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Summer 2016


Latest WCEC Awarded Projects from the Energy Commission

Market Barriers to Energy Efficient HVAC Adoption

Recent WCEC Graduates

WCEC Affiliate Forum Highlights

The Western Cooling Efficiency Center was established in 2007, alongside our UC Davis partner centers, the Energy Efficiency Center, California Lighting Technology Center, Center for Water-Energy Efficiency and the PHEV Research Center through a grant from the California Clean Energy Fund and in partnership with the California Energy Commission Public Interest Energy Research Program.

WCEC partners with industry stakeholders to stimulate the development of impactful cooling technologies that can enable reduced electrical demand, energy and water consumption in buildings.

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In WCEC's Summer Newsletter, we will look at:

  • » WCEC's upcoming projects funded by the CEC's EPIC program
  • » Research being done to help bridge some of the market barriers for energy efficient HVAC adoption with links to a video presentation and the project paper
  • » Recent WCEC Graduates
  • » Highlights from this year's Affiliates Forum with presentation slides and poster session posters

WCEC's Latest Projects beginning soon. Funded Through the California Energy Commission's EPIC Program.

Cost-Constrained Optimization of Energy Efficiency for Multifamily and Commercial Buildings

This project will develop an automated EnergyPlus simulation package, and utilize that package to identify combinations of electricity savings/generation measures that most closely approach zero net energy cost-effectively. This will be done for 11 types of buildings and at least 18 different electricity savings/generation measures in 16 California climate zones.

The goal of the project is to provide California stakeholders with cost-optimized strategies and technology packages for building high-efficiency multi-family residential and commercial buildings in each California climate zone. A detailed cost analysis will be used to identify measures and packages that most closely approach zero net energy cost-effectively for each building type in each climate zone. The specific objectives are to:
1) Develop EnergyPlus models for 11 commercial and multifamily building types representative of baseline California construction,
2) Model photovoltaic and energy efficiency measures in applicable building types,
3) Run automated simulations of every permutation of building type and climate zone with applicable electricity savings/generation measures,
4) Post-process outputs from the simulations, including energy use, water use, and indoor conditions,
5) Calculate building operation costs based on Time Dependent Valuation electricity and water costs,
6) Build a database for construction and maintenance costs by measure and building type,
7) Combine operational costs with construction/maintenance costs to determine the maximum cost-effective reduction in net electricity consumption toward ZNE goals.

Ventilation Solutions for Energy Efficient California Schools

This project will survey the energy efficiency and ventilation characteristics of recent HVAC retrofits in schools, field test the technical performance of advanced HVAC systems designed to deliver improved ventilation and energy efficiency, estimate the potential environmental and health impacts of technology diffusion, and identify ways to address market barriers that currently impede broader market adoption.

This goal of this project is to develop and demonstrate approaches to synergistically improve ventilation and indoor environmental quality while providing heating, ventilation, and air conditioning (HVAC) and whole building energy efficiency retrofits in California schools, in which millions of California children, who are especially vulnerable to poor IEQ, spend a large portion of their time. The ultimate target is to identify and demonstrate the approaches and technologies that are needed for net zero energy schools.

Low Cost, Large Diameter, Shallow Ground Loops for Ground Coupled Heat Pumps

This project seeks to validate less expensive methods of building the ground heat exchangers (GHEs) that are a key component of ground source heat pumps (GSHPs).

Performance of vertical and horizontal GHEs have been thoroughly studied, are well understood, and sizing methods and performance models exist for them. Line source theory and other analytical methods can be used to characterize performance of traditional GHEs, which use piping strung out over long distances. The geometry of large diameter shallow bore GHEs is significantly different and current models do not apply. Large diameter shallow bore GHEs have a large volume of dry earth or damp or wet fill in their core. The core is charged with heat (or “cool”) while the heat pump is operating, and then relaxes and exchanges heat with surrounding soils during off cycles. Thus, performance is more greatly influenced by the type of load imposed on them. Specialized models will be needed to estimate their performance under different load conditions.

