If you want to convert from an electric furnace to a gas furnace, you will need to have gas piping and ductwork installed first. This will add an additional up-front cost to the furnace and installation process of around $5,000 to $15,000 or more depending on the space. Leaky ducts can also cost homeowners about 10 percent to 30 percent in efficiency. 2  This will make a 96 AFUE high-efficiency furnace run at 66 percent to 86 percent and make an economical 80 AFUE not much better than an open fireplace. 3  The cost to replace ductwork is about $8 to $12 per linear foot of ducting.
A flood basalt is the result of a giant volcanic eruption or series of eruptions that coats large stretches of land or the ocean floor with basalt lava. Flood basalt provinces such as the Deccan Traps of India are often called traps, which derives from the characteristic stairstep geomorphology of many associated landscapes.
A Dictionary of Earth Sciences | 1999 | 588 words. Â© A Dictionary of Earth Sciences 1999, originally published by Oxford University Press 1999. Plinian eruption An explosive volcanic eruption of pyroclastic ejecta forming an eruption column which may be up to 55 km high, dispersing ejecta over an area of 500â5000 km.The eruption column has the distinctive, spreading, branched shape of the stone pine (Pinus pinea) native to the Mediterranean region. Plinian eruption may produce thick, airfall, pumice deposits, or the eruption column may collapse to generate a pyroclastic flow. This type of eruption is named after Pliny the elder, who died at Pompeii in AD79 during the eruption of Vesuvius that destroyed the city.