ashrae std 62.1-2010 update where are we now?mnashrae.org/images/meeting/101712/stanke_62.1.pdf ·...

ASHRAE Std 62.1-2010 Update

Where Are We Now? October 2012

Dennis A. Stanke

Trane • La Crosse, WI

© 2009 Trane 2

ASHRAE Standard 62.1

What Is It?

• Title: “Ventilation for Acceptable Indoor Air

Quality”

• Purpose: “… to specify minimum ventilation rates

and indoor air quality that will be acceptable to

human occupants and are intended to minimize

… adverse health effects.”

• Scope: All commercial, institutional, and high-rise

residential buildings

© 2009 Trane 4

ASHRAE Standard 62.1

Why Care?

• Section 6 is the basis for many ventilation codes,

include both US model codes (UMC and IMC)

• Compliance with Std 62.1-2010 (Sections 4 thru 7)

is a LEED prerequisite for any credits

• Compliance with Std 62.1-2010 (Sections 4 thru 8)

is required for compliance with:

– Std 189.1-2011 “High Performance Green Buildings”

– ENERGY STAR and bEQ energy label

© 2009 Trane 5

what does Std 62.1 require?

Must Comply With …

• (Sect 4 and 5) Mandatory general requirements

– To reduce generation of indoor contaminants and

introduction of outdoor contaminants

• (Sect 6) Ventilation requirements

– Prescribed rates to dilute indoor contaminants

– Performance rates to limit contaminant concentrations

– Natural ventilation provisions

• (Sect 7) Mandatory construction, startup reqmts

• (Sect 8) Mandatory operation, maintenance reqmts

© 2009 Trane 6

Std 62.1-2010 Section 4

Outdoor Air Quality

• 4.1.1 Regional Air Quality. Assess regional

outdoor air (OA) quality to determine NAAQS

compliance status

– Check for non-attainment for any EPA criteria

contaminants

• 4.1.2 Local Air Quality. Survey site for unusual local

sources

– Visit the site, look around

These assessments inform air cleaning

decisions

Project Team

© 2009 Trane 7


Systems and Equipment

• 5.1 Ventilation Air Distribution. Design to assure that ventilation air can get to occupied zones

– Provide means to adjust (balance) airflows

– Design to assure mixing in RA/OA mixing plenums

– Document assumptions and air balancing requirements

Important in 100% OA systems – should really duct OA to zone

Mech Designer

© 2009 Trane 8



• 5.2 Exhaust Duct Location. Prevent leakage of harmful exhaust contaminants into the building

– Design exhaust ducts to operate at negative pressure

Room Duct Fan Outdoors

Mech Designer

© 2009 Trane 9



• 5.3 Ventilation System Controls. Design to assure minimum ventilation

– Provide controls to enable fan

– Provide controls to maintain minimum OA flow at any load or dynamic reset condition.

– VAV systems must include modulating dampers or injection fans

Mech Designer

© 2009 Trane 10



• 5.4 Airstream Surfaces. Reduce space contamination due to air distribution system

– Use duct materials that resist microbial growth per UL 181

– Use duct materials that resist erosion per UL 181

Most matte-face finishes meet these requirements

Mech Designer

© 2009 Trane 11



• 5.5 Outdoor Air Intakes. Reduce contamination from outdoors

– Locate intake a minimum distance from outdoor

sources, per Table 5.2. Examples sources/distances:

Loading dock 25 ft

Dumpster 15 ft

Surface below intake 1 ft

Cooling tower exhaust 25 ft

– Design to limit rain water penetration (using hood,

proper velocity, etc.) or manage water that penetrates

– Use bird screens and prevent bird nesting at intake

architect

© 2009 Trane 12



• 5.6 Local Capture of Contaminants. Reduce recirculation of indoor contaminants

– Exhaust locally captured contaminants (from printers, for instance) directly to outdoors

