Cosmo-Dec

Sno-Cote® brochure(42)

Product list    Back Home    Next brochure(42 A)    Previous brochure(41)    Price list

This exceptional thermal insulating coating is the very best available and encompasses the most modern approach to this technology utilizing an advanced  metalic, string oxidised, sulphonation complex to achieve it`s extraordinary properties.

Sno-Cote® has superior adhesion propensity, better opacity, extended coverage, higher cooling capacity and is also chip blister, crack and peel resistant and displays excellent rust fighting capabilities.

Sno-Cote® is a liquid paint-like coating, radiation barrier, highly effective as reflector of radiation and a good thermal non-conductor (insulator) due to advanced technology employed and confirmed by SABS tests.

Sno-Cote® is applied to the roof of the building or structure etc. and also to the walls where necessary for the purpose of cooling the building or structure dramatically. Air temperatures measured inside buildings can drop by up to 15 degrees centigrade and temperatures of roof sheets or walls can drop by up to 30 degrees centigrade.

Sno-Cote® is an exciting new development in paint or coating technology. The product is water based and consists of an emulsion containing a mixture of state of the art hi-tech  particles.

Sno-Cote® can be applied by brush, roller or spray applicators. It is unaffected by ultra violet light, is acid resistant, waterproof, hard wearing, long lasting, flexible, impact resistant, etc.

Sno-Cote® can be applied to ANY surface including galvanized iron without the necessity for an undercoat. (Although Dead-End is strongly recommended )

Sno-Cote® has a wide variety of applications including factory and house roofs, poultry houses, pig sties, warehouses and shops.

Sno-Cote® when used by the fresh fruit and vegetable industry helps to significantly reduce inside  storage temperatures, thereby prolonging shelf life which translates into huge financial savings.

Sno-Cote® is a one pack system i.e. pre-mixed emulsion which has a prolonged shelf life. When applied outside in dry weather, the drying time will be no more than 30 minutes to the touch.

Colours;  White, Grey, Red, Blue, Green Yellow

Uses

ADVANTAGES

Prevents thermal shock to roof sheets, thereby ensuring no roof bolts popping or loose roof bolts which means prolonged roof life.

Sno-Cote® applied to flat concrete roofs helps to prevent thermal shock here, to a remarkable degree thus putting an end to expansion and contraction of these structures which in turn prevents these roofs from cracking and leaking which is a feature of these types of structures. Architects, builders engineers etc. often go to enormous lengths  at great expense to achieve similar results on flat concrete roofs to what a simple application of Sno-Cote will.

In-Situ applications, no need to stop production or interfere in any way with on going activities in order to apply Sno-Cote®, Quiet interference free applications ensure this, no fumes, no problems! 

Surface preparation

The substrate should be clean dry and stable.

Application: Ensure that the surface is free of loose paint, dirt, grease, grime etc. and that it is dry prior to applying Sno-Cote®. Apply by brush roller or spray applicators

When used in conjunction with Dead-End Sno-Cote® achieves a 100% adhesion

as tested by SABS.

Coverage : 4 to 5 square metres per litre depending on the substrate and method of application.

Colour : Sno-Cote® is available in most light colours

Technical Information

Sno-Cote® is a wet in the can paint on coating with thermal insulating, rust preventing and other properties.

SABS TESTS CONDUCTED AND RESULTS OBTAINED

 Thermal Insulation Coating.

Test report 7222/ 2090038/v 76

Product was tested for: 

Heat absorption of air inside treated  and non-treated containers.

Adhesion of thermal coating.

Test methods:

Adhesion - requirements in accordance with SABS ISO 2409 : 1992

Two containers - one coated one non-coated.

Inside temperatures measured with thermocouple at 1 hour intervals

Between 11:00 and 15:00.

 

Test window:

12 April 2002

Results:

Adhesion - 100 % adhesion, no loss.

Inside Temp - Temp in coated container is always lower than uncoated by approx. 18%.

