9.36.3. HVAC Requirements

9.36.3. HVAC Requirements
9.36.3.1. Scope and Application
  1. This Subsection is concerned with the efficient use of energy by systems and equipment used for heating, ventilating and air-conditioning (HVAC).
  2. Where HVAC systems, equipment or techniques other than those described in this Subsection are used, the building shall be designed and constructed in accordance with the energy efficiency requirements of the NECB.
9.36.3.2. Equipment and Ducts
  1. HVAC systems shall be sized in accordance with good practice as described in Sections 9.32. and 9.33. (See Note A-9.36.3.2.(1).)
  2. Ducts shall be designed and installed in accordance with Sections 9.32. and 9.33. (See Note A-9.36.3.2.(2).)
  3. Except for exhaust ducts leading directly to the exterior, ducts and plenums carrying conditioned air and located outside the plane of insulation shall
    1. except as provided in Sentence (4), have all joints sealed against air infiltration and exfiltration with
      1. sealants or gaskets made from liquids, mastics or heat-applied materials,
      2. mastic with embedded fabric, or
      3. foil-faced butyl tape, and
    2. except as provided in Sentence (5), be insulated to the same level as required in Subsection 9.36.2. for exterior above-ground walls.
  4. Fabric-backed tape with rubber adhesives shall not be used as a primary sealant to meet the requirements of Clause (3)(a).
  5. The underside of rectangular ducts installed under an insulated floor over an unconditioned space is permitted to be insulated to a lower level than required in Sentence (3) but not to less than 2.11 (m2·K)/W, provided both sides of such ducts are insulated to a compensating higher thermal resistance so that the resulting heat loss does not exceed that of ducts complying with Sentence (3). (See Note A-9.36.3.2.(5).)
9.36.3.3. Air Intake and Outlet Dampers
  1. Except as provided in Sentences (3) and (4), every duct or opening intended to discharge air to the outdoors shall be equipped with
    1. a motorized damper, or
    2. a gravity- or spring-operated backflow damper.
  2. Except as provided in Sentences (3) and (4) and except in locations with fewer than 3500 heating degree-days as listed in Appendix C, every outdoor air intake duct or opening shall be equipped with a motorized damper that remains in the "open" position if the damper fails.
  3. Where other regulations are in effect that do not permit dampers, air intakes and outlets need not comply with Sentences (1) and (2).
  4. Air intakes and outlets serving HVAC systems that are required to operate continuously need not comply with Sentences (1) and (2). (See Note A-9.36.3.3.(4).)
9.36.3.4. Piping for Heating and Cooling Systems
  1. Piping for heating and cooling systems shall be designed and installed in accordance with Subsection 9.33.8. (See Note A-9.36.2.10.(5)(b).)
  2. Except for high-temperature refrigerant piping, all piping forming part of a heating or air-conditioning system shall be located
    1. inside the plane of insulation, or
    2. within or outside the plane of insulation, provided the piping is insulated to a thermal resistance not less than that required in Subsection 9.36.2. for exterior above-ground walls. (See Note A-9.36.3.4.(2).)
9.36.3.5. Equipment for Heating and Air-conditioning Systems
  1. Equipment for heating and air-conditioning systems shall be located
    1. inside the plane of insulation, or
    2. outdoors or in an unconditioned space, provided the equipment is designated by the manufacturer for such installation. (See Note A-9.36.3.5.(1).)
9.36.3.6. Temperature Controls
  1. Except for manually fuelled solid-fuel-fired appliances, the supply of heating and cooling energy to each dwelling unit, suite or common space shall be controlled by thermostatic controls that activate the appropriate supply when the temperature in a conditioned space fluctuates ±0.5°C from the set-point temperature for that space.
  2. Where heating and cooling systems are controlled by separate thermostatic controls, means shall be provided to prevent these controls from simultaneously calling for heating and cooling.
  3. Space temperature control devices used to control unitary electric resistance space heaters shall conform to CSA C828, "Thermostats Used with Individual Room Electric Space Heating Devices."
  4. Controls required by Sentence (1) shall be designed such that lowering the set-point temperature on the thermostat for the heating system will not cause cooling energy to be expended to reach the lowered setting, and raising the set-point temperature on the thermostat for the cooling system will not cause heating energy to be expended to reach the raised setting.
  5. Automatic devices or manually operated dampers, valves or switches shall be provided, as appropriate for the heating system used, to allow the heating of each zone to be adjusted.
  6. Heat pumps equipped with supplementary heaters shall incorporate controls to prevent supplementary heater operation when the heating load can be met by the heat pump alone, except during defrost cycles.
  7. Heat pumps with a programmable thermostat shall be equipped with setback controls that will temporarily suppress electrical back-up or adaptive anticipation of the recovery point, in order to prevent the activation of supplementary heat during the heat pump's recovery. (See Note A-9.36.3.6.(7).)
9.36.3.7. Humidification
  1. Where an HVAC system is equipped with a means for adding moisture to maintain specific humidity levels, an automatic humidity control device shall be provided.
9.36.3.8. Heat Recovery from Dehumidification in Spaces with an Indoor Pool or Hot Tub
(See Note A-9.36.3.8.)
  1. Except as provided in Sentences (2) and (3), spaces containing an indoor pool or hot tub shall be equipped with air exhaust systems conforming to Sentence (4) at design conditions. (See also Article 9.25.4.2.)
  2. Spaces containing an indoor pool need not comply with Sentence (1), provided a stationary mechanical or desiccant dehumidification system is installed that provides at least 80% of the dehumidification that would result from compliance with Sentence (1).
  3. Spaces containing an indoor pool or hot tub having a total water surface area of less than 10 m2 need not comply with Sentence (1), provided they are equipped with a cover having a nominal thermal resistance not less than 2.1 (m2·K)/W.
  4. Heat-recovery systems used to meet the requirements of Sentence (1) shall
    1. be capable of recovering at least 40% of the sensible heat from exhausted air when tested in accordance with AHRI 1060 (I-P), "Performance Rating of Air-to-Air Exchangers for Energy Recovery Ventilation Equipment,"(see Note A-9.36.3.8.(4)(a)), or
    2. have a sensible-heat-recovery efficiency complying with Sentence 9.36.3.9.(3) when tested in accordance with CAN/CSA-C439, "Rating the Performance of Heat/Energy-Recovery Ventilators."
  5. The sensible heat, in kW, referred to in Clause (4)(a), which is the sensible heat content of the total quantity of exhausted air, shall be calculated as follows:

