Part 1 General

Part 2 Outpatient Facility Types

ANSI/ASHRAE/ASHE Standard 170-2017 Ventilation of Health Care Facilities

Heads up: There are no amended sections in this chapter.
Specific terms and definitions are provided to facilitate consistency in the interpretation and application of the Guidelines. Some of these terms may have a broader definition in other contexts, but the definitions provided here reflect the use of the terms in the Guidelines. For words that do not appear here, please refer to the Merriam-Webster Collegiate Dictionary.
Adjacent: See Location terminology.
Administrative areas: Designated spaces such as offices and meeting rooms that accommodate admission and discharge processes, medical records storage, medical and nursing administration, business management and financial services, human resources, purchasing, community services, education, and public relations.
Airborne infection isolation (AII) room: A room designated for persons having or suspected of having an infection that is spread through coughing or other ways of suspending droplets of pathogens (e.g., tuberculosis, varicella-zoster virus, measles) into the air.
Area: A particular extent of space or surface serving a defined function.
Authority having jurisdiction (AHJ): An individual or organization designated by a state or government agency to enforce building codes and other regulations related to construction projects.
Bariatric patient: A patient admitted specifically for bariatric care. See also Patient (or person) of size.
Bay (patient): See Patient care locations.
Bio-hazardous waste or bio-waste: Waste that contains or has come into contact with bacteria or other pathogens, blood, or body fluids.
Chemical waste: Waste that contains toxic, caustic, or otherwise dangerous chemicals.
Clearance: The required minimum distance between a specified object (e.g., a patient bed or exam table) and any fixed or immovable element of the environment. Note: Movable equipment and furniture that do not interfere with functions or could be easily moved out of the way are not used to calculate minimum clearance.
Clear dimension: An unobstructed room dimension exclusive of built-in casework and equipment and available for functional use.
Clear floor area: The floor area of a defined space that is available for functional use excluding toilet rooms, closets, lockers, wardrobes, alcoves, vestibules, anterooms, and auxiliary work areas. Note: Door swings and floor space below sinks, counters, cabinets, modular units, or other wall-hung equipment that is mounted to provide usable floor space count toward "clear floor area." Space taken up by minor fixed encroachments that do not interfere with room functions can be included in calculating clear floor area.
Client: A psychiatric patient. For purposes of this document, "psychiatric patient" will refer to a psychiatric client in an inpatient or outpatient facility.
Clinical sink: A flushing-rim sink or "hopper" used for disposal of blood or body fluids (e.g., bedpan washing). Note: This is not the same as a hand-washing sink or an instrument-cleaning sink (single- or double-sink type).
Cubicle: See Patient care locations.
Differential pressure: A measurable difference in air pressure that creates a directional airflow between adjacent spaces.
Directly accessible: See Location terminology.
Documentation area: A work area associated with or near a patient care area where information specific to patients is recorded, stored, and reviewed to facilitate ready access by authorized individuals.
Emergency call station. A device that is activated to indicate the need for staff assistance. Note: Such devices produce an audible or visual indication (or both) or may be connected to or transmit to an area alert monitor or personal hand-held device.
Environment of care: Those physical environment features in a health care facility that are created, structured, and maintained to support and enhance the delivery of health care.
Environmental services (housekeeping): Services anywhere in a health care facility that provide general cleaning and supply identified cleaning materials (e.g., soaps, towels). Note: Although routine disinfection protocols can be included in such a definition, the definition is not intended to include complex, non-routine disinfection procedures nor the non-routine disposition of hazardous materials such as potentially toxic drugs or other chemicals.
Examination room: A room with a bed, gurney, or examination table and capability for periodic monitoring (e.g., measurement of blood pressure or pulse oximetry) in which procedures that do not require a specialized suite can be performed (e.g., pelvic examinations).
Facility: A discrete physical entity composed of various functional units as described in the Guidelines.
Fixed equipment: Equipment with track systems attached at some point in the room. Note: Fixed equipment includes ceiling-mounted or overhead lifts, wall-mounted lifts, and other lifting devices with fixed tracking. An alternative would be a demountable track that may be fully or partially disassembled and removed from the space.
