Motor efficiency can have a major influence on overall fan and ventilation system energy efficiency, and hence operating costs. Some manufacturers offer fan models with high efficiency motors. Although usually more expensive initially, high efficiency motors can require over 20 percent less energy to operate than low efficiency motors. Speed of the fan motor and blade also influences fan efficiency. As the speed of a fan increases, turbulence of the air moving through the fan increases and efficiency decreases.
Turbulence is a primary factor influencing the noise level of a fan.
A fan or ventilation system does not need to be noisy. Blade design or shape is important for determining the energy efficiency of a fan. In addition, some fan companies utilize blade designs that reduce or minimize the buildup of dirt. This is particularly important because of the high levels of moisture and dust in most livestock housing facilities. Housing design also influences fan efficiency.