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What is a « Cool Roof » ?

How does Cool Roof France go beyond to a « Cool Roof » ?
 
Why focus on the roof ?
 
When and why did you launch Cool Roof France ?
 
What are your main achievements ?
 
What are the main advantages of Cool Roof France painting ?
 
How can a thin layer of painting a few millimeters « isolate » ?
So, in winter what does it work ?
Which IRR – Internal Rate of Return if I make a « Cool Roof » ?
How do you calculate the € 20 000 savings on E. Leclerc supermarket ?
On which support can we apply Cool Roof France painting ?
Who makes the painting ? Do you have a patent ?
Who applies the painting ?
What is the guarantee of the efficiency and durability ?
 What maintenance tips ?
What is the Cool Roof France ecosystem ?
With the application of this product the roofing complex loses its initial fire rating ?
 
To what extent are we waterproof, can we intervene in case of perforation or tearing of the complex with a blowtorch ? 

The DTU roof specifies that the sealents or various products put in place must be recognized is this part of it ? 

 

How is your product positioned in relation to sealants coming on the market ?

What impact on my photovoltaic panels (PP) ?

 

How does Cool Roof France meet the regulatory requirements ?

What impact on the CDAC and institutional relations ?

How does a « Cool Roof » improve my certification odds (LEED for example) ?

Vegetable roof or « Cool Roof » ?

What is the difference in heat flux between a « Cool Roof » painting, a standard painting and a color painting for example ?

 
What is a « Cool Roof » ?

It is literally a fresh roof.

It is called a « Cool Roof » usually a roof whose white color can return heat in space thus limited the need for air conditioning.

A white roof stores 10 times less heat than a dark roof.

This is a principle well known for a long time in hot countries, in Greece or the Maghreb for example.

The principle has developed a lot on the impulse of the governement in the 2000s in USA too, which estimated that painting roofs in white would allow 750 million $US per year of energy savings in the US (Heat Island Group, US Government).

Understand the "Cool Roof" in 2 minutes

 
How does Cool Roof France go beyond to a « Cool Roof » ?

Cool Roof France painting is more than just a white painting.

It is reflective AND thermal.

In other words, it contains components that reflects the rays of the sun more than a classic painting.

And components (amorphous silica microspheres) that can significantly slow the heat transfer (4x more than a conventional painting).

Heat of the sun enters the building less in summer, so it is less necessary to cool.

Heat comes out of the building less quickly in winter, so it is less necessary to heat.

 

>>> See here the reports of the CoolRoof France painting tests validated by the European Cool Roof Council

 
 
Why focus on the roof ?

30% of the energy leaks in a building go throught the roof.

The implentation on a roof is also fast and simple.

In France alone there are 50 million sqm of commercial roofing over 10 years old.

There are mostly heat sieves which are expensive to heat and cool.

If already Cool Roof France managed to cover 1/10th of commercial roofing it would be a huge ecological and economic success !

 

When and why did you launch Cool Roof France ?

In 2014, Frédéric Lachèvre manager of E. Leclerc supermarket of Quimper (Brittany – Western of France) must find solutions for the roof of 1988 in very bad condition.

Following the discovery of the Cool Roof experiences in the US he made the first tests with Cédric Corre (peinture Corre), Ronan Caradec (Madec-électricité) and Roland Soun (A-Therm).

First painting trials begin in 2014. The E. Leclerc supermarket roof is painted and instrumented (9 heat probes) in June 2015. Company is officially registered in 2015.

Antoine Horellou joined the team in December 2016.

 
What are your main achievements ?

First full implementation was done on the roof of E. Leclerc supermarket of Quimper (7 000 sqm) before summer 2015.

This is the biggest « Cool Roof » of France. It is fully instrumented.

Cool Roof France also painted an already white container, allowing comparison white vs white Cool Roof painting

Several projects were completed in 2017 with, for example, the Crédit Mutuel Arkéa Group, the Boulanger brand, the Quimper Town hall and the Paris City Hall.

 
 
What are the main advantages of Cool Roof painting ?
  • It reduces the energy bill : for example the E. Leclerc building manager saw his bill decrease by more than 15% or 20 000 € in one year

  • It increases the life of the roof by plugging the microcracks

  • You continue to use your building while the painters apply the paint

  • It is self-cleaning : the smear doesn’t become encrusted, a simple brush stoke every 2-3 years is enough to make them leave

  • It improves your carbon footprint

  • It costs much less than another insulation : as it is a light, it doesn’t require to revise your framework

 

 
How can a thin layer of painting a few millimeters « isolate » ?

