Color
Book a demo
Glossary
Healthcare

What is ASHRAE 188?

Definition

ASHRAE Standard 188 sets the minimum requirements for managing legionellosis risk in building water systems, built around a documented water management program for each building.

Who works to it

ASHRAE aims it at everyone who designs, builds, commissions, operates, maintains or services centralized building water systems. CMS expects hospitals, critical access hospitals and nursing homes to base their water management programs on this industry standard.

Editions and companion guidance

ASHRAE first published Standard 188 in 2015. The current 2021 edition replaces permissive language with enforceable language so codes and regulations can adopt it, per ASHRAE. Guideline 12-2023 sits beside it with prescriptive guidance for the people operating the program.

Logging the control limits a program sets

A program names control points and limits, then has to prove they hold. On the Aqueduct water twin, temperature, flow and level sensors on hot and cold headers and storage tanks keep a timestamped record, so a branch with almost no flow or a tank that sits stagnant is visible as data. Sampling for Legionella stays a laboratory task.

Questions

ASHRAE 188: common questions

ASHRAE Standard 188 is the US consensus standard for preventing Legionnaires' disease through building water management. It requires a program team to describe the water systems, assess where Legionella could grow, set control measures with limits, and verify they work. Aqueduct's view is on the ASHRAE 188 compliance page.

Only where a code, regulator or accreditor adopts or references it. Otherwise ASHRAE 188 is a voluntary consensus standard. In US health care it carries weight through CMS QSO-17-30, which expects programs based on industry standards.

Standard 188 says what a program must contain. Guideline 12 gives operators prescriptive practices for running one, such as temperature management, flushing and disinfection approaches, so many program teams use the two together when writing control measures.

Continuous temperature and flow at the control points the program names, such as hot water return loops and storage tanks, plus alerts when readings leave their limits. Aqueduct records these on the water twin, giving the team a documented history to review at each program verification, while lab sampling stays separate.

See Aqueduct on your own facility.

Bring a site, a utility bill or a question. We will show you where the loss is.

Book a demo Talk to our team