• 5.7 Combustion Air. Reduce pollutants from combustion appliances

– Provide sufficient combustion air

– Provide sufficient air for removal of combustion products

Mech Designer

© 2009 Trane 13



• 5.8 Particulate Matter Removal. Reduce rate of dirt accumulation on HVAC devices

– Use at least a MERV 6 filter upstream of dehumidifying coils and other wet-surface devices (about 20% to 30% Dust Spot)

Mech Designer

© 2009 Trane 14



• 5.9 Dehumidification Systems. Design to reduce

dampness in buildings during mechanical cooling

– By analysis, limit RH to 65% or less at design dew

point condition without solar load

– Design so that intake exceeds exhaust airflow

Basic constant volume systems with sensible-only thermostat might not comply with 65% limit

Mech Designer

© 2009 Trane 15



• 5.10 Drain Pans. Assure condensate drainage without flooding or carryover

– Slope drain pan at least 1/8 “ per foot

– Locate drain opening at lowest point of drain pan and size to prevent overflow under normal conditions

– Use P-trap or other seal to prevent ingestion of air while allowing complete drainage with fan on or off

– Size drain pan to limit carryover

Proper P-trap design helps avoid common water carryover problems

Mech Designer

© 2009 Trane 16

total trap height T = D + H

where … H = air-handler casing pressure + 1 in. wg D = trap depth = ½ H + d d = drain pipe diameter

Drain Seals Mech Designer

© 2009 Trane 17



• 5.11 Finned Tube Coils and Heat Exchangers. Select to reduce water droplet carryover

– Limit coil pressure drop to 0.75 in.wc.@ 500 fpm

– Exception: No pressure drop limit when design provides access to both faces for cleaning

• 5.12 Humidifiers and Water Spray Systems. Reduce water-borne contaminants and design to reduce carryover

– Use potable water

– No downstream devices within absorption distance

Mech Designer

© 2009 Trane 18



• 5.13 Access for Inspection, Cleaning and Maintenance. Reduce dirt accumulation in air distribution system

– Design system with adequate clearance around ventilation equipment

– Provide access doors/panels for ventilation equipment (air handlers, terminal units)

– Provide access doors/panels for devices in air distribution system (air plenums, coils, air cleaners, drain pans, fans, humidifiers)

Mech Designer

© 2009 Trane 19



• 5.14 Building Envelope and Interior Surfaces.

Reduce intrusion of water and water vapor and

uncontrolled condensation

– Use a weather barrier within the building envelope

– Use a vapor retarder within the building envelope

(typically on the warm side, but it really depends on

wall design)

– Seal all envelope seams, joints and penetrations

– Insulate pipes, ducts and other cold surfaces

Architect

© 2009 Trane 20



• 5.15 Buildings with Attached Parking Garages.

Reduce infiltration of vehicular exhaust

– Maintain garage pressure below adjacent occupied

space

– Or, use a vestibule

– Or, otherwise design to minimize air migration from

garage to occupied space

Architect

© 2009 Trane 21



• 5.16 Air Classification and Recirculation. Reduce

recirculation of “dirty” air to “cleaner” spaces

– Designate air from each space/location (see Table 6.1)

Class 1: Low contaminant concentration (office)

Class 2: Mild concentration (dining room)

Class 3: Significant concentration (daycare sick room)

Class 4: Highly objectionable/potentially harmful

– Design to limit air recirculation as follows:

Class 1 to any space or location

Class 2 to self, other Class 2 or Class 3

Class 3 to self

Class 4 to outdoors only

Mech Designer

© 2009 Trane 22



• 5.17 Buildings Containing ETS Areas and ETS-Free

Areas. Reduce level of ETS in ETS-free areas

– Classify each area as ETS or ETS-free

– Pressurize ETS-free areas with respect to ETS areas

– Separate ETS/ETS-free areas with solid walls, doors, etc

(or engineer to assure airflow into ETS areas

– Maintain transfer airflow paths

– Don’t recirculate from ETS to ETS-free at air handler

– Exhaust from ETS areas

– Post sign: “This area may contain ETS”

