Designed for HVAC applications, Climatherm® SDR 17.6 is now available in large pipe sizes up to 24 inches in diameter. SDR, or standard dimension ratio, is the ratio of pipe-diameter-to-wall-thickness, and these larger pipe offerings have reduced SDRs in order to keep weight and costs down. According to the manufacturer, the SDR 17.6 product is ideally positioned for energy-efficient applications like heat pumps and large chilled water systems. The polypropylene-random (PP-R) highly engineered pressure pipe is resistant to polyolester (POE) oil and other oils in HVAC mechanical systems. The pipe is engineered to last more than 50 years. Features include heat stabilization and a faser-composite layer that reduces thermal expansion by as much as 75 percent compared to other plastics, claims the company. The new pipe sizes can be used in direct-bore applications that allow district cooling without all the surface disruption associated with trenching. Additionally, the natural insulation value of the PP-R pipe (with an R-value of 1) allows it to be utilized for direct-buried applications, and the product is extremely freeze-resistant, says the company. The large diameter Climatherm offers an alternative to steel pipe in high-rise buildings, district energy, and campus applications.