Strategies for Balancing Indoor Air Quality and Energy Consumption

Presented by:�

Kyle Hasenkox

Todd Backus

Rocky Point Engineering Ltd.

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May 11^th, 2022

Presented to:

RFABC

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Topics

Climate-Resiliency/Flexibility

Energy/Greenhouse Gas Emissions

Epidemic Task Force Final Recommendations

Indoor Environmental Quality

IAQ/IEQ

Strategies/Path to Net Zero

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Mechanical and

Control Systems

• “Transmission of SARS-CoV-2 through the air is sufficiently likely… … Changes to building operations, including the operation of HVAC systems, can reduce airborne exposures.” ASHRAE- March 2020
• “Aerosol transmission can occur in specific settings, particularly in indoor, crowded and inadequately ventilated spaces, where infected person(s) spend long periods of time with others, such as restaurants, choir practices, fitness classes, nightclubs, offices and/or places of worship.” World Health Organization October 2020

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ASHRAE Epidemic Task Force

• Established March 2020

All volunteers, very active during initial stages

• Initial Guidance sent out Early May 2020
• Presentations developed and presented July 2020

Guidance continually updated as research develops

• Presented to RFABC August 2020

Additional Aerosol Discussion November 2020

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British Columbia

• Free Cooling

Majority of building mechanical systems utilize free cooling

• Typically requires 6-8 Air changes
• Works very well in moderate climates

Especially in summer

• Unless there are outdoor air quality issues

Summer 2021

*https://www.energystar.gov/products/low_carbon_it_campaign/12_ways_save_energy_data_center/air_side_economizer

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ASHRAE TC 9.7

• 2022-Phasing Down

Guidance being documented and sent to relevant technical committees

• Consideration of Energy Impacts and Balance
• Larger concept of IAQ
• Connection of Education and Recreation

• The scope and intent of this document is to provide guidance to Owners, Operators, Designers, and Professional Service Providers on how to best implement Indoor Air Quality (IAQ) improvements, including risk mitigation strategies, in educational facilities. The guide will also help facilitate discussion between designers and stakeholders, identify minimum recommendations and discuss further considerations to improve IAQ and reduce the risk of transmission of infectious pathogens and other contaminants of concern

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ASHRAE TC 9.7 Guidance

• Pre-Requisite Tasks

Considered to be fundamental to any IAQ plan

TAB

Risk Assessment

• Very High Priority Tasks

HVAC Equipment Filtration Upgrades

Medical Rooms

Space Air Distribution Effectiveness

• High Priority Tasks

IAQ Sensors

Air change rates

Room Level Air Cleaning

Restroom/Changeroom Exhaust

Staff Training and Documentation Organizational Platform

UV-C/UVGI for Air handlers

• Medium Priority Tasks

Humidification systems

Energy Efficiency Offset Control

Operable Windows

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Pre-Requisite-Testing, Adjusting, Balancing

• Document Filter Values
• Verify Supply/ Exhaust Volumes, pressure relationships and Demand Control Sensors

10% base+ AHU totals

100% advanced

• Verify Sequence of Operation is being followed
• Particulate matter spot testing min 10% of spaces over 1 week
• Advanced-Trend CO2 levels where applicable
• Advanced-Schedule testing on 5 year cycle

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Pre-Requisite-Risk Assessment

• What Level of risk is acceptable?

Risk can not be eliminated, only reduced

• Calculators available, ventilation, scheduling, space density all play a role

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Very High Priority-Filtration

• Improve Filtration

Depth/Pressure/configuration all play a role

• More filtration does not mean higher pressure drop

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Very High Priority- Medical Rooms

• Protocols

Consideration of procedures when a suspected infection risk is on risk temporarily

• Negative Pressure
• Location
• Min. 6 Air Changes, 10 or 12 is better
• Room isolation- non connected return

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Very High Priority- Air Distribution

• Generally- mixing is better

Unless potential infector location is known

• Increased ventilation effectiveness credit should not be used

Room activity factor should be considered

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High Priority- IAQ Sensors

• Carbon Dioxide, PM1, PM 2.5, PM 10, VOC

UL2905

• Base-10%+ spaces, recorded on trend logs, advanced- all spaces over 3,000 sf
• Establish on going verification plan

Table 8.1 in ASHRAE 62.1

• Advanced-Control Strategy action plan
• Advanced-Specific VOC types (Radon?)