Energy Efficient HVAC Packages for Existing Residential Buildings

This project will demonstrate and evaluate two residential retrofit packages that use advanced technologies to improve single-family building envelopes, indoor air quality, and cooling efficiency. Package A includes a sub-wetbulb evaporative chiller (SWEC) with distributed fan coils, combined with a Smart Residential Ventilation system and extra-tight envelope/ducts obtained with a new aerosol sealing technology. Package B includes the same sub-wetbulb evaporative chiller connected to a central-system fan coil, combined with a NightBreeze whole-house ventilation/pre-cooling system and extra-tight aerosol-sealed envelope/ducts.

Preliminary estimates show that the proposed technologies, albeit at the pre-commercial scale, are reasonably cost-effective. With expected preliminary market prices of the various retrofits (i.e., NexaJoule- $1700/ton; Envelope sealing- $1/sq. ft; ventilation technologies- $1000 per home) and projected installation costs, the retrofit packages are under $10,000 for a 1500 square foot home. Key benefits to the homeowner are a 30% reduction in electric power costs for cooling and improved health through better indoor air quality. Key benefits to the state and utilities are reductions in overall electricity load and peak load, and a reduction in greenhouse gas emissions due to elimination of conventional refrigerants (as a benefit of using the SWEC).

Improving Water & Energy Efficiency in California's Dairy Industry

This Group 1 project will pilot test two innovative strategies to save energy and water among California’s dairy producers. In the first phase, the team will test at the UC Davis Dairy two different approaches for cooling dairy cows, which is vital for preserving their health and milk production: conduction cooling and targeted convection cooling. The more promising approach will then be field tested at a commercial dairy in Tulare, CA. Simultaneously, the team will analyze user experience, market barriers, and opportunities to accelerate market deployment.

Market Barriers to Widespread Diffusion of Climate-Appropriate HVAC Retrofit Technologies

Sarah Outcault, WCEC's Behavioral Scientist, giving a presentation on Market Barriers at WCEC's Affiliates Forum in May.

Climate Appropriate technologies save significant energy, so why aren't they more widespread?

While parallels could be made when examining the fundamentals of completely different industries—such as the smartphone industry or, pertinent to our work, the HVAC industry; there are market barriers regarding technological advancement that are quite unique to the HVAC world.

You likely have a smartphone, and you also likely change or upgrade that smartphone once every 2- to 3-years for a new, more powerful and more efficient version. With the success of the iPhone and Samsung’s Galaxy line for Android, bleeding edge technology and build quality are top on the list of desires, cost is not much of a concern to their consumers.

Unfortunately, for HVAC manufacturers, the newest technology is often looked at with a healthy dose of skepticism, especially large commercial consumers. These purchasers worry about longevity, uncertainty of upkeep costs and the simple human tendency to prefer the current state of affairs. So what will it take to trigger a potential buyer to be motivated in purchasing these new, extremely efficient climate appropriate HVAC technologies?

WCEC’s team of behavioral researchers, led by Dr. Sarah Outcault spends the majority of their time tackling just this issue. In their latest published report: Market Barriers to Widespread Diffusion of Climate-Appropriate HVAC Retrofit Technologies WCEC seeks to understand the market for these technologies and to identify key factors that influence stakeholders’ motivation, ability and ultimately triggers to adopt and promote climate-appropriate retrofit technologies.

The report identified 8 factors that influence stakeholder motivations to adopt and promote climate-appropriate HVAC retrofit technologies:

  • Technology requirements and performance: the human, material, and logistical resources required by the technology or policy for proper installation, commissioning, maintenance and performance
  • Technology costs: the initial and ongoing financial costs, uncertainty surrounding such costs, and diffused responsibility for such costs
  • Additional benefits: value besides energy savings provided by the retrofits
  • Access to information: whether and how stakeholders can obtain pertinent information on retrofits
  • Endorsements: the influence of recommendations by utilities, distributors and contractors, as well as the influence of social norms
  • Status quo bias: the human tendency to prefer the current state of affairs
  • Stakeholder coordination: the need for synchronized activities within and across stakeholder groups
  • Accountability and support: the ability to hold responsible and gain assistance from appropriate parties in the event of a problem

In addition, the project team identified six factors that particularly influence stakeholders’ ability to adopt and promote climate-appropriate HVAC retrofit technologies:

  • Technical feasibility: the viability of a technology given the climate, building and rooftop air conditioning unit (RTU) characteristics, as well as the human resources required
  • Cost: the financial cost of retrofits, the impact of potential utility incentives, and the uncertainties surrounding both cost elements
  • Effort: the amount of work involved in selling retrofits, obtaining rebates, and installing and maintaining the equipment
  • Awareness, knowledge and communication: stakeholders’ level of awareness and knowledge about retrofit opportunities, as well as the transmission of information among stakeholders
  • Access: the logistical details surrounding the acquisition of retrofits from those in the supply chain
  • Empowerment: whether or not stakeholders are endowed with the power to adopt and/or promote retrofits

Recommendations and methodologies used are provided in the published report.

