This session will discuss the advantages and challenges of using CO2 Heat Pumps for decarbonizing and efficiently electrifying commercial Domestic Hot Water systems. The session will outline and discuss the Mitsubishi Electric Heat2O DHW solution along with other CO2 DHW systems and their applications. The functionality, operation, scalability, and relevant design challenges related to these types of solutions will be explained. This session will discuss the use and benefit of CO2 as a refrigerant and its impact on environmentally sustainable buildings.

As the energy and carbon landscape evolves, the design and construction of hospitals must change to meet new challenges. New techniques, perspectives and methodologies must be applied to drive innovation and achieve outstanding results. From the dual perspective of a CPHC and experienced HVAC design engineer, we will provide an overview of Passive House principles in the context of hospital design and construction. We will review three case studies: one occupied, one in construction, and one in design.

Many classroom environments are unhealthy and uncomfortable, creating poor learning environments with high absenteeism. Older, unventilated classrooms can be economically decarbonized with improved air quality and comfort. This session will present the conversion of a junior high school classroom, featuring a "rolling" room-by-room installation process using a community's local HVAC installation labor with one day of classroom downtime.

With rising determination to fight the climate crisis worldwide, practitioners are finding the Passive House standard a potent solution for the building sector. As passive and other sustainable building standards are proliferating worldwide, those standards meet a host of different location-specific challenges. This diverse panel of women architects and certified Passive House consultants are seeking to understand the adaptation of the Passive House standard globally.

Typical university dormitory projects are capital intensive and take several years to complete. This project turned this practice on its head. Using modular construction, on-site precast foundations, an integrated design-build team and low-embodied-carbon materials in a holistic approach, Colby College housed students as quickly as possible while ensuring the highest standards of beauty, accessibility, energy consumption, and healthy materials. Design started in September 2021, and students moved in in August 2022.

The Massachusetts Maritime Academy consists of 16 buildings comprising approximately 600,000 sf, with heating for the buildings is provided by gas fired hot water boilers in each. They have undertaken a planning effort and initial design for a distributed campus-wide ground source heat pump system, combined with extensive energy retrofits. The plan consists of a neutral temperature Energy Transfer Loop that will tie various geo-exchange systems together to feed heat pump plants in each building.

Recent technology developments and incentive programs are creating new opportunities for ground-source heat pumps (GSHPs) at the building and neighborhood scale (networked geothermal). Practitioners designing and piloting GSHPs will describe how GSHPs can reduce the environmental burden on LMI communities by decarbonizing space and water heating.  Through design and case studies, they will describe what characteristics make a building or neighborhood a promising fit for GSHP implementation, and those posing significant challenges.

Electrification of HVAC systems and the elimination of fossil fuel heating in high rise building space conditioning systems poses unique design and system selection challenges.  Presenters will share two case studies for the design of VRF HVAC, one using air-to-air systems and one using air-to-water systems. They will discuss challenges including maximum piping lengths, acoustical restrictions, and airflow problems, and solutions including closely spaced condensers using CFD analysis and the design of access to piping and wiring in large condenser farms.

Before PVs became affordable, excess solar energy was stored thermally. Energy storage, both thermal and electrical, aids grid penetration of renewables and builds resilience on-site. We’ll look at passive and active thermal storage in advanced buildings, either integrated with the structure or as remote storage. We’ll also look at battery storage in an off-grid project and hydronic storage in a proposed small commercial project and show via an interactive model the effects of varying PV and storage capacity, and how storage increases the percentage of solar energy used on-site.

Concrete accounts for approximately 11% of annual global carbon emissions. It is a material too important to ignore. Learn how BU’s Center for Computing and Data Sciences applied low-carbon concrete goals and selected structural elements to reach the highest Portland replacement concrete in Boston to date. See how opportunities in design, construction and supply chain were used to substantially decrease the climate impact of concrete used. Then discover national and local low-carbon material initiatives that are underway and growing.