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High Priority- Air Change

• Effective Clean Air

Combination of filtration+ Outside air

• Ventilation both outside and recirculated can be added

Do not go below ASHRAE 62.1 minimums

• Energy Impacts also related due to supply air temperature limits
• Min MERV 13
• Avoid directional drafts- Target 6-8 Air Changes
• Consider additional capacity

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High Priority- Air Cleaners

• Consider Noise Level

Generally NC 35 is a good target

• For rooms that do not have sufficient mechanical ventilation
• Consider airflow patterns, maintenance and occupant interaction
• Develop maintenance protocols for handling equipment
• NIADE-Non Infectious Air Delivery Rate can be used in combination with Outside air to achieve target air changes

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Example:

• 2 Air Changes outside air
• 4.5 Air changes filtered air at 90%=4.05 Air Change
• Room total 6.05 Air changes

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High Priority- Restrooms/ Changerooms

• Higher Occupancy density
• Cohort crossing
• Consider Higher system capacity, potentially with sensors for increased rate
• Advanced-Consider lower partitions

Security Concerns

• Advanced-Local stall exhaust instead of general space
• Advanced- UVGI
• Advanced-Touchless fixtures

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High Priority- Staff Training

• Educate

Understand what systems are in place, how they work and what their capacities are

• Build the Plan

Establish Plans and Procedures, contingency plans for different probable situations

• Work the Plan

Implement plans, establish regular updates verifications and maintenance

• Improve the Plan

Create a feedback system for success/failures and method to revise

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High Priority- UV-C/UVGI

• Air Handlers
• High Air UVGI
• Far UV-222nm Spectrum-Ongoing research

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Medium Priority- �Humidification/Offset Controls/Operable Windows

• Humidifiers have shown some relationship with improved health

Consider hours outside of recommended range

Consider Building Envelope Impacts

• Offset Controls

Don’t waste ventilation when not required-More on this later!

• Operable Windows

Develop manual for operable window operation

• Conditions where it should be used or not. Temperature, weather etc. Consider automation with indicators
• Relationships with Pressure
• Consider Directional flow pattern and turbulence
• Consider Sash Sensors

IEQ/IAQ

Carbon Dioxide

Volatile Organic Compounds

Thermal Comfort & Humidity

Particulate Matter

Air Filtration

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Indoor Environment/Air

Quality

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What is IEQ & IAQ?

• INDOOR AIR QUALITY
• Fresh air
• Quantity of air pollutants

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• INDOOR ENVIRONMENTAL QUALITY
• Thermal comfort
• Humidity control
• Indoor air quality
• Airflow speed and direction
• Lighting & Architecture

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Hillcrest Aquatic Center

City of Vancouver Facilities Standard Manual

Thermal Comfort

• DESIGN FOR INDIVIDUALS
• Metabolic rate
• Physical traits

https://www.sciencedirect.com/topics/engineering/basal-metabolic-rate

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• Activity
• Clothing

Thermal Comfort

• TEMPERATURE CONTROL
• Body temperature vs. Environment temperature
• Dry bulb temperature
• Surface temperatures & radiation
• Appropriate air velocities
• Local controller & sensors

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https://www.samsunghvac.com/controls/individual-wired-controls

Humidity

• PSYCHROMETRICS
• Relative vs Absolute humidity
• Ideal relative humidity levels (typ. 50-60%)
• Humidity is controlled through ventilation & temperature
• Airflow can help control condensation

Humidity

• WHY CONTROL HUMIDITY?
• Protects the building
• Prevents mold and condensation
• Potential for infectious agent stability
• Improved occupant comfort
• Critical for certain buildings

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PoolPak Natatorium Design Guide / Condensation Control

Humidity Control

• METHODS OF CONTROLLING HUMIDITY
• Ventilate the space
• Maintain appropriate levels relative humidity & air temperature
• Proper insulation and vapour barriers on ducting

PoolPak Natatorium Design Guide / Condensation Control

Particulate Matter

• TYPICAL PARTICLE POLLUTANTS
• Dust
• Dirt
• Smoke & Soot

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• SOURCES OF PARTICULATE MATTER
• Wood fire
• Factories
• Vehicle emissions
• Industry
• Construction
• Smudging

