Chill Out! Reduce Operational Energy and Carbon with Thermal Mass

Monday, November 4, 2024  4:00 PM - 6:00 PM, Grand BR Salon C

Mass walls are at risk. With energy codes continuing to escalate
insulation requirements and thermal bridging requirements, it can be harder for designers to justify constructing energy efficient buildings with thermal mass, despite its energy-saving benefits. Reducing operational energy is a key goal in overall carbon reduction for buildings. Recently published codes, ACI/TMS 122.1, 122.2, and 122.3, are valuable tools that can be used to ensure that mass walls meet energy code requirements. Speakers will demonstrate how the content of these codes are used for thermal bridging as well as using COMcheck and REScheck programs for code compliance.

Practical solutions for thermal bridging and insulation of concrete and masonry walls will also be discussed.

Learning Objectives:
(1) To gain insight into the history of U.S. Energy Codes and their favorable stance towards insulation versus concrete and masonry mass walls;
(2) To learn that buildings built with exterior mass walls are energy efficient despite having lower R-Values than other, highly insulated exterior frame wall systems;
(3) To understand what is in the three new joint ACI/TMS Energy Codes and how to use them to demonstrate energy code compliance;
(4) To see practical design examples and details of mass walls that are easy to build, economical and readily available across North America.

Threats to Mass Walls in Energy Codes

Presented By: Kevin Cavanaugh
Affiliation: Cavanaugh & Assocs
Description: For the past 50 years, energy codes in the US have been strongly influenced by insulation manufacturers. This influence has led to a deeply rooted belief in the design and construction communities that ever-increasing amounts of insulation in exterior envelope wall systems is the key to making energy efficient buildings. This presentation will give some history into the development of US energy codes and explain how todays’ energy code is moving beyond exterior wall insulation requirements.

Reducing Operational Energy Use with Thermal Mass

Presented By: William McGinley
Affiliation: University of Louisville
Description: Most designers use the Prescriptive Path, which lists mandatory minimum exterior wall R-Values, to demonstrate building energy code compliance. The 'Whole Building' energy analysis path, which uses sophisticated building energy modeling programs such as EnergyPlus, is rarely used. This presentation will discuss results from several EnergyPlus modeling studies to demonstrate how thermal mass in concrete and masonry exterior walls favorably impacted energy use in several different building types. The building types range from schools, to grocery stores and big-box retail stores and to residential systems, including passive solar houses.

Why Use ACI 122.1 for Compliance with Thermal Bridging Requirements Instead of ASHRAE 90.1 and IECC

Presented By: Martha Vangeem
Affiliation: Vangeem Consulting
Description: ACI/TMS 122.1, Thermal Bridge Mitigation for Buildings having Concrete and Masonry Walls/Veneer, is a consensus code/standard developed by technical experts that pushes the concrete and masonry industry to further mitigate thermal bridges. It is in a format that can be adopted by energy codes and standards such as the IECC and ASHRAE 90.1, but is easier to understand than their current requirements, and therefore aids in code adoption and use. Mitigating thermal bridges will increase the cost of construction but saves energy and therefore also reduces carbon (greenhouse gases). The code covers major thermal bridges - parapets, balconies and projections, shelf angles and other significantly large thermal bridges. Thermal bridges are inherent in structural materials. So, while this standard reduces thermal bridges, it does not eliminate them. The presentation reviews the types of thermal bridges covered by the code, the specific requirements, and how to comply. In most cases, complicated analyses are not required.

Why Use ACI 122.2 & 122.3 (and COMcheck and REScheck) for Energy Code Compliance for Mass Walls

Presented By: Nicholas Lang
Affiliation: Concrete Masonry & Hardscapes Association
Description: Recently published ACI/TMS 122.2 and 122.3 are consensus code documents for energy code compliance for concrete and masonry systems. These documents, for both residential and commercial buildings, provide an alternative compliance path for these systems as an alternative to the IECC or ASHRAE 90.1. Because they have been developed specifically with concrete and masonry in mind, they can streamline the code compliance process for designers and engineers. This presentation will review both of these new standards, as well as demonstrate how software packages such as COMcheck and REScheck can be used to demonstrate code-compliant structures for concrete and masonry systems.

Insulation Options and Detailing for Mass Walls

Presented By: Darryl Dixon
Affiliation: National Ready Mixed Concrete Association
Description: The ACI/TMS 122.1 code on Thermal Bridging is not a document that discusses practical solutions, but rather a building code that prescribes minimum requirements for mitigating thermal bridges in concrete and masonry building envelopes. While this code itself may not provide those specifics, the existence of a code focused on thermal bridging in these assemblies implies that thermal bridging is a concern and there are solutions to address it. In other words, practical solutions exist to mitigate thermal bridging in concrete and masonry walls. This presentation is for those wanting to learn more about those solutions, and resources that focus on building practices and materials related to thermal bridging in concrete and masonry construction. This presentation will illustrate practical solutions for thermal bridging and insulation of concrete and masonry walls and will explore cases demonstrating good thermal performance of concrete in the built environment.