Overview Building Features Grade JK-6 Grade 7-12

Mechanical and Electrical Basis of Design

The following has been compiled for the purpose of summarizing the design parameters and the subsequent mechanical & electrical systems and materials that are incorporated into the Dr. David Suzuki Public School project. This shall also be used as a tool with the commissioning process to identify systems utilised at the design, construction and post-construction project phases as per LEED Prerequisit EAp1: Fundamental Commissioning of the Building Energy Systems.

Download the Mechanical and Electrical Basis of Design.

1.0 General Information:

  1. Building is designed in accordance with the 2006 Ontario Building Code (OBC) Compendium containing the Building code Act, and Ontario Regulation 350/06 including all amendments.
  2. Site is located in Windsor, Ontario.
  3. This building is a 58,000 ft2, two storey elementary school that is to be designed and constructed with the goal of obtaining a LEED platinum certification.
  4. Ventilation rates are based on ASHRAE Standard 62.1-2004.
  5. Anticipated Operating Setpoint Conditions:
    1. Indoor Summer Setpoint 78°F/50% RH
    2. Indoor Winter Setpoint 70°F/30% RH
      (note: installed heating equipment capacity is sufficient to meet a 72°F setpoint in all occupied spaces as required by the OBC)
  6. Owner Assigned Occupancy Schedules:
    1. Classrooms: 8:30am to 4:00 pm, mon-fri
    2. Administration: 8:00 am to 6:00 pm, mon-fri
    3. Daycare: 7:00 am to 6:00 pm, mon-fri

2.0 Building Services:

  1. There is a 4” metered incoming water connection for domestic water supply.
  2. There is 6” incoming water supply for fire protection systems.
  3. There is a 6” sanitary sewer connection.
  4. There is a 10” storm overflow connection from the rainwater storage cistern to site stormwater management system.
  5. There is no natural gas service to the building.
  6. The electrical service to the school is rated for 800 Ampere, 347/600 Volt, 3 phase, 4 wire (main circuit breaker rated for 80% loading).

3.0 Plumbing and Drainage:

  1. Rainwater Harvesting System:
    1. Precast concrete water cisterns with a total storage capacity of 706 ft3 (20 m3) are utilised to store rainwater harvested from the entire roof area of the building (approx. 30,000 ft2). Clean condensate from air handling units, fan coils, and water-to-air heat pumps is also collected and piped to the cistern system by means of a dedicated condensate piping system.
    2. Cisterns are located below grade at the South East side of the building.
    3. Cistern access hatches are located 4” above grade level and are a sealed manhole cover type to prevent ground surface water from infiltrating the system.
    4. The cistern system has a feed connection from the roof drainage system piping, an outlet pipe to an internal non-potable water manhole, and an overflow connection to the site storm drainage system.
    5. Roof drains which facilitate water collection are provided with a mesh screen to prevent large debris from entering the rain water harvesting system.

  2. Non-Potable Domestic Water System:
    1. A non-potable piping system is utilised to supply all water closets and exterior wall hydrants.
    2. The non-potable water system is supplied with harvested rainwater that is extracted from the interior manhole with the use of submersible pumps.
    3. Water from the cistern passes through basket strainers, 100 micron bag filters, and finally UV treatment prior to entering the building piping distribution system.
    4. A variable speed pumping system is used to draw water from the cistern storage and supply the non-potable system; pumps are controlled to maintain a system pressure of 40 PSI to ensure proper operation of the corresponding plumbing fixtures.
    5. A connection from the domestic water system is provided with automatic control and reduced pressure backflow preventer. In the event that the cistern water level is too low or the pressure pumps fail, the domestic water back-up feed line shall supply the non-potable system.
    6. The non-potable wall hydrant main is connected upstream of the domestic water back-up feed and shall be inoperable in the event that the domestic water back-up feed is being utilised; this is to ensure the domestic water supply cannot be used for irrigation.
    7. Wall hydrants and all interior piping are clearly labelled “non-potable domestic water”.

