AAAOM’s Thermal Energy (Natural Gas) Consumption

by Stephanie Parent

The AAAOM headquarters, built in 1896, is an historic building. A new focus of the organization is to expand awareness in the AOM community on the implementation of going green. The practitioner community can implement this as well. To this extent, the AAAOM has determined that it will present itself as the example to gain awareness of measures that can both reduce energy consumption and make wiser choices in its consumption of green supplies and products. The AAAOM hopes its journey into greater environmental awareness can spur kindred activity in the AOM community-at-large.

The prior owner of the AAAOM facility insulated the building, including the attic and installed weather-efficient windows. While the current owners renovated nearly the entire building prior to occupying it, the square footage (sf) remains the same, and only an enclosed back porch needs renovation. In 2002, the owners installed the highest efficiency Trane unit, converting an inefficient floor furnace to a high efficiency natural gas furnace. The current square footage is 750 sf and did not change during the measurement period of 2007- 2008.

Pacific Gas and Electric (PGE) supplies natural gas to the AAAOM building for gas appliances such as a furnace, stove and water heater. AAAOM has little control over the type of gas provided, since they do not generate their own heat source, but rather receives fuel for heat from PGE. However, they do have control over the amount of gas consumed and the efficiency of the building (how well the building retains heat).

A programmable thermostat regulates the temperature in the office building. During winter months, AAAOM employees maintain the temperature at 68 degrees F° between 8 a.m. - 5 p.m. and at 56 degrees F° when the building is unoccupied.

Performance

Over the past two years, AAAOM’s natural gas consumption increased. The benchmarks used to analyze gas consumption include total thermal energy consumed annually and energy consumed per square foot of office space. In 2007 they consumed 15.0 million British Thermal Units (MBTUs) and in 2008 they consumed 17.9 MBTUs. However, for January through March 2007, I averaged the data for the other 8 months since data for these months was not available from the utility company. Therefore, the 2007 total is an estimate.

Assuming that natural gas consumption was actually greater in 2008 than 2007, we can examine why that occurred. Square footage did not increased in 2007 or 2008 so the increased consumption is not due to this. In 2007 AAAOM added two more employees. This may have increased natural gas consumption due to more use of hot water, but it should not have added to the heat consumption. So adding two employees should not increase natural gas consumption very much. Since natural gas consumption is greater in the winter than summer due to heating, it is possible that 2008 had a greater number of colder months than 2007. The change could also be due to the need for maintenance of the building and gas appliances to ensure proper function.

Goals & Next Steps

Given that natural gas consumption increased between 2007 and 2008, AAAOM should consider ways to reduce consumption and increase efficiency. Lowering the thermostat to 55° F when the office is unoccupied may help. (Most utility companies recommend 55° F when an office is unoccupied.) There are plans to renovate the back porch which should significantly reduce gas consumption since the back porch may have many leaks allowing heat to escape. The organization may wish to check windows and doors for drafts and then weatherize these to keep heat in during winter.

Making sure that gas appliances work properly is also important to reduce gas consumption and ensure good indoor air quality. If not already doing so, AAAOM should change furnace filters regularly, such as prior to the start of the heating season and every month or couple of months during use. Have gas appliances checked annually, in August, prior to the start of the heating season, to make sure there are no leaks and that appliances are functioning properly. The local utility company or a consultant may offer such services.

These are suggestions that the management will need to consider, taking care to balance environment, economics and social needs.

Steps You Might Take in Your Office

Of course, these ideas depend on the particular situation at your office – whether you have gas appliances, the budget for this cost, and the time to address these items: