SPF insulation ... protected with a UV coating.
Foam spray ‘saves more energy’
Spray polyurethane foam is growing in popularity in the region’s insulation market, says Amir Naqvi, commercial development manager, Honeywell Specialty Materials, Middle East.
01 December 2009
RESIDENTIAL and commercial buildings have used closed-cell spray polyurethane foam for insulation and sealing purposes for many decades in the US, Europe and Japanese markets and this concept is now gaining popularity among builders, designers and architects in the Middle East.
As green building initiatives gather momentum in the GCC, building regulations have become more stringent over the years with the focus being on energy conservation.
Closed-cell spray polyurethane foam (SPF) has evolved as an excellent choice not only to comply with the standards but also to provide excellent energy benefits. The system comprises a two-component foam plastic in liquid form that is sprayed onsite to a wall or roof. It then expands up to 30 times its original volume to fully cover the surface as a rigid foam without any voids or gaps. Because it becomes a monolithic sealed surface, it acts as a thermal insulator, and an air and moisture barrier. It also fully waterproofs the surfaces to which it is applied. A ultra-violet (UV) protective and highly-reflective coating is usually applied to roofs to provide UV and additional weathering protection. Acrylic, silicone and polyurethane one-component coatings are typically used for the protection of foam against UV light.
Closed-cell spray polyurethane foam bonds extremely well with most construction material substrates such as metal, concrete, wood, asphalt, clay tiles and corrugated tin sheet.
Multi-tasking material
SPF is a multi-tasking building construction material. As a thermal insulator, it provides optimum levels of Lambda-value. SPF insulates and eliminates thermal bridges (which can exist with other forms of insulation).
It provides air-barrier protection and assistance in moisture control in buildings as it forms a continuous waterproofed surface.
It also provides structural strength and a long-lasting, sustainable insulation system that can last indefinitely if properly maintained. The life of roofing systems can be extended indefinitely by re-coating the SPF surface typically about every 15 years, depending on the extent of weathering and severity of use.
Energy saver
Closed-cell spray polyurethane foam provides a unique system that meets or exceeds energy performance standards associated with the building envelope, which is by far the most significant contributor to energy losses.
Closed-cell SPF provides contiguous building-envelope thermal insulation, air-barrier and moisture-management systems that outperform its competitors.
One of the simplest, quickest and least expensive energy improvements to a commercial building can be achieved by air-sealing the area between a roof deck (such as metal decking) and the exterior walls with closed-cell SPF insulation.
In addition, air-sealing with SPF around all penetrations, such as pipes, drains, curbs, heating, ventilation and air-conditioning (HVAC equipment) doors and windows, eliminates the loss of heating and cooling energy through the stack-effect of unconditioned air flow in and out of the building. This process can be performed on new buildings, existing facilities and during re-roofing application.
Air-conditioning in the Middle East accounts for 65 to 70 per cent of the electricity consumption in the residential and commercial sectors. According to the EPA (Environmental Protection Agency), the savings potential through proper design and installation of energy-efficient upgrades is more than 35 per cent. It has been well documented that significant energy savings can be obtained by using closed-cell SPF insulation to reduce the HVAC load.
Closed-cell spray polyurethane can be applied over the roof and walls of new commercial, industrial or residential buildings to provide insulation and waterproofing benefits.
Because of its ease of application, the product can be sprayed over the roofs of existing buildings – commercial or industrial sheds/warehouses – to reduce the transfer of heat, thereby providing energy savings through reduced HVAC load in case of air-conditioned buildings. Apart from insulation, it also addresses the problem of water seepage seen in most tin/steel-roofed buildings, warehouses or factories during rains as it can also be used as an effective waterproofing material.
Thermal insulation standards
Thermal insulation regulations for buildings were prepared and agreed upon by the GCC member states in Doha, Qatar, in 1984. The proposed U values were 0.74 W/sq m K for walls and 0.75 w/sq m K for the roof.
Dubai was the first city in the region to implement regulations regarding the technical specifications of thermal insulation material (U value of 0.44 W/sq m K for roofs and 0.57 W/sq m K for walls).
To meet the above levels, builders have a range of insulating material options to choose from. In the Middle East, the commonly-used insulating materials were expanded polystyrene or versions of natural fibres.
Closed-cell SPF is now emerging as the preferred choice in the region on account of its high R-value and because it provides maximum opportunity to reduce energy consumption in new and existing buildings. Spray foam also reduces the amount of direct sunlight on the more thermally-conductive materials that roofs are typically constructed from, and thus the total heat load on the air-conditioning system.
Benefits
Closed-cell SPF reduces energy costs because it can be applied above or below the roof deck; it eliminates thermal bridging by providing a seamless continuous layer of insulation over an existing substrate in both roof deck and/or wall assemblies; and has a very high aged R-value of between six to seven (per inch). It is typically coated with light-coloured, highly-reflective coatings when installed externally in roofing applications; and easily conforms to various shapes and configurations.
Many large companies and institutions have documented energy savings from the use of SPF roofing systems. Texas A&M calculated the energy consumption of their buildings before and after the application of such systems. After studying more than 743,224 sq m of roofing, they concluded the energy savings paid for the cost of SPF retrofits within three to four years.
Commercial buildings
Quite simply, energy costs and building codes are creating a critical demand for the adoption of cost-effective systems that efficiently and consistently insulate and seal commercial buildings, while maintaining reasonable costs, low environmental impact and systems engineering implications. For this reason, designers and builders of commercial buildings are urged to take the following actions:
• Understand the energy performance of their buildings and how it can be improved – now and with future energy costs in mind. Audit the performance of the building’s envelope systems and look for ways to improve it. Adopt a culture of continuous improvement in their buildings’ energy use.
• Design their buildings for the future, and seek to understand the performance and cost trade-offs of various moisture, air-barrier and insulation systems compared to the multi-purpose closed-cell SPF insulation and waterproofing system.
• Promote the improvement of energy performance in commercial buildings, and set a higher bar for minimum energy performance for all new and existing buildings. A commitment to improve the performance of buildings increases national energy security, reduces our dependence on oil, decreases the impact of buildings on our environment and improves our bottom line.
• Evaluate the use of closed-cell SPF insulation and waterproofing systems for all construction projects.
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