Functional program: A record of the key environment of care considerations and facility functional and operational parameters that drive the space program for a project. Note: The governing body or its delegate develops the functional program, which is intended to inform the designers of record, authority having jurisdiction, and users of the facility. The size and complexity of the project will determine the length and complexity of the functional program.
Governing body: The person or persons who have the overall legal responsibility for the operation of a health care facility. Note: Often, the owner is the governing body; for example, the governing body may be a doctor who owns a clinic or the board or administrator of a larger organization.
Hand sanitation dispenser: A dispenser that contains a liquid solution that has been approved by the FDA for hand hygiene.
Hand-washing station: An area that has a sink with a faucet that can be operated without using hands; cleansing agents; and means for drying hands.
Hands-free controls: Faucets that are controlled by knee- or foot-operated pedals or by motion sensors such as electric eye controls. Note: This term does not refer to faucets operated using wrist blades or single-lever faucets.
Hazard: Anything that has the potential to cause harm.
Hybrid operating room: See Surgical facilities.
Immediately accessible: See Location terminology.
In: See Location terminology.
In the same building: See Location terminology.
Infection control risk assessment: A multidisciplinary organizational process that focuses on reducing risk from infection throughout facility planning, design, and construction (including renovation) activities. The environment, infectious agents, and human factors and the impact of the proposed project are considered by a multidisciplinary team that includes, at minimum, those with expertise in infectious disease, infection prevention, patient care, epidemiology, facility design, engineering, construction, and safety, as circumstances dictate.
Invasive fluoroscopy: Therapeutic or diagnostic invasive procedures that require fluoroscopic imaging (e.g., cardiac catheterization, interventional angiography, cardiac stenting, or implantation of devices). Note: These procedures are typically performed in a restricted or semi-restricted area, based on the classification of the imaging procedure being performed.
Invasive procedure: A procedure that is performed in an aseptic surgical field and penetrates the protective surfaces of a patient's body (e.g., subcutaneous tissue, mucous membranes, cornea). An invasive procedure may fall into one or more of the following categories:
  • Requires entry into or opening of a sterile body cavity (i.e., cranium, chest, abdomen, pelvis, joint spaces)
  • Involves insertion of an indwelling foreign body
  • Includes excision and grafting of burns that cover more than 20 percent of total body area
  • Does not begin as an open procedure but has a recognized measurable risk of requiring conversion to an open procedure
Note: Invasive procedures are performed in locations suitable to the technical requirements of the procedure with consideration of infection control and anesthetic risks and goals. Accepted standards of patient care are used to determine where an invasive procedure is performed. "Invasive procedure" is a broad term commonly used to describe procedures ranging from a simple injection to a major surgical procedure. For the purposes of this document, the term is limited to the above description. The intent is to differentiate those procedures that carry a high risk of infection, either by exposure of a usually sterile body cavity to the external environment or by implantation of a foreign object(s) into a normally sterile site. Procedures performed through orifices normally colonized with bacteria and percutaneous procedures that do not involve an incision deeper than skin would not be included in this definition.
Ionizing radiation: Invisible electromagnetic radiation that may be damaging to health (e.g., conventional x-rays, fluoroscopy, CT scans).
Ligature-resistant: Without points where a cord, rope, bed sheet, or other fabric/material can be looped or tied to create a sustainable point of attachment that may result in self-harm or loss of life.
Location terminology (terms for relationship to an area or room):
In Located within the identified area or room
Directly accessible Connected to the identified area or room through a doorway, pass-through, or other opening without going through an intervening room or public space
Adjacent Located next to but not necessarily connected to the identified area or room
Immediately accessible Available either in or adjacent to the identified area or room
Readily accessible Available on the same floor or in the same clinic as the identified area or room
In the same building Available in the same building or an adjoining building as the identified area or room, but not necessarily on the same floor
Major fraction: One-half or more.
Medication safety zone: A critical area where medications are prescribed, orders are entered into a computer or transcribed onto paper documents, or where medications are prepared or administered. (Definition from the U.S. Pharmacopeia and National Formulary, or USP-NF). Also see Zone.
Minimum clearance: See Clearance and Clear dimension.
