ANSI/ASHRAE/ASHE Standard 170-2021 Ventilation of Health Care Facilities

ANSI/ASHRAE/ASHE Standard 170 offers guidance, regulation, and mandates to designers and operators of health care facilities. The revised 2021 edition incorporates 17 addenda to the 2017 standard.

The updated standard includes the following significant changes:

• Revised scope, with improved guidance on thermal comfort conditions provided
• Extensive modifications to address the Outpatient and Residential sections
• Addition of a new outpatient ventilation table to address nonacute-type spaces
• Extensive revisions to air filtration requirements.
• Addition of new columns in the ventilation tables to prescribe filtration requirement and designate unoccupied turndown
• Expanded guidance on separation distance requirements for varied intake and exhaust arrangements, coordinating with related ASHRAE Standard 62.1 data
• Expanded requirements to allow airborne infectious isolation room exhaust discharge to general exhaust under certain conditions
• Improved guidance on space ventilation requirements needed for anesthetic gas use
• Clarification of Class 1/Class 2/Class 3 imaging in coordination with FGI
• Revised definition of invasive procedure
• Improved guidance related to behavioral and mental health

Most notably, the 2021 edition incorporates content in support of the new framework introduced in 2017, which expanded the standard into three distinct sections: hospital spaces, outpatient spaces, and residential healthcare spaces in alignment with the Facility Guidelines Institute (FGI) publications.