ASHRAE Guideline 36: Key to building optimization

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Did you know that nearly 40% of global CO₂ emissions come from buildings? Even more surprising, 30% of the energy used in these structures goes to waste. Despite the prevalence of advanced HVAC systems, the building industry is hindered by a cost-driven approach favoring simplicity over efficiency. This is a major driver of energy loss. It’s time to rethink how we manage our buildings to reduce waste and create a more sustainable future.

Most commercial buildings have programmable central heating, cooling, and ventilation (HVAC) systems. These systems use control sequences that provide automated direction, such as setting up operational schedules and planning proactive maintenance. When used effectively, they can ensure that systems maximize both operational and energy efficiency while also reducing carbon emissions.

Standardization Supports Optimization

However, the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) identified that most HVAC control systems were custom one-off implementations unique to each building or structure. They also found that many HVAC control system implementations were simplified during installation. This occurred to reduce costs or to meet the inexpert operational abilities of building management staff.  

Projects specified to include high-performance HVAC systems require complex, expert programming, but the needed sequences are high risk and high cost. Therefore, system programming can be difficult to maintain once the commissioning is completed and the experts leave.

Given these risks, in most cases, the high cost of entry for optimal performance design and implementation will be removed as part of routine project cost cuts. This leads to subpar building performance and increased emissions.

By providing a standardized, high-performance sequence of operations, ASHRAE Guideline 36 can lower the cost of high-performance sequences for specifiers by providing a repeatable standardized sequence of operations. This by itself does not get around the fact that implementations will vary depending on who performed the work. Instead, GL 36 recommends that manufacturers perform the programming pre-emptively, making it available to their independent dealers and factory branches at no cost. This approach reduces costs and improves quality control by having the programming only be done once and not multiple times. It also makes future changes easier for staff or contractors.

How ASHRAE Guideline 36 Improves Standardization

Using standardized sequences of operations provides substantial advantages.

• Reduced engineering time. Starting with a proven standard sequence already optimized to perform the core task limits the time and the potential for errors.
• Decreased programming and commissioning time. Manufacturers pre-program sequences while HVAC control system technicians, along with commissioning agents, use a common document for functional testing.
• Better control of energy consumption, cost, and system downtime. GL 36 saves energy by reducing the need for simultaneous heating and cooling and optimizes airflow in VAV systems.
• Improved conditions for tenants. In particular, the standardized guidelines can help improve indoor air quality by closely controlling air flow and minimizing carbon dioxide in workspaces.
• Enhanced communication. By creating a language of common terms, ASHRAE 36 clarifies communications between specifiers, contractors, and operators.

These factors add up to serious gains: A study funded by the US Department of Energy and the California Energy Commission found an average savings of 31% in HVAC energy through the use of ASHRAE 36[GS1] .

Who Benefits from Implementing ASHRAE Guideline 36

ASHRAE developed Guideline 36 to reduce the custom one-off nature of HVAC control systems and their associated cost by providing a standardized high-performance sequence of operations that can be utilized by multiple stakeholders. Ultimately, the HVAC control system manufacturer is providing the resources necessary for standardized programming and quality control to properly implement GL 36 SOO.

This approach provides major benefits to stakeholders throughout the process:

• Design Firms: ASHRAE GL 36 reduces the firm’s need to spend designing and commissioning HVAC SOO without sacrificing quality. GL 36 complies with other established ASHRAE standards and CA title 24. ASHRAE Standards 90.1 (energy code) and 62.1 (ventilation) have started to reference GL 36 as a recommendation for implementing the codes in the respective standards.
• Facility Managers: GL 36 sequences ensure occupant comfort and provide energy-efficient operations while also allowing facility managers to perform their duties more efficiently.
• Executives: GL 36 standardizes operations between multiple facilities while conserving energy and providing increased occupant well-being and comfort.

Specifying ASHRAE Guideline 36

The benefits of ASHRAE Guideline 36 are clear, and the adoption of the guideline has increased as energy efficiency standards continue to advance in response to evolving emissions requirements. However, appropriate due diligence must be done when considering using GL 36 for a retrofit or brownfield project. Mature HVAC control product lines may not be able to support the advanced sequences of GL 36, and, in some cases, modernization of the HVAC control system may be required to fully comply with GL 36 on a retrofit project.

As of today, the guideline is still under revision, and it does not support certain kinds of HVAC mechanical equipment. Consultation with your manufacturer to learn best practices and whether the sequence implementation complies with GL36 is recommended.

When putting together a request for a proposal or specification document, make sure to be as detailed as possible when adding GL 36 content by including some of the following:

• Simply referring to the need to comply with the GL 36 in your spec or RFP.
• Referencing the specific section number– e.g., “Comply with ASHRAE Guideline 36 2021, section 5.5.”
• Copy and paste from the original GL 36 document into your document, then edit as needed.
• Use a specification design tool. Check out the Schneider Electric one here.

For more information

To learn more, access our free and secure Spec Designer tool. With embedded ASHRAE 36 guidelines, this tool simplifies specification writing, helping you navigate the vast number of products, services, and technologies that are offered today.