Silica aerogels are the best insulators in the world. That’s why we included them in the painting. Even if the painting is only a few microns it is 4x more insulating than a classic painting. Heat goes out less quickly so your building needs less heating.

So, in winter what does it work ?

As in summer, the heat comes in through the roof in winter.

But this effect is offset by the insulating properties of the painting : it is 4x more insulating than a classic painting.

In addition solar radiation isn’t the same in winter and summer. In winter the rays are lower than in summer : therefore, on a flat roof the solar thermal imputs don’t pass more mainly by the walls and windows. Moreover the rays are much less « strong » and frequent (clouds) in winter.

By cons the roof (if poorly insulated) will be the main cause of heat loss (because the heat rises).

Since Cool Roof France painting contains million of silica microspheres that encapsulate air (see below), it is more resistent than a conventional painting, so your roof will partially block heat transfer.

In short the Cool Roof France technology is an effective complement to reinforce insulation.

=> Study report : The role of « Cool Roofs » on the reduction of energy comsuption of commercial buildings : Levinson R, Akbari H. 2010. Potential benefits of cool roofs on commercial buildings: conserving energy, saving money, and reducing emission of greenhouse gases and air pollutants. Energy Efficiency. 3:53-109.

=> Test on a spove (in French)

 

Which IRR – Internal Rate of Return if I make a « Cool Roof » ?

Example of E. Leclerc supermarket of Quimper (« service » pack) :

Roof : 7 000 sqm, bituminous two-layer steel sandwich tank 1988

Pose of the Cool Roof France elatomer complex : June 2015

Initial invesment : € 18/sqm ($US 21/sqm) = € 140k ($US 161k) for 7 000 sqm. This therefore represents € 13k($US 15k) per year of depreciation on the product life (10 years)

Economy of annual consumption observes : € 20k per year

($US 23k/year).

Economy related to the cost of kWh (which undergoes an annual increase of 3%)

Economy related to the maintenance cost of the roof

(€ 1k/sqm/year or $US 1,2k/sqm/year) = € 7k ($US 8k)

Creation of a maintenance cost (about € 1,5/sqm/year -

$US 2/sqm/year for a conventional contract, € 2/sqm –

$US 3/sqm for a « packService » contract indicated here by CoolRoof France which guarantees 100% of the effectiveness of the device).

IRR is here above 28%. 

 

+ It goes without saying that the same building in a sunnier area will have an even better return

+ This E. Leclerc supermarket isn’t equipped with photovoltaic panels (PP), this table doesn’t include potential gains of a photovoltaic power station which can reach 10%

+ CO2 win is estimated at 4tCO2eq per year

How do you calculate the € 20 000 savings on E. Leclerc supermarket ?

  • We have indoor temperature readings with several probes (under white and under black) that clearly show that the solar heat doesn’t pass under the white at all while it continues to pass under the black (unpainted).

  • So : if the hot doesn’t enter the building it means that there is no need to cool by consuming kWh by the cold-groups.

  • This hypothesis is corroborated by the testimony of the staff present on the spot in the building who found the non-start-up cold-groups all summer 2016 when it was much hotter than in summer 2015.

  • If the group didn’t start they didn’t consume.

  • To estimate this percentage of economy without differentiated meter, we take the main source of variation which are the LEDs :

  • Before the installation of the LEDs we had 2000 tubes at 60W/tube = 2000*60*315days*12h = 450,000kW*0,08cts (without taxes) /kWh = 40k€ (without taxes) (46k $US)

  • By installing LEDs we divide the consumption of the lighting station by 2 (an LED tube is 28W) = 20 000 € savings (23 000 $US).

  • The overall savings of consumption of the board being about 40k€ since the installation of the « Cool Roof » + of LEDs on one side, and having not taken any particular of decision of saving of energy elsewhere we concluded that the remaining € 20k ($US 23k) in saving was due to Cool Roof France.

 
 

On which support can we apply Cool Roof France painting ?

Cool Roof France painting is applied on the most common substrates : bitumious bilayer, steel tank but also asbestos

Who makes the painting ? Do you have a patent ?

