ASHRAE 189.1: A Higher Standard for High-Performance Green Buildings, Pt. 1
Understanding the current parameters for energy efficient buildings
In the quest to build more sustainably, different organizations have set forth a variety of standards and certifications to realize high-performance green buildings. Chief among these is Standard 189.1 created by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE).
Standard 189.1 provides stringent green-building parameters to achieve the most sustainable buildings possible. Many factors are incorporated to create a green building, with energy recovery ventilation at the core of the standard’s requirements to design healthier structures that use less energy.
Why is 189.1 a higher standard for high-performance green building? This white paper addresses that question by looking at what building green means, what’s covered in Standard 189.1, and how energy recovery ventilation technologies play a key role in making green buildings a reality.
Hurdles to Cross When Building Green
Residential and commercial buildings face two main challenges in the pursuit to reach green status. First, as structures become more airtight, contaminants are locked inside, thus impairing indoor air quality. Second, buildings are incredibly wasteful and use tremendous amounts of energy to run, which is harmful to the environment and leads to substantial costs.
Let’s look at IAQ. When indoor air contaminants increase, this results in deficient IAQ, which can impair people’s health, productivity, cognitive function, and well-being. This is especially concerning since people spend about 90 percent of their time indoors, where concentrations of some pollutants are often two to five times higher than typical outdoor concentrations.
Now, onto the energy issue. Residential and commercial buildings in the U.S. are energy hogs and use about 40 percent of the energy and 70 percent of the electricity in the country, and produce about 40 percent of the CO2 emissions. What’s more, they waste about 30 percent of their energy input, so there has to be a better – and more efficient – way to operate a building.
Certainly there are more optimal methods for creating healthy and energy-efficient buildings, but it’s complicated since so many factors are involved. That’s a central question ASHRAE deals with, and the association does this by establishing building standards to increase sustainability in the built environment.
Realizing Green Buildings via ASHRAE Standard 189.1
For many years, ASHRAE has created numerous standards to make better buildings, and they’ve all culminated in 189.1, the “Standard for the Design of High-Performance Green Buildings Except Low-Rise Residential Buildings.” It’s the most stringent standard to date for realizing green buildings.
In fact, according to ASHRAE, Standard 189.1 “provides a ‘total building sustainability package’ for those who strive to design, build and operate green buildings.” From site location to energy use to recycling, 189.1 sets a higher standard for high-performance green buildings.
How is this done? Standard 189.1 sets the foundation for green buildings by addressing site sustainability, water use efficiency, energy efficiency, indoor environmental quality, and the building’s impact on the atmosphere, materials, and resources.
Further, the reason that 189.1 is the authority for green-building design is because it’s the pinnacle of several other ASHRAE standards. These include Standard 90.1, “Energy Standard for Buildings Except Low-Rise Residential Buildings,” Standard 62.1, “Ventilation for Acceptable Indoor Air Quality” and Standard 55, “Thermal Environmental Conditions for Human Occupancy,” among others.
Standard 90.1 as the Foundation for Standard 189.1
Standard 189.1 builds upon several previous standards, but the real cornerstone is Standard 90.1. This is because of 90.1’s total focus on reducing building energy consumption. In fact, 90.1 has been a benchmark for commercial building energy codes in the U.S., and a key basis for codes and standards around the world, for more than 35 years.
However, 189.1 goes even further than 90.1 and is broader in scope with the goal of creating a completely sustainable building. In 189.1, the goal is not just energy efficiency, but also a balance of environmental responsibility, resource efficiency, occupant comfort and well-being, community sensitivity, and responsible development.
Standard 189.1 Optimizes Energy Efficiency
Bolstering building energy efficiency is at the core of Standard 189.1. In that spirit, when it was first unveiled in 2010, its goal was to increase building site energy efficiency by 30 percent compared to Standard 90.1-2007. In addition, it seeks to enable buildings to be ready to become net zero – which means zero net energy consumption – by 2020.
The standard has an entire section dedicated to energy efficiency, and it touches on areas such as renewable energy, lighting, and energy-consumption management. It also includes energy-efficiency prescriptions for HVAC systems, including:
- Based on Standard 90.1, but modified to gain improved energy performance over minimum code standards.
- Demand control ventilation (DCV) for occupied spaces with a lower occupancy threshold.
- Economizers shown for equipment size and climate zone.
- Restricts amount of reheated or re-cooled air.
Standard 189.1 is constantly evolving and adding ever-stricter energy-efficiency requirements. The 2017 edition of Standard 189.1 made several additions in the energy-efficiency section, including:
- Updated requirements to reflect changes in ANSI/ASHRAE/IES Standard 90.1-2016, including reference to Climate Zone 0.
- Updated lighting tables with improved efficiencies.
- Updated equipment efficiency tables.
- Revised envelope requirements.
- Updated CO2 emission factors for different energy sources.
- New requirements for automated demand response.
- New informative appendix with an energy-compliance path that builds on the International Energy Conservation Code (IECC) instead of Standard 90.1.
Standard 189.1 Enhances Indoor Environmental Quality (IEQ)
Another key component of Standard 189.1 is establishing a cleaner and healthier indoor environment, which starts with improving IAQ. The section on IEQ sets requirements for the following areas: outdoor airflow, tobacco-smoke control, outdoor-air monitoring, filtration and air cleaning, day lighting, thermal comfort, acoustics, and vibration.
For IAQ, Standard 189.1 sets requirements for materials that may emit volatile organic compounds (VOCs). It looks at them either as a total amount or as individual compounds, such as formaldehyde. Particular contaminant sources it covers include: adhesives and sealants, paints and coatings, floor coverings, composite wood, wood structures, and agricultural fibers.
The 2017 edition of 189.1 made several updates to support IEQ and IAQ. These include new requirements for control of soil gas entry, material emissions, acoustical control, day lighting, control of moisture associated with envelope infiltration and HVAC systems, venting of combustion products to the outdoors, IEQ surveys of building occupants, and glare control.
To be continued…