Builder Forum Series: Ventilation and Step Code Presented by TOL Green Buildings and Focal Engineering
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Builder Forum Series:
Ventilation and
Step Code
Presented by TOL Green Buildings
and Focal Engineering
Wednesday, January 27, 2021
9:00 – 10:30 am
Reminders / Updates
AGENDA
•
• Live Polling
• Ventilation and Step Code
• Closing
• Mentimeter poll coming up soon!
• Go to menti.com and use the code 26 97 57
November
BFS Recap
• Air Tightness
• Step Code – ACH targets
• Plan from the START
• Work with trades
• Mid-construction testing
• Heat Pumps
• Important for meeting Upper Steps
• Understand heat pump’s recommended operations
• Holistic design is critical
• Mentimeter poll coming up soon!
• Go to menti.com and use the code 26 97 57
tol.ca/stepcode
Reminders
• 2021
• GHG DPA - Step 3 is required
• NON-GHG DPA - Step 2 is compliant
• 2022
• GHG DPA – Step 3 is required
• NON-GHG DPA – Step 3 is required
• 2022 – onwards
• Tracked results will inform future
adoption
BP Submissions
Make sure you submit all documents
• Easy for us to review
• Fewer requests for documentation
tol.ca/stepcode
• Mentimeter poll coming up soon!
• Go to menti.com and use the code 26 97 57
Documentation for Step Code Part 3 BP application
• BC Energy Intensity Report – Completed and Signed by P.Eng.
• Part 3 Energy Design report
• Calculations or analysis showing effective building envelope performance
including thermal bridging.
• Energy Modeling Report Recommended reference
Whole Building Energy modeling
• Energy Statement on drawings services guideline by AIBC
• Mentimeter poll coming up soon!
• Go to menti.com and use the code 26 97 57
Remember!!
All Energy Analysis in Langley – Use Abbotsford Weather file
Part 9 buildings in Langley:
- Use the latest version of BC Energy compliance report
- Use HDD 2700 for TEDI calculations
- Section F of Compliance form is now required to be completed.
For Part 3 Passively Cooled Buildings
- Refer to ASHRAE 55-2010 as per Vancouver Modeling Guidelines.
- Use Abbotsford Weather file (2016_CAN_BC_ABBOTSFORD-A_1100031_CWEC)
• Mentimeter poll coming up soon!
• Go to menti.com and use the code 26 97 57
NEW Incentives
• Significant new construction
incentives
• Focuses on
• Upper Steps
• Heat pumps
• Electrification
• CAN combine with GBRP
• Mentimeter poll coming up soon!
• Go to menti.com and use the code 26 97 57NEW Incentives
• Mentimeter poll coming up soon! • Go to menti.com and use the code 26 97 57
Upcoming Builder Forum
• Fenestration and Building
Performance
• Cost effective high performance
fenestration solutions
• Fenestration and thermal comfort
• Lessons learned and examples of
design/install
• Aiming for March 23rd
Credit: RDH Building Science Passive House Pattern LanguageCity of Abbotsford upcoming Step Code Cafe
COMING SOON! Part 3 Non-Res Step Code • Consultation coming soon • Keep eyes open for email • We appreciate your input
Climate Action Strategy (CAS) • Unanimously Approved by Council Jan 25th, 2021 • Buildings are a large chunk of the C02 portfolio • Anticipate buildings policy aligning with CAS
Mentimeter time! Go to menti.com and use code 26 97 57
NOVEMBER 19 BUILDER FORUM
SERIES: WHAT WE HEARD FROM YOU Has your airtightness knowledge
“Mid-construction blower door tests are
increased? an excellent way to correct weaknesses in
Level of satisfaction with the webinar: 52% the air barrier at an early stage“
Somewhat 26%
Somewhat 23%
Satisfied 10% 3% Dissatisfied
0% “Seeing how [airtightness] testing was
carried out helped with understanding
Stayed the Increased Increased Not what is required to make the building
same a bit greatly applicable airtight.“
Satisfied
87%
Has your heat pump knowledge Has the webinar increased your
“I would like to see more about cost issues. I increased? confidence in building to the Upper
have heard a lot of comments from perspective 68% Steps of the Step Code?
buyers who have purchased used houses
Increased 19% Stayed the
because of new construction costs.” 16% 16% 19% same
0% greatly
Any fears or concerns building to
Stayed the Increased Increased Not
Upper Steps?
same a bit greatly applicable
No fears/concerns 6% 61%
Failing inspections 29% “I was happy to hear the message presented Increased a
(strongly) that the air barrier is made up of bit
Trades are inexperienced 65%
many components, and that the various
Not meeting deadlines 19%
tradespeople have a responsibility in ensuring
Increased costs 61% the air barrier’s integrity […]“FOCAL Engineering • Mechanical engineer with over 15 years of industry experience • Sits on several code committees related to energy modelling and the BC Step Code. • A principal at Focal Engineering –Energy efficiency, new construction and retrofit
Builder Forum Series:
Ventilation & Step Code
WES BOWLEY, E.I.T / SUSAN MACDOUGALL, P.ENG.