Project Team

© 2009 Trane 23









– Natural ventilation provisions



© 2009 Trane 24

Std 62.1-2010 Section 6.0

Procedures

• 6.1 General. Find minimum zone and intake OA flow using either the VRP, the IAQP, or the NVP

– 6.1.1 Ventilation Rate Procedure (VRP). Prescribes procedures and OA rates, assuming typical space contaminant sources and source strengths

– 6.1.2 IAQ Procedure (IAQP). Requires analysis of contaminants (“performance”) based on sources and target concentrations to find minimum OA rates

– 6.1.3 Natural Ventilation Procedure (NVP). Prescribes opening areas, and requires mechanical ventilation in most climates (mixed-mode ventilation)

Mech Designer

© 2009 Trane 25

• 6.2 Ventilation Rate Procedure. Find OA intake flow (Vot) using prescribed zone OA rates & system intake calculation procedures in this section


Ventilation Rate Procedure Mech Designer

© 2009 Trane 26

• 6.2.1 Outdoor Air Treatment. If OA is unacceptable per Section 4.1 assessment, must use air cleaning

– 6.2.1.1 PM10. Where PM10 exceeds the NAAQS (non-

attainment areas), use MERV 6 filter

– 6.2.1.2 PM2.5. Where PM2.5 exceeds the NAAQS

(non-attainment areas) use MERV 11 filter

– 6.2.1.3 Ozone. Where ozone greatly exceeds the

NAAQS (very high non-attainment area) use 40%

efficient ozone air cleaner


Ventilation Rate Procedure Mech Designer

NAAQS: “… the most recent three-year average annual fourth-

highest daily maximum eight-hour average ozone

concentration exceeds 0.107 ppm (209 μg/m3) …”

© 2009 Trane 30


VRP – Zone Calculaitons

• 6.2.2 Zone Calculations. To assure reasonable breathing-zone dilution for each zone:

– Use Table 6.1 rates (cfm/per and cfm/sf) and Equation 6-1 to find breathing zone outdoor airflow: Vbz = Rp*Pz + Ra*Az

– Use Table 6.2 defaults to find zone air distribution effectiveness, Ez (typically 1.0 for cooling)

– Use Equation 6-2 to find zone outdoor airflow: Voz = Vbz/Ez

Mech Designer

© 2009 Trane 31

ventilation rate procedure

Minimum Ventilation Rates

Table 6-1: Minimum breathing-zone rates for 63 categories

Office 20 0.0 5.0 0.06

Classroom (ages 5-8) 15 0.0 10.0 0.12

Lecture classroom 15 0.0 7.5 0.06

Retail sales 0 0.3 7.5 0.12

Auditorium 15 0.0 5.0 0.06

Std 62-2001 Std 62.1-2010

Rp Ra Rp Ra Occupancy category cfm/p cfm/ft² cfm/p cfm/ft²

Prescribes both per-person and per-area rates

Mech Designer

© 2009 Trane 32

Office (5p) 100 20.0 85 17.0

Classroom (ages 5-8) (25p) 375 15.0 370 15.0

Lecture classroom (65p) 975 15.0 550 8.5

Retail sales (20p) 300 15.0 270 14.0

Auditorium (150p) 2250 15.0 810 5.4

Occupancy category (default density/1000 ft²)

Std 62-2001

Vbz cfm

Effective

cfm/p

ventilation rate procedure

Effective Minimum Rates

Std 62.1-2010

70% of OA rates drop; 30% stay same or rise

Comparison of breathing-zone OA flow

Vbz cfm

Effective

cfm/p

Mech Designer

© 2009 Trane 33

• 6.2.3 Single-Zone Systems. For ventilation systems with one air handler per zone:

– Find system-level outdoor air intake flow: Vot = Voz

• 6.2.4 100% Outdoor Air Systems. For ventilation systems with one air handler supplying only outdoor air to many zones.