Volatile Organic Compounds (VOCs)

• PROPERTIES OF VOCs

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• Chemicals that can cause adverse health effects

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• Higher vapour pressure

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• Low water solubility

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Volatile Organic Compounds (VOCs)

• SOURCES OF VOCs
• Solvents; paints & thinners
• Petroleum fuels & products
• By-products from chlorination

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• Glues and adhesives
• Inks and photographic solutions
• Radon gas

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Toluene

• PRIMARY SOURCES OF TOLUENE
• Typically distilled from crude petroleum
• Paints, lacquers, thinners, and adhesives

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• CHARACTERISTICS
• Clear
• Colourless
• Heavier than air
• Sweet, pungent odor
• Volatile

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• MITIGATION
• Sensors
• Ventilation

https://en.gazdetect.com/gas-information/c7h8-toluene-gas-detector/

Radon Gas

https://radoncorp.com/mapping

Radon Gas

• PROPERTIES OF RADON
• Inert
• Colourless
• Odorless
• Carcinogenic (2^nd leading cause of lung cancer in USA – epa.gov)

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• MITIGATING RADON
• Testing/measuring
• Underground ventilation system
• Prevent infiltration with pressure

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Carbon Dioxide (CO₂)

• PROPERTIES OF CO₂
• Natural component of air
• Outdoor air contains roughly 380 ppm CO_{2 (variance between day/night)}
• High levels of CO₂ cause drowsiness and poor indoor air quality
• Often used as a proxy for measuring oxygen levels

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• SOURCES OF CO₂
• High rates of CO₂ in building typically caused by humans
• Vehicle traffic & combustion
• Recirculation of indoor air
• Lack of ventilation and outdoor air

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Carbon Dioxide (CO₂)

• MEASURING CO₂
• Measuring O₂ is difficult!
• CO₂ can be measured by reflection & absorption
• Other carbon molecules can reduce accuracy of measurement
• Tendency for sensor error to drift up over time

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https://physicstoday.scitation.org/do/10.1063/PT.5.4006/full/

Air Filter Efficacy

• MINIMUM EFFICIENCY REPORTING VALUE (MERV)
• MERV ratings are the most common measurement for mechanical filter effectiveness of removing particles from the air
• MERV-8 or 11 was the previous industry standard
• MERV-13 is ASHRAE’s recommendation for new systems

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• WHY NOT MERV-14?
• Cost
• Potential for increase in static pressure drop*
• Diminishing returns

Particle Size

• ARRESTANCE: >10μm
• Large airborne particles: Dirt & Hair

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• RANGE 3: 3 - 10μm
• Mold, Aerosols & Fine Dust

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• RANGE 2: 1 - 3μm
• Anthrax, Car Emissions, Aerosols & Super Fine Dust

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• RANGE 1: 0.3 - 1μm
• Asbestos, Bacteria, Smoke, & Largest Viruses*

ASHRAE STANDARD 52.2-2017 MERV PARAMETERS

Filtration Airflow Rates

• FACTORS IMPACTING FILTRATION EFFECTIVENESS
• Airflow rate – CFM (ft³/min)
• Velocity – FPM (ft/min)
• Filter area (ft²)

https://www.grainger.com/product/AIR-HANDLER-General-Use-Pleated-Air-Filter-2W232

Upgrading Existing Systems

• DIFFICULTIES INCREASING FILTRATION IN EXISTING BUILDING SYSTEMS
• Expensive
• Space Restrictions & Access
• Equipment Limitations

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Energy Use/GHG

Facility Types-Breakdown

Energy/Greenhouse Gas Emissions

Energy Use- Source

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Mechanical and

Control Systems

Currently the BC Building Code only requires Step Code 1 energy performance target for facilities which is NECB-215 compliance and is not that difficult to achieve.

We do know that changes are coming and that all levels of governments are trying to reduce greenhouse gas reduction strategies.

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Energy Use and �Greenhouse Gas Emission Targets

• Current Government of BC Target, Next Building Code in 2024.