As ambient temp. drops air in coated container drops slower than uncoated container confirming insulating properties

 

Saving Energy with Cooling(Thermal insulating) Roof Coatings

Special roof coatings can save energy in hot climates and can help utilities in warm climates reduce peak demand.

Architects are using special coatings to cool off buildings in hot climates, but until recently there was little research on the measured cooling-energy savings of these roofs.

Over the past two years, however, researchers in Florida and California have examined the impact of these roof coatings on air-conditioning energy use in retrofits of monitored homes. Simulation analysis suggests that a specially coated roof  can cut a building's cooling load by 10-60%. The higher numbers are associated with uninsulated roofs.

 Cooling coatings are increasingly being used for manufactured homes in the Southeast, based on homeowner reports that such coatings can reduce summer air conditioning costs. Until now, however, no investigation in a cooling-dominated climate examined the effect of coated roof on time-of-day air conditioning electrical demand in occupied residential buildings--important information for utilities where summertime peak demand is a concern.

One of the earliest whole-building studies that measured cooling-energy savings from cool roof coatings was performed by the Mississippi Power Company. The utility monitored two identical side-by-side single-story commercial office buildings after the roof of one had been covered with a cooling coating. Both existing buildings had R-11 roof insulation. The results of the experiment? Summertime air conditioning was reduced by 22% in the building with the reflective roof coating.

More recently, researchers at LBL measured very significant cooling-energy savings from applying cooling coatings to three buildings in central California . At one site, energy demand for space cooling was nearly eliminated. But regardless of the potential of cooling roof coatings in California, Florida's higher humidity and nighttime temperatures make prospects for near elimination of space cooling energy use in that state very unlikely.

An Initial Experiment

In the summer of 1991 we conducted a preliminary experiment in Merritt Island, Florida. Our first test building (Site #0) was a 1,800 ft2 detached single-family, single-story home of conventional concrete-block construction. The pitched roof faced north-south, with plywood decking covered by green/gray asphalt shingles. The home's attic was well insulated with approximately two inches of fiberglass covered by an additional six inches of cellulose insulation, yielding a thermal resistance of about R-25. Air infiltration from the attic area into the conditioned interior (a common problem due to duct leakage), had been largely eliminated in a previous audit and retrofit. Beginning in May 1991, we submetered the home's air conditioner while maintaining a constant thermostat setting of 79deg.F. We also recorded the underside roof deck, attic air, and living room temperatures.

When we applied the cooling coating on September 5 of that year, the roof's reflectivity increased from 0.22 to 0.73.2 Spot measurements under full sun at midsummer had shown shingle surface temperatures of 160-170deg.F, prior to the roof treatment, compared to 110deg.F after we applied the coating. Analysis assuming an 81deg.F average summer temperature indicated that a cooling roof coating would reduce energy consumption by 10% (35 kWh versus 39 kWh per day).

Yet this test house probably understated the savings, since most existing Florida residences have fairly poor attic insulation and attic air frequently leaks into the conditioned interiors. Therefore, we obtained more "typical" residences for the detailed experiments we conducted the following year.

A Five-House Follow-up

To learn about how cooling roof coatings affect peak cooling demand we measured the 15-minute air-conditioning electricity demand in our follow-up study, along with meteorological conditions for three weeks before and after each home was retrofitted. We also used infrared thermography to examine how interior heat fluxes from the roof/ceiling were altered by the retrofit.

