ASHRAE Indoor Air Quality Guide

Presented For: Chicago ASHRAE

By: James Livingston, Regional Sales Manager, Ruskin Company

1 Purpose of Presentation • Comment on ASHRAE IAQ Guide topics as related to air control devices • Provide information on the function and benefits of these devices • Provide advice on their application

2 Presentation Agenda IAQ Guide Basics Objectives 1 Design & Construction 2 Control Moisture 4 Moisture in HVAC 6 Capture/Exhaust Contaminants 7 Reduce Contaminants 8 Advanced Ventilation Approaches

3 Purpose of IAQ Guide • Provide advice on how provide good IAQ via means that are: – Cost effective – Practical – Currently available – Technologically sound – Sustainable – Goal: Increased usage & IAQ!

4 Guide Approach • 8 “Objectives” • Objectives address components of building IAQ • Each Objective contains individual “Strategies” to help achieve the Objective • Benefits designers, constructors, owners and facility managers

5 Scope of IAQ Guide • Buildings covered: – Commercial & institutional • Office • Retail • Educational • Lodging • Public assembly

6 Scope of IAQ Guide • Buildings not covered: – Kitchens – Medical procedure rooms – Natatoriums – Cold buildings – Laboratory – Industrial – Residential – Chemical storage

7 Why IAQ? • Health & well being of occupants • Financial success & sustainability of building

8 Common Sources of Poor IAQ

• Two Basic Categories – Gaseous • Radon, C02, chemical vapors, etc. – Biological (with 2 subcategories) • Microbial – Bacteria, molds, mildews, viruses, dust mites, animal dander, etc. • Particulate – Dust, pollen, building material fibers, process byproduct (such as saw dust), etc.

“THE SOLUTION TO POLLUTION IS DILUTION”

W. K. Health Issues • Increased allergy & asthma symptoms • Colds & infections • Carbon monoxide poisoning • Legionnaires’ disease • Lung cancer from Radon exposure

10 Financial Impact

• Repairs or modifications to correct issues • Potential temporary building closure • Difficulty in renting spaces • Legal action due to sick building or other issues

11 A Different Way Of Thinking • Traditional high priority features include cost, space, aesthetics, etc. • Make IAQ a priority in the beginning! • Early discussions & strategies by all parties • Improving IAQ after the fact is difficult and sometimes impossible

12 Objective 1 Manage the Design & Construction Process to Achieve Good IAQ • Strategy 1.1 Traditional Design

13 Objective 1 • Strategy 1.1 Integrated Design

14 Objective 1

• Strategy 1.2 Commissioning – Not just post-construction – Employ a Commissioning Authority (CxA) for pre-design and during construction – Ensure the design meets owners requirements and is being constructed correctly

15 Objective 1

• Strategy 1.3 Selecting HVAC Systems – Use environmentally-friendly & energy efficient systems when possible – Displacement ventilation – If conventional means are used (CV, VAV, etc.), be sure good IAQ practices are used (62.1 ventilation for example).

16 Objective 1 • Strategy 1.5 Effective Operation & Maintenance – O&M can be just as important as design & construction – Expected level of owner’s O&M efforts? – Consider O&M during design & construction – Provide documentation & training

17 Objective 2 Control Moisture in Building Assemblies • Moisture is a common cause of IAQ problems and responsible for the most costly litigation and remediation • Thermal bridging enables interior frost build-up & condensation • Condensation liquid can travel through capillary action to inaccessible locations

18 Objective 2 • Strategy 2.2 Limit Condensation of Water Vapor within the Building Envelope and on Interior Surfaces – Use Thermally Efficient (Insulated) Control Dampers at outside air intakes

19 Strategy 2.2 • Why use Thermally Efficient Dampers? – Reduce condensation to prevent bacteria, mold, mildew – Thermally broken to prevent frost build-up – Lessen leakage into or out of space • Generally Class 1 leakage – 4 cfm/ft² at 1” w.g. AMCA 500-D Section 6.9

• Thermal Efficiency Test • Test setup Figure 5.10 • Damper tested in both airflow directions • ±2°F Steady State Temperature for a period of 10 minutes • Applied torque AMCA 500-D

• V-groove reference damper • 9 cfm per square foot at 1” w.c. • How much more efficient is the test damper when compared to the reference damper? Thermally Efficient Damper Features