JANUARY 27, 2021
Building. Performance.Introduction
Agenda Step Code Overview
Ventilation Overview
Ventilation & Step Code
Key Design Strategies
Other Design Considerations
ConclusionPurpose Focus on Part 9 & Part 3 residential buildings
Discuss how ventilation impacts Step Code compliance
and various metrics
Present successful, cost-effective design strategies and
tips to achieve Step CodeStep Code
Stepped Approach
From BC Energy Step Code:
A Best Practices Guide for Local Governments
www.energystepcode.ca
© Focal Engineering Inc.Step Code Metrics
Overheating
n/a
Passively-cooled
Buildings
Definitions
• MEUI = Mechanical Energy Use Intensity
• TEUI = Total EUI
• TEDI = Thermal Energy Demand Intensity
© Focal Engineering Inc.Ventilation
Ventilation Overview
Outdoor airflow requirement in buildings
◦ Typically in occupied spaces
◦ Other reasons (e.g. pollutants, such as parkades)
Outdoor Air (O/A) delivered to & Exhaust Air (E/A) from spaces
◦ Usually described as flow rate, i.e. air volume over period of time
Typically mechanical
◦ Can also be passive (e.g. windows)
Can impact
◦ Energy consumption
◦ Thermal comfort
◦ Envelope performance
© Focal Engineering Inc.Residential Ventilation
Typically O/A or E/A requirement for:
◦ The home, or each suite in a MURB
◦ Common spaces (e.g. corridors, amenity, mech rooms, parkade)
Older strategies used exhaust only
◦ Bathroom & kitchen fans
◦ Downside = can’t control incoming air
◦ Would leak in through envelope (potential issues)
◦ Can’t pre-heat
Move towards balanced ventilation, supply & exhaust
◦ Opportunity to add heat recovery
◦ Can filter incoming air; better indoor air quality & more resilience (e.g. smoke events)
© Focal Engineering Inc.BC Building Code 2018 Rev2
Ventilation requirements in BC, references some other documents/ standards (noted with )
ASHRAE 62-2001
Division B, 6.3
Ventilation
Systems Flow rate requirements
9.32
Housing and Small Buildings
Ventilation
CAN/CSA F-326-M
© Focal Engineering Inc.Other Standards
ASHRAE 62.1-2001 CAN/CSA F-326
Ventilation for Acceptable Indoor Air Quality Residential Mechanical Ventilation Systems
◦ Applies to all buildings/ spaces ◦ Ventilation for in the home/ suite
◦ Corridors included
◦ Generally not used within homes/ suites
© Focal Engineering Inc.Step Code Buildings
A few extra rules for Step Code Buildings…
ASHRAE 62-2001 Flow rate requirements
Division B, 6.3 9.32
Ventilation Housing and Small Buildings CAN/CSA F-326-M
Systems Ventilation
6.3.1.1(4) O/A must be 9.32.3.4(6)(iv) O/A can not be
mechanically ducted to each passively supplied from
suite (can not be indirect) outdoors
© Focal Engineering Inc.Some organizational requirements
Example: BC Housing
Central HRV flow rate requirements for
◦ Based on # of bedrooms
In-suite HRV flow rate requirements
◦ Based on # of bathrooms
Also require minimum 75% sensible heat recovery
© Focal Engineering Inc.Example Projects
Part 9: Single Family Home
Step 5 (Passive House)
Saanich, BC (HDD 2650)
Area: 188 m2 (2020 ft2)
Bedrooms: 3
Bathrooms: 2
© Focal Engineering Inc.Part 3: Multi-Unit Residential Building
Step 2 MURB
Victoria, BC (HDD 2750)
5 floors
◦ 1 concrete
◦ 4 wood-framed
72 suites plus amenity
Area: 3,952 m2 (42,500 ft2)
© Focal Engineering Inc.Ventilation & Step Code
Step Code & Ventilation
How does ventilation impact step code?
