Schinnerer's RM Blog - efficiency tag

Study of MIT Buildings Suggests Additional Approaches to Energy Efficiency

Tue, 10 Apr 2012 12:11:00 GMT

Colleges and universities are notorious for inefficiency in energy use. A recent study by the Massachusetts Institute of Technology of two MIT buildings can assist both other educational institutions and other types of facility owners in reducing energy use through planning and scheduling. Titled “ENERNET: Studying the dynamic relationship between building occupancy and energy consumption,” the paper deals with the significant issue of matching building and equipment schedules with dynamic occupancy patterns.

Many workplaces feature major changes in occupancy over the course of a day or throughout the week. As a result, energy use tends to be inefficient—too large or too small—in relation to the use pattern.

The MIT study reveals some data that could help designers and building managers, on campuses or in the commercial sector, optimize energy usage. It also sets the stage for more research on the subject. The study, published in the April issue of the Energy and Buildings journal, finds that while electricity use corresponds to occupancy fairly well in those spaces, the activity of heating, ventilation, and air conditioning (HVAC) systems in the buildings does not correlate closely to occupancy.

The researchers analyzed two very different kinds of buildings—one housing researchers in a combination of offices, classrooms, and labs, and the other a stand-alone classroom building with a sizable entrance atrium and a large number of offices inside. The study used data about Wi-Fi connections as a proxy for building occupancy, a method the researchers believe could be replicated elsewhere at low cost; while the data does not necessarily reveal an exact population count inside buildings, it does indicate relative occupancy levels over time.

Analyzing data from all four seasons of 2006, the researchers found that both buildings have a distinctive cyclical “signature” of electricity usage that rises and falls daily. Both buildings use more steam (for heat) in winter and spring, and more chilled water (for air conditioning) in summer and fall. But while about two-thirds of the variation in electricity levels can be accounted for by changing occupancy levels, the use of the HVAC systems correlated only weakly to occupancy. These MIT buildings tended to be heated or cooled according to the season but not in a way that optimized the use of energy.

The researchers, part of MIT’s SENSEable City Lab, noted that part of the variance between occupancy and energy use may derive from the special needs of academic buildings, which often house labs with around-the-clock heating or refrigeration demands.

There are many possible architectural or engineering solutions to this issue. Co-author of the study, Carlo Ratti, notes “You can move the people to the energy, in which case the architecture can help a lot, or you can move the energy to the people, which is more futuristic.” The larger point, he says, is that “you want to have a better match.”

The study suggested possible design-based solutions including:

rearranging plans so that heat from larger, less used spaces can seep into more rooms
using sensing based thermometers that regulate temperatures on a more granular basis within buildings,according to the number of people
repurposing large spaces for more intensive and improved use

LEED Certification

Thu, 14 Apr 2011 18:25:00 GMT

The increasing emphasis on sustainability and high-performance buildings presents both opportunities and risks for design professionals. The most important factor in preventing claims based on the underperformance of a sustainable design is that all parties involved understand, and acknowledge in writing, the inherent risks with such a project, the factors that make the outcome unpredictable, and the limits and responsibilities of each stakeholder to manage risks.

We recently reviewed a contract that contained the following provision:

In the event Owner requests but is denied the level of LEED certification it seeks from the U.S. Green Building Council because of deficiencies that are the fault of Engineer with regard to the design or construction of the Project, the required records of the construction or otherwise, then, in such event, Engineer shall be liable to Owner for all costs, expenses, losses, liabilities, diminished value or other damages incurred by Owner as a result of not obtaining such level of LEED certification.

This language increases the insured’s liability to beyond what is expected under the law and could result in claims not covered by insurance. Under U.S. common law, design professionals have the responsibility of using due care in providing their services. There is no warranty of the efficacy of professional services, nor does the design professional provide a warranty for the work of the contractor or others based on the services or instruments of service provided by the design professional. Professional liability insurance policies exclude coverage for claims arising out of express warranties or guarantees. Because coverage is for professional services provided, and not assumed contractual obligations, professional liability insurance does not "stretch" to provide coverage for a warranty of services beyond meeting the standard of care.

Establishing reasonable expectations at the beginning of the project is vital. One way to avoid unreasonable contractual provisions and unrealistic expectations is by informing the client that design services are recommendations that the client has to understand, and once satisfied, accept. It is essential to avoid language that could be construed to establish a warranty of service or results.