• Insulated & thermally broken blades • Blade & jamb seals for low leakage • Thermally broken frames • Non-metallic bearings Thermally Efficient Damper Performance

• AMCA Standard 500-D – AMCA certified leakage – AMCA certified performance – AMCA certified Thermal Efficiency Objective 2 • Strategy 2.3 Maintain Proper Building Pressurization – Building pressure affects moisture infiltration and exfiltration – Negative pressure in hot, humid conditions promotes moisture infiltration into spaces – Positive pressure in humid spaces increases condensation buildup within envelope

25 Strategy 2.3 • Pressurization often is not consistent throughout building due to: – Stack effect – Wind speed & direction – Temperature – HVAC supply & exhaust rates

26 Strategy 2.3 • Airflow measuring stations can assist with pressurization

27 Use Electronic Air Flow Measurement for for Measurement Flow Air Electronic Use openings and large velocities low very high for Measurement Pressure Velocity Use orsmall openings. velocities • •

Pick the Product for the Application the Product the for Pick Electronic Airflow Measuring • Thermistors, heated mass flow sensors, hot film anemometers, etc. – Measures energy to heat element – Low velocities – as little as 0 fpm

29 Velocity Pressure Airflow Measuring • Differential Pressure – Minimum 300 fpm

Total Pressure Chamber Pt Ps

Static Pressure Chamber Pv = Pt - Ps Locations For Airflow Measuring Stations Measuring Airflow For Locations Suggestions for Measuring Outside Air

VAV & CV Systems DCV Systems Any system, limited • Air measuring • Air measuring space station w/ control station with built-in • Air measuring damper built-in control damper and combined with • Damper control is control system outside air louver manual or by BAS • Control system • Can be as little as maintains CFM set 4” total depth point as fans scroll up and down

32 Suggestions for Measuring Supply Air

Retrofit – single floor New construction – or pressure area single floor or pressure Fan inlet • Probes or stations area • Highest velocity • Can install as close • Air measuring point in the system as 4” in front of station w/ control • Total system supply existing dampers damper built-in airflow • Damper control is manual or by BAS

33 Suggestions for Measuring Return Air

Retrofit – single floor New construction – or pressure area single floor or pressure • Probes or stations area • Can install as close • Air measuring as 4” in front of station w/ control existing dampers damper built-in • Damper control is manual or by BAS

34 Suggestions for Measuring Exhaust Air

Use velocity pressure probes or stations • Works well with high velocity exhaust airflow • Much less expensive than electronic airflow stations

35 Objective 4 Control Moisture & Contaminants Related to Mechanical Systems • Strategy 4.1 Control Moisture and Dirt in Air- Handling Systems – Fungi & bacteria are normally present on building interior surfaces, including HVAC components – Microorganism growth in HVAC system results in malodors, nasal & throat irritation and building- related illnesses

36 Strategy 4.1 • Outside air louvers can prevent rain penetration Louvers

37 Louvers With Plenum Behind

38 Water Penetration

39 Sloped Plenum Detail

40 Strategy 4.1 • Traditional louvers provide protection from non-storm rain • Wind Driven Rain Resistant louver provide storm condition protection • Let’s look at the differences…

41 Strategy 4.1

• Traditional Louvers: – Horizontal blades – Drain Gutters – Wide Spacing – High Free Area – Low Cost – Stops some rain – Not effective in storms

42 Strategy 4.1 • Traditional louver sizing – AMCA Water Penetration test – Beginning Point of Water Penetration free area velocity (FAV) – Determine design FAV considering AMCA test data – CFM/FAV = Total Free Area required – Reference louver Free Area Guide to determine appropriate louver size

43 Standard 500-L Louvers 5.6 Water Penetration Waterdrop Manifold Air Exhaust Wetted Wall Manifold Water Test Unit Droplets

Air Entrained into chamber “Still Air” Condition! through louver

Exhaust Air Flow Collection Fan Measurement Zone Standard 500-L Louvers Test Conditions • 48” x 48” size • 15 minute intervals • Manifold (raindrops) - 4” per hour (3.15 gal/15 min) • Wetted wall - .25 gpm (3.75 gallons/15 min) • Ventilation airflow only – no wind • 1250 fpm max free area velocity AMCA “Still Air” Water Test Water Penetration Graph Beginning Point Of Water Penetration: .01 oz/ft² at 1,023 fpm Free Area Velocity