  3. Plumbing Fixtures:
    1. All plumbing fixtures are high efficiency type and exceed OBC minimum requirements.
    2. Electronic sensors are utilised on faucets and urinals located in common washroom areas.
    3. Manual dual-flush valves are used with all water closets located in common washrooms.
    4. A shower is provided in the staff room washroom equipped with a low flow shower head.
    5. Water closets and urinals are supplied by the non-potable domestic water system.
    6. Drinking fountains are non-refrigerated, fully recessed type.
    7. Fixture flow rates are as follows:
      1. 1. Water closets1.6 GPF (6 LPF)
        2. Urinals0.13 GPF (0.5 LPF)
        3. Faucets0.5 GPM (1.9 LPM)
        4. Shower1.5 GPM (5.7 LPM)

  4. Piping:
    1. Domestic water piping material is type L copper to ASTM B88-83.
    2. Domestic water piping is sized as per ASPE guidelines.
    3. Domestic piping is insulated as follows:
      1. 1. CW1/2" (13 mm) to 1 1/4" (32 mm) – 1” (25 mm)
        2. CW1 1/2" (38 mm) to 8" (203 mm) – 1 1/2” (38 mm)
        3. HW/HWR1/2" (13 mm) to 2" (32 mm) – 1” (25 mm)
        4. HW/HWR2 1/2" (64 mm) to 4" (100 mm) – 1 1/2” (38 mm)

  5. Sanitary drainage:
    1. All plumbing fixtures are connected to the sanitary drainage system.
    2. The building sanitary drainage system is connected to the municipal sewer.
    3. Sanitary drainage piping is sized as per the OBC.
    4. Sanitary piping materials may be PVC or ABS below grade, and type MJ medium weight cast iron or DWV copper within building.

  6. Domestic Hot Water:
    1. A solar heated domestic hot water system is utilised to produce domestic hot water for the building.
    2. System components include two (2) roof mounted flat panel solar collectors, an 80 gallon solar water storage tank, an 80 gallon electric water heater, and packaged pumping and control system.
    3. The electric water heater shall be utilised to provide top-up heating for the system during low solar gain periods.
    4. A hot water recirculation pump is used to maintain system temperature throughout the building.

  7. Metering:
    1. Domestic water consumption is metered at the incoming service with additional sub-meters at the make-up connection to the non-potable piping system, and the make-up connection to the domestic hot water system.

4.0 Fire Protection:

  1. The building is fully sprinklered with a wet pipe automatic sprinkler system designed in accordance with NFPA-13.
  2. All spaces are designed for Light Hazard occupancy coverage.
  3. The fire protection system is comprised of 2 zones; first & second floor.
  4. Upright sprinkler heads are used in areas with exposed ceilings and semi-recessed type used for lay-in tile and drywall ceilings.
  5. Piping used for the fire protection system piping is Schedule 40 black steel.
  6. A siamese fire department pumper connection is located at the South East side of the building adjacent to the fire access route.

5.0 Heating, Ventilating & Air Conditioning (HVAC) Systems:

  1. General:
    1. The building HVAC system shall be comprised of two (2) ground source supplied modern two-pipe heating/cooling hydronic loops, five (5) dedicated outside air handling units (AHU), displacement ventilation air distribution arrangement, infloor heating throughout, infloor cooling in classrooms, supplemental heating terminal units, supplemental cooling only water-to-air heat pumps, and variable refrigerant volume fan coil unit system with water cooled condensing units.
    2. Specialty sustainable technologies also integrated with the HVAC systems include a biowall, solarwall, and earthtube system.

