Post on 05-Jun-2018
∗ Model Code developed by Canadian Commission on Building and Fire Codes
∗ NECB must be adopted by provincial/territorial authorities to become law
Introduction
∗ Referenced in Ontario Building Code ∗ Used in voluntary and incentive programs
∗ Commercial Buildings Incentive Program ∗ Utility and other programs ∗ LEED®
MNECB 1997 – use
∗ Energy/economics code ∗Requirements and exemptions based on ∗Principal energy source ∗“Administrative region” ∗Climatic criteria (sometimes) ∗Energy distributor ∗Outdated very quickly ∗“Energy budget” code
MNECB 1997 – why low adoption rate?
∗ Energy used by building → energy source neutral
∗ Based on climatic zone – heating degree-days (HDD)
NECB 2011 – approach
Average Annual Heating-Degree Days
(C-degrees)
∗ Silent on renewable, waste and site-generated energy
∗ Wide variety of technology ∗ No barriers placed for their use ∗ Reference standards for use,
not necessarily efficiency ∗ Silent on most process loads ∗ Except pools and ice surfaces
NECB 2011 – approach
∗ No differentiation based on occupancy ∗ Same structure
∗ Part 3: Building Envelope ∗ Part 4: Lighting ∗ Part 5: Heating, Ventilating and Air-Conditioning Systems ∗ Part 6: Service Water Heating Systems ∗ Part 7: Electrical Power Systems and Motors ∗ Part 8: Performance Path
MNECB 1997 and NECB 2011
Compliance Paths
MNECB 1997 ∗ Simple prescriptive ∗ Building envelope trade-off
∗ Simple ∗ Computer-assisted
∗ Performance compliance ∗ Whole-building modeling
– engineering solution
NECB 2011 • Simple prescriptive • Building envelope trade-off
- Simple - Detailed
• Lighting, HVAC, service water trade-off
• Performance compliance - Whole-building modeling –
engineering solution
∗ Mix and match simple prescriptive and trade-off paths
∗ Use trade-off within same Part only
NECB 2011 compliance paths
∗ 26.2 % overall performance improvement
∗ Population weighted
NECB performance results
35%
30%
25%
20%
15%
10%
5%
0% Large Office
Warehouse Mid-Rise Apartment
Strip Mall Secondary School
Big Box Store
OE Environment ∗ An objective of this Code is to limit the probability that, as a result of the
design or construction of the building, the environment will be affected in an unacceptable manner.
OE1 Resources ∗ An objective of this Code is to limit the probability that, as a result of the
design or construction of the building, resources will be used in a manner that will have an unacceptable effect on the environment. The risks of unacceptable effect on the environment due to use of resources addressed in this Code are those caused by –
OE1.1 excessive use of energy
Objective-based code
• Part 3 concerned with transfer of heat and air through the building envelope – Building materials – Building components – Building assemblies – Interfaces between them
NECB 2011 – Building Envelope
• Prescriptive requirements – Protection of insulation materials – Continuity of insulation – Building envelope thermal characteristics – Allowable areas of fenestration and doors – Air leakage
• Trade-off paths – Simple – Detailed
NECB 2011 – Building Envelope
Thermal characteristics vary only with heating degree-day of building location
