use and occupancy of nearly all older building’s has changed over its life but
the building’s HVAC systems and controls have not been optimized for each
Extensive research by a number of organizations has validated the value of building system monitoring as an effective means to reduce and maintain lower energy consumption. A few of these organizations are the Lawrence Berkeley National Laboratories, the California Energy Commission and Texas A & M University.
HVAC “performance drift” is the deterioration of an HVAC system over time, resulting from a number of preventable issues. Performance drift typically results in a 5% to 15 % increase in energy consumption. Lawrence Berkeley National Laboratories identified these common contributors to performance drift:
- Manually over-ridden automatic control settings including programmable
thermostats, motor control switches, disabled variable frequency motor
- Timer clocks not used or disabled
- Duct and/or valve leakage or dysfunction
- Pumps, fans or actuators not operating correctly
- Scheduling, resets and/or setbacks not matching building usage
- Degradation of sensors
A study of 60 commercial buildings by the same organization found that 40% had HVAC equipment problems, 15% had missing equipment and 25% had energy management systems, economizers and/or variable speed drives that were not operating properly.
At an absolute minimum, the building operator should be tracking energy consumption on a monthly basis in a simple spreadsheet.
Commissioning and Retro-Commissioning
Another relatively inexpensive source of energy savings is re-commissioning or retro-commissioning an existing building. The use and occupancy of nearly all older buildings change over their lives but the HVAC systems and controls are often not optimized for each change. A collaboration between California’s Energy Commission and Lawrence Berkely National Laboratory showed a 16% median whole-building energy savings in existing buildings after retro-commissioning.
The US Department of Agriculture’s (USDA) Rural Energy for America Program (REAP) will reimburse for-profit building owners 25% of the cost of eligible energy efficiency upgrades as determined by a qualified energy auditor. Energy Audits of Alaska and Global Energy Audits are qualified auditing firms with the USDA REAP program.
Alaska Energy Efficiency Revolving Loan Fund – Designed to help public buildings implement energy efficiency measures, this program finances retrofits for the State of Alaska, school district, university, and municipal buildings. Loans are sized to be repaid from the energy savings. For more information: Eric Havelock, Alaska Housing Finance Corporation (907) 330-8245.
Energy Service Companies (ESCOs) – can offer financing for both public and private buildings through different contract options for a broad range of energy solutions. ESCOs can be a single point of contact for an energy upgrade project, and accept complete responsibility for the project and guarantee annual energy savings. Two of the larger ESCO’s are Johnson Controls and Siemens.