  2. Modern Two-Pipe Heating/Cooling Loops:
    1. Each building modern two-pipe hydronic distribution system (East Wing and West Wing) is supplied by a 30 nominal ton water-to-water heat pump unit. Water supply temperature is switched from a fixed 58°F chilled water supply in the cooling season, to a maximum of 90°F low temperature heating supply in the heating season via the Building Automation System (BAS).
    2. The hydronic system is arranged in a primary-secondary piping arrangement in which the primary heating/cooling production loop is decoupled from the secondary distribution loop.
    3. A variable speed pumping system is utilized on the secondary loop to distribute the hydronic water supply throughout the building. The pumping system has both a heating and cooling season operation mode.
    4. A brazed plate water-to-water heat exchanger is provided at each water-to-water heat pump unit to facilitate a free cooling or water economiser mode that enables the compressors in the heat pump to remain off during favourable source side loop temperature conditions.
    5. Dedicated water-to-water source heat pump units which serve AHU-1 & 2 are piped in such that they may be utilised as either primary or back-up heating source for their respective hydronic loops.
    6. The fluid used in the load side of the hydronic system is 100% water.
    7. Piping distribution system material is Schedule 40 black steel.
    8. Hydronic piping system is sized such that the pressure drop at peak flowrate does not exceed 0.3 in.w.c./100 ft.
    9. All hydronic piping is insulated as follows:
      1. 3/4" (19 mm) to 1 1/4" (32 mm) – 1/2” (13 mm)
      2. 1 1/2" (38 mm) to 8" (203 mm) – 1” (25 mm)

  3. Geothermal Heat Exchanger (GHE):
    1. A GHE is used as the heat source/sink for the building’s water source connected equipment.
    2. The GHE is comprised of 28 boreholes each 370 feet in depth with a 1 ¼” SDR 11 high density polyethylene (HDPE) tubing loop, and packed with a grout mixture consisting of silica sand and bentonite that yields a minimum thermal conductivity of 0.88 Btu/hr ft2 °F.
    3. The individual borehole loops are piped utilising a reverse return arrangement picked up with eight run out main pipes, and then run into the building to a common header. This header is connected to the ground source hydronic piping system that further extends throughout the building.
    4. The GHE is sized to supply a maximum cooling season supply water temperature of 85°F and a minimum heating season supply water temperature of 40°F.
    5. The entire GHE installation covers an exterior footprint of approximately 4,050 ft2. All components of this system shall reside at a minimum of 5 feet below grade.
    6. The fluid used in the GHE is a 20% ethanol/water mix.

  4. Dedicated Outdoor Air Systems (DOAS):
    1. Five (5) DOAS are used to provide mechanical ventilation to the various building spaces.
    2. AHU-1 and AHU-2:
      1. These units serve the West Wing first and second floor classrooms, and the East Wing first and second floor classrooms respectively.
      2. Air handling units are comprised of a supply and return fan with variable frequency drives (VFDs), split hydronic heating/cooling coil section, total enthalpy recovery wheel section, passive dehumidification recovery wheel section, MERV 13 filtration on supply air side, and MERV 8 filtration on exhaust air side.
      3. 100% of return air is utilised for energy recovery.
      4. Air is supplied from these units at a minimum of 63°F and 50 gr/lbm in the cooling season to maintain a maximum 55°F space dew point temperature and to provide partial cooling, and supplied at 68°F in the heating season to provide tempered ventilation.
      5. The hydronic coil is coupled with a dedicated water-to-water source heat pump unit which provides the appropriate heated/chilled water supply temperature.
    3. AHU-3:
      1. This unit serves the JK/SK classrooms on the South East part of the building, and the Administration Area located centrally.
      2. Unit is comprised of a supply and return fan with VFDs, single hydronic heating/cooling coil section, total enthalpy recovery wheel section, MERV 13 filtration on supply air side, and MERV 8 filtration on exhaust air side.
      3. This unit is also coupled with a transpired solar collector (solarwall) that preconditions the outside air prior to entering the unit during the heating season; this solar collector is bypassed during the cooling season.
      4. 68% of the air supplied by this unit is returned and utilised for energy recovery (includes washroom exhaust component); Administration Area photocopier and washroom exhaust is not returned.
      5. Air is supplied at 65°F in the cooling season, and at 68°F in the heating season to provide tempered ventilation.
      6. The hydronic coil is supplied directly from the East Wing modern two-pipe hydronic loop for cooling and heating.
    4. AHU-4:
      1. This unit provides West Wing corridor ventilation and washroom exhaust.
      2. Unit is comprised of a constant volume supply and return fan, single hydronic heating/cooling coil section, total enthalpy recovery wheel section, MERV 13 filtration on supply air side, and MERV 8 filtration on exhaust air side.
      3. The supply air side is balanced with the washroom exhaust and 100% of the exhaust air is utilised for energy recovery.
      4. This unit is also coupled with an earthtube air intake system which preconditions the outside air using the constant ground temperature prior to entering the unit.
      5. Air is supplied at 65°F in the cooling season, and at 68°F in the heating season to provide tempered ventilation.
      6. The hydronic coil is supplied directly from the West Wing modern two-pipe hydronic loop for cooling and heating.
    5. AHU-5:
      1. This unit serves the gymnasium and ancillary spaces.
      2. Unit is comprised of a supply and return fan with VFDs, single hydronic heating/cooling coil section, total enthalpy recovery wheel section, MERV 13 filtration on supply air side, and MERV 8 filtration on exhaust air side.
      3. 100% of the return air is utilised for energy recovery (includes washroom exhaust component).
      4. Air is supplied at 65°F in the cooling season, and at 68°F in the heating season to provide tempered ventilation.
      5. The hydronic coil is supplied directly from the West Wing modern two-pipe hydronic loop for cooling and heating.

