Engineers integral to success of energy-efficient construction

Collaboration between the local utility and design teams spells success for a leading energy-efficiency program in San Diego.

02/02/2012


Engineers are playing an integral role in one of the top-performing energy efficiency programs in San Diego. Savings by Design is a utility-funded initiative that supports high-performance design in commercial building construction and renovation. Over the last two years, nearly 100 participating building projects have achieved a collective energy savings of almost 48 million kWh and 1.4 million therms. The savings is roughly equivalent to powering 6,987 homes for a year.

Model for collaborative partnerships

While rebates and incentives for energy efficiency are available nationally, the hallmark of this program’s success is the collaboration between the local utility and design teams, which include architects, lighting engineers, and mechanical engineers. San Diego Gas & Electric’s (SDG&E) strategic partnership with the American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) and the Illuminating Engineers Society (IES) includes regular educational outreach to association members with the latest information on new technologies, policies, and products. The working relationship also invites reciprocal introductions to new building owners committed to incorporating energy-efficient design into their workspaces.

“This is one of the best programs I’ve seen to support energy-efficient construction, and the way it’s implemented by SDG&E has been particularly effective in advancing regional energy initiatives,” said Frank Shadpour, president of SC Engineers, who is also an ASHRAE Fellow, author of “The Fundamentals of HVAC Direct Digital Control,” and an instructor at University of California, San Diego Extension. “One of the biggest obstacles in new construction is getting the attention of building owners and getting the best system within their budget limitations. During the conceptual design phase, I bring in SDG&E to help evaluate the options and incentives for systems that will reduce waste now and reduce long-term energy costs to the building owner.”

Savings by Design is a model for how collaborative partnerships between a utility and the region’s engineers offer smart and strategic, forward-thinking solutions to offset the cost of high-performance building design, as well as effect ongoing utility cost savings that can significantly impact the bottom line of any business. In fact, the partnerships have been so successful that Savings by Design is at 122% of projected energy savings. Based on the program’s performance, the California Public Utilities Commission recently announced its extension into 2014.

Savings by Design incentivizes new buildings that exceed California’s Title 24 Energy Efficiency Standards by at least 10%, awarding greater incentives to those that perform at least 30% better. The additional incentives can be earned for U.S. Green Building Council LEED certification, enhanced commissioning, and end-use monitoring.

For example, current California Title 24 standards allow additional energy credits for advanced direct digital control (DDC) (see Figure 1). Frequently, the cost of these energy-saving advanced controls may be offset by the additional Savings by Design incentives. SDG&E will review the project early in the design phase to ensure that the building will qualify for as much of an incentive as possible to buy down the cost of innovative technology.

This diagram shows the direct digital control (DDC) system for an energy-efficient variable air volume (VAV) system. Courtesy: Frank Shadpour

During the program’s current two-year cycle, SDG&E has awarded almost $10 million in incentives to design teams and building owners. In turn, SDG&E and the design teams have been able to effect an estimated $8.6 million in annual energy cost savings to the building operators.

Two approaches for energy savings

Savings by Design invites two approaches to energy-efficient construction. The Whole Building Approach considers integrated energy-efficiency solutions, while for less complex projects the Systems Approach uses a simplified energy simulation modeling tool that identifies system options, associated savings, and qualifying incentives on daylighting; interior lighting; heating, ventilation, and air conditioning; service hot water; plus manufacturing, refrigeration, and food processing systems.

Some of the most effective energy-efficient systems the SDG+E and partner engineers have employed include the following:

• Valuable refrigerant flow system

This technology originated in Japan and is now prevalent in the United States. Relatively inexpensive, it can be easily implemented in small- to medium-sized businesses. It saves a great deal of energy by eliminating dedicated condensing units for each interior zone with one condensing unit that provides heating and cooling to all interior zones through heat recovery technology.

• Chilled beam system

Used in Europe for many years, this system can result in as much as 30% in energy savings by eliminating the need for large motorized fans to transfer energy through air in favor of employing induction via chilled water through a ceiling coil.

• Hybrid natural ventilation

While San Diego is a compatible environment for a natural ventilation concept, other regions can take a hybrid approach that utilizes window sensors that respond to the external temperature by shutting down the heating or air conditioning system and auto-opening windows. In hospital settings, studies have shown that natural ventilation enhances a patient’s recovery, so engineers now are applying that value proposition to achieve enhanced productivity in office workspaces.

• Geothermal heating pumps

Using the Earth as a heat source can save a building owner as much as 25% in energy costs. Geothermal heat pumps draw and reject heat from deep underground, where temperatures remain constant throughout the year.

While engineers and their design teams are incentivized for their contribution, they participate in the program because they believe in what it’s trying to accomplish—and that’s made all the difference to its success.

“My profession allows me to make an impact on the environment,” said Shadpour, who has been working with SDG+E for almost 30 years and has witnessed the evolution of energy-efficiency initiatives. “Rather than saving a quick buck today, my vision is to build a sustainable community that will reduce waste for years to come. What the utility accomplishes with programs like Savings by Design is opening the minds of building owners to the possibilities. I’m a big believer in that and think it’s a win-win for everyone involved.”

Reguly is the director of customer programs and assistance at San Diego Gas and Electric.