To develop and manufacture its painting, Cool Roof France works with one of the best European research laboratories certified ISO 14001 : 2004 and UKAS.

It is the partner laboratory of Cool Roof France which has the patent.

Cool Roof France has the exclusivity of its marketing on France.

 
 
 
Who applies the painting ?

She is applied by professionals of painting and refacing, certified RGE & Qualibat validated by Cool Roof France.

 

 
What is the guarantee of the efficiency and durability ?

The product has been tested in aging chamber without any degradation on 3600 hours of exposure.

Application has guaranteed perfect completion and Cool Roof France is committed to a goal of 10 years of general performance.

For maximal efficiency it is recommended to clean the roof regularly (see next point).

 What maintenance tips ?

Painting rejects any development of mushroom and moss.

This doesn’t prevent the dust from landing on the roof.

To optimize performance and hold over time a simple brush stoke every two years is enought to regaint the original color and extend life of the painting. Depending of the situation of the roof especially if it is close to a motorway, an annual visit makes it possible to make sure of the perfect whiteness of the roof.

 
What is the Cool Roof France ecosystem ?

Cool Roof France is a member of the Quimper-Cornouaille Technopole and is supported by the Brittany Region.

His scientific work in painting design is followed by a European laboratory, by the Ecole des Mines of Nancy and by a biotechnology laboratory (CBB Capbiotek).

Several companies are technical partners of Cool Roof France (Peinture Corre, A-Therm, Madec-Electricité, BOPS, …)

 
 
With the application of this product the roofing complex loses its initial fire rating ?

Cool Roof France doesn’t improve or degrade the existing fire rating.

To what extent are we waterproof, can we intervene in case of perforation or tearing of the complex with a blowtorch ?

Cool Roof France painting doesn’t improve or degrade the existing seal. In case of clutter after the installation Of Cool Roof France painting you can easily intervene on the roof to restore the disorder and if necessary pose the Cool Roof painting on the repaired part.

 
The DTU roof specifies that the sealents or various products put in place must be recognized is this part of it ?

Cool Roof painting isn’t a sealing solution so we are out of the DTU field, CSTB technical advice, ten-year guarantee, … Cool Roof France painting is considerated as a solution for substantial and economic improvement of your energy balance.

 
How is your product positioned in relation to sealants coming on the market ?
  • Our offer isn’t a sealing solution. We noticed that our painting can plug the microcracks up to 1.2 mm and therefore contribute to a better seal but it isn’t a commitment on your part. Our commitment is on non-thermal transmission of the roof especially in summer.

  • Our offer is mainly for roofs over 10 years to give them a second life of several years.

  • Our product offers the best reflectivity, emissivity (more than 90%) and durability of the market. Reflectivity tests of our product are certified by the European Cool Roof Council.

  • Our offer is much more affordable than all the solutions currently proposed (€ 20 (without taxes)/sqm – $US 23 (without taxes)/sqm provided and posed)

  • Approach is simple and doesn’t require to revise the whole of the building’s frame

  • Your customers can continue to shop in the store during the work.

 
 
What impact on my photovoltaic panels (PP) ?

Cool Roof France painting increases the brightness and lowers the roof temperature which increase the efficiency of the PP (of the order of 10%).

Cool Roofs and Photovoltaic panels, sources :

http://www.coloradogreenbuildingguild.org/news/104965/Cool-Roofs-and-Photovoltaics-Boost-System-Performance.htm

http://coolroofs.org/documents/711CoatNCoolFMJArticle.pdf

https://www.linkedin.com/pulse/pourquoi-carrefour-peint-en-blanc-sous-ses-panneaux-%C3%A0-horellou/

 

How does Cool Roof France meet the regulatory requirements ?

If you are in the context of a new construction or a major renovation two particular regulations apply :

  • RT2012 for new buildings

  • RTex for existing buildings

 

In both cases you have indeed thermal performance objectives to achieve (which are expressed in kWhEP/sqm per year).

Legistrator translates this thermal performance by calculation rules (rules THBCE 2012 of the RT2012 and TH-Ce-ex of the RT-existant) which don’t list strictly speaking « processes » but propose various calculation factor including :

 

1. The « R Factor of thermal resistance » (conductivity x thickness)

 

For our painting, this factor is much better than a classic painting and therefore contributes mechanically to improving the thermal resistance of the building. The less the building will be isolated the more impact the painting will have.