Overheating
n/a
Passively-cooled
Buildings
Biggest impact on TEDI
Our residential strategy: focus on TEDI and MEUI/ TEUI passes
© Focal Engineering Inc.Impact on TEDI
Step 2 MURB
Glazing, 7.1
◦ TEDI requirement = 45 kWh/m2/year
Ventilation,
17.6
Compare the big 3 losses
17.6 16.9 Walls, 5.5
◦ Ventilation
43.5
◦ Envelope- Infiltration
◦ Envelope- Assemblies
Roof, 1.9 ◦ Ventilation ~40% of TEDI
8.9
Floor, 2.2
Door, 0.2 Typically, ventilation ~25-50%
Infiltration, ◦ For step code projects that pass
8.9 ◦ Generally lower for higher steps
© Focal Engineering Inc.Impact on MEUI/TEUI
Step 2 MURB
◦ TEUI Requirement = 130 kWh/m2/year
Result 123.7
Step 4 3 2
0 10 20 30 40 50 60 70 80 90 100 110 120 130
TEUI (kWh/m²/yr)
Ventilation impacts
© Focal Engineering Inc.Adjustment: Corridor Pressurization
Part 3 Corridor pressurization adjustment
◦ Accounts for local, typical practice of over-ventilation
◦ Reduces TEDI/ TEUI
◦ Limited to adjustment of 10 kWh/m2/year
◦ Can have a big impact, especially on higher steps
Calculation based on
Vancouver Energy
◦ Pressurization airflow
Modelling
◦ Corridor area Guidelines
◦ Modelled building area Section 2.5.2
◦ # units
◦ HDD Available at: https://vancouver.ca/files/cov/
guidelines-energy-modelling.pdf
© Focal Engineering Inc.Example: Step 2 MURB
Comparing ASHRAE 62.1-2001 ventilation rate to actual design
Step 2 MURB (totals for 5 floors)
Corridor Area [m2] 298
ASHRAE 62 Ventilation Flow Rate 74.5 L/s 160 CFM
Ventilation per Suite Door 1.0 L/s 2 CFM
Actual Design Ventilation Flow Rate 320 L/s 680 CFM
Ventilation per Suite Door 4.4 L/s 9 CFM
© Focal Engineering Inc.Example: Step 2 MURB
TEDI requirement = 45 kWh/m2/year
Project before adjustment
◦ TEDI = 48.4 kWh/m2/year
◦ Fails
Corridor Adjustment calculated as 4.8
Project after adjustment
◦ TEDI = 43.6 kWh/m2/year
◦ Passes
Note
◦ Only on pressurization airflow
◦ If 150 CFM supplied to corridor and 50 CFM exhausted,
adjustment will only apply to 100 CFM
© Focal Engineering Inc.Key Strategies
Strategy 1: Don’t over ventilate
Applied to: all spaces
May seem obvious, but rates easily creep up with:
◦ Conservative calculations
◦ Safety factor/ rounding up
◦ Selecting larger equipment
◦ Testing/ balancing/ commissioning (more later)
© Focal Engineering Inc.Strategy 2: Heat recovery
Pretty much every step code project we see has heat recovery
Suggested target efficiencies
◦ Remember some organizational requirements (e.g. BC Housing min. 75%)
Part 3 Part 9
◦ Step 2: 60-70+% ◦ Step 2: 60+%
◦ Step 3: 70-80+% ◦ Step 3: 60-70+%
◦ Step 4: 80-90+% ◦ Step 4: 70-80+%
◦ Step 5: 80-90+%
© Focal Engineering Inc.Example: Step 2 MURB Heat
Recovery
Graph on right compares gains/ losses that
contribute to TEDI Ventilation
Fan Heat
Pickup
Remember Step 2 MURB TEDI was ~40%
Plugs
from ventilation?
◦ That’s after heat recovery Occupants
Lighting
Infiltration Solar Gains
Ventilation is biggest loss
Doors
◦ Only reduced to 40% because of H/R Floor
Roof
◦ Note: graph shows more H/R opportunities Walls Heating
available Skylight
Load (TEDI)
Glazing
Losses Gains
© Focal Engineering Inc.Strategy 3:
MURBs Central versus Local
LOCAL (IN-SUITE) CENTRAL
Pros Pros
◦ Easier to bill each suite ◦ Less maintenance (single unit/ filter, etc.)
◦ Less floor area lost to shafts between floors ◦ Fewer penetrations through the envelope
◦ No fire/ smoke dampers ◦ Possibly fewer dropped ceilings in suites
◦ Individual suite control (i.e. easier to increase
when cooking/ showering/ etc.)
Con
◦ Providing individual control is expensive
requiring costly pressure sensors…
one solution on next slide
© Focal Engineering Inc.Strategy 3:
Overcoming Central Control Challenge
Instead of running : Size HRV system for 65%
◦ HRV at 60% continuous ◦ Run continuously
◦ Bump up airflow 3 hrs/day to 100% for ◦ Better consistent air quality
showers, cooking, etc.
