Q & A
There are many questions out there in the market that are relevant and need to get answered. We are putting together a list of questions we received from you and hope that the answers are what you are looking for.
Everyone knows of the famous whitewashed buildings that stay cool in the Mediterranean. But not all white coatings are created equal. Cooling living environments in an energy-efficient manner has become a “big challenge” as climate changes cause Heat Islands everywhere.
White ‘reflective paints’ are an established method that helps to bring down indoor temperatures and so save the energy used for air-conditioning. Most paints work by reflecting heat-producing infrared radiation and are typically made with titanium dioxide in an acrylic polymer base. The best white roof paints available today reflect about 85 percent of solar radiation falling on them.
A mainly used Titanium dioxide reflects most visible and near-infrared light well, but it absorbs ultraviolet rays, while the polymer binder can absorb near-infrared light. This causes some heating under sunlight, so the paints don’t work very efficiently under harsh, bright sunshine.
Adding any Colour to your paint will dramatically change the behaviour of the efficiency towards the heat under sunshine.
What to Do
-
What is a Radiant Barrier?
-
​
-
A radiant barrier is a type of building material that reflects thermal radiation and reduces heat transfer. A radiant barrier reflects heat radiation (radiant heat), preventing transfer from one side of the barrier to another due to a reflective, low emittance surface.
-
​
-
Do Reflective surfaces reflect heat?
-
​
-
Reflective surfaces can deliver high solar reflectance (the ability to reflect the visible, infrared, and ultraviolet wavelengths of the sun, reducing heat transfer to the surface) and high thermal emittance (the ability to radiate absorbed, or non-reflected, solar energy).
-
​
-
What material reflects the most heat?
-
​
-
Many solar installations harvest energy by converting sunlight to heat; metal components efficiently absorb and transfer heat while withstanding high temperatures. For solar applications that use mirrors, thin coatings of silver, aluminium, and other metals serve as good reflectors of light.
-
​
-
How do you reflect heat?
-
​
-
Another way to reflect heat is to install a radiant barrier on the underside of your roof. A radiant barrier is simply a sheet of aluminium foil with a paper backing. When installed correctly, a radiant barrier can reduce heat gains through your ceiling by about 25 percent.
-
​
-
Does aluminum foil reflect heat?
-
​
-
Answer and Explanation: Common foil used in the kitchen today made of aluminium does reflect heat very well. Aluminium foil reflects about 95% of the infrared heat that hits.
-
​
-
How do you insulate heat?
-
​
-
You can use products like a radiant barrier on the underside of the roof, spray foam, or even good old-fashioned batts of rock wool or fiberglass. The usage of concrete or terracotta Tiles are better in thermal mass than the use of Zink aluminum sheets.
-
​
-
Does reflective insulation really work?
-
​
-
Radiant barriers and reflective insulation systems work by reducing radiant heat gain. To be effective, the reflective surface must face an air space! Reflective measures only have a limited heat reduction.
-
Radiant barriers are more effective in hot climates than in cool climates, especially when cooling air ducts are located in the attic.
-
​
-
What is the coolest roof material?
-
​
-
Clay tiles are a popular cool roofing material, with an SRI of over 50% and a thermal emittance of up to 86%. They are known to be extremely durable and 100% recyclable at their end-of-life use.
-
​
-
What is reflective insulation used for
-
​
-
Reflective insulations are designed to reduce heat transfer through radiation by placing a surface that reflects thermal radiation in combination with an air gap. The reflective surface reflects most of the thermal radiation toward the air space, preventing it from being absorbed by the material. This is only viable when the sun shines.
-
​
-
What materials can absorb heat?
-
​
-
Known (sensibly enough) as “sensible heat materials,” substances like stone, cast iron, and aluminium get noticeably hotter as they absorb heat, they are conductors of heat.
-
​
-
Can you reflect heat?
-
​
-
Heat Reflection. Reflection is the opposite of absorption. Instead of being absorbed, some of the heat energy is bounced or reflected off in the opposite direction. As this happens, the heat waves are unchanged, as is the object itself.