All buildings to be Net Zero Ready by 2032

• Step Code Targets
• City of Vancouver Green Building Policy GHGI Target

GHGI=5.0 KgCO₂/m²/yr

We need to increase electrical capacity and decrease natural gas

Some tasks are easily done with low grade heating sources while others require higher grade heat

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Energy Use -General

Rinks have high cooling loads due to ice sheet so large potential for heat recovery but typically at lower grade.

Solar is one of the larger loads on an ice surface

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Energy Use-Rinks

Pools have a large base load and can use a lot of low grade heat

Dehumidification

Ventilation Rates

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Energy Use - Pools

Climate

Role in Community

Refrigerant Phase out

Weather Extremes

Flexibility

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Mechanical and

Control Systems

Facilities are expected to operate continuously, especially in periods of extreme weather. Plans should be developed such that they can expand capacity when needed.

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Resiliency-Flexibility Climate Extremes

• Low differential equipment

Higher differential potential

• N+1 redundancy can be used to for N in extreme events
• Higher airflow rates

Increased filtration

Increased capacity

Recreational Facilities are often used as community resources so many spaces have to change their role depending on condition

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Resiliency-Flexibility Multi-use

• Increased occupant loading

Ventilation rates 6 -8 air changes, economizers

• Control Sequences/ Sensors
• Staff utilization
• 1% design condition versus 99% operation

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High GWP refrigerants are being phased out and new refrigerants will need to be put into service

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Resiliency-Flexibility Montreal Protocol-�Kigali Amendment

• Many low GWP refrigerants are A2L

Flammability consideration

• Many low GWP Refrigerants have different characteristics
• City of Vancouver Green Building Policy GHGI Target

GHGI=5.0 KgCO₂/m²/yr

During extreme events Community facilities are called upon as hubs. The systems in place need to operable even in the extreme condition

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Role in Community

• Develop an understanding of what facility capacity is

Establish community planning and what role each facility can or will have to play

• How can existing infrastructure be repurposed?
• How can systems be configured to adapt quickly?

preferably automated

Strategies

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Mechanical and

Control Systems

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Filtration

• Maintain better air quality

Improves outside air and recirculated air

• Reduces Smoke, infectious particles, allergens, dust etc
• When properly configured and maintained does not significantly impact Energy use

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New/Renovated Facilities should target MERV 13 as a baseline

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IAQ Sensors

• Allows systems to make smart decisions based off what is happening

Responds to changing roles

• Reduce wasted energy on un-utilized space
• Leaves capacity for other systems

Install IAQ sensors in critical spaces

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Air Change Rates

• Economizers allow for free cooling resulting in lower energy use

Good Filtration allows more utilization

• Higher Air changes mean better IAQ
• Lower Supply Air Temperatures are more efficient

Allows for more flexibility

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Target 6-8 Air Changes in most spaces (when occupied)

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Central Heating �Cooling Plant Options

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High Efficiency Gas Fired Condensing Boilers (Heating)

Bio-mass Boiler (Wood Pellets) (Heating)

Geo-exchange with Water to Water Heat Pumps (Heating/Cooling)

Air-Source Heat Pump (Heating/Cooling)

Sewage Based Heat Geo-exchange with Water to Water Heat Pumps

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Low Temperature heating water in the range of 120F (48.8C) provides flexibility alternate sources

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High Efficiency �Gas Fired Boilers

IBC Model SLO-40-399

Viessmann Vitocrossal CA3B

Low mass, high efficiency modular boiler, below 400MBH

• Class - A gas fitter is not required, Class-B is acceptable.
• Constant water flow through heat exchanger required.
• Efficiencies in the range of 94% when return water at 80F.

High Mass, high efficiency modular boiler, larger sizes

• Class-A- gas fitter is required for set up.
• Variable water flow through heat exchanger can be achieved with up to 80 deg delta T.
• Efficiencies in the range of 96% when return water at 80F.

Air Source Heat Pump/ Air Cooled Chiller

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Aermec NRP

Air-Source heat pump with heat recovery

• Sensitive to water flow, capacity, water temperature
• Capable of simultaneous heating and cooling
• Efficiencies vary with outside air temperature and able to operate down to -10C. Coefficient of Performance in the range of 2.75 to 3.50.
• COP up to 6.5 when heating and cooling.