Watch the webinar presentation on Market Barriers

WCEC Congratulates Two of Our Most Recent Graduates

WCEC would like to congratulate two of our graduate student researchers who have just recently earned their Ph.Ds this spring.

Nasim Tajmand earned her Ph.D in Civil and Environmental Engineering for her thesis "An Analysis of Water-Use and Energy-Use Impacts of Residential-Scale Evaporative Cooling Technologies".

Thesis Abstract

Increased marketplace demand of energy efficient, evaporative technologies for cooling also increase the demand for high quality water (e.g. treated municipal water), especially in climates that have water shortfalls. The problem is further aggravated in regions with poor water quality and where long-term droughts have decreased the available amount of the water. At the same time, new evaporative cooling technologies have attracted attention in the hot and dry climatic zones due to energy saving improvements compared to conventional systems.

In this study, the balance between water consumption, and energy savings as well as the importance of adequate quantity and quality water concerns were considered to clarify the ambiguities and problems as stated above.
First the trade-off between water use and energy savings using three different water resources (tap water, rainwater, desalination water) was explored by comparing energy base and cost analyses. Laboratory experiments and field studies were developed to understand the water quality impact and concerns in evaporative cooling technologies.

The main conclusion is that evaporative cooling technologies make sense energy and cost wise in under studied hot and dry climates, even when using high energy water from desalination. Laboratory experiments were also conducted to better understand the precipitation reaction mechanism in evaporative cooling systems. Scale deposition was formed both from low hardness and high hardness water sources (representative of municipal water) due to a high degree of saturation Rainwater could mitigate the challenges of deposition from municipal tap water by providing excellent water quality and indeed decreasing water consumption by reducing the bleed rate.


Marco Pritoni earned his Ph.D in Mechanical Engineering for his thesis titled "Automated Deployment of Advanced Controls and Analytics in Buildings" . Marco has also just recently accepted a position at UC Berkeley.

Thesis Abstract

Buildings use 40% of primary energy in the US. Recent studies show that developing energy analytics and enhancing control strategies can significantly improve their energy performance. However, the deployment of advanced control software applications has been mostly limited to academic studies. Larger-scale implementations are prevented by the significant engineering time and customization required, due to significant differences among buildings. This study demonstrates how physics-inspired data-driven models can be used to develop portable analytics and control applications for buildings. Specifically, I demonstrate application of these models in all phases of the deployment of advanced controls and analytics in buildings: in the first phase, “Site Preparation and Interface with Legacy Systems” I used models to discover or map relationships among building components, automatically gathering metadata (information about data points) necessary to run the applications. During the second phase: “Application Deployment and Commissioning”, models automatically learn system parameters, used for advanced controls and analytics. In the third phase: “Continuous Monitoring and Verification” I utilized models to automatically measure the energy performance of a building that has implemented advanced control strategies. In the conclusions, I discuss future challenges and suggest potential strategies for these innovative control systems to be widely deployed in the market. This dissertation provides useful new tools in terms of procedures, algorithms, and models to facilitate the automation of deployment of advanced controls and analytics and accelerate their wide adoption in buildings.

Highlights from WCEC's Affiliate's Forum

WCEC Director Mark Modera's Year in Review presentation at WCEC's Affiliates Forum

WCEC’s annual affiliates forum brings together HVAC industry stakeholders to discuss recent energy policy affecting the State of California, affiliate member news and developments, and research results published by WCEC. The forum’s goal is to create a diverse and relevant discussion on HVAC energy efficiency, pushing forward toward solutions and facilitating market impacts.

Download all of the PDF presentations and posters from this year's Affiliates Forum here: http://bit.ly/AF2016slides