ASHRAE Standard 189.1 offers guidance in code language
When a team prepares to design a sustainable or high-performance building, the designers usually seek to comply with a rating system such as the U.S. Green Building Council's (USGBC’s) Leadership in Energy and Environmental Design (LEED) or Green Globes. Now, there is a third option available to designers: meeting the criteria spelled out in ANSI/ASHRAE/USGBC/IES Standard 189.1, Standard for the Design of High Performance Green Buildings Except Low-Rise Residential Buildings.
Fans of the J.R.R. Tolkien trilogy The Lord of the Rings may recognize some similarities between that saga's "one ring of power" and Standard 189.1. Although the standard does not seek to rule the actions of all engineers in a mythical land, it does bring together and bind a number of other American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) standards into a cohesive approach to high-performance building design.
Standard 189.1 is an "overlay" standard. It picks up all of the requirements of ANSI/ASHRAE/IES Standard 90.1, Energy Standard for Buildings Except Low-Rise Residential Buildings, and adds to them in terms of energy-related provisions. It also picks up all of ANSI/ASHRAE Standard 62.1, Ventilation for Acceptable Indoor Air Quality, and adds to its ventilation requirements.
Standard 189.1 is based primarily on those two standards, in terms of its energy-use and indoor-environmental-quality sections. Yet it also incorporates elements of ANSI/ASHRAE Standard 55, Thermal Environmental Conditions for Human Occupancy, as well as ANSI/ASHRAE/ACCA Standard 180, Standard Practice for Inspection of Maintenance of Commercial Building HVAC Systems.
Given that all these other standards already exist, the question may beg to be asked: Why do we need Standard 189.1? Because it brings them all together in a cohesive manner. The other standards are independent of each other in most regards—and, in some ways, may even compete with each other. Standard 189.1, on the other hand, requires a building that not only uses less energy, but is comfortable for occupancy, is built on a sustainable site, uses less water, and has a lower impact on the atmosphere and the planet compared with a building that does not meet the standard.
Standard 62.1, taken at its truest interpretation, does not really address whether people are comfortable or not, as long as the building smells OK and does not make its occupants ill. Meanwhile, Standard 90.1 does not really address indoor-environmental-quality issues, such as whether or not drain pans are sloped or cold pipes are insulated to prevent condensation. It only deals with energy.
Standard 189.1 brings the requirements of both of those standards together because system designers must care about both of them. Energy and indoor environmental quality are parts of it, but so are site selection, water use, atmospheric impact, material use, and construction and operation provisions. Standard 189.1 is bigger than it looks.
Another important aspect of Standard 189.1 is that it covers roughly the same areas as LEED Building Design and Construction requirements, yet it is written in mandatory language. The standard is co-sponsored by both the illuminating Engineering Society and the U.S. Green Building Council—in part because USGBC wished to have some of the LEED provisions re-written by engineers in mandatory language and reviewed by the public. In the future, the LEED products are likely to reference portions of standard 189.1. It gives USGBC a way to have a mandatory-language document that it can reference in its rating system.
Standard 189.1 presents a minimum standard for high-performance buildings. Many code jurisdictions are interested creating a high-performance green-building code, and the International Code Council (ICC) is in the midst of developing the International Green Construction Code (IGCC). The IGCC will have two compliance paths that are jurisdictional options. One compliance path will be to meet all of the requirements written by the ICC using its model-code-development process. The alternative compliance path will be to follow the requirements in Standard 189.1.
Jurisdictions can choose their option, and either way the end result will be a building that meets the minimum requirements for a high-performance green building. That was one of the motivating factors for ASHRAE in creating this standard: to provide a mandatory-language high-performance green-building standard for use in the model codes. Standard 189.1 is not a rating system, so although the provisions of Standard 189.1 may be less detailed than those of rating systems such as LEED or Green Globes, they will be well above those of a code-minimum building.
Standard 189.1 will be updated every three years based on changes to the standards it references, the key ones being 90.1 and 62.1. (All ASHRAE code-intended standards are updated on a three-year cycle to correspond to the ICC code-development cycle.) It always will be keeping just ahead of the requirements of 90.1 and 62.1 and any other standard that becomes a major reference, such as Standard 180. It will be keeping its provisions more stringent than the provisions in the minimum mandatory language, code-intended standards upon which it is based. And it will offer designers another path that will lead them to a high-performance building.
Dennis Stanke is a staff applications engineer at Trane, La Crosse, WI, specializing in airside systems and airside controls during his 38 years with Trane, a business of Ingersoll-Rand. He is a Fellow in the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE). He serves as chairman of the Standard 189.1 committee and is immediate past-chairman of the Standard 62.1 committee. He can be reached at dstanke@trane.com