissivity value of .03. This means that aluminium will only allow 3% of radiant heat that comes in contact with its surface to pass through it, the rest will be reflected back to the source.

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Aluminium

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Asphalt

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Brick

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Fiberglass/cellulose

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Glass

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Wood

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Concrete

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Plaster

“Radiation is the primary mode of all heat transfer. The other two modes… come into play only as they interfere with the primary mode.”

Energy Design Update, Feb. 93. Stated by C.M. Pelanne, Senior Research Specialist for Johns Manville

What should I know?

Before we talk about Low-E Insulation we need to define three thermal values.

R-values

R-values are the inverse of U-values: the resistance to heat flow.Low-E insulation products do have an R-value but the reason they work so well is in the name.

U-values

U-values are a measure of a materials ability to conduct heat. The thermal performance of windows and doors is commonly stated in U-values. U-value is equal to 1/R (R-value).

E-values

E-values or the ‘E’ in Low-E stands for Emissivity. Emissivity is the ability of a surface to emit or transfer radiant energy through itself – everything has an E-value.

Convection

Convection is a warm air current, you can see convective heat from a hairdryer or from the surface of hot road

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Conduction

Conduction is when heat travels between two touching objects or through one solid object.

Radiation

Radiant heat is electromagnetic waves which can pass through anything.

Why is so much importance put on ‘U’ & ‘R’ values?

Regardless of how high the R value on an insulation product is, unless it also has a low – E value it has no ability to reflect radiant energy.

It will always need to absorb the heat in order to work.

Very high R values don’t stop heat transfer, they simply slow it down. You cannot ignore the need for good U values, but by addressing the U values alone a large percentage of heat transfer is being ignored.

Low-E, because it is made from pure aluminium, has an e-value of 0.03 which means 3% of radiant energy that comes in contact with its surface will pass through it.

Or another way to look at it is that Low-E will reflect 97% of radiant energy that comes in contact with it.

“If a surface emittance is changed from .90 to .03 the part of the heat flow that is radiation is reduced to 3.3% of its initial value.”

100 Btu/hour – 3.3 Btu/hour

Dr. David Yarbrough

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