.01 oz./ft² of free area “Still Air” Test with Non-drainable Louver Traditional Louvers • Where to use: – Properly drained applications • Sloped plenums & ductwork • Floor drains – Protected areas (overhangs, barriers, interior, non-prevailing wind elevations) – “Screen” applications (vision barriers) • Sizing – Use Safety Factor (15% to 20% min) • Does NOT stop storm rain Traditional Drainable Louver 29 mph wind, 3”/hr rain, 1,000 fpm intake velocity New Louver Technology • Wind Driven Rain Louvers – Horizontal or Vertical blades – Drain Gutters on horizontal – Hooks on vertical – Close spacing – Lower Free Area – Higher Velocity – Effective in storms

51 Std 500-L Wind Driven Rain Test

5.11 Water Rejection Wind Driven Rain

Air Exhaust Test Louver Rain Water Wind/Rain Discharge Machine Nozzles Wind Driven Rain plus Air Entrained Into Chamber Through Louver

Exhaust Fan Collection Zone

52 Std 500-L Wind Driven Rain Test • Rejection Effectiveness Classes A 99% to 100% B 95% to 98.9% C 94.9% to 80% D below 80% (std. louvers) • 3” rain/29 mph wind • 8” rain/50 mph wind

53 Wind Driven Rain Louver 29 mph wind, 3”/hr rain, 2,000 fpm intake velocity Rear view, 29 mph wind, 3”/hr rain, 2,000 fpm intake velocity How Much Water Is Applied? • 3” Per Hour Rain On 1m X 1m • 21 Gallons Applied Over 1 Hr. – Class A (99% or better) allows 27 fl. oz penetration – Class D (80% or worse) allows over 4 gallons – Std Louvers (60% or lower) - over 7 gallons Wind Driven Rain Louver Benefits • Prevent rain infiltration – Lessens interior water damage & mold growth – Helps keep walls & floors dry – Helps keep filters dry – Excellent for Penthouses • Allow higher intake velocities – Use smaller louvers! • Reduce future problems & liability Wind Driven Rain Louvers Horizontal blade models Vertical blade models

40% - 50% 40% - 45% free area free area 2” to 8” deep 3” to 7” deep Class A @ Class A @ 800 to 1200 1500 to 2100 fpm fpm Moderate ∆p Low ∆p Traditional Best appearance performance

58 Sizing Example • 48” x 48” & 7,000 cfm

• 6” Traditional • 5” Horizontal WDR • 6” Vertical WDR • 710 fpm • 1,002 fpm • 1,030 fpm • .07” ∆p • .16” ∆p • .09” ∆p • 60% Wind Driven • 99.8% Wind Driven • 99.8% Wind Driven Rain Effectiveness Rain Effectiveness Rain Effectiveness (50 (29 mph) (29 mph) mph) • Cost 1.0 • Cost 1.7 • Cost 2.7 • 48” x 36” (25% smaller) • 1,488 fpm • .18” ∆p • 99.8% Wind Driven Rain Effectiveness (50 mph) • Cost 2.3 Rooftop Intakes

Traditional style, allows Wind Driven Rain Design, rain penetration prevents rain penetration What About Snow?

61 Suggestion for Stopping Snow Penetration • Heated screen behind louver • Prevents snow blowing into ductwork • Reasonable pressure drop • Relatively slow airflow - 350 FPM Face area velocity. Objective 7 Reduce Contaminant Concentrations through Ventilation, Filtration and Air Cleaning • First goal is to reducing contaminant sources, then capturing & exhausting • Remaining contaminants should be – Diluted with ventilation air, or – Reduced by filtration and gas-phased air cleaning (FAC)

63 Strategy 7.2 Continuously Monitor and Control Outdoor Air Delivery • Fixed minimum outdoor air dampers may not provide optimum control of intake CFM, particularly in VAV systems • Over-ventilation is common now – estimated 30% annual savings in U.S. building energy costs if ventilation per standards is maintained

64 Suggestion for Maintaining Proper Outdoor Air Intake Levels

• Use air measuring station with built-in control damper and control system to maintain CFM set point

65 Air Measuring & Control Stations • Advantages – System automatically modulates damper to maintain CFM – Can be used as minimum outside air damper only (overridden when economizer damper opens), or – Can be used as entire outside air damper