NECB 2011 – Building Envelope
Average Annual Heating-Degree Days
(C-degrees)
∗ Overall Thermal Transmittance (Above Ground Opaque) 7A = 5000-5999 HDD (˚C) 7B = 6000-6999 HDD (˚C)
NECB 2011 – Building Envelope
Assembly Zone 7A Zone 7B U-Value R
W/(m2∙K) Btuh∙ft2∙˚F ft2∙˚F∙hr/Btu
Walls 0.210 0.037 27
Roofs 0.162 0.028 35.7
Floors 0.162 0.028 35.7
• Overall Thermal Transmittance of Fenestration ∗ All fenestration = 2.2 W/(m2∙K) ∗ (0.38 Btuh∙ft2∙˚F) ∗ Exceptions = Skylights
NECB 2011 – Building Envelope
Slope derived from FDWR formula
NECB 2011 – Building Envelope
FDWR Equation
0.15
0.20
0.25
0.30
0.35
0.40
0.45
3000 4000 5000 6000 7000 8000
HDD
FDW
R
∗ Very easy to apply ∗ Allows flexibility while maintaining minimum
performance level set by prescriptive ∗ Based on trading U-values, FDWR
- Not permitted for additions - Above-ground only - Trade only vertical to vertical, horizontal to horizontal
Building Envelope Simple Trade-off
Building Envelope Simple Trade-off
Example – Building in Winnipeg Prescriptive = 29% Simple Trade-off = 55% (with better windows and walls)
• Part 4 applies to lighting components and systems connected to building's electrical service
• Exemptions: - Emergency lighting automatically off during normal building
operation - Lighting in dwelling units - Where impractical
NECB 2011 – Lighting
∗ Prescriptive requirements – Interior lighting power – Interior lighting controls – Exterior lighting power – Exterior lighting controls
∗ Interior lighting trade-off path
∗ Similar to ASHRAE 90.1-2010 (with trade-off)
NECB 2011 – Lighting
• Prescriptive requirements - Heating equipment - Ventilating equipment - Air-conditioning equipment - HVAC control systems - Piping and ducts
• Trade-off path
NECB 2011 HVAC Systems – Part 5
∗ Ability to balance ∗ Duct Sealing ∗ Constructed and installed to SMACNA (Duct
Construction Standards – Metal and Flexible) ∗ Sealed per static pressure classes ≤ 2”, > 2” and < 4”,
≥ 4” ∗ Exemptions
HVAC – Part 5 – Air Distribution Systems
∗ Requirements based on temperature difference
HVAC – Part 5 – Duct and Plenum Insulation
Temperature Difference,
°C
Min. Thermal Resistance for Ducts
and Plenums, m2•C/W
Min. Thermal Resistance for Run-outs,
m2•C/W
< 5 0 0 5 to 22 0.58 0.58 > 22 0.88 0.58
∗ Ability to cool with outdoor air when ∗ Mechanical A.C. capacity > 20 kW (5.5 tons) or ∗ Air handler > 1500 L/s ∗ Exception for dwelling units and hotel/motel rooms
∗ Direct use of outdoor air ∗ Mixed air with up to 100% outside air (economizer) ∗ > 20 tons = 25% capacity ∗ > 6 and ≤ 20 tons = 50% capacity
∗ Water Economizer = provide 100% cooling
HVAC – Part 5 – Cooling with outdoor air
∗ Constant Volume (supply plus return) ∗ 1.6 W per L/s (0.75 W per cfm)
∗ Variable Air Volume (supply plus return) ∗ 2.65 W per L/s (1.25 W per cfm) and, ∗ ≤ 55% design W at 50% design air flow when > 7.5 kW
and < 25 kW
HVAC – Part 5 – Fan Systems
∗ Locations ∗ > 0.08 m2 motorized dampers required ∗ ≤ 0.08 m2 manual on intake, back-draft on outlet
∗ Outside air damper leakage ∗ Closed = ≤ 15 L/s per m2 at 250 Pa (3 cfm per ft2 at 1”
w.c.)
