A recirculating room HVAC unit is installed in a hospital space where Table 4-A permits air recirculation by room units. According to CMC Section 407.4.1.7, which of the following is a requirement for such a unit?

• It must have a filter with a minimum MERV rating of 13.
• It must serve only a single space.
• It must be capable of providing 100% of the required outdoor air changes for the space.
• It may serve multiple adjacent rooms if they are in the same pressure relationship.