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North American Mechanical Inc.

School District of Cambridge. A Business Relationship Presentation. North American Mechanical Inc. Use our energy to save yours®. Tonight’s Goals. Summary and general condition of the HVAC systems in the three district school buildings

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North American Mechanical Inc.

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  1. School District of Cambridge A Business Relationship Presentation North American Mechanical Inc. Use our energy to save yours®

  2. Tonight’s Goals • Summary and general condition of the HVAC systems in the three district school buildings • Expected useful life of the HVAC systems at all three schools • Our Recommendations 2

  3. Our History • Entered into a 3 year HVAC Proactive Maintenance Agreement in Dec 2009 • Provide Energy related services including reports upon request • Installed new pool boiler/heat exchanger in the Elementary School pool to improve performance and system longevity as well as many other system improvement projects 3

  4. Nikolay MS • Built in 1955 • Addition in 1964 • 1990 (small addition) • 1998 (Major Electrical/Mechanical upgrades) • 2003 (Control system upgrade) 4

  5. Nikolay MS • Description of systems • HW – CW (Chiller/Boiler System) • Unit Ventilators • Pneumatic Control system with digital front end (Johnson Controls) 5

  6. Nikolay MS • Assessment of systems • Major equipment is in very good condition • Since NAMI’s involvement, several significant issues have been resolved to improve system performance and improve system longevity. (I.E. Boiler/Chiller starts – Short cycling) • Controls are all pneumatic – Regular control issues, leaking air. 6

  7. Nikolay MS ENERGY Review The total cost of energy for 2010/2011 for the middle school was $82,414 compared to $86,843 in 2008/2009. The cost per square foot in 08/09 was $0.987 and $0.937/sfin 2010/2011. Like the high school, this performance is very good. The building does not have as much after-hour use as the high school, so the expectations would be to operate at a slightly lower cost/sf. One concern warranting further investigation is the electrical usage has increased by almost 16% from 2008/2009 to 2010/2011. This is significantly higher than the increase for the entire district. 7

  8. Nikolay MS • Recommendations • Replace the HVAC system controls with one that provides better air quality, comfort, and is more efficient 8

  9. Cambridge ES • Built in 1998 • 2003 (control system upgrade) • New Pool Boiler/Heat Exchanger Dec 2010 9

  10. Cambridge ES • Description of systems • HW – CW (Chiller/Boiler System) • VAV (Variable Air Volume) • Pneumatic Control system with digital front end (Johnson Controls) 10

  11. Cambridge ES • Assessment of systems • Major equipment is in very good condition • Since NAMI’s involvement, several significant issues have been resolved to improve system performance and improve system longevity. (I.E. Boiler/Chiller starts – Short cycling) • Controls are all pneumatic – Regular control issues, leaking air. 11

  12. Cambridge ES ENERGY Review The energy use at the elementary school is much higher than the other two schools. In 2010/2011, the total cost of energy was $183,188 or $1.53/sf(compared with approximately $0.95/sf for the Middle and High Schools). It should be noted that the elementary school is fully air-conditioned and has a swimming pool and that the usage is down significantly from 2008/2009 ($208,471, $1.73/sf). 12

  13. Cambridge ES • Recommendations • Replace the HVAC system controls with one that provides better air quality, comfort, and is more efficient 13

  14. Cambridge HS (1969) • 1969 Original High School HVAC Systems • Description of systems • One large, central gas heating furnace (June Aire) • Dual duct, under floor air distribution system • A/C for interior core area • No A/C for exterior areas 14

  15. Cambridge HS (1969) 15

  16. Cambridge HS (1969) • Assessment of systems • At 43 years old the HVAC system has well exceeded its expected useful life • The A/C condensing unit is in need of replacement in the near future • Major repairs to furnace refractory are needed in the near future 16

  17. Cambridge HS (1969) • Assessment of systems • Air tunnels need to be cleaned, some repairs made and measures need to be taken to keep ground water from entering them • Buried ductwork is corroding • Controls are all pneumatic – Regular control issues, leaking air. 17

  18. Cambridge HS (90-98) Picture 1 – Insulation on Tunnel Floor 18

  19. Cambridge HS (90-98) Picture 2 – Water in Tunnel 19

  20. Cambridge HS (90-98) Picture 3 – Frog Carcass 20

  21. Cambridge HS (90-98) Picture 4 - Trash 21

  22. Cambridge HS (90-98) Picture 5 – Dirty ductwork, damaged fiberglass 22

  23. Cambridge HS (90-98) Picture 6 – Dirty ductwork, damaged fiberglass 23

  24. Cambridge HS (1969) • Recommendations • Replace the HVAC system (and controls) with one that provides better air quality, comfort, and is more efficient • Add A/C for the exterior classrooms 24

  25. Cambridge HS (90-98) • 1990 Additions & 1998 Alterations to HVAC Systems • Description of Systems • Hot water boilers • Air handling units (AHU’s)/variable air volume (VAV) • A/C for interior areas and music area 25

  26. Cambridge HS (90-98) • Assessment of systems • The system is generally in good condition • Pneumatic Control system with digital front end (Johnson Controls) • The overall HVAC system can be expected to last another 10 to 20 years. Controls, boilers, and possibly other minor equipment may need to be replaced sooner depending on wear 26

  27. Cambridge HS (90-98) ENERGY Review Total energy cost for the high school for 2008/2009 was $115,294 or $0.97/sf. For the school year 2010/2011, the total energy cost was $113,355 or $0.953/sf; a decrease of 1.7%. This performance is very good. The electrical use/sf for 10/11 was 5.24 kWh/sf and the natural gas was .39 therms/sf. Considering all of the after-hours use of a high school, the energy costs are well under control and shows the building is well operated. Please note that older HVAC systems may not be set-up to bring in as much ventilation air as required by today’s building codes. The heating/cooling of ventilation air may be a significant part of any building’s energy use. 27

  28. Cambridge HS (90-98) • Recommendations • Replace the temperature control system to make it compatible with the controls recommended for replacement in the 1969 building • Consider adding A/C for the exterior classrooms • Continue to maintain the HVAC system 28

  29. Cambridge HS (90-98) • Thank You! • Questions? 29

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