– Find system-level outdoor air intake flow: Vot = S Voz


VRP – System Calculations Mech Designer

© 2009 Trane 34

• 6.2.5 Multiple-Zone Recirculating Systems. For ventilation systems with one AHU serving many zones: – Find outdoor air intake flow (Vot) using prescribed

equations and procedure to account for system ventilation efficiency (Ev):

Vot = Vou/Ev … outdoor air intake flow Vou = D* S Rp*Pz + S Ra*Az … OA used in zones D = Ps/ S Pz … population diversity factor Ev = min(Evz) … system vent efficiency

Evz = 1 + Xs – Zpz … zone vent efficiency

Xs = Vou/Vps … average OA fraction

Zpz = Voz/Vpz … zone primary OA fraction



© 2009 Trane 35

• 6.2.5 Multiple-Zone Recirculating Systems. For ventilation systems with one AHU serving many zones: – Find outdoor air intake flow (Vot) using prescribed

equations and procedure to account for system ventilation efficiency (Ev):

Vot = Vou/Ev … outdoor air intake flow Vou = D* S Rp*Pz + S Ra*Az … OA used in zones D = Ps/ S Pz … population diversity factor Ev = min(Evz) … system vent efficiency

Evz = 1 + Xs – Zpz … zone vent efficiency

Xs = Vou/Vps … average OA fraction

Zpz = Voz/Vpz … zone primary OA fraction



For design, Vpz = Vpz-exp, where Vpz-exp is the lowest expected primary airflow at the design condition. I use the reheat minimum airflow setting, Vpzm; it’s easy but very conservative.

For design, Vps = Vps-exp, where Vps-exp is the highest expected system primary airflow value at the design condition. I use fan block airflow Vps-des: it’s easy and usually worst-case.

© 2009 Trane 36


OA Calculation Example

Do we have time for an example?

– No

– But, I found total OA intake for a 6-zone school,

using different systems and methods:

One RTU per zone (six single-zone systems), both in

cooling and heating

One FC per zone, and a 100% OA system, with both

CV and VAV ventilation airflow

A reheat VAV (single-path multiple-zone) system

using both default Ev and calculated Ev

A series fan-powered VAV (dual-path multiple-zone)

system using calculated Ev

© 2009 Trane 41

VRP 6-zone school example

OA Intake Flow Summary

Ventilation System OA Intake (2001 Vot)

OA Intake (2010 Vot)

% Chg

Single-Zone Clg 12,600 8,900 -29

Single-Zone Htg 15,800 11,100 -30

100% OA – CV 12,600 8,900 -29

100% OA – VAV 8,800 7,000 -20

MZS-VAV Default Ev 10,900 10,800 -1

MZS-VAV Calc Ev 10,900 8,400 -23

MZS-VAV Series FP 10,900 7,800 -28

© 2009 Trane 43

• 6.2.7 Dynamic Reset. To assure outdoor airflow meets requirement for ventilation load, without over-ventilating, optional controls may:

– Reset zone minimum OA flow based on variations in occupancy, i.e., demand controlled ventilation (DCV)

– Reset OA intake flow based on variations in ventilation efficiency (ventilation reset control)

– Reset VAV zone minimum airflow based on variations in outdoor air fraction due to free cooling or exhaust-air make-up operation


VRP – Dynamic Reset

This Section includes operating control options, (rather than design requirements)

Mech Designer

© 2009 Trane 44

• 6.3. Indoor Air Quality (IAQ) Procedure

– Find breathing zone OA flow (Vbz) and system OA intake flow (Vot) based on “performance”

– Compliance addresses

Contaminant sources

Contaminant concentration

Perceived indoor air quality

Design approach

Combined IAQP and VRP

Documentation


IAQ Procedure Mech Designer

© 2009 Trane 45

• 6.3.1 Contaminant Sources. Must identify contaminants of concern including mixtures, sources, source strengths

• 6.3.2 Contaminant Concentration. Must specify

target concentration, for each C of C

• 6.3.3 Perceived IAQ. Must specify target perceived

air quality in terms of percent satisfied


IAQ Procedure

Requires designer judgment to identify contaminants/mixtures of concern, source and source strength for each, targets concentrations.

