Make Up air is the fresh outside air that is introduced into a building through a mechanical system. This is essential to the proper balance and function of the HVAC system since there are exhaust systems which are constantly removing air from places such as bathrooms, kitchens, etc. In addition to balancing the air pressure, the benefits of outdoor air for maintaining proper oxygen levels and diluting contaminants within the indoor space are significant. These systems which provide the fresh outdoor air can also be equipped with sophisticated filters, dehumidification, and temperature control technologies to further benefit the air hygiene within a building