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

Tonights 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

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 (small addition) 1998 (Major Electrical/Mechanical upgrades) 2003 (Control system upgrade)

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

6 Nikolay MS Assessment of systems Major equipment is in very good condition Since NAMIs 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.

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/sf in 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.

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

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

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

11 Assessment of systems Major equipment is in very good condition Since NAMIs 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. Cambridge ES

12 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). Cambridge ES

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

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 Cambridge HS (1969)

15 Cambridge HS (1969)

16 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 Cambridge HS (1969)

17 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. Cambridge HS (1969)

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

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

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

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

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

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

24 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 Cambridge HS (1969)

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

26 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 Cambridge HS (90-98)

27 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 todays building codes. The heating/cooling of ventilation air may be a significant part of any buildings energy use. Cambridge HS (90-98)

28 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 Cambridge HS (90-98)

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