66 Pressure Signal Chart text
Air Measuring & Control Damper Documentation I/O Chart
Provided w/ unit
Calibration Certificate

0 - 10 VDC Input - CFM Setpoint

0 – 10 VDC Output - Measured CFM

Alarm when CFM falls below setpoint Strategy 7.2 Continuously Monitor and Control Outdoor Air Delivery

• Proper placement of airflow stations is critical • Installing too close to an elbow or other disrupting feature can affect performance

68 Air Measurement Station Placements for AcceptableInstallations Measurement Air for Placements Station Air Air Measurement should in be the Mechanical Spec!

Air Measurement Station Placements for AcceptableMeasurement Airfor Placements Station Installations 5D 1D 5D DEGREE UNVANED ELBOW DEGREE UNVANED ° 90

Air Measurement Station Placements for AcceptableMeasurement Airfor Placements Station Installations Strategy 7.2 Continuously Monitor and Control Outdoor Air Delivery • Consider using airflow measuring sensors between fixed louver blades – Higher velocity, better accuracy Accuracy Considerations: Outside Air Measurement Advantage

Outside Air 20,000 CFM supply air measured ±±±1,000 CFM @ 5% accuracy (S.A.)

16,000 CFM return air measured ±±±800 CFM @ 5% accuracy (R.A.)

THE DIFFERENCE Air Flow ±±± Sensing Could be off by 1,800 CFM Stations Versus measurement at the intake 4,000 CFM @ 5% accuracy (O.A.) ±±±200 CFM @ 5% accuracy (O.A.) Objective 8 Apply More Advanced Ventilation Approaches

• Strategy 8.2 Use Energy Recovery Ventilation Where Appropriate – Required by ASHRAE 90.1 2007 & 2010 in some cases

74 Code Driven Requirements ASHRAE 90.1 2007 Energy Standard Energy recovery is required on individual fan systems that are: 5000 cfm or greater, and Outside air accounts for 70% or more of the design supply air quantity Energy recovery system shall have 50% effectiveness: Change in enthalpy equal to 50% of the difference between outdoor air and return air at design conditions Status of Code Adoption: Commercial

www.energycodes.gov/adoption/states As of February 2013 Most States are Expected to Adopt 90.1 2010 by End of 2013! DOE Climate Zone Map – for 90.1 Helena MT Duluth, MN

Burlington, VT Boise, ID Chicago, IL

Salem, OR

Baltimore MD

San Francisco CA

Phoenix, AZ El Paso, TX Miami FL Memphis TN

Figure B-1 Albuquerque, NM Houston, TX How do Climate Zones affect ERV?

ASHRAE 90.1 2010 states: 6.5.6.1 Exhaust Air Energy Recovery. Each fan system shall have an energy recovery system when the system’s supply air flow rate exceeds the value listed in table 6.5.6.1 based on the climate zone and percentage of outdoor air flow rate at design conditions. ASHRAE 189.1 Standard • Stretch standard for energy efficiency • “Glimpse” of the future of 90.1 • Currently being specified for some government buildings • Requires even more energy recovery • As low as 10% outside air requires energy recovery in some cases • The energy recovery effectiveness shall be 60% Energy Recovery

• ERV – Latent Recovery – Energy Recovery Wheels – Fixed Plate w/ Latent Transfer • HRV – Sensible Only (no latent) – Fixed Plate – Heat Pipe – Runaround Loops

80 Outdoor Air is tempered Outdoor (Heated/Cooled) asflows it across the Wheel Air Humidity Outdoor Decreases or Increases airas flows acrossthe Wheel

Wheel ERV’s – Wheel ERV’s They How Work Wheel Rotates between the Air Air and the Outdoor Return Airstreams and Temperature Air Return Humidity isabsorbed onto the DesiccantWheel Exhaust Air Transfer Ratio

EATR is the % of air being exhausted from the occupied space that leaks around the ERV wheel and re-enters occupied space.

Importance: Per ASHRAE 62.1…… Dedicated Duct System Ducted to Rooftop Unit Common ERV Configurations

Stand Alone Unitized

Typically 300 to 12,000 CFM Small ERV’s – 150 to 1000 CFM

Only 18” to 22” tall! Example of small ERV application Small ERV Installation Questions?

89 Thank You!

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