  5. Infloor Heating/Cooling System:
    1. Infloor heating is utilised as the primary heating source throughout the entire building while secondary source infloor cooling is limited to classrooms served by AHU-1 and AHU-2.
    2. The infloor hydronic components include 5/8” cross-linked polyethylene (PEX) tubing that is embedded in both the first and second level concrete floors, various heating manifolds which connect each individual tubing loop, and a cabinet for each manifold that also houses the associated valves, gauges and system controls.
    3. Each heating/cooling manifold is fed from the respective modern two-pipe hydronic heating/cooling loop.
    4. Vestibules and stairwells have a supplemental convector or cabinet unit heater to make-up any shortfall from the infloor heating loops in these spaces.

  6. Air Distribution System:
    1. Supply ductwork is sized with a pressure drop not greater than 0.08 in.w.c./100 ft.
    2. Return ductwork is sized with a pressure drop not greater than 0.04 in.w.c./100 ft.
    3. Exhaust ductwork is sized with a pressure drop not greater than 0.05 in.w.c./100 ft.
    4. Variable air volume (VAV) boxes are used to measure and control the supply airflow rate to spaces served by AHU-1, 2, 3, &5.
    5. A displacement ventilation air distribution arrangement is used throughout the majority of the building including classrooms, gymnasium and the administration area to achieve a ventilation effectiveness coefficient of 1.2.
    6. Displacement ventilation diffusers are selected to discharge at a supply air velocity less than 50 ft./min.
    7. Symmetrical duct design is used wherever possible to limit the reliance on balancing dampers.
    8. All ductwork and fittings are constructed in accordance with SMACNA standards.
    9. Refer to specifications for ducting material and insulation requirements.

  7. Variable Refrigerant Volume (VRV) System:
    1. The VRV system provides supplemental cooling to spaces that do not have infloor cooling capability.
    2. The VRV system consists of ten (10) direct expansion (DX) fan coil units which are connected to two (2) indoor water-cooled condensing units.

  8. Water to Air Heat Pumps (HPA-1 & 2):
    1. Supplemental cooling for the gymnasium is provided with two (2) 6 ton water-to-air heat pump units.

  9. Living Wall System (biowall):
    1. Fan coil unit FC-7 is coupled with a living wall system and provides cooling to the resource centre.
    2. The air drawn through the wall is monitored for humidity level, temperature, CO2 content, and volatile organic compound (VOC) content.
    3. When air conditions downstream of the wall are not suitable for recirculation back to the resource centre, the living wall shall be bypassed from the air system.

6.0 Controls:

  1. All equipment is monitored and controlled with the BAS.
  2. Refer to specifications for equipment sequence of operation.

