Even though the building owners continuously upgrade Bozeman Job Service, Montana Resource Efficiency (MREP) auditors located several cost-effective efficiency measures, all with a payback period of a three years or less.
The Bozeman Job Service is a one-story office building located in downtown Bozeman. In 2010, the building owner installed new furnaces, new ductwork, and fluorescent lighting. The MREP audit identified energy-efficiency opportunities for the plug-load, lighting, building envelope, thermostats, and heating, ventilation, and air condition (HVAC) systems.
Energy-efficiency measures found in the HVAC system include installation of compressors and variable-frequency drives to their existing furnaces. The compressors will have an energy-efficiency rating greater than 12, which will result in savings of approximately 2,600 kWh of energy. The variable-frequency drives (VFDs) will accommodate the demand of air flow through the building. This measure would save approximately 1,055 KWH annually. The economics associated with these two measures is:
- Annual energy savings: 3,655 kWh
- Projected cost: $841.63
- Simple payback with energy savings: 2.57 years
The office also has a large plug-load energy use from computers, copiers, printers, and other large office equipment. This building houses 42 computers with monitors that are powered on all hours of the day due to software and/or computer updates from the state. Each computer uses approximately 1.408 kWh per workday and 1.968 kWh per weekend left running. That adds up to almost 21,500 kWh per year. This is almost half of the building’s current usage. There are two options to cut down on this usage:
- Computers OFF weeknights and ON weekends
- Annual energy saved: 7,160 kWh
- Approximate energy bill savings: $574.66
- Computers ON weeknights and OFF weekends
- Annual energy saved: 4,300 kWh
- Approximate energy bill savings: $354.12
Within the office space, the lighting consists of CFLs and fluorescent T8 bulbs. MREP recommended an LED conversion with the following economics:
- LED cost: $5,438
- Utility incentives: $3,135
- Net cost: $2,303
- Annual energy savings: 13,974 kWh
- Simple payback with energy savings: 1.31 years
Additional energy-efficiency measures identified in the audit include weatherizing windows and doors, as well as programmable thermostat setbacks and scheduling.