WALLS & ROOFS takes a look at the impact of roofing and ceilings on the environment and individuals.
Roofing has become somewhat of a playground for new innovation and technologies. The effects of its colours, materials and styles on the aesthetic quality and energy-efficiency of a building, make roofs and ceilings an integral part of the planning and construction of residential and commercial buildings.
The latest new ceiling products cover everything from acoustics to recyclability and integrated lighting systems.
Hear no evil
The recent trends in design of buildings include the use of open plan spaces, particularly in offices. The perceived benefits are efficient use of available floor surface, increase knowledge exchange between staff and flexibility of space.
At the same time office workers mention noise in the workplace as the most common disturbance factor. Here we need to balance between communication and concentration. Constant exposure to noise will lead to lack of privacy, poor concentration and an increased stress levels. Research shows that our accuracy with high noise levels reduces with 50%. This is a huge and unnecessary cost.
Companies that build open plan for initial cost savings, risk being less profitable if optimised room acoustics are not safeguarded in the initial programme of demands and throughout the design.
The suspended ceiling was originally developed to hide various installations such as cable and HVAC. Obviously the suspended ceiling is by far the biggest of available surfaces to get the necessary amount of sound absorption from. The acoustic performance of suspended ceilings has developed impressive properties, such as enhanced sound absorption and attenuation. This is respectively achieved by using panels with absorption Class A, providing the highest absorption coefficient of sound in a broad range of frequencies. Addressing attenuation could be done by using sound insulating material above the acoustic suspended ceiling and the partition in particular to limiting the sound to be overheard and keep adjacent rooms quieter.
An increasing amount of studies have shown that improved room acoustics are conducive to learning, working and healing. The benefits of well planned room acoustics in other areas than offices are improved learning and teaching in schools. In healthcare premises we’ve seen that adding absorption Class A ceilings has resulted in reduced intake of pain medication, reduced number of readmission rates and improved sleep and recovery, implying that well planned room acoustics will positively impact on medical as well as economic outcomes.
To get the best possible conditions for working, learning and healing, good room acoustics is the most important thing to create.
Sound transmission refers to the obvious impact of the noise when either entering or leaving a room. Structural isolation becomes an important consideration in the acoustic design of buildings. A tightly sealed door might have reasonable sound reduction properties, but if left open its effectiveness may be significantly reduced. The most important acoustic control method is adding mass into the structure, such as a heavy dividing wall, which will usually reduce airborne sound transmission better than a light one.
Acoustic absorption refers to a material, structure or object absorbing sound energy when sound waves collide with it, as opposed to reflecting the energy.
The fraction of sound absorbed is governed by the acoustic absorption coefficient of the core material. Also the surface finish is important, an acoustic panel is never better than its surface. The porous surface with microporous holes in it allows sound waves from different directions to penetrate the panel and interact with the core material.
Any large interior space needs some form of sound absorption. Many of the typical noise issues in open designs, such as the industrial trend of exposed ceilings, will benefit from the installation of acoustic canopies, blades or baffles. Needless to say that from an acoustic perspective a wall to wall suspended ceiling will give the best result. Covering a 50-60% of the equivalent floor surface area with these units in an absorption class A will be comparable to a wall to wall ceiling. Additional absorption on walls will secure the low frequency absorption, while working with these free hanging units.
To enhance the acoustic comfort of a space, it must first be determined which activities will take place in the area and what the sound preferences for that particular activity is. Saint-Gobain Ecophon has developed a concept about what it takes to create a good sound environment, which is based on the interaction between the person, the room and the activity determining the room’s acoustic comfort, which contributes to human well-being.
The company’s latest innovation is sound light comfort ceiling is a unique, integrated light and acoustic ceiling system that offers the ultimate in ceiling integration. It inspires tranquility as it improves well-being and performance in the office space by integrating comfortable LED lighting with superior sound absorption.
A softer blow
Another benefit of suspended ceilings and external roofing systems, include the fact that it can significantly reduce the environmental impact of a building, due to its thermal control properties.
White roofs have continuously proven to reduce buildings’ energy usage and lower utility bills. On a clear day, a conventional dark roof can get 40°C to 50°C hotter than the outside air. According to the International Energy Agency (IEA), a clean white roof, by comparison, is only 5°C to 10°C warmer than the ambient air.
With roofs accounting for roughly 25% of the urban surface area and with cities occupying 1% to 2% of the global land area, converting most flat roofs in warm cities to white would cancel warming from more than one gigatonne of CO2 per year for the average lifetime of the roofs.
SolarWorld Africa and its engineering, procurement and construction (EPC) partner, African Technical Innovations, recently supplied and installed Southern Africa’s largest agricultural rooftop photovoltaic (PV) system (1,015MWp) for Ceres Fruit Growers.
The 4060 SW250 SolarWorld polycrystalline panels are being installed on four north-facing roofs of Ceres Fruit Growers’ coldrooms. The SolarWorld system will supply Ceres Fruit Growers’ electrical grid with power to be largely consumed by the refrigeration compressor rooms during peak season.
The system will generate approximately 6% (1 690MWh) of Ceres Fruit Growers’ annual electricity consumption, reducing their carbon footprint by approximately 1 622 tons per annum over the next 25 years and more. In addition, Ceres Fruit Growers’ sustainability policy places great emphasis on exploring new technologies that will reduce energy usage with the goal of reducing their energy consumption by 10% over the next three years.
Full thanks and acknowledgement are given to the International Energy Agency, Saint-Gobain Ecophon and SolarWorld Africa for the information given to write this article.