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.
World War 1 trenches were dirty, smelly and riddled with disease. For soldiers life in the trenches meant living in fear. In fear of diseases (like cholera and trench foot) and of course, the constant fear of enemy attack.orld War 1 trench warfare was so intense that 10% of all the soliders who fought were killed. Thatâs more than double the percentage of fighting soldiers who were killed in the Second World War (4.5%).