Judgment = Risk

Mech Designer

© 2009 Trane 46

• 6.3.4 Design Approaches. Find highest required

zone and system OA flow rates using:

– Mass balance analysis AND

– Subjective evaluation, either after construction, OR

using OA needed in a substantially similar zone

• 6.3.5 Combined IAQP and VRP. May use VRP to

find minimum OA and IAQP to find additional OA (or

air cleaning required)

• 6.3.6 Documentation. Must document assumptions

and calculations.


IAQ Procedure

IAQP meets Std 62.1 but does NOT meet Std 189.1 or LEED requirements

Mech Designer

© 2009 Trane 47


Natural Ventilation

• 6.4 Natural Ventilation Procedure. Use NV with mechanical ventilation in most climates:

– Perimeter areas must be within defined distance from OA opening with free area at least 4% of floor area

– Interior areas must be within defined distance from OA opening, and interior-perimeter opening with free area at least 8% of interior floor area, but not less than 25 ft2

Defined distance depends on window location and ceiling height (2H for single-side, 5H for double-side)

– “Mixed mode” controls must coordinate operation of NV and MV systems

Project Team

© 2009 Trane 48

• 6.2.8 Exhaust Ventilation. To assure minimum removal of local contaminants, some zones require exhaust rates prescribed in Table 6.4.

• Examples of more than 20 zones listed: Art classroom 0.70 cfm/ft2

Beauty and nail salons 0.60

Kitchenettes 0.30

Locker/dressing rooms 0.25

Copy, printing rooms 0.50

Toilet – public 50 (cont.) or 70 (cyc.) cfm/wtr closet


Exhaust Ventilation Mech Designer

© 2009 Trane 50


Construction/Start-Up

• 7.1 Construction Phase. Must reduce IAQ problems

introduced during construction. For example:

– 7.1.2. Install unit filters before operating fans

– 7.1.3. Protect materials from rain and moisture. Don’t

install materials with visible microbial growth

– 7.1.4. Reduce transfer of construction contaminants

into occupied areas

– 7.1.5. Construct ducts per SMACNA standards

Project Team

© 2009 Trane 51


Construction/Start-Up

• 7.2 System Start-Up. Must reduce potential for IAQ

problems prior to occupancy. For example:

– Balance air flows

– Test (or certify) drain pan drainage

– Clean air distribution system before start up

– Test OA dampers for proper operation

– Provide ventilation system documentation (HVAC

controls information, air balance report, design criteria

and assumptions, drawings, etc.) to owner or owner’s

agent

Project Team

© 2009 Trane 52


8.0 Operation & Maintenance

• 8.2 Operations and Maintenance Manual. Develop

a building operations and maintenance manual

• 8.3 Ventilation System Operation. Operate it

whenever spaces are expected to be occupied

• 8.4 Ventilation System Maintenance.

Maintain it in accordance with Manual

Compliance with Section 8 is required by Std 189.1-2010 but

not by LEED

Project Team

© 2009 Trane 53

Std 62.1-2010

Summary

• The 2010 version has a few new requirements

• It’s continually improved (next version in 2013)

• It’s VRP rates and procedures are required by

IMC and UMC and by LEED

• It’s required by reference in Std 189.1, which is

one of two IgCC project compliance paths

• We’re out of time!

Questions? ASHRAE 62.1 update:

Where are we now?

ashrae std 62.1-2010 update where are we now?mnashrae.org/images/meeting/101712/stanke_62.1.pdf ·...

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