The simulator includes other factors including :

 

2. Heat fluxed due to absorbed solar radiation

 

In RT2012 (ThBCE 2012 certifications), the calculations take into account the heat fluxes due to solar radiation absorbed by the opaque walls throught a « solar factor » make it possible to translate the reflectivity of the wall (see from page 331 onwards) including Form (Form 452, page 334).

Same thing in the TH-CE-ex certification of the RTexistant (see from page 67).

In both cases the calculations take into account a solar factor of 0.8 for the horizontal opaque walls (that is to say that the calculations consider by default that 80% of the solar radiation is absorbed by the wall and 20% reflected). This parameter is accessible and therefore adejustable in the two modeling tools, but it must be set correctly. The application of a reflective coating on a wall will impact its solar factor : for example in the case of Cool Roof France,  reflective painting the wall will go from 80% of absorption (given by default by the simulator) to 2,5% of absorption, a delta of more than  65% (!).  It is therefore important that the consulting firms in charge of these calculations now integrate the"coolroof" process  to improve the calculated performance.

 

Moreover the RT also evoke the criteria « summer comfort » on which strongly influences the « cool roof ». Extract :

« In order to limit occupant discomfort and the use of air conditioning, the renovated building must provide acceptable summer comfort to the extent that is possible within the existing building ». Conventional indoor temperature reached in summer must therefore less than a reference temperature ».

 

What impact on the CDAC and institutional relations ?

The « Cool Roof » process is an additional sustainable development argument to be made to store extension or construction record (CDAC).

Multiple institutional commitments (Paris Agreement up to the PCETs) make CoolRoofing a solution not only for limiting urban heat island effects. We will also soon realize a « Cool Roof » for a very large city in this logic. For example the city of Paris has summer comfort goals, and also carries the C40 presidency which recommends the duplication of the New York Cool Roof initiative (see here)

 

But above all beyond the regulatory aspects you have like the E. Leclerc supermarket of Quimper, any interest in equipping stores that aren’t being inovated for reasons of pure probability (energy savings, extension of the duration cool life, …).

 
How does a « Cool Roof » improve my certification odds (LEED for example) ?

As part of the LEED Accreditation Sustainable Program, version 7.2 2009, roof surface heat islands must have a minimum of 75% material with an IRS solar reflectance rating at least 78. Taking into account an IRS = 112, the Cool Roof France painting far exceeds the LEED requirements.

Vegetable roof or « Cool Roof » ?

There are several scientific publications about the « Cool Roof » /green roof comparison.

On the issue of protection against heat, the « Cool Roof » is a least as effective see more than the green roofs. See for example the summary of this study : http://www.sciencedirect.com/science/article/pii/S0378778815003527

And again these studies are based on « Cool Roof » technologies that are less efficient than our painting. Indeed our painting contains mesoporous silica particles (basically sand and air) which provide a better reflectance, emissivity and effective resistance for the summer but also the winter.

Then comes the question of return of investment because the green roof will cost much more to install, may require a revision of framework (heavy car) and requires more maintenance.

Let ‘s say it’s another approach.

 

What is the difference in heat flux between a « Cool Roof » painting, a standard painting and a color painting for example ?

Differences between a « Cool Roof » painting and a classic painting (white or blue for example) lies in the absorption coefficient and the emissivity. Below an idea of the values for three types. Absorption plays on the flux absorbed by the surface. Emissivity plays on the radiated flux (which also depends on the surface temperature of the absorbed flux the convection and the internal charge) which is therefore is little more difficult to quantify simply.

 

 
 

By taking a solar flux of 1000 W/sqm the difference in flux absorbed between a « Cool Roof » surface and a dark blue surface = 790 W/sqm. Below is a comparison between each case.

To complete the reflection (of the brain this time !) compared to a classic white painting we must consider the durability of the painting (resistance to UVB and fouling) which ensures reflective and emissive properties over time.

 

OTHERS QUESTIONS ?

 +33 (0)2 44 84 08 04

    price for a local call from France 

COOL ROOF FRANCE

287 Rue Ernest Hemingway

29200 BREST

FRANCE

contact@coolroof-france.com

+33 (0)2 44 84 08 04

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(c)CR-France 2016 - SAS au capital de 100,000 € - RCS 812 775 443 le 29/07/15 à Quimper