Views:7 Author:Site Editor Publish Time: 2015-05-14 Origin:Site
PVC building products have numerous energy and environmental benefits. Since the late 1980s, more than 20 life-cycle evaluations have been completed on PVC building products and many of those products are compared with the similar products made of other materials. PVC products were found to perform favorably in terms of energy efficiency, thermal-insulating value, low contribution to greenhouse gases and product durability, which means using fewer resources.
Energy efficiency and reducing greenhouse gas emissions. PVC saves energy and reduces CO2 emissions. PVC consumes less energy to produce than many competing products, and 20 percent less than other plastics. PVC also saves fossil fuels. Its principal raw material (nearly 60 percent) is chlorine derived from common salt. PVC building products are highly energy-efficient. PVC pipe requires less energy to pump water.
Durability. PVC building products are highly durable, which conserves resources. They will not rot or corrode like many other materials and do not need cleaning with harsh chemicals or frequent painting.
Recycling. PVC is inherently recyclable. More than 1 billion pounds are recycled annually (mostly post-industrial) according to a recent study. Many carpet manufacturers using PVC backing have highly successful recycling programs, including C&A Floorcoverings (which has recycled over 100 million pounds of vinyl backed carpet). The Vinyl Institute recently won an award from WasteCap Wisconsin for support for recycling vinyl siding cutoffs at job sites.
Water Savings. 2.2 trillion gallons of treated water are lost every year in the United States because of leaks from aging and corroded metal pipes. Because PVC pipes do not corrode and have the lowest pipe breaks, they save precious water resources.
Life Cycle Analysis. PVC's impacts on the environment are comparable to or lower than most alternatives. A 2004 study of environmental life-cycle analyses (LCAs) of PVC and competing building materials by the European Commission (EC) found that PVC offered environmental benefits equal to or better than those of other materials in many applications. The USGBC PVC Task Group reached similar conclusions in its draft report issued December 2004.
Dioxin? PVC is an extremely small source of dioxin – so small that levels in the environment would be essentially unchanged even if vinyl were not being manufactured and used every day in important products. The proof: dioxin levels in the environment have been declining for decades, according to data from the U.S. Environmental Protection Agency. During this time, production and use of vinyl have soared.
Worker Safety? OSHA statistics show that injury and illness rates among PVC workers are significantly lower than the manufacturing average. In the 1970s, industry scientists discovered that vinyl chloride, a chemical used to make PVC, could cause angiosarcoma, a rare form of liver cancer, in workers exposed at that time to very high doses. This led to a complete overhaul of the PVC production process, which became essentially a closed loop, recycling wastes back into production and minimizing worker exposure. The U.S. Occupational Safety and Health Administration issued strict regulations in 1975, and there have been no documented cases of angiosarcoma among PVC production workers whose careers in the industry after the new regulations were promulgated.
Indoor Air? Odors and "offgassing" from building products are generally due to dyes, adhesive, and additives. Many building-product manufacturers today are working to reduce use of volatile chemicals and release of their odors. Resilient PVC flooring that is qualified under the Resilient Floor Covering Institute's FloorScore™ program can be certified to help to obtain the Green Building Council's indoor air credit under the LEED rating system. PVC-backed carpet can meet the comparable Green Label program of the Carpet & Rug Institute.
PVC in Building and Construction
Approximately 76 percent of PVC is used in building and construction. The following overview of the major types of PVC building products discusses the reasons why these building products are used.
PVC's durability is an important environmental benefit, because the longer a product lasts, the less energy and other resources must be expended to make and install replacement products. PVC also conserves energy in manufacture and, more importantly, in use.
PVC building and construction applications are typically divided into rigid and flexible categories. The use of plasticizers differentiates flexible PVC products from rigid. Generally speaking, PVC materials are classified as rigid when plasticizers have not been added to the resin, such as pipe, siding, windows and fence, deck and rail. PVC flooring, wallcovering and reflective roofing are classified as flexible, and are available in a multitude of styles and colors.
PVC Pipe and Fittings
Overview. Pipes and fittings comprise the largest portion (44 percent) of PVC usage for building and construction. PVC has become the leading material for large diameter buried pipelines installed by both water and wastewater utilities as well as for smaller diameter drain waste and vent (DWV) piping. CPVC pipes are used for indoor water plumbing pipe. On a lineal basis, PVC has become the leading pipe material in the United States today, accounting for more than 70 percent of all water and sewer pipe now being installed. Alternative metal pipe materials (iron, steel, copper) are vulnerable to corrosion and premature failure. Concrete and clay pipe materials are prone to cracking or fracturing which results in leakage or contamination. PVC is certified for contacting with drinking water by NSF International and offers complete immunity to electrochemical corrosion. PVC's flexibility enables it to resist cracking and leakage.
On January 29, 2007, the state of California gave unrestricted approval to CPVC piping for residential plumbing based on a lengthy and thorough environmental impact review by the state's Department of Housing and Community Development. It had already been approved in other 49 states.
Energy Efficiency and Reduce CO2 Emissions. PVC pipe manufacturing is energy efficient, consuming fewer BTUs than alternative materials for equal lengths of pipe. A Franklin Associates study has indicated that the manufacture of pressure piping used in the building, construction and transportation industries required 56,497 trillion fewer BTUs than iron and concrete/aggregate alternatives would require if they were substituted for all PVC pipe. PVC pipe and fittings also weigh less than alternative piping materials, allowing for significant energy savings in their transportation. Their lighter weight enables them to be installed more easily and efficiently than alternatives.
Resource Conservation. PVC pipe's durability results in resource conservation. When it is properly designed and installed, PVC pipe has an estimated life span well beyond 100 years, with little or no loss of strength. The National Research Council of Canada found that the "break rate" for vinyl water distribution pipe was 0.5 breaks per 100 km (62 miles) per year as compared with 32.6 breaks per 100 km per year for cast iron and 7.9 breaks per 100 km per year for ductile iron. Lower break rates minimize the risk of contamination and provide major savings in time and resources. Pipe breaks and water loss are major problems for water utilities with corroding metal pipes. According to the American Water Works Association approximately 15 percent of treated water is lost due to line breaks and leaks. That is 2.2 trillion gallons of water every year. A recent Federally funded study estimates that the corrosion of water and sewer pipes costs the US economy $36 billion annually.
Certification. All PVC drinking water pipes are certified under NSF International's Standard 61, to assure the preservation of drinking water quality standards established by the US EPA.