-
​
-
What is the difference between Thermal Dynamic or Reflective Paint?
-
​
-
​
-
Does wood reflect heat?
-
-
Wood floors provide heat that lasts Wood also maintains heat longer than carpet because it has a higher thermal mass. Wood and other solid materials significantly reduce your home's temperature fluctuation because they absorb and store heat while light carpet fibers simply become a barrier.
​
-
What is SRI?
-
-
The Solar Reflectance Index (SRI.) is a measure of the roof's ability to reject solar heat, as shown by a small temperature rise. It is defined so that a standard black (reflectance 0.05, emittance 0.90) is 0 and a standard white (reflectance 0.80, emittance 0.90) is 1.
-
-
What is R-value?
-
-
An R-Value refers to a material's ability to resist heat flowing through / thermal dynamics at a certain thickness. The higher the R-Value, the better it can resist heat transfer. Thus, when you are searching for the best materials to insulate a home, it is best to look for materials with a high R-Value.
-
-
What colour reflects heat the most?
-
-
If you consider it a colour, black absorbs the most heat. A black object absorbs all wavelengths of light and reflects none. Objects that are white, on the other hand, reflect all wavelengths of light and therefore absorb the least heat.
-
-
What is solar absorptance?
-
-
From the UNI tech book: ‘The resultant solar heat gain each hour will then be multiplied by the schedule value. For shading coefficient values of different surface types. Or simply; it is the part of the sun’s radiation that the surface absorbs. The classification value is expressed from 0 to 1, higher value higher absorption.
-
-
What colours absorb the most?
-
As a guideline:
-
-
White would be around 0.23-49 -
-
Off White/Light Cream 0.3-0.35
-
Yellow 0.45 - Light Grey 0.55 - Red, Green 0.70 - Dark Grey 0.85 - Black 0.98
-
-
Bringing this into content using Colorbond™ colours as used by the Industry
-
-
Classic Cream/ Surfmist 0.32 - Paperbark 0.42 - Dune 0.47 - Windspray 0.58
-
Basalt/ Manor Red 0.69 - Nightsky 0.96
-
-
Keeping all this in mind, anything higher than a value of 0.45-47 is an absorption of heat, no matter what;
-
Any zincalume sheet un-coated is rated around a 0.35 value! Polished Aluminum is around 0.09, Terracotta tiles are around 0.65-75!
-
​
-
-
-
Why use TDC?
-
-
TDC coatings are much more effective as a Heat Barrier than so-called ‘cool paints’ because they use more UV stable and reflective thermal dynamic minerals that slow down the heat transfer and they have a much more durable polymer base no matter the colour that is used. The base mix is Aliphatic Urethane Not Acrylic.
-
-
Why use Aliphatic Urethane?
-
-
Aliphatic, is a better choice because it will not turn to the colour amber when exposed to UV light (from the sun), Aliphatic Urethanes are most well known for offering UV stability and protection from the suns rays, and are highly resistant to severe weather, due to their chemical composition. Their bonds are extremely strong, and they typically last for a long time. The typical lifespan of Aliphatic Urethane, unlike Acrylic paints (3-5yrs) is 10+ yrs depending on circumstances;
-
-
Why use TDC – Primer?
-
-
For best coating durability, adhesion and performance, we always recommend a primer first.
-
-
What does the TDC - Primer do?
-
Primers by nature have a much higher surface particle size, hence a rougher surface, which leads to a much higher bonding ability. Greater bond strength provides greater inter-coat adhesion, which leads to higher thorough performance – more paint better performance
-
-
How long does it last?
-
-
Our goods come with guarantees that cannot be excluded under the Australian Consumer Law. You are entitled to a replacement or refund for a major failure and compensation for any other reasonably foreseeable loss or damage. However, the application needs to follow HYDRO™TDC Application step by step Exterior Finish has had no change to colour or gloss after 5,000 hours in an accelerated weathering chamber which is equivalent to all typical water-based coatings in Australia.