Air-Source heat pump with change over operation

• Sensitive to water flow, capacity, water temperature
• Capable of either heating or cooling but not both and must be switched over.
• Coefficient of Performance in the range 3.25 to 3.75.

Aermec NRB

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Air Source �Heat Pump Performance

1. Simplified system schematic and operation.
2. Functional testing required during commissioning process.
3. Summer and winter commissioning and proof of performance required.
4. Specify a minimum 2 year warranty and extended 10 year warranty on compressors.

Geo-exchange �Vertical Borehole

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1. Water to water heat pumps can be integrated into heat recovery systems.
2. Indoor modular low temperature water to water heat pumps.
3. Not impacted by outside air temperature and the COP in the 4.25 range.
4. Ground temperature management is required for long term stability

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Biomass Boiler System

Kob/Viessmann

Biomass Boiler

Biomass at Northern Lights College �– Dawson Creek

1. Burns waste wood chips or wood pellets.
2. Has secondary combustion chamber for complete burning and no smoke.
3. Automatic wood pellet feed and ash removal system.
4. Low fuel costs and carbon offsets due to using waste wood.
5. Disadvantages: different technology, large space relative to output, fuel delivery and storage is required.

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HVAC Distribution Systems

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Room Distribution Systems

• Overhead diffusers and grilles
• Variable Air Volume delivery
• Displacement Ventilation
• Radiant Floor Heating
• Perimeter Baseboard Heating
• Active Chilled Beam

Air Delivery Systems

• Central air-handling units (heating water/chilled water)
• Unit Ventilators (heating water/chilled water)
• Distributed 4-pipe Fan Coils (heating water / chilled water)
• Ceiling Mounted Heat Pumps
• Roof top Units (dual-fuel heat pump)

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Air Delivery Systems

1. Central air-handling units (heating water/chilled water)
2. Unit Ventilators (heating water/chilled water)
3. Distributed 4-pipe Fan Coils (heating water / chilled water)
4. Ceiling Mounted Heat Pumps
5. Roof top Units (dual-fuel heat pump)

Packaged Rooftop

4 Pipe Fan Coil

Ceiling Mounted Hydronic Heat Pump

Vertical Unit Ventilator

Central Air-handling Unit

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Distribution Systems

Option 1: Overhead diffusers and grilles

• Simple to Operate
• VAV box in ceiling space with reheat coil
• Common in many facilities
• Lower Cost, many options
• Large Zones
• Static pressure vs control
• Not impacted by activity/more mixing

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Variable Air Volume (VAV) Box

Ceiling Mounted Diffuser

Slot Diffuser

Drum Diffuser

nozzle Diffuser

Double Deflection Diffuser

Perforated Diffuser

Linear Bar Grilles

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Distribution Systems

Option 2: Displacement Ventilation

• Low noise system (40 FPM)
• Requires a perimeter heating
• Higher ventilation effectiveness*
• Crosstalk, room activity factor
• Needs Perimeter heating

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Displacement Diffuser

Displacement Effect

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Zone Heating/Cooling

Distributed Systems

Option 3: Active Chilled Beam

• Originated in Sweden
• Heating/cooling with water
• Low maintenance fan coil, some still required
• High air exchange through induction

Ceiling Active Chilled Beam

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Zone Heating/Cooling

Distributed Systems

Option 4: Other Systems not recommended

• Trickle– inadequate/over ventilation/maintenance
• Radiant Floor Heating– slow reacting, good in some applications
• Fan powered VAV boxes – noisy operation
• Radiant Ceiling Panels
• Variable Refrigerant Flow

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Control Strategies

• Sensors allow us know what is happening

We can trend and determine potential problems

• We can allocate resources to specific areas
• Consider pre-configured modes with simple interfaces
• Simple controls, smart algorithms

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Control Strategies-Occupancy

• Can be integrated into schedules

Requires web based interface

• Occupancy sensors can be used in some spaces
• Configure occupied/unoccupied/occupied-vacant modes.
• Consider Smart start type warmup modes
• Don’t ventilate spaces when it is not required
• Larger spaces consider variable speed with PID control on IAQ conditions

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Control Strategies-Demand based Reset

• Guideline 36 outlines trim and respond, ASHRAE 90.1 requires reset

Building Load is often more complicated that just air temperature,

• Consider time of day offset and give parameters on variance

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Control Strategies-Efficiency and Redundancy