Mobile/transportable medical unit: Any trailer or self-propelled unit equipped with a chassis on wheels, without a permanent foundation, and intended for provision of medical services on a temporary basis. Note: These units are maintained and equipped to be moved.
Modular/relocatable medical unit: A structure that is prefabricated and finished off-site. Note: Modular units may be built to be capable of relocation, but typically are attached to a permanent foundation, rendering them unmovable.
Monolithic ceiling: A ceiling constructed with a surface free of fissures, cracks, and crevices. Any penetrations such as lights, diffusers, and access panels shall be sealed or gasketed. ("Lay-in" ceilings are not considered "monolithic.")
Nurse station: A multipurpose staff work area used by all caretakers in a patient care unit.
Observation room: A room in a recovery care center or other facility where a patient stays for a limited period as regulated by state or federal law.
Office: See Room.
Operating room: See Surgical facilities.
Patient: A person receiving medical, surgical, or psychiatric care.
Patient (or person) of size: A person whose height, body width, weight, and weight distribution throughout the body require increased space for care and mobilization as well as for use of expanded-capacity devices, equipment, furniture, technology, and supplies. Note: Such patients are not necessarily receiving bariatric care, thus, the term "patient (or person) of size" is often used in place of obese, morbidly obese, or bariatric.
Patient care area: An area used primarily for the provision of clinical care to patients. Such care includes monitoring, evaluation, and treatment services.
Patient care locations
  • Bay (patient): A space for human occupancy with one hard wall at the headwall and three soft walls (e.g., cubicle curtains or portable privacy screen).
  • Cubicle: A space intended for human occupancy that has at least one opening and no door and is enclosed on three sides with full-height or partial-height partitions.
  • Patient care station: A designated space for a specific patient care function. This term does not imply any structural requirement (e.g., a PACU can have 10 patient care stations of which three are rooms, three are cubicles, and four are bays).
Person of size: See Patient of size.
Procedure room: A room designated for the performance of patient care that requires high-level disinfection or sterile instruments and some environmental controls but is not required to be performed with the environmental controls of an operating room.
Provisions for drinking water: Availability of readily accessible potable water for patient, staff, and visitor needs. Note: This may be provided in a variety of ways, including fountains, water bottle refilling stations, and bottled water.
Provisions for telephone access: Readily accessible audible communications for patients, visitors, and staff. Note: This may be provided in a variety of ways: public pay phone, house phone with appropriate instructions, computer with Voice over Internet Protocol capabilities, etc.
Public areas: Designated spaces freely accessible to the public. Note: These spaces include parking areas, entrances, entrance lobbies, reception and waiting areas, public toilets, snack bars, cafeterias, vending areas, gift shops and other retail locations, health education libraries and meeting rooms, chapels, and gardens.
Radioactive waste: Waste containing radioactive materials.
Readily accessible: See Location terminology.
Regulated waste: Waste regulated by federal, state, or local governments that requires special handling and disposal, including biological, chemical, or radioactive waste.
Room: A space enclosed by hard walls and having a door. Note: Where the word "room" or "office" is used in the Guidelines, a separate, enclosed space for the one named function is intended. Otherwise, the described area may be a specific space in another room or common area.
Safety risk assessment (SRA): An assessment of the potential risks to a patient inherent in each space and building component of the health care project being planned. Note: For each space or component, this safety risk assessment defines each specific hazard's likelihood of occurrence based on historical data and its potential to harm patients.
Scrub position: A space equipped with a hands-free plumbing fixture equipped to enable medical personnel to scrub their hands prior to a surgical procedure. The hot and cold water supply is activated by a knee-action mixing valve or foot control.
Scrub station: A space with one or more scrub positions.
Secure area: A space to which entry is restricted for reasons of security rather than infection control (e.g., areas where prisoners are treated or where drugs or hazardous materials are stored) that do not have infection control issues but do require traffic to be limited to authorized personnel and patients.
Service areas: Designated spaces that house auxiliary functions that do not routinely involve contact with patients, clients, or the public. Note: Examples of these spaces include supply, processing, storage, and maintenance services such as pharmacy, dietary, sterile processing, laundry processing and storage, environmental services, engineering operations, and waste collection and storage facilities.