With equipment to instrument two buildings, we sought one residence with typical ceiling insulation levels (approximately R-11) and a second structure without any insulation at all. (Many homes built in Florida prior to 1965 have no attic insulation and were built with flat roofs that make retrofits difficult.) Data from Site #1 would be used to obtain results from a more-typical existing residential building, while Site #2 would help us define the maximum savings potential for cooling roof coatings in Florida. Experiments on three more houses in the summer of 1993 extended our sample size. Each house in the second round of experiments had unique characteristics that broadened our knowledge of how cooling roof coatings reduce air-conditioning needs.(Table 1)

Results

Site #1

Site #1 was a fairly typical existing Florida home. The attic was insulated to approximately R-11, but the air conditioner was old and inefficient. Although pre- and post- application air temperatures and solar radiation were comparable, air-conditioning power demand was reduced by an average of 25% (from 40 to 30 kWh per day) after we applied the roof coating. The average electrical consumption of the air conditioning system during the utility coincident peak period (5-6 pm) was 2.4 kWh before the coating and 1.7 kWh afterward. This 700 W savings represents a 28% reduction in peak power demand attributable to the coating. Furthermore, average 24-hour attic air temperatures were reduced by 6deg.F, while peak attic temperatures between 2 pm and 6 pm fell by an average of 15deg.F.

Site #2

Site #2 was an ideal candidate for a cooling roof coating. The house had a flat roof and no space was available to insulate the ceiling assembly. Prior to the coating, the 2.5-ton air conditioner was unable to control the interior temperature adequately, running continuously each day from noon until 7 pm when the thermostat was finally satisfied.

Average air-conditioner electricity consumption dropped from 36 kWh to 20 kWh per day after the application--a 43% reduction. Savings would have been higher if the house had possessed a larger air conditioner, but the results did demonstrate the huge potential for gaining cooling-energy savings by applying  a cooling roof coatings to the roofs of homes without ceiling insulation.

The temperature reductions to the deck, deck airspace and ceilings were also striking, as was the change in the air conditioner's load profile. Before the retrofit, the daily interior temperature had ranged above the thermostat set point by 4deg.F or more. The average electrical demand of the air conditioning system during the utility coincident peak period (5-6 pm) was 2.2 kW before the coating and 1.4 kW after the application--a 38% reduction.

Site #3

Site #3 was a small house, cooled with a through-the-wall air conditioner. Since there was no attic duct system the site was of unique research value. The attic above the dropped ceiling contained no insulation, and the 1.5-ton air conditioner ran constantly prior to the coating (from 1-10 pm) unable to satisfy the thermostat. After the coating, the air conditioner cycled on and off during the same time period, maintaining improved interior comfort while reducing the utility coincident peak demand (5-6 pm) by nearly 960 W. Total daily air conditioning use was 11.9 kWh lower after the coating was applied--a reduction of 47% under peak-day conditions. After the retrofit, the average daily air conditioning savings totalled 5.6 kWh, or 25% during the summer period (Table 1) and peak demand savings averaged 30% (500 W).

Site #4

We selected Site #4 to see how applying a cooling roof coating to a gravel roof (common in South Florida) might reduce energy use, and also because the household complained of high utility bills. The ceiling was well-insulated for a Miami home (R--11-R-19 blown fiberglass) and its 3-ton air conditioner was relatively efficient. But while auditing the home, we found a large duct-system supply leak in an inaccessible portion of the attic. (We found the leak with an infrared camera.) The leak was not repaired, but the roof was later coated with a cooling roof coating. Although the percentage savings of air conditioning energy (15%) were lowest at Site 4, the absolute savings of 8.0 kWh per day were nevertheless significant.

Site #5

Site #5 had a tile roof, but the cement barrel tiles were old and stained a dark gray. The house also had relatively poor ceiling insulation and an inefficient air conditioner. The measured solar albedo was 20% before coating, but after being coated with a sprayed-on cooling coating, it was 64%. The absolute savings at this site were quite large at 11.6 kWh per day with a 988 W reduction in coincident peak-cooling demand.

Reflecting on cool roofs

Cool roofs can reduce space-cooling energy consumption and demand in Florida. Data collected so far suggest that air conditioning savings of 10-40% can be realized, with the larger reductions associated with poorly insulated roof assemblies or buildings with excessive attic air infiltration due to air handler return air leakage. cooling coatings may be particularly suitable in existing residences where the roof structure makes it difficult to add insulation.

