Energy Conservation Measures (ECMs)

ECMs are any type of project or technology implemented to reduce the consumption of energy in a facility. There is a multitude of Energy Conservation Measures (ECMs) that can be considered for each particular site. The ECMs proposed and selected for the Worcester's ESPC were broken into the following categories:

Building Air Infiltration

  • Building Infiltration Sealing
  • Attic Insulation
  • Window Replacements
  • Door Replacements
  • Roof Replacement

The Investment Grade Energy Audit found every City building to have varying levels of air leakage that warranted implementation. Therefore, caulking, foam, and weather-stripping work was done to reduce air leakage from windows (some windows were also replaced), roof/wall and floor/wall intersections, vents, and wire passages. Additionally, loose fill cellulose insulation was added in the walls and attics of many buildings.

Building Automation Controls (upgrading the existing ones or installing the new ones)

  • Time of Day Scheduling (regulates building occupancy for each zone and time period)
  • Demand Control Ventilation (modulates the outside air settings to match the actual needs of the space, which prevents over-ventilation of these spaces and results in lower heating and cooling costs)
  • Optimum Start/Stop (delays the start of a building’s primary heating, ventilating and air conditioning equipment until the last possible moment necessary to ensure a comfortable environment for the occupants)
  • Occupancy Sensor Control (sets back space temperature when rooms are unoccupied)

The IGA found that a large number of City buildings suffered from inefficient and outdated heating and cooling control equipment, such as older, non-compatible energy management systems, non-programmable thermostats, simple valves to control radiators, and inefficient night temperature controls and boiler burners.

Therefore, the City decided to replace a variety of outdated equipment with a modern energy management system which can be programmed, monitored and controlled remotely.

Computer Power Management

The City installed a computer management software program that allows for remote power control of the City’s approximately 6,200 computers. Prior to this improvement, computers were typically not shut off at night or on weekends due to the need to install security upgrades. By installing remote power control, the City’s Technical Services Division is now able to send computers into hibernation mode during non-working hours and power them on remotely to install updates as needed.

Lighting Retrofits

  • Lighting Retrofit & Redesign
  • Outdoor Lighting Upgrades

The energy audit found that many City buildings are using inefficient lighting technologies. New, more efficient lighting fixtures and occupancy sensors have been installed in some buildings to reduce electrical consumption and costs.

Mechanical Modifications

  • AHU-VAV Retrofit (Air Handling Units - Variable Air Volume)
  • Kitchen - VAV Retrofit
  • AHU-Heat Recovery
  • Retrofit Fans with VSD (Variable Speed Drive)
  • Boiler Replacements
  • Steam Trap Replacements
  • DHW - Replacements
  • Chiller Replacements
  • Pumps - Retrofits with VSD
  • Unit heater Modifications
  • De-stratification Fan Installation
  • DCW Cooled Equipment
  • Comprehensive HVAC Upgrade
  • Replace Existing Rooftop Units
  • Piping Insulation
  • Boiler Linkage Controls
  • Retrofit Cooling Tower Fan with VSD

Various buildings had inefficient air control systems, kitchen overhead vents, hot water boilers, and chillers. As a result, many of these were replaced. For example, boilers were replaced at Union Hill Elementary School, Norrback Community School, Fire Headquarters, Quinsigamond Elementary School, and Worcester Arts Magnet.

Renewable Energy Projects (Including Feasibility Studies)

  • Solar Photovoltaic Array
  • Feasibility of:
  • Wind Turbine
  • Wind Hybrid
  • Solar Air Heating
  • Solar Water Heating
  • Biomass-Fueled Boilers
  • Geothermal Potential (Ground Source Heat Pumps)
  • Landfill Gas Recovery

As part of the original scope of work, Sullivan Middle School and Worcester Technical High School received roof-mounted solar arrays; 9 more solar arrays were constructed as part of subsequent phases of the ESPC.

Feasibility of other renewable technologies were also explored but were not found to be feasible or practical at the time either due to natural resource constraints (e.g. limited wind) or financial viability.

Water Conservation

  • Low-flow and/or low consumption toilets, urinals, faucets, and showerheads were installed in a number of buildings