Building Systems

Building electrification using air-source heat pumps (ASHPs) is costly and requires a significant amount of space. Ice heating has the potential to reduce the capacity of ASHPs needed for full electrification by 50%, while also allowing for grid interactive peak shifting for added energy resilience and time-of-use carbon savings in order to meet decarbonization policies and local stretch codes. This thermal storage solution can dramatically reduce first costs, carbon emissions, and space required for full electrification of new construction and existing buildings.

Our window to avoid catastrophic climate change is closing. Existing buildings are one of the largest sources of emissions and among the hardest to decarbonize. At BuildingEnergy Boston 2023, Rachel advocated for “moderate” retrofits as a scalable strategy. Michael responded that deep energy retrofits must be pursued wherever possible. Despite the disagreement, Rachel and Michael share a common goal and are struggling with the same question.

Producing domestic hot water is costly in terms of energy required to physically heat water, and financially when opting to use electricity to do so. Advances in DHW system efficiencies and industry best practices can mitigate these operational costs to a degree. Other good news is that the recently adopted MA plumbing code now allows engineered water systems, leading to additional first cost savings and reduced embodied carbon. This session will quantify how an engineered approach can result in meaningful upfront savings and ongoing dividends when it comes to dollars and carbon.

An existing house represents an enormous amount of “up front” carbon that has already been committed. The more we can re-use it, the less carbon we are releasing per unit of housing. But when is enough enough? This session is about finding the sweet spot between existing and desired, and how to balance expense vs savings.

Join us for an enlightening panel session that delves into the pivotal role geothermal can play in commercial and network scale building decarbonization, energy consumption reduction, and climate resiliency in our communities. We will guide you through key considerations and strategies for site identification and project evaluation to enable successful ground source heat pump implementation in your projects.

This session will present a case study of the 544,000 sf Harvard Science and Engineering Complex, one of the most sustainable and resilient buildings ever constructed. The project employed a highly integrated design process to satisfy the aggressive performance goals set by Harvard. These included resiliency measures to address climate change, in particular sea level rise, and the highest possible energy efficiency, while providing a healthy environment for occupants, extensive water use reduction, and recycling.

This session will present RMI’s new freely available economic modeling software for different home decarbonization technologies (e.g., rooftop solar, battery storage, weatherization, air-source heat pumps, heat pump water heaters), demonstrate how different types of energy professionals can leverage it (e.g., estimating bill impacts of whole home versus hybrid air-source heat pumps), and visualize results for different retrofit types across the northeast (e.g., percent of homes that can cost-effectively electrify).

While electrification of domestic hot water is picking up steam, outdated sizing guidelines result in oversized, expensive, and inefficient systems, especially in affordable multifamily housing. New Ecology’s data, from over 20 affordable multifamily housing sites, reveals differences between the measured loads and traditional sizing guidelines, presenting opportunities for higher system efficiency, reduced operating costs, and lower first costs as these buildings move to electrify their domestic hot water.

MassCEC’s Decarbonization Pathways pilot has tested and refined a protocol for a home decarbonization assessment with a goal of eliminating the use of fossil fuels in small residential buildings. The pilot also tested approaches to providing targeted support at the time customers are ready to act. This panel will cover the outcomes from the first cohort, discuss the ongoing second cohort, and describe further refinements for the upcoming third cohort.

When used early in the design process, energy modeling is a powerful tool for decision making, not only for sizing equipment but also for shaping buildings and selecting materials. Iterative energy modeling results in reductions in construction costs, embodied carbon, and energy use. With current climate and energy goals, energy modeling must be a tool available to all design and building professionals. Learn to create energy models of your own today!

In light of the catastrophic flooding which occurred throughout the Northeast region in 2023, we must challenge ourselves to confront the increased likelihood of extreme weather events and diminished water resilience that our projects now face. Resilience can only be achieved if we embrace the reality of new weather patterns and adjust both design and funding strategies accordingly.

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.

To achieve mass adoption of offsite construction, the building process as we know it has to be reevaluated from multiple perspectives. This is especially true when combined with the goals of scaling up low-carbon and high-performance objectives. The session will explore how the three primarily residential companies have built their businesses around offsite manufacturing principles and have developed strategies to “unsilo” the industry.

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.

Methods for electrification of DHW in multifamily buildings all pose challenges. This session will provide an overview of existing technologies and a brief history of how we arrived at central air-source heat pump technology as the least problematic solution today. We will use recent design-phase case studies to illustrate cost, estimated energy use, mechanical space requirements, system and equipment peculiarities, metering strategies, maintenance requirements, what we’d like to learn from systems as they’re installed, and why the alternatives for electrification of DHW are even worse!

Passive House buildings go hand-in-hand with on-site generation and electrification, but what happens when you have code-required emergency power backup? The Kenzi tackled the wicked problem of designing, pricing, and permitting the first all-electric building above four floors in the City of Boston. We will dive into the nitty gritty of design, funding, and procurement, reveal our strategy for Boston Fire Department concerns, and discuss what code language we leaned on to pull it all together.

This session offers a case study of a curtainwall building in which the project team collaborated on an iterative energy modeling and design process to achieve aggressive energy reduction goals. Our panel will share insight on the process that led to significant energy and carbon reductions, predictive versus post occupancy usage data, and how this building will adapt to BERDO 2.0 and future energy and resilience considerations – a challenge facing recently constructed buildings that will need to decarbonize in the near future in Boston.

Think you know effective heat pump sizing and design? Significant market growth of cold-climate air-source heat pumps has resulted in new insights and lessons learned. Come explore new tools and best practices to enable improved design, sizing, and selection of ASHPs in this session with NEEP and Abode, and stay on the leading edge!

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.

Join principals of New Frameworks and Builders for Climate Action for a critical look at our practices that have endeavored to embed justice and belonging alongside the highest goals for building health, efficiency, and carbon storage in projects - for the purpose of workshopping how our industry can scale carbon storage and justice, rapidly, to address climate justice.

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.

Windows are a key part of the building enclosure, but they are also the costliest, most fragile, and worst thermally performing component. We will present on windows from our viewpoint as building enclosure consultants and forensic failure specialists. We will explore energy and comfort impacts of glazing and glazing ratios, and then move on to water control detailing and the window-to-wall interface. Covered topics will include sill pan and rough opening flashings, “innie” vs.

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.