Average electricity consumption for central air conditioning in single family homes in Florida is approximately 4,400 kWh/year. Based on a savings level of 10-40%, cool roofs can be expected to reduce household electricity use by 440 to 1,760 kWh per year--an annual savings of $35-$140 at current electricity rates (assuming 8cents per kWh). Obviously, the savings will vary depending upon the severity of the cooling season.

What About the Payback?

A frequent question concerns payback of cool roofing. There are several angles on the answer, but generally speaking, cooling coatings are most appropriate when one is re-roofing. If the coating is applied to an existing roof that is in otherwise pristine condition, the cost equation is straightforward. The typical coverage of a cooling coating is 25 ft2 per gallon,(0,6 sq. meters per liter) (Sno-Cote® gives 6 square meters per liter reducing the application cost factor by a factor of 10!!!! This makes a massive difference to these calulations and results) based on an application of two coats to a target thickness of 40 mils.

Cost for the material from vendors varies by 50% or more but averages about $60 per 5-gallon container when purchased in quantity. It is important to keep in mind that roof area is generally considered greater than building floor area, particularly with a steep roof pitch. For instance, a typical 1,500 ft2 home may have 2,200 ft2 of roof to be covered. The application then requires 90 gallons of coating material for a materials cost of approximately $1,100.

The cost of labor for installation depends greatly on the roof surface, on whether the coating is to be rolled on or sprayed, and on labor rates. A typical labor cost might be approximately 50cents per ft2 for the required two applications. Thus the overall application would cost about $1 per ft2, or approximately $2,200 for a typical home. With annual energy savings in Florida of $35-$140, the payback times are long--usually lasting longer than the roof itself.(With the exception of Sno-Cote®)

A completely different scenario emerges if the home is soon in need of re-roofing, however. Here the roof coating (which essentially creates a new weatherproof surface) might be seen as a way of extending the life of the roof by 5 to 10 years at half of the cost of re-roofing. The energy savings then become a side benefit.

For new homes, the situation is even more interesting. Here it is often possible to choose roofing types--such as metal roofing, tile roofing, or metal or ceramic shingles--that can be specified in a reflective white at significant additional cost. Unfortunately, no truly reflective asphalt roofing shingles yet exist for the residential market, but this situation may change as researchers work with the roofing industry to develop new products and spread the word about the energy benefits to help create a market for the materials. For commercial buildings, a variety of reflective roofing materials are already available: Hypalon, white EPDM, and PVC single-ply membranes. Once such products are widely available for the residential market, the economics may be significantly altered as the cost of reflective roofing becomes inconsequential. n

Notes

1. Reflectivity or albedo is the hemispherical reflectivity integrated over a particular wavelength band of the electromagnetic spectrum. For the purposes of this article, the terms reflectivity and albedo are used interchangeably and refer to the wavelengths encompassing the range of solar irradiance from 0.28 to 2.8 microns.

2. Surface solar reflectivity is measured using a precision spectral pyranometer with the device alternately faced upward towards the sun and downward towards the roof to determine the ratio of incident to reflected solar radiation.

Urban Heat Islands

Large cities typically contain darker surfaces and less vegetation than rural environments; these circumstances increase solar gain and thereby raise summertime cooling-energy demand. The dark surfaces and lack of vegetation also warm the summer air, leading to the creation of the urban "heat island." In fact, the average temperature in a typical city on a clear afternoon can be 1deg.F-5deg.F hotter than that of the surrounding rural area. Researchers at LBL Heat Island Project estimate that the additional air-conditioning use caused by this urban air temperature increase is responsible for 5%-10% of urban peak electric demand, at an annual cost of several billion dollars.

The power needed to compensate for these higher temperatures requires additional generating capacity, which often contributes to urban air pollution. Moreover, the elevated temperatures themselves accelerate smog formation. According to researchers with LBL, the probability of smog increases by 2%-4% per deg.F increase in maximum daily temperature. But shade trees and light-colored surfaces can offset, and may even reverse the summer heat island effect.

In one experiment, LBL examined the savings due to cooling roofi