    Sensible Heat = 0.00123 ⦁ Q ⦁ (Te - To)

    where
    Te = temperature of exhausted air before heat recovery, in °C,
    To = outdoor 2.5% January design temperature as listed in Appendix C, in °C, and
    Q = rated capacity of exhaust system at normal temperature of exhausted air, in L/s.
9.36.3.9. Heat Recovery from Ventilation Systems
  1. This Article applies where a self-contained mechanical ventilation system is installed whose principal exhaust component is equipped with heat-recovery capability. (See Note A-9.36.3.9.(1).)
  2. Where an integrated mechanical system (IMS) with a heat-recovery ventilator provides the principal exhaust ventilation, the IMS shall
    1. be tested in accordance with CSA P.10, "Performance of Integrated Mechanical Systems for Residential Heating and Ventilation," and
    2. have a minimum overall thermal performance factor conforming to Table 9.36.3.10.
  3. When tested in conformance with the low-temperature thermal and ventilation test methods described in CAN/CSA-C439, "Rating the Performance of Heat/Energy-Recovery Ventilators," heat-recovery ventilators described in Sentence (1) shall have a sensible heat-recovery efficiency of
    1. at least 60% at an outside air test temperature of 0°C for locations with a 2.5% January design temperature greater than or equal to -10°C, and
    2. at least 60% at an outside air test temperature of 0°C and at least 55% at an outside air test temperature of -25°C for locations with a 2.5% January design temperature less than -10°C. (See Note A-9.36.3.9.(3).)
  4. The requirements of Sentence (3) shall be met using a principal ventilation rate not less than that required in Section 9.32. (See Note A-9.36.3.9.(3).)
9.36.3.10. Equipment Efficiency
  1. 1) HVAC equipment and components shall comply with the performance requirements stated in Table 9.36.3.10. (See Note A-9.36.3.10.(1).)


    Table 9.36.3.10.
    HVAC Equipment Performance Requirements
    Forming Part of Sentences 9.36.3.9.(2) and 9.36.3.10.(1)

    Table 9.36.3.10. HVAC Equipment Performance Requirements


    Notes to Table 9.36.3.10.:
    (1) The symbols and abbreviations that appear in this column have the following meanings:
    AFUE = annual fuel utilization efficiency
    COP = coefficient of performance, in W/W (COPc = in cooling mode and COPh = in heating mode)
    Ec = combustion efficiency, in %
    EER = energy efficiency ratio, in (Btu/h)/W (no metric equivalent)
    Et = thermal efficiency
    FE = fireplace efficiency
    HSPF = heating season performance factor, in watt-hours
    ICOP = integrated coefficient of performance, in W/W
    OTPF = overall thermal performance factor
    SEER = seasonal energy efficiency ratio, in (Btu/h)/W (no metric equivalent)
    TPF = thermal performance factor
    (2) No standard addresses the performance efficiency of electric boilers; however, their efficiency typically approaches 100%.
    (3) Includes propane.
    (4) See the exception stated in Sentence (3).
    (5) See Sentence (2).
    (6) CSA B415.1 does not apply to stoves with an oven whose volume is greater than 0.028 m3 and automatically fuelled appliances.
    (7) Minimum performance values are omitted from the Table in cases where the referenced standard itself contains such requirements.

  2. Natural gas and propane fireplaces shall be
    1. direct-vent (sealed), and
    2. pilot-on-demand, interrupted or intermittent ignition systems without a standing pilot light.
  3. The heat source component of combined space- and service water heating systems that are not within the scope of CAN/CSA-P.9, "Performance of Combined Space and Water Heating Systems (Combos)," shall meet the performance requirements stated in Table 9.36.3.10. for the applicable equipment type. (See Note A-9.36.3.10.(3).)
9.36.3.11. Solar Thermal Systems
  1. Space-heating systems that use solar thermal technology shall conform to the manufacturer's design requirements and installation procedures.
  2. Service water heating systems that use solar thermal technology shall be installed in accordance with the NPC.
  3. Hot water storage tanks associated with the systems referred to in Sentence (2) shall be installed in a conditioned space.

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