• Many pieces of equipment can benefit from part load efficiency

Affinity Laws

• Design around regular operation and bulk of operating hours/Modeling
• Heat Recovery Systems can be included in flexibility plans
• Low Temperature systems can use higher grade heat to boost capacity during extreme events
• Allows for easier maintenance without disruption

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Control Strategies-Fault Detection

• Diagnose issues prior to demand periods

Allows for potential planning of disruption

• Calibration subroutines to ensure things are working within parameters

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Types of Heat Recovery

• Recover or reject heat to match building profile

Will change constantly

• Consider Mass flow of Thermal energy
• Consider Both Recovery and Rejection

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Passive Ventilation Heat Recovery

1. Air Side Heat Recovery (60% to 90% available) �- Dual Core, Reverse Flow, Heat Wheel
2. Consider Humidity
3. Consider shoulder and cooling season

Cross Flow Heat Recovery Core

Reverse Flow Heat Recovery

Heat Recovery Wheel

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Active Ventilation Heat Recovery

1. Energy is recovered from condensation but not humidity
2. Can result in lower than outside air temperature
3. Existing run around loops can have capacity substantially increased
4. Works for both heating and cooling

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Dehumidification Heat Recovery

• Pools-Can reclaim energy used for dehumidification to heat the pool and reduce outside air intake

Not below ASHRAE 62.1 minimums-Chloramines

Consider Electronic expansion to reduce energy consumption/ increase capacity

• Rink Dehumidifiers can use lower grade heat to regenerate desiccant wheels
• Pool Exhaust air heat reclaim

Consider pressure drop

Consider Coil Coatings

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Refrigeration Heat Recovery

• Different Categories of Heat

Super heat-High Grade- DHW

Condensation-Mid Grade

Equipment Cooling-Low Grade

• Head Pressure/Condensation point and capacity/efficiency

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Sewage Heat Recovery

1. Heating or cooling using sanitary sewage as the source
2. Requires a continuous flow of sewage for stable performance
3. Largest system in Vancouver is the Southeast False Creek City of Vancouver Energy Centre.
4. Ideally suited for a waste water treatment plant, hospital, large residential developments.
5. Low temperature heat pumps are not required
6. Developed in Port Coquitlam and being used around the world.

Sharc Packaged System

Path to Net Zero

Energy Recovery and Strategies

Resiliency/Flexibility

Epidemic Task Force Final Recommendations

Indoor Environmental Quality

IAQ/IEQ

Path to Net Zero

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Mechanical and

Control Systems

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Steps in the Path-New Buildings

• Set an Energy/GHGI Target Beyond Step Code (50 to 80 Kwhr/m²/yr) (5 to 8 KgCO₂/m²/yr)
• Lower the building energy consumption to reduce renewable energy
• Provide life cycle costing for all energy/GHGI saving measures (future utility rates)
• Involve the entire design team in the process
• Allow for renewable energy to offset building energy use
• Implement energy metering to measure on going performance
• Provide hands on commissioning of the systems
• Educate building occupants on use of the building

Path to Net Zero

Province of BC-All buildings to be Net Zero Ready by 2032.

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Steps in the Path-Existing Buildings

• What is current use, how does it compare-Std 100?
• Establish plan for the future of the facility, what does the 2050 version look like and do?
• What is the lifecycle of the building and its components? What needs to be done to allow for the change at each stage?
• Compare Renewable Energy to potential upgrades
• Develop saving strategies for building envelope, lighting systems, mechanical systems, controls and plug loads

Path to Net Zero

For Existing Buildings use Lifecycle Analysis to create a plan framework

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Renewable Energy

• Solar Wall Heating System, South Facing Facade
• Photo Voltaic $3.50 to $4.50/Watt (140KW=$600,000)(1,600Sqm)- Roof Systems
• Wind Power $15 to $18/Watt-Location
• Evacuated Tube Solar Hot Water $5/KWh/yr
• PV on roof can provide shading
• Integrated PVT Panels

Thank You

Kyle Hasenkox

Kyle@RPEng.ca

Todd Backus

Todd.Backus@RPEng.ca

Richard Corra

Richard.Corra@RPEng.ca