7.0 Electrical:

  1. Lighting:
    1. Interior Lighting
      1. Two rows of two lamp indirect/direct fluorescent fixtures shall be provided in the classrooms providing 45fc average levels at desk surfaces and consuming approximately 9W/m² (0.84W/sf). Rows are mounted at 14’ on center and suspended 2’-9” below ceiling.
      2. Continuous row of direct fluorescent lighting in the gymnasium mounted below joists providing 54fc average and consuming approximately 14.75W/m² (1.37w/sf).
      3. Single row of one lamp indirect/direct fluorescent fixtures in corridors providing 18fc average and using 5.8W/m² (.54w/sf)
      4. Fluorescent indirect/direct linears shall be used in private offices and secretarial office providing 35fc average and using 13.2W/m² (1.24w/sf)
      5. Recessed LED downlights in vestibules and portion of corridors providing 9fc average and using 3.1W/m² (.29w/sf)
      6. Fluorescent strip lights to be used in mechanical and electrical spaces providing 17fc average and using 5W/m² (.47w/sf)
      7. LED fixtures shall be provided above feature ceiling in upper lobby to provide illumination above the panel and within the space. Illuminated ceiling will provide an average of 12 footcandles on the second floor walkway. Power consumption within the two storey lobby will be 20.9W/m² (1.96w/sf).
      8. Metal Halide track mounted fixtures are being used for illumination of the Living Wall.
      9. A downlight with fluorescent induction lamp is provided at top of open area in front of the Living Wall.
      10. LED fixtures shall be provided in display cabinets.

    2. Lamp source:
      1. T8 lamps will be used in all linear fluorescent and 4’ long fluorescents with a CRI of 82 and colour temperature of 4100K with the exception of the gymnasium.
      2. T5 HO lamps will be used in the gymnasium with CRI of 85 and colour temperature of 4100K.
      3. Fluorescent, compact fluorescent and HID lamps shall have low mercury content.
      4. LED lamps shall have CRI of 91 and colour temperature of 3500K.
      5. Halogen lamps to be used for stage performance highlight only and illumination for special displays.
      6. Induction and Metal Halide lamps will be used in the area of the Living Wall.

    3. Ballasts:
      1. Fluorescent ballasts, dimming and non-dimming shall be electronic, instant start, high ballast factor.

    4. Exterior Lighting:
      1. Canopy downlighting, wall packs and pole mounted fixtures shall be LED lamp source and total cutoff. Average illumination level for the parking area is 1.53 fc; (4.9 maximum).

    5. Exit Signs:
      1. Lamps shall be LED with maximum 2 watts per face.

  2. Lighting Controls:
    1. Interior lighting controls:
      1. All interior lighting areas shall be controlled through occupancy sensors and controlled through a lighting control system/BAS/or local sensor control.
      2. Daylighting sensors shall be provided for perimeter rows of lighting with continuous dimming and where daylighting is available from windows parallel to fixtures.
      3. Daylighting sensors shall be provided for gymnasium for continuous dimming where side windows and light pipes are provided.
      4. Classroom switches to be used to turn on lights when first entering classroom. Separate switch will be provided for task lighting at teacher’s desk.
      5. Second floor corridor lighting will also be equipped with daylight controls for stepped dimming.

    2. Exterior lighting controls:
      1. Exterior lighting will be turned on through daylight sensor and turned off through lighting control system (BAS).

  3. Renewable Energy:
    1. Photovoltaic Panels:
      1. Photovoltaic panels will be roof mounted and grid tied to provide 36kW to supply 10% of proposed demand load.

    2. Wind Turbine:
      1. 2400 Watt wind turbine to be mounted on front lawn of school for demonstrative purposes; to be tied into grid.

  4. Metering:
    1. Main switchboard, photovoltaic utility intertie, wind power intertie and all distribution panels shall be metered.
    2. Lighting Panels shall be metered.
    3. Metering shall be provided on branch circuits so that usage in each classroom can be determined.



Greater Essex County District School Board