Harvard University has spent a considerable amount of effort developing its Green Building Guidelines, a set of building design standards for projects over 5 million dollars requiring the use of particular materials and power efficiency levels to ensure that all future construction projects meet certain sustainability benchmarks. As the institution creates a strategy to meet its lofty greenhouse gas reduction goal by 2016, it is becoming increasingly apparent that the school’s existing portfolio of over 600 buildings must operate more efficiently.
One Harvard Real Estate (HRES) office building, 1033 Massachusetts Avenue, has already begun this effort through a process called Existing Building Commissioning. Existing Building Commissioning is an in-depth engineering analysis of the sequencing, operation, and performance of a building’s base systems. Based on the findings, the engineering company provides the building operation’s staff with a report itemizing a number of recommendations for projects that will save energy categorized by cost.
The study conducted at 1033 Mass Ave focused on the investigation and analysis portion of recommissioning. Engineering firms can be contracted to remedy the low or no-cost measures that are identified and conduct another series of testing after the building upgrades have been completed.
Costs and Savings
The investigation and analysis of the building systems at 1033 Mass Ave uncovered a number of energy and cost-saving opportunities. The low or no cost measures instituted as a result of the recommissioning process are listed in the table below.
| Significant Sustainability Actions | Date of Implementation | Cost of Implementation ($) | Annual Net Operating Savings ($) | Simple Payback (years) |
|---|---|---|---|---|
| 1. Repair leaks in AHU-4 | Sep-08 | $120 | $866 | 0.14 |
| 2. Install Enthalpy sensors | Sep-08 | $7,000 | $4,339 | 1.61 |
| 3. Program off AHU-4 at night | Sep-08 | $160 | $6,558 | 0.02 |
| 4. Install Secondary Hot Water Pumping Control | Sep-08 | $1,000 | $122 | 8.20 |
| 5. Confirm Chilled Water Reset Routine | Sep-08 | $0 | $0 | - |
| 6. Testing and Balancing of Ventilation System | Sep-08 | $11,000 | $0 | - |
| 7. Recommissioning study | Sep-08 | $5,430 | $0 | - |
| TOTAL | $24,710 | $11,885 | 2.08 |
The opportunity with the best payback of 0.02 years, or 7.3 days, was programming an Air-Handling Unit (AHU) off during unoccupied hours. This initiative will provide a substantial annual operating savings of $6,558, a sum capable of paying for the recommissioning study itself. Overall, the costs and net operating savings of the recommended projects, including the cost of the recommissioning study, provided a simple payback of 2.08 years.
Rebate Opportunity
The Existing Building Commissioning was relatively inexpensive because Harvard Real Estate Services pursued a rebate from NSTAR, the local utility. The table above indicates the price of the study was $5,430, but this is after the rebate. Before the NSTAR discount, the study was fairly expensive, around $22,000. By applying for NSTAR funding, the project received a rebate worth over $15,000! Chuck O’Brien, the property manager at 1033 Massachusetts Avenue, was especially pleased with the recommissioning study. He reflected, “It helped to shed some light on energy savings opportunities and offered ways to provide a more comfortable work environment for building tenants.” Of course, it did not hurt that NSTAR offered to pay for 75% of the investigation and analysis portion of the recommissioning process.
Valued Lesson
Another factor contributing to the success of the Existing Building Commissioning process was the development and review of the Request for Proposals (RFP) that was sent out to a number of engineering firms in the area. HRES in conjunction with the Office for Sustainability provided a concise summary of the project building and clearly outlined the specific building systems and deliverables that HRES wanted as a result of the study. The explicit language describing the building and deliverables ensured that the engineering firms were bidding on a similar scope, and that HRES received the information they desired.
Further Study
A forthcoming thesis written by a graduate student enrolled in the Harvard Extension School’s Environmental Management Masters Program studies the benefits of Existing Building Commissioning when applied together with the LEED for Existing Buildings rating system. The study surveyed a number of projects and found that the average payback of an Existing Building Commissioning project is 2.5 years, further making the case that Existing Buildings Commissioning is valuable.
As documented above, Existing Building Commissioning is a valuable tool that can identify substantial energy and cost-saving opportunities in buildings’ base systems. With sizable rebates available, hopefully more Harvard buildings will follow suit and invest in a study designed to save energy and money.
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Programming an Air-Handling Unit (AHU) off during unoccupied hours...will provide a substantial annual operating savings of $6,558, a sum capable of paying for the recommissioning study.