ASHRAE Research: Medical Imaging Equipment Energy Use

How Mazzetti Is Reshaping Healthcare Facility Design Through Evidence-Based Engineering

Overview

ASHRAE Research Project RP-1816, Reporting the Energy Use and Heat Gain from Imaging Equipment, was awarded to Mazzetti in Fall 2019 under the oversight of ASHRAE Technical Committee 9.6 (Healthcare Facilities). The purpose of the research was to develop measured data on the actual energy use and heat gain of imaging equipment, providing a more accurate basis for HVAC sizing and load calculations.

This landmark project represents one of the most comprehensive, real-world investigations into the energy behavior of medical imaging equipment, and its findings have the potential to transform how engineers design healthcare facilities for decades to come.

The Problem: Designing in the Dark

Medical imaging equipment is a major driver of HVAC and electrical system design in healthcare facilities, yet infrastructure is often sized using conservative assumptions and nameplate ratings rather than measured operating conditions. Mazzetti was contracted by ASHRAE to conduct research on the heat gain of large medical imaging equipment. Due to the limited data and information about the heat gain from this equipment from the manufacturers, ASHRAE set out to conduct its own research into energy consumption and heat dissipation.

In short, engineers had long been forced to overestimate, relying on worst-case assumptions and nameplate values rather than how equipment behaves during clinical operations. Traditional electrical system designs for medical imaging equipment are often based on manufacturer nameplate ratings rather than measured operating loads. HVAC systems are typically designed from heat gain assumptions provided by the manufacturer rather than actually measured heat gain from equipment. Many times, the actual energy and heat rejection from imaging equipment is less than the published maximum provided by the manufacturers.

Research Objectives

The primary goal of ASHRAE RP-1816 was clear: characterize actual energy consumption and heat rejection of medical imaging equipment.

The research aimed to enable engineers to:

Scope of Work: A Nationwide Effort

This research project includes the study of 9 different imaging modalities at 5 hospitals across the country. The 9 imaging modalities are CT scan, Fluoroscopy, Cyber Knife, Linear Accelerator, MRI, Nuclear Camera, PET Scan, Ultrasound, and X-Ray. The hospitals that Mazzetti partnered with are located in San Francisco and Sacramento, CA, Portland, OR, Rochester, MN, and Charlotte, NC.

Measurement Methodology

To gather accurate, real-world data, Mazzetti employed a rigorous, multi-layered measurement approach:

The Research Team

The project was led by a highly experienced team from Mazzetti:

Industry Partnerships & Collaboration

This research was built on a foundation of multi-stakeholder collaboration. Mazzetti partnered with imaging departments around the country, Veterans Affairs (VA), and Green Radiology partners at UCSF, and Providence Health. This research also connected with Siemens Healthineers to understand the operation of imaging equipment and review a future manufacturer led method of testing.

Mazzetti also partnered with PG&E’s tool lending library for measurement equipment, building on a prior successful collaboration. Mazzetti had previously worked with PG&E during 2020 to install meters from the lending library at hospitals across the country for a Pandemic Plug Load Study. The electric circuit data collection from that study was used as evidence to reduce Class 1 plug loads in the National Electric Code NFPA 99 Healthcare Code 2020 edition.

Additionally, the data being collected was shared with ENERGY STAR’s Medical Equipment team that consists of members from the U.S. Environmental Protection Agency (EPA), Department of Energy (DOE), and National Laboratory of the Rockies (NRL) formerly National Renewable Energy Laboratory (NREL).This data helped establish ENERGY STAR certified medical imaging equipment for MRIs effective November 3, 2025. It was also used to support research article “Multi-facility analysis using metered power data to quantify MRI energy use and utility bill costs across scanner operating modes” in Science Direct Applied Energy.

Policy & Standards Impact

The research carries significant weight beyond the engineering community. Its implications reach into federal regulation and national code reform:

ENERGY STAR Program

Mazzetti met with the Energy Star team to ensure their method of testing aligns with the ENERGY STAR’s “Test Method for Determining Medical Imaging Equipment Energy Use,” and the data will be used by the EPA as it created an ENERGY STAR specification for medical imaging equipment. Manufacturers participating in the ENERGY STAR program will drive advancements in energy efficient equipment and provide an indicator of energy efficiency for hospital stakeholders looking to purchase new medical equipment.

NFPA 99 Healthcare Code Reform

Mazzetti’s CEO Walt Vernon serves on the National Electric Code (NEC) Panel 15 for the Electrical Systems Technical Committee of NFPA 99 (Healthcare Code) and has started a task force with the technical committee for the electrical demand factors in hospitals. The demand factors for diagnostic imaging equipment in NFPA 99 have not changed for many decades, despite the advancement of medical equipment. The energy usage data from the ASHRAE Medical Imaging Equipment research will be used as evidence to support the reduction of class 2 hospital electric demand factors in the upcoming NFPA 99 code edition.

ASHRAE Handbooks & Standards

The data gathered from this research will be published in Chapter 18 “Nonresidential Cooling and Heating Load Calculations” of the ASHRAE Fundamentals Handbook, HVAC Design Manual for Hospitals and Clinics, and Chapter 8 of ASHRAE Applications.

Key Findings & Engineering Implications

The research delivers transformational insight for healthcare facility engineers. Medical imaging equipment is a major driver of HVAC and electrical system design in healthcare facilities. Research from field-monitored medical imaging systems, including MRI, CT, X-Ray, and other imaging modalities, characterizes actual energy consumption, electrical demand, and heat rejection profiles.

Among the most important takeaways:

Looking Ahead: Beyond Nameplate Ratings

The culmination of this work is being presented under the banner “Beyond Nameplate Ratings: Right-Sizing Building Systems for Medical Imaging Equipment,” a call to action for the engineering profession. Engineers will learn how measured loads differ from traditional design assumptions and how these findings can be applied to right-size HVAC and electrical systems. The presentation highlights opportunities to reduce capital costs, improve energy efficiency, support decarbonization goals, and maintain reliable clinical operations.

This research signals a paradigm shift in healthcare facility design, moving from conservative estimations to  evidence-based engineering. As hospitals across the country face increasing pressure to reduce their carbon footprint, lower operating costs, and maintain high-quality patient care environments, the data generated by Mazzetti’s ASHRAE RP-1816 research provides the foundation for a smarter, leaner, and more sustainable future.