HVAC – Part 5 - Dampers
∗ Ability to balance all hydronic systems ∗ Minimum piping insulation ∗ By temperature range (design) Table 5.2.5.3 ∗ Thermal conductivity requirements of
insulation ∗ Minimum insulation thickness by pipe
diameter ∗ No longer “office” standards, will increase
in future ∗ Protection of insulation (subject to damage)
HVAC – Part 5 – Piping and Insulation
∗ Variable Flow Pumping ∗ HVAC Pumping – control valves
∗ Variable fluid flow ∗ Reduce system flow ≤ 50%
∗ Does not apply ∗ Minimum flow > 50% (chiller or boilers) ∗ Reset fluid supply temperature based on O.A. temp or load
HVAC – Part 5 – Pumping System Design
∗ Installations of thermostats ∗ 1.4 – 1.5 m above floor, accurate to 1˚C ∗ Exposure to sunlight or heat source ∗ Away from drafts and dead air
∗ Heat Pump Controls ∗ Prevention of supplementary heat if load can be met by
heat pump alone
HVAC – Part 5 – Temperature Controls
∗ Space Temperature Controls ∗ Zone specific – heating and cooling ∗ Independent (de-coupled) perimeter heating or cooling
systems allowed if: ∗ One thermostat for each exposure ∗ Heating and cooling controlled by control device in zone
∗ Vestibules require a device limiting temperature to maximum 15˚C
HVAC – Part 5 – Temperature Controls
∗ Supply Air Handler Leaving Air Temperature ∗ Controls required to achieve design supply air temperature
without: ∗ Heating previously cooled air ∗ Cooling previously heated air ∗ Heating outside air in excess of the minimum for
ventilation
HVAC – Part 5 – Temperature Controls
∗ Control of Space Temperature by Reheating or Re-cooling ∗ HVAC systems that control temperature of a space by
reheating previously cooled air shall be equipped with controls that automatically adjust the temperature of the cool air supply to the highest temperature that will satisfy the zone requiring the coolest air
HVAC – Part 5 – Temperature Controls
∗ Exhaust Air System Sensible Heat >150 kW ∗ Shall be equipped with recovery apparatus ≥ 50%
efficiency ∗ Heat recovered shall be used in building system ∗ Exemptions: toxic, flammable, dust or corrosive fumes
HVAC – Part 5 – Heat Recovery Systems
∗ Exhaust Air System Sensible Heat >150 kW Sensible Heat = 0.00123 x Q x (Te – To) Q = rated capacity of exhaust L/s Te = temperature of exhaust ˚C before heat recovery To = outdoor 2.5% January design temperature ˚C
∗ 2360 L/s at 55 ˚C temperature difference
HVAC – Part 5 – Heat Recovery Systems
• Swimming pools ∗ 40% recovery of sensible heat from exhaust air ∗ Exemption if dehumidification system provides 80%
of dehumidification that would be accomplished by exhaust system
• Ice arenas ∗ Required if heating load elsewhere ∗ allow use for either space
or service water heating
HVAC – Part 5 – Heat Recovery Systems
∗ Heat Recovery in Dwelling Units • Dwellings with self-contained mechanical
ventilation (except in climatic zones 4, 5 and 6) ∗ Principal exhaust only ∗ <-10 C and >-30 C require 55% sensible HR efficiency ∗ ≤ - 30 C require 45% sensible HR efficiency ∗ 2.5% January design temperatures which are less than and greater
than
HVAC – Part 5 – Heat Recovery Systems
∗ Off-hours Controls ∗ Includes dwelling units ∗ Systems > 5 kW heating or cooling ∗ Required to set back or up, or shut down ∗ Reduce or shut off outside air when space not in use ∗ Heat Pump – adaptive anticipation to prevent
supplementary heat during recovery
HVAC – Part 5 – Shut-off and Set Back Control
∗ Air Flow Control Areas ∗ Size > 2500 m2 shall be divided into Air Flow Control Areas ∗ Or systems shall serve < 2500 m2 ∗ Shall have separate shut-off and set back control ∗ Each AFCA limited to one storey ∗ DDC controls required
