ASHRAE 170 healthcare ventilation, measured room by room
ASHRAE 170 is the standard for ventilation of health care facilities. It sets design requirements for air change rates, pressure relationships, filtration, temperature and humidity by space type, such as operating rooms and isolation rooms. Aqueduct supplies the operational evidence: room pressure, temperature, humidity and air handler status logged continuously per space, with excursions flagged. Your engineers and accrediting bodies judge compliance.
What ASHRAE 170 is and who it applies to
ANSI/ASHRAE/ASHE Standard 170, Ventilation of Health Care Facilities, is published jointly by ASHRAE and the American Society for Health Care Engineering. It defines ventilation system design requirements for hospitals, outpatient facilities and other healthcare spaces. For each space type it lists design parameters such as minimum outdoor and total air changes, whether the room is held positive, negative or neutral to its neighbors, filtration levels and design temperature and humidity ranges.
The standard is written for design and renovation, and it reaches existing buildings through the codes and guidelines that adopt it, such as the FGI Guidelines and state and local codes. Surveyors and accrediting bodies then ask whether the spaces still perform as designed. That is where operational evidence matters: an operating room designed for positive pressure needs a record that shows it stayed positive, not only a commissioning report from the year it opened. The standard is revised on a regular cycle, so always check the edition your jurisdiction has adopted.
ASHRAE 170 requirements and the evidence Aqueduct supplies
Aqueduct supplies measured records. Your facility engineers, infection prevention team and the authority having jurisdiction own compliance.
| Requirement | Evidence needed | How Aqueduct supplies it |
|---|---|---|
| Pressure relationships by space | A record that operating rooms, protective environments and airborne infection isolation rooms hold their designed relationship | Differential pressure readings from room monitors or BMS points, logged per room with excursions flagged and timestamped |
| Air change rates | Supply and exhaust airflow consistent with the design rates for each space type | Airflow and terminal unit points read from the BMS over BACnet, trended per room and compared with the design value you enter |
| Temperature design ranges | Space temperature held within the range the design calls for | Temperature per zone from AirSafe sensors or BMS points, with time outside range reported per room |
| Relative humidity design ranges | Humidity held within range, especially in surgical and sterile spaces | Relative humidity per zone, trended and alarmed, with history kept for the survey |
| Filtration | Filters of the specified efficiency in place and maintained | Filter loading alerts where a pressure point is available, routed to your CMMS as work orders |
| Air handler operation | Units serving critical spaces running to sequence, including after hours | Fan status, damper position and supply air temperature from the air handler, with sequence exceptions flagged |
| Corrective action | Proof that excursions were noticed and fixed | Alert, owner, work order and closing reading kept together in one event record |
| Records for surveyors | Retrievable history by room and period | Exports by room, space type and date range, with device health shown so gaps are explained |
How to prepare for an ASHRAE 170 review or survey
List the critical spaces
Build a register of operating rooms, procedure rooms, isolation rooms, protective environments, sterile processing and pharmacy compounding spaces, with the design pressure, temperature and humidity for each from your design documents.
Map the points you already have
Most hospitals already have room pressure monitors and BMS trends. Aqueduct reads them over BACnet or Modbus and adds wireless sensors only where a room has no reliable point.
Set the limits per room
Enter each room's design values in aQ Core so every reading is judged against its own space type, not a building-wide average.
Run a month of continuous records
Review excursions weekly with facilities and infection prevention. Each one should end with a cause, an action and a reading that confirms the fix.
Assemble the survey pack
Export room-level histories, excursion logs and work orders for the review period. Keep the design basis and your engineer's assessment alongside them.
What stays with your engineers and surveyors
Aqueduct measures how spaces perform. People decide whether they meet the standard.
Design and balancing
Mechanical engineers design the system and test and balance contractors set the airflows. Aqueduct records what happens after they leave.
Risk assessments
Infection prevention and facilities teams run infection control risk assessments for construction and changes of use.
Compliance decisions
The authority having jurisdiction and accrediting bodies decide compliance. Aqueduct does not certify any space.
Related standards
Often read alongside ASHRAE 170.
sites in 21 countries run on Aqueduct.
and 9 clinics in one of India’s top hospital chains.
US airport running water intelligence on Aqueduct.
of commercial real estate under Aqueduct.
FMCG manufacturing campus.
operations run on Aqueduct.
Related
Common questions
ASHRAE 170 is the standard for ventilation of health care facilities, published by ASHRAE and ASHE. It sets design requirements for air changes, pressure relationships, filtration, temperature and humidity by space type. Aqueduct supplies the operating records that show how those spaces perform day to day.
The standard governs design, and it applies to existing buildings mainly through adopted codes, renovation projects and accreditation surveys. Check which edition your jurisdiction and accrediting body reference, since editions change.
Room pressure monitors measure the differential between the operating room and the corridor. Aqueduct reads those monitors or the BMS points behind them, logs every reading and flags any period where the relationship reverses or drifts.
Aqueduct calculates and trends air changes where supply and exhaust airflow points exist in the BMS. It does not replace test and balance measurements, which your contractor performs.
No. Aqueduct supplies measured evidence and flags excursions. Your engineers, the authority having jurisdiction and your accrediting body decide compliance.
Many hospitals run Aqueduct read-only in critical spaces. Where control is enabled, with owner approval, every command is logged with who approved it and when.
See Aqueduct on your own facility.
Bring a site, a utility bill or a question. We will show you where the loss is.