Ashrae Table 7.1. At least 75 of all the replacement air is transfer air that would otherwise be exhausted. You need to understand the function of the room and possible.
Note f states that higher ventilation rates above the total ach listed shall be used when dictated by the laboratory program requirements and the hazard level of the potential contaminants in each laboratory work area. Hospital spaces Outpatient spaces Nursing Home spaces This is also the drive behind a major change to ANSIASHRAEASHE Standard 170-2017. Except where indicated by a No in this column recirculating room HVAC units with heating or cooling coils are acceptable for providing that portion of the minimum total air changes per hour that is.
For design purposes the minimum number of tota l air changes indicated shall be either sup-plied for positive pressure rooms or exhausted.
All documents linked from this page are in PDF-format. Figure 1 below is an excerpt from Table 71 from ASHRAE Standard 170-2017. All documents linked from this page are in PDF-format. According to Std 170 section 71a2.
