client: Region of Sudbury
location: Sudbury, Ontario
project description:
In April of 2000 R.V. Anderson Associates Limited (RVA) /Dennis Consultants completed a 2.5 million dollar capital cost Energy Conservation Upgrade design for the Regional Municipality of Sudbury at the Sudbury Sewage Treatment Plant. The Region's criteria required R.V. Anderson/Dennis Consultants provide specific energy cost savings in the future operation of the plant. Particular emphasis in the RVA/DC design was placed on:
The existing Control Building component upgrade including the installation of a unique 'solar' wall comprising a solar absorptive colored metal wall cladding with small perforations to facilitate the introduction of solar heated convected air into the building enclosure. This passive system will provide preheat make-up air for the Control Building HVAC unit, blower and gallery area ventilation and preheat air for the aeration tank blower intakes.
Pre-painted metal cladding will be installed with back-up insulation on the north, east and west walls of the Control building together with new low 'E' glazed windows and access door upgrades providing a substantially improved energy efficient building envelope.
Mechanical upgrades include the installation of a new high efficiency 75 horsepower electric boiler to operate in off-peak hours, retrofit of the pneumatic radiation temperature controls with electronic controls and replacement of an existing heating/ventilation air handling unit with a high efficiency effluent water supplied water source heat pump.
Process operation upgrades include replacement of the existing aeration system with fine pore bubble diffusers and two new 250 horsepower blowers, replacing the three existing 500 horsepower blowers, Automation of the aeration process utilizing programmable logic controllers, motorized control valves, dissolved oxygen probes and air flow monitors, the installation of a variable frequency drive on the primary, 525 horsepower raw sewage lift pumps, retrofit and upgrade various pumping systems, retrofit and automate the existing return sludge pumping system complete with variable frequency drives and programmable logic controllers, modifications to existing automated process controls utilizing the new and existing equipment to improve energy efficiency. Lighting upgrades include energy efficient fluorescent fixtures, lighting fixtures placed on ambient light sensors, portable auxiliary lighting within the plant buildings and perimeter. Lighting fixtures in access areas connected to motion detector sensors.
The estimated capital cost of this energy retrofit totals 1.8 million dollars with an additional $700,000 in non energy related upgrades. The total project cost is estimated at 2.5 million dollars. An estimated 6.0-year pay back period has been determined projecting savings of approximately $300,000 per year in operational cost. |
