tailieunhanh - ENERGY MANAGEMENT HANDBOOKS phần 5

và một giới hạn thấp nhiệt ngăn ngừa nhiệt độ của không khí bên ngoài xuống thấp hơn nhiệt độ đặt trước (thường là 55 đến 60 ° F, 13-16 ° C). Một lỗi phổ biến của người cư ngụ hoặc người chăm sóc xây dựng một cảm giác rằng không khí được cung cấp bởi các máy thở đơn vị là quá lạnh để tăng giá trị điểm đặt nhiệt thấp, | 358 Energy Management Handbook Table Lamp characteristics Incandescent Including Tungsten Halogen Wattages lamp only 15-1500 Fluorescent 15-219 Compact Fluorescent 4-40 Mercury Vapor Self-ballasted 40-1000 Metal Halide 175-1000 High-Pressure Sodium Low-Pressure Improved Color Sodium 70-1000 35-180 Life hr 750-12 000 7 500-24 000 10 000-20 000 16 000-15 000 1 500-15 000 24 000 10 000 18 000 Efficacy 15-25 lumens W lamp only 55-100 50-80 50-60 20-25 80-100 75-140 67-112 Up to 180 Lumen maintenance Fair to excellent Fair to excellent Fair Color rendition Excellent Good to excellent Good to excellent Very good good Poor to excellent Good Very good Excellent Fair Excellent Poor Light direction control Very good to excellent Fair Fair Very good Very good Very good Fair Relight time Immediate Comparative fixture cost Low simple Comparative operating High cost Immediate Moderate Lower than incandescent Imm- 3 seconds Moderate Lower than incandescent 3-10 min. Higher than fluorescent Lower than incandescent 10-20 min. Generally higher than mercury Lower than mercury Less than 1 min. High Lowest of HID types Immediate High Low Incandescent The oldest electric lighting technology is the incandescent lamp. Incandescent lamps are also the least efficacious have the lowest lumens per watt and have the shortest life. They produce light by passing a current through a tungsten filament causing it to become hot and glow. As the tungsten emits light it gradually evaporates eventually causing the filament to break. When this happens the lamps is said to be burned-out. Although incandescent sources are the least efficacious they are still sold in great quantities because of economies of scale and market barriers. Consumers still purchase incandescent bulbs because they have low initial costs. However if life-cycle cost analyses are used incandescent lamps are usually more expensive than other lighting systems with higher efficacies. Compact Fluorescent Lamps CFLs Overview of CFLs