GOC376875 & GOC376877 - Consulting - GOC376875 & GOC376877 - VFD and CO2 Sensor Retrofit & AHU Coil Replacements

GOC376875 VFD and CO2 Sensor Retrofit
 
This recommendation is a combination of 2 energy efficiency recommendations from the Dual Oceans audit from 2012. Install VFD's on return fans and C02 sensors on return ducts or offices/conference rooms to control damper position for the AHU's. Scope of work should include investigation of current motor compatibility and suggested location of C02 sensors to optimize energy savings, investigate possibility of lowering space pressure set points (currently set at 35 Pa which is creating issues arising from the building being over pressurized), investigating AH-9&13 and making recommendations to address supply airflow issues (multiple tenants complaints in this area, SRs registered thru NSCC, 2nd floor North-East). Control modifications will be required to existing Delta system to alter return airflow to be controlled by VFD instead of the vortex damper.  Vortex should be locked open or removed completely.  C02 control programming will be required to override fresh air damper control to keep levels below 800 ppm but to maintain mixed air temperature control when the levels are below this threshold.  Consultant will prepare feasibility study and all required documentation for Manitoba Hydro custom measures incentive program and/or CO2 sensor program showing expected savings and calculate an expected incentive payout.
 
GOC376877 AHU Coil Replacements
 
Set up a replacement schedule for the 15 AHU coils with priority on replacing AHU 3 first.  The other units can be scheduled as required based on priority.  Construction to take place during winter heating seasons.
 
AHU 3 coil is badly worn and needs replacement.  Other coils are suspected to be nearing end of lifecycle.  This was identified during the 2013 BPR. AHU's distributed amongst the 4 penthouse mechanical rooms supply air to the entire building.  The cooling coils require considerable maintenance in particular on AHU 3.  This coil has had numerous patch jobs and has sections removed that can no longer be used. Tech on site reported that cooling coil in AHU 13 does not provide enough cooling.