Ventilation Central Control Solution
1
Continous 60%, with 100% bump
0.8 Continous, 65%
0.6
0.4
0.2 Same daily airflow
0
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
© Focal Engineering Inc.Strategy 4: Corridors
Reduce air volumes
◦ If adjustment is over the limit of 10, corridors likely over-ventilated
Add/ improve heat recovery
◦ Remember this will impact the corridor adjustment if not pressurizing space
◦ Option: Pre-heat with central HRV but don’t return air; still pressurizes space
Reduce heating setpoint temperatures
◦ For example, could heat to 18°C instead of 20°C in winter
Consider external corridors
◦ No ventilation required
◦ Needs to be planned early on
◦ Use caution: Other implications (reduces area for TEDI & other calcs, lose adjustment, etc.)
© Focal Engineering Inc.Strategy 5: Achieving highest steps
Common strategy seen on most PH projects can be adapted for higher steps
Step 5 (PH) Home example
HRV
◦ Supply to living spaces (bedrooms, living room, etc.)
◦ Exhaust from bathrooms, kitchen
◦ Run continuously = good IAQ
Bathroom
◦ Controls for balanced increase in supply & exhaust
Kitchen
◦ Constant exhaust
◦ Recirculating hood with
◦ Mesh filter for water vapour
◦ Charcoal filter for odour removal
© Focal Engineering Inc.Other Considerations
HRV versus ERV
HEAT RECOVERY VENTILATION ENERGY RECOVERY VENTILATION
Sensible heat recovery only Sensible & latent heat (moisture transfer)
recovery
Good for Lower Mainland in most
applications Can prevent air from getting too dry in
winter (more for cold climates)
Moisture buildup on cold days requires
condensate drain (additional plumbing) Not allowed in some sensitive applications
due to potential particle transfer
Note: Both realize benefits of better energy efficiency & IAQ over exhaust-only
© Focal Engineering Inc.Commissioning, TAB, Maintenance
In real life, construction & operation will impact utility bills
Important to test, balance, commission, system to match design
◦ Check airflows are correct, in the space & at the unit
◦ Test HRV/ERV
◦ At low (continuous) and high rates
◦ In bypass mode
Provide manual to owners
◦ Explaining: bypass mode, preheat (if applicable), etc.
◦ How frequently should filters be changed
◦ Other maintenance considerations
© Focal Engineering Inc.Commercial buildings
For Step Code, this means: office, retail, hotel buildings & public sector buildings (step 1)
Also amenity spaces within MURBs
Same strategies as Demand Control Sub-meter energy
before Ventilation usage
• Don’t over ventilate • Only provides outdoor air • Helpful to the building
• Use heat recovery when needed owner
• Lower heating setpoint, • Useful in spaces with • Can track actual building
where possible varied usage (e.g. use to realize true
amenity rooms) energy/ cost savings
• Commercial kitchens,
separate make-up air
with efficient heating
© Focal Engineering Inc.GHGI reduction opportunities
Strategies to reduce TEDI and MEUI/ TEUI will generally
reduce GHGI
GHG
Also consider: Emissions
◦ If using gas, highest efficiency units (condensing over regular)
◦ Switching fuel from gas to electric
◦ Corridor makeup air units
◦ Boilers & backup boilers for hydronic heating systems
(costing comes in cheaper than gas)
◦ Note: Could have impact on electrical service
◦ Renewables
© Focal Engineering Inc.Conclusion
Key Takeaways
◦ TEDI is the hardest Part 9 & 3 metric to meet
◦ Ventilation is one of the big 3 contributors (remember the donut!)
◦ Reducing the ventilation portion is an easy win
◦ Addressing TEDI will improve MEUI/ TEUI & GHGI
◦ Strategies
◦ Don’t over ventilate (design and controls)
◦ Use good heat recovery
◦ Consider special strategies for corridors, unique spaces & higher steps
◦ Build well, balance, commission & maintain
© Focal Engineering Inc.Additional Resources
Energy Step Code Website, www.energystepcode.ca
Part 9 Handbook for Building Officials
◦ Has section on ventilation with design examples
Part 3 Energy Design Report
◦ Includes corridor adjustment calculator
Part 3 Step Code Design Guide & Supplement
◦ Sections on Ventilation system & strategies
© Focal Engineering Inc.Thank you! susan@focaleng.com 10 minutes for Q+A
Credits • BC Housing CPD - We will send you the proof of attendance. Your registration/sign-in today acts as your proof • AIBC - No work on your part! • Attendance is tracked – One credit per hour • Sarah will send the attendee list to AIBC and they will give you your LUs
Acknowledgements
• Susan MacDougall, Wes Bowley FOCAL - susan@focaleng.com
• BC Hydro
Thank you
• FortisBC
• YOU!
Greenbuildings@tol.catol.ca/greenbuildings
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