SBA 491: Breaking Down ASHRAE 90.1

Episode Description:

If you've worked on new construction, retrofits, or green building certifications, ASHRAE 90.1 is already familiar. However, using it effectively is another matter.

This episode focuses on how ASHRAE 90.1 influences your designs, energy compliance, and system planning. The discussion clarifies how this standard applies across key areas and what it means for your daily responsibilities in building automation.

For professionals seeking to improve building performance, align with energy codes, or support LEED goals, this episode offers practical context.

Topics covered include:

• The building systems and design elements governed by ASHRAE 90.1
• The role of the standard in state codes and federal guidelines
• Energy use targets across power, HVAC, lighting, and water heating
• Prescriptive vs. performance-based compliance methods
• Coordination strategies for efficient design and modeling

Explore how ASHRAE 90.1 shapes your work by listening now.  

Podcast Video

ASHRAE 90.1: What Building Automation Professionals Need to Know

ASHRAE 90.1 defines minimum energy efficiency requirements for commercial buildings. It directly affects how systems are designed, specified, and integrated. For building automation professionals, this standard shapes project requirements, influences certifications, and impacts energy performance strategies.

In Podcast Episode 491, Smart Buildings Academy outlines the key systems ASHRAE 90.1 addresses and how to approach compliance effectively.

Areas Covered by ASHRAE 90.1

ASHRAE 90.1 applies to new construction, renovations, system replacements, and additions in commercial buildings. It excludes low-rise residential and non-comfort process equipment. The standard focuses on the following systems:

Building Envelope

Requirements include insulation values, window performance, air leakage limits, and climate zone adjustments. Design choices here influence load calculations and HVAC performance.

HVAC Systems

This section includes minimum efficiency standards, control requirements, demand-controlled ventilation, duct insulation, part-load performance, and load sizing rules. HVAC systems often represent the largest portion of building energy use.

Service Water Heating

Focuses on high-efficiency heaters, pipe insulation, and heat recovery. Specific upgrades are recommended for high-consumption facilities like hospitals and hotels.

Power Systems

Addresses voltage drop limits, motor and transformer efficiencies, and energy monitoring through metering. Accurate measurement supports operational visibility and energy analysis.

Lighting Systems

Includes limits on lighting power density, mandatory controls such as occupancy sensors and daylight harvesting, and LED adoption. Emphasizes scheduling and zoning to reduce unnecessary use.

Other Equipment

Covers systems like elevators, escalators, refrigerated display cases, and data centers. These systems contribute significantly to energy use in many facilities and are subject to targeted efficiency requirements.

Compliance Paths

Three compliance options are available:

1. Prescriptive Path
   A checklist approach with no trade-offs. Each system must meet specific standards. Suitable for standardized building designs with limited variation.
2. Performance Path (Appendix G)
   Uses full energy modeling to balance trade-offs across systems. Allows flexibility by simulating how building systems interact to meet performance targets.
3. Energy Cost Budget Method
   Requires simulations to demonstrate that total energy costs stay within a defined limit. This method is stricter and cost-focused.

Implementation Guidelines

• Begin compliance planning early in the design phase
• Use accurate climate zone data to guide system selections
• Coordinate closely with architects, engineers, and energy modelers
• Use energy modeling tools such as eQUEST, EnergyPlus, TRACE, or HAP
• Maintain detailed documentation for compliance and operational use
• Monitor changes in local codes and future ASHRAE updates

ASHRAE 90.1 establishes a performance baseline for commercial buildings. By aligning system design and integration with its standards, building automation professionals contribute to energy-efficient, code-compliant, and high-performing facilities.

For a deeper discussion and insights from the field, listen to this episode on the Smart Buildings Academy podcast