HVAC – Part 5 – Shut-off and Set Back Control
∗ Multiple Boilers ∗ > 176 kW (600,000 Btuh) ∗ More than one boiler or, ∗ 2 stage or multi-stage firing
∗ > 352 kW (1,200,000 Btuh) shall be fully modulating
HVAC – Part 5 – Shut-off and Set Back Control
∗ Loop Temperature Reset ∗ Chilled or Hot Water Systems > 88 kW (300,000 Btuh) ∗ Indoor/outdoor controller, or, ∗ Represent building load using return water temperature
HVAC – Part 5 – Shut-off and Set Back Control
∗ Table 5.2.12.1 HVAC Equipment Performance Requirements ∗ Component groups and capacities ∗ Referenced Standards and Rating Conditions ∗ Minimum performance in EER, COP, IPLV, AFUE, Ec and
Et
HVAC – Part 5 – Unitary/Packaged Equipment
∗ Table 5.2.12.1 HVAC Equipment Performance Requirements ∗ Fossil fuel heating equipment is slightly higher than
the Federal EE Regulations, in most appliances ∗ Other appliances close to EER ∗ Design practitioners need to be diligent in specifying
minimum equipment efficiencies and familiarize themselves the other federal and provincial regulations
HVAC – Part 5 – Unitary/Packaged Equipment
∗ Part 6 addresses service water heating (SWH) systems
“Service water means water for plumbing
services, excluding systems exclusively for space heating or cooling or for processes”
NECB 2011 – Service Water Heating Systems
∗ Prescriptive requirements - Heating equipment - Piping insulation - Controls - Hot water discharge flow
∗ Trade-off path ∗ NRC/NRCan developing a tool for the industry
Service Water Heating Systems – Part 6
∗ Equipment minimum efficiency performance ∗ Table 6.2.2.1 SWH Equipment Performance Standards ∗ Aligned with Energy Efficiency Regulations (EER) as of
May 2010 ∗ Performance required shall not be lower than NECB,
EER, or Provincial Requirements (most stringent shall apply)
∗ Standby losses (SL), Thermal Efficiency (Et), Energy Factor (EF)
SWH – Part 6 – Equipment Performance
∗ Manitoba Amendments
SWH – Part 6 – Equipment Performance
Water Heaters Input Performance Requirement
Gas-fired instantaneous
≥ 14.7 kW and ≤ 73.2 kW
EF ≥ 0.8
Gas-fired storage ≤ 21.98 kW EF ≥ 0.67 – 0.0005 V
Gas- Fired storage
> 21.98 kW and ≤ 117 kW
Et ≥ 80%
∗ Equipment Insulation ∗ Storage Tank Insulation – maximum U-value ∗ O.45 W/(m2∙K) or (0.08 Btu/h∙ft2∙F)
∗ Combination SWH and Space Heating ∗ Permitted where input to combo unit is: ∗ < 22 kW (75,000 Btuh) or, ∗ < twice SWH load
SWH – Part 6
∗ Required for ∗ Hot water circulation systems ∗ Hot water non-circulation systems ∗ Without heat traps ∗ With heating elements or heat tracing
∗ Minimum thickness table for conditioned and non-conditioned spaces
SWH – Part 6 – Piping Insulation
∗ Clarification on heat traps requirements and location of insulation on runouts
SWH – Part 6 – Piping Insulation
∗ Booster Heaters required when ∗ More than one end use temperature on system ∗ Design discharge temperature is > 60 ˚C, and, ∗ < 50% of the total design flow
SWH – Part 6 – More than one end use temperature
∗ Individual Showers (Manitoba) ∗ Maximum hot water discharge 6.6 L/min (1.45 Imp
gal/min) ∗ Lavatory Faucets (Manitoba) ∗ Maximum hot water discharge 5.7 L/min (1.25 Imp gal/min)
∗ Automatic shut-off valves for assembly occupancies
SWH – Part 6 – Hot Service Water
∗ Part 7 applies to electrical power systems and motors connected to the building’s electrical service
NECB 2011 Electrical Power Systems and Motors
∗ Prescriptive requirements - Electrical distribution system - Voltage drop - feeder conductors and branch circuits - Transformers - Electrical motors ∗There is no trade-off path in Part 7
Electrical Systems and Motors Part 7