The following is an example of language that can be used when a client wants third-party certification of sustainability:

Client has made Design Firm aware that Client intends to pursue [specific certification standard] for this Project. Design Firm shall research the applicable certification requirements, design the Project with the intention of having the Project meet the requirements, and document the design of the Project for submission by the Client to the certifying organization. Client recognizes that certification is not based on design alone, but also on the construction, operation, and maintenance of the Project and therefore agrees that it shall bring no claim against Design Firm if the project is not certified as intended, unless the negligence of the Design Firm is the sole cause of the Project not being certified.

Client also recognizes that during the design of the Project, Design Firm shall use professional judgment in the selection of materials, products, and systems for the Project with the goal of meeting certification criteria, but that Design Firm cannot and does not warrant the performance of any specified material, product, or system. Design Firm will identify for Client any material, product, or system that, in the Design Firm’s judgment based on examination of available performance information, might provide Client with a benefit on this Project, but does not have adequate information on its performance in actual construction or operation. Client acknowledges that it shall look solely to the manufacturer, supplier, or installer of materials, products, or systems if performance does not meet expectations.

Contractual provisions such as disclaimers and other exculpatory language need to be worded carefully and should be drafted with the assistance of local legal counsel.

Sustainability in the Desert

Wed, 18 Aug 2010 14:06:00 GMT

The City of Las Vegas has a sustainability officer. That might seem like hiring a nutritionist for a candy store or a stand-up comedian for a funeral home, but the city of excess and artificiality appears serious about reducing its energy and water use.

Thomas Perrigo is the city official in charge of the sustainability initiatives. He recently was interviewed for SmartPlanet.com. Perrigo pointed out that both the city and its tourist service industry are working to change both operations and image. He pointed out that hotels are taking the lead on sustainability by significantly cutting energy use (and carbon emissions) and reducing water use. The efforts are not aimed at influencing visitors as much as it is on saving money. Perrigo mentioned that MGM Resorts and Harrah’s – the two resort/gaming operations that run 80% of the properties on the Las Vegas Strip – have been recognized as top green corporations.

Although the tourist industry accounts for much of the energy usage, it is the residential areas of Las Vegas that consume the most water. Perrigo mentioned that the big user of water is irrigation for residential landscaping. So the city has an education program on the beauties of desert landscaping and the Southern Nevada Water Authority is pushing desert-friendly plantings instead of turf. The authority is providing a $1.50 per-square foot incentive payment when lawns are replaced by native vegetation. It states that over 147 million square feet have been converted from grass to desert-friendly cover, through 42,000 participants, resulting in the conservation of 8.2 billion gallons of water annually.

Perrigo also stated that Las Vegas is taking advantage of its location with substantial investments in renewable energy – with solar power being the top priority – as well as achieving energy efficiencies. The regional transportation commission is even purchasing electric bicycles for city employees to use in place of automobiles for city business.

So next time you emerge from a 70 degree casino into the 100 degree Las Vegas summer to take a dip in a gigantic pool or view a frenetic waterscape, you can feel a little better that at least someone is working on conserving power and water.

First LEED and Now SEED

Thu, 15 Apr 2010 13:26:00 GMT

Evaluation tools for the built environment address many aspects of design and construction. From the LEED evaluation of sustainability to the defense assessment being developed by the Building Security Council of the American Society of Civil Engineers, programs provide measures of “success.” Add to these evaluation tools a new effort to evaluate the aspects of a socially, economically, and environmentally-healthy community.

ASHRAE Publishes 189.1: A Code-Enforceable Standard for Green Buildings

Fri, 29 Jan 2010 15:33:00 GMT

Working together, the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), the U.S. Green Building Council (USGBC) and the Illuminating Engineering Society of North America (IES) have published ASHRAE Standard 189.1, The Standard for the Design of High-Performance, Green Buildings Except Low-Rise Residential Buildings. It covers site sustainability, water use efficiency, energy efficiency, indoor environmental quality, and the building’s impact on the atmosphere, materials, and resources. ASHRAE Standard 189.1 also covers the building’s construction and plans for operation.

It is important to note that ASHRAE Standard 189.1 is not a design guide and it’s not a rating system. It is written using code language and, if adopted by a jurisdiction, will establish a standard that can be enforced by officials.

For more information you can read ASHRAE’s press release announcing publication of 189.1, or go to ASHRAE’s publications page for a full description of 189.1.