Example - for a 3-bedroom, 2,000-sq.ft. home, with an exhaust-only ventilation strategy, and a target ventilation rate of 50 CFM you would need to install a 50 CFM fan with an adjustable-speed DC motor for continuous operation.
Quick Answer. Trenches were built during World War I to protect stalemated troops on both sides from artillery and rifle fire. Although the war began with rapid movement of the German army, when the Allied forces stopped the Germans, both sides dug trenches to help avoid losing territory they had gained.
The goal of The Middle Ages is to help students understand the basic concepts of this historical period, including the barbarian invasions, feudalism, the Crusades, the devastation of the plague, the causes of the Renaissance and the beginning of the Reformation. This is accomplished through hands-on and project-based activities.