Space program: A translation of the owner's operational needs into architectural and engineering requirements. Note: The size and complexity of the project will determine the length and complexity of the space program.
Speech privacy: Techniques to render speech unintelligible to casual listeners. (Definition from ANSI T1.523-2001: Glossary, a standard maintained by the U.S. Department of Commerce, National Telecommunications and Information Administration, Information Security Program.) Note: This definition matches earlier ones in ANSI S3.5 (1969) and ASTM E1130 (1997 & 2001) and is consistent with ASTM E2638 (2011). See ASTM E1130 and ASTM E2638 for four defined, measurable levels of speech privacy. Speech privacy is a condition required by HIPAA (the Health Insurance Portability and Accountability Act) and is the subject of the "noise-at-night question" on the HCAHPS patient satisfaction survey.
Station: See Hand-washing station, Nurse station, Patient care locations, Scrub station.
Support areas (for patient care units, diagnostic and treatment areas, etc.): Designated spaces or areas in which staff members perform auxiliary functions that support the main purpose of the unit or other location. Note: Where the word "room" or "office" is used, a separate, enclosed space for the one named function is intended. Otherwise, the described area is permitted to be a specific space in another room or common area.
Support areas (for patients, families, and/or visitors): Designated spaces for the use of patients, clients, registrants, or visitors (e.g., changing areas, dining rooms, toilet rooms, lounges) or families and visitors (e.g., waiting areas and lounges, children's play areas, toilet rooms). Note: Where the word "room" or "office" is used, a separate, enclosed space for the one named function is intended. Otherwise, the described area is permitted to be a specific space in another room or common area.
Support areas (for staff): Designated spaces for the personal use of staff (e.g., changing areas, toilet rooms, showers, lounges, dining areas). Note: Where the word "room" or "office" is used, a separate, enclosed space for the one named function is intended. Otherwise, the described area is permitted to be a specific space in another room or common area.
Surgical facilities:
  • Operating room (OR): A room in the surgical suite that meets the requirements of a restricted area and is designated and equipped for performing invasive procedures.
  • Hybrid operating room: A room that meets the definition of an operating room and has permanently installed equipment to enable diagnostic imaging before, during, and after surgical procedures. Note: Imaging equipment may include MRI, fixed single-plane and bi-plane tomographic imaging systems, and computed tomography equipment. Use of portable imaging technology does not make an OR a hybrid operating room.
Sustainability: A means of configuring human activity so that society, its members, and its economies are able to meet their needs and express their greatest potential in the present, while preserving biodiversity and natural ecosystems in the long term; improving the quality of human life while living within the carrying capacity of supporting ecosystems.
Sustainable design: The art of designing physical objects, the built environment, and services to comply with principles of economic, social, and ecological sustainability.
System component room: A room that contains the electrical components for various imaging modalities (e.g., CT, MRI, fluoroscopy). Note: This room is not the same as the control room required for some imaging modalities.
Telemedicine: The use of electronic information and communications technologies to provide and support health care when distance separates the patient and medical provider. Note: Clinical applications of telemedicine may encompass diagnostic, therapeutic, and forensic modalities. Common applications include pre-hospitalization assessment and post-hospital follow-up care, scheduled and urgent outpatient visits, medication management, psychotherapy, and consultation. Patient and provider consultations, medical imaging, remote monitoring, and education are all services that can be provided via telemedicine. A variety of technologies, including videoconferencing systems, internet-based websites, digital phones, and secure e-mail, can be used to deliver telemedicine services. Telemedicine facilitates the exchange of health information, services, and education between providers and providers or patients through electronic means.
Treatment room: A standard patient room in an emergency department (ED) or urgent care center that may be used for a variety of functions, including patient examination and various treatments or procedures, including wound packing, suture placement, or casting. Note: This room may contain specialized equipment as identified in the functional program.
Unit: An area or space usually dedicated to a single defined organizational function.
Zone: A space in an area or room that is dedicated to a particular function and is not separated from the rest of the area or room by walls, partitions, curtains, or other means (e.g., family zone, medication safety zone).
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