What is the definition of a parallel fan powered box? It is an efficient, space-saving, and cost-effective solution for delivering conditioned air to a space. A parallel fan powered box is a type of terminal unit that consists of two components: a primary fan and a secondary fan. The primary fan is used to draw in supply air from the outside and push it into the conditioned space. The secondary fan then further conditions the air by mixing the supply air with recirculated air from the space. This mixing helps to reduce energy consumption by providing a more even air distribution. The parallel fan powered box is an ideal choice when multiple air changes are needed in a space, as multiple fans can be utilized to achieve the desired level of air movement. Additionally, the fans used in a parallel fan powered box can be controlled independently, allowing for greater control over the air distribution within a space. The parallel fan powered box is an efficient and cost-effective solution for large spaces that require multiple air changes