Ceiling fan
Meanwhile, electric ceiling fans became very popular in other countries, particularly those with hot climates, such as India and the Middle East, where a lack of infrastructure and/or financial resources made energy-hungry and complex freon-based air conditioning equipment impractical. In 1973, Texas entrepreneur H. W. (Hub) Markwardt began importing highly efficient ceiling fans to the United States that were manufactured in India by Crompton Greaves, Ltd. Crompton Greaves had been manufacturing ceiling fans since 1937 through a joint venture formed by Greaves Cotton of India and Crompton Parkinson of England, and had perfected the world's most energy efficient ceiling fans thanks to its patented 20 pole induction motor with a highly efficient heat-dissipating cast aluminum rotor. These Indian manufactured ceiling fans caught on slowly at first, but Markwardt's Encon Industries branded ceiling fans (which stood for ENergy CONservation) eventually found great success during the energy crisis of the late 1970s and early 1980s, since they consumed far less energy (under 70 watts of electricity) than the antiquated shaded pole motors used in most other American made fans. The fans became very effective energy saving appliances for residential and commercial use by supplementing expensive air conditioning with a cooling wind-chill effect. Fans used for comfort create a wind chill by increasing the heat transfer coefficient, but do not lower temperatures directly.
Due to this renewed commercial success using ceiling fans effectively as an energy conservation application, many American manufacturers also started to produce, or significantly increase production of, ceiling fans. In addition to the imported Encon ceiling fans, the Casablanca Fan Company was founded in 1974. Other American manufacturers of the time included the Hunter Fan Co. (which was then a division of Robbins & Myers, Inc), FASCO (F. A. Smith Co.), and Emerson Electric; which was often branded as Sears-Roebuck.
General Electric GE9X
The GE9X should increase fuel efficiency by 10% over the GE90. Its 61:1 overall pressure ratio should help provide a 5% lower thrust specific fuel consumption (TSFC) than the XWB-97 with maintenance costs comparable to the GE90-115B The initial thrust of will be followed by derated variants.
GE invested more than $2 billion for its development, its nacelle is wide.
Most efficiency increase comes from the better propulsion efficiency of the higher-bypass-ratio fan. The bypass ratio is planned for 10:1. The fan diameter is . It has only 16 blades, whereas the GE90 has 22 and the GEnx has 18. This makes the engine lighter, and allows the low pressure (LP) fan and booster to spin faster to better match its speed with the LP turbine. The fan blades feature steel leading edges and glass-fibre trailing edges to better absorb bird impacts with more flexibility than carbon fiber. Fourth generation carbon fiber composite materials, comprising the bulk of the fan blades, make them lighter, thinner, stronger, and more efficient. Using a composite fan case will also reduce weight.
The high pressure (HP) compressor is up to 2% more efficient. As the GE90 fan left little room to improve the bypass ratio, GE looked for additional efficiency by upping the overall pressure ratio from 40 to 60, focusing on boosting the high-pressure core's ratio from 19:1 to 27:1 by using 11 compressor stages instead of 9 or 10, and a third-generation, twin-annular pre-swirl (TAPS) combustor instead of the previous dual annular combustor. Able to endure hotter temperatures, ceramic matrix composites (CMC) are used in two combustor liners, two nozzles, and the shroud up from the CFM International LEAP stage 2 turbine shroud. CMCs are not used for the first-stage turbine blades, which have to endure extreme heat and centrifugal forces. These are improvements planned for the next iteration of engine technology.
The first-stage HP turbine shroud, the first- and second-stage HP turbine nozzles and the inner and outer combustor linings are made from CMCs, only static components, operating hotter than nickel alloys with some cooling. CMCs have twice the strength and one-third the weight of metal. The compressor is designed with 3D aerodynamics and its first five stages are blisks, combined bladed-disk. The combustor is lean burning for greater efficiency and 30% NOx margin to CAEP/8. The compressor and high pressure turbine are made from powdered metal. The low-pressure turbine airfoils made of titanium aluminide (TiAl) are stronger, lighter, and more durable than nickel-based parts. 3D printing is used to manufacture parts that would otherwise be impossible to make using traditional manufacturing processes. CMCs need 20% less cooling.