Indoor Air Quality in Schools Building Codes Ventilation ... · PDF fileIndoor Air Quality in Schools Building Codes Ventilation and Energy ... IMC (Mechanical) IPC ... Last two are

Indoor Air Quality in Schools

Building Codes Ventilation and Energy

Sue O’Dell

2 HONEYWELL - CONFIDENTIAL File Number

IAQ In Homes and Buildings •How bad is it?

-Indoor air pollution among top 5 environmental risks to public health3

-US schools 50% with IAQ issues4 -US Office Buildings 15 to 30% significant issues5

-Globally possibly 30% of buildings issues6

Sources: 2US Dept of Energy and Lawrence Berkley National Laboratory; 3EPA; 4EPA ; 5National Contractors Association; 6World Health Organization


Agenda

•EPA Recommendations for IAQ in Schools •Ventilation in Buildings

-Needs and Codes •Energy

-Needs and Codes •Applicable Code Summary

-IECC 2009 Code •Future Code Direction •Wrap up and questions


All Children Deserve a Healthy Learning Environment

• Children vulnerable, bodies developing • Substandard conditions can cause serious health

problems for children • Evidence that indoor air quality (IAQ) directly impacts

health and student academic performance continues to mount.

Taking steps to improve the IAQ of schools is critical to

bettering student health and academic performance

Source: http://www.epa.gov/iaq/schools/pdfs/student_performance_findings.pdf

http://www.epa.gov/iaq/schools/pdfs/student_performance_findings.pdf


The Scientific Evidence is Mounting

• Studies demonstrate that improved IAQ: - increases productivity, and - improves the performance of mental tasks Concentration Recall in both children and adults

• Regular Maintenance is critical to maintaining a healthy environment: - Health, attendance and academic performance can improve with

increased maintenance - Schools with better physical conditions show improved academic

performance, while schools with fewer janitorial staff and higher maintenance backlogs show poorer academic performance


http://www.epa.gov/iaq/schools/pdfs/student_performance_findings.pdf


EPA Recommendation

Effective IAQ management plans will focus on the following:

• Maintain the HVAC System • Control Moisture to Avoid Dampness and Mold • Clean Thoroughly and Control Allergen Sources • Select Products and Materials with Low Emissions • Control Pests Using an Integrated Pest Management

Program • Source Control


Maintain the HVAC System

Features of the HVAC system most associated with health and learning include:

• Compliance with American Society of Heating, Refrigerating, and Air-Conditioning Engineers, or ASHRAE, outdoor air ventilation standards in every occupied space.

• Uniform temperature and humidity conditions that are within comfort standards with lower rather than higher temperatures preferred.

• Regularly changed medium efficiency (MERV of 5-13) filters.

• Clean and freely draining drain pans. • Dry insulation. • No major contaminant sources near any intake vent

openings.


Recommendation: Ventilation per ASHRAE standard

Effects of Air Ventilation on Health and Performance:

• Reduce absences and the transmission of infectious diseases.

• Improve the overall health and productivity of teachers.

• Improve test scores and student performance in completing mental tasks.

In one study, students in classrooms with higher outdoor air ventilation rates scored 14 to 15 percent higher on standardized test scores than children in classrooms with lower outdoor air ventilation rates.

Source:http://www.epa.gov/iaq/schools/pdfs/student_performance_findings.pdf


Inspection of O.A. Grill - Plugged Recommendation: Ventilation


Recommendation: Comfortable Environment

Uniform temperature and humidity conditions that are within comfort standards with lower rather than higher temperatures preferred.


Inspection of Coils/Filters - Plugged Recommendation: Regularly changed medium efficiency filters.


Inspection of Drain Pan - Plugged Recommendation: Clean and Freely Draining Drain Pans


Dry Insulation

Mold Avoidance key to healthy environment

Wall Insulation

Duct Insulation, before and after cleaning


Control Mold and Moisture to Reduce Asthma Symptoms

• Dampness and mold in homes, offices and schools cause a significant increase in several respiratory and asthma--related health outcomes.

• Asthma is the leading cause of absenteeism in schools, which hinders classrom achievement.

• Symptoms identified in building occupants exposed to dampness or mold include: - coughing - throat irritation - tiredness - headache and - increased wheezing.



IAQ and Energy Savings are not mutually exclusive!

Regular HVAC maintenance also saves energy:

• Experience with ENERGYSTAR® qualified buildings demonstrates that well-maintained HVAC systems of average efficiency save more energy than high-efficiency HVAC systems that are poorly maintained.

• Well-maintained systems reduce energy use by an average of 15 to 20 percent.


Outcome of Integrated IAQ Management Approach

“Our district implemented an IAQ management plan that led to unprecedented academic success for our students. Since 2005, we have seen an increase of 17.3 percent on test scores and an increase in the average daily attendance rate to 97 percent, allowing students to have more classroom time.”

– Frank DiNella, Keller Independent School District, Texas


Ventilation


Why do we Ventilate Buildings?

•The reasons we ventilate buildings are: -To ensure a healthy atmosphere for occupants by diluting indoor contaminants and providing fresh air

-To pressurize the building positively to prevent unfiltered and unconditioned air from entering the building

-To provide cooling and save energy -To replace exhausted air (provide make-up air)


Typical Symptoms of Poor IAQ

Source: Cornell University 2002

•What are the typical symptoms of poor IAQ? - Irritations of eyes, nose and throat -Dry mucous membranes and skin -Rashes -Mental fatigue, headaches and sleepiness -Airway infections, cough -Wheezing


IAQ In Homes and Buildings

•How do we control it? -Ventilate more -Ventilate correctly


Codes and Standards

• ASHRAE 90.1 – Energy Standard for New Buildings

• ASHRAE 90.2 - Energy Standard for Residential • ASHRAE 62.1 – Ventilation Standard for Buildings • ASHRAE 100 - Energy Standard for New Buildings • ASHRAE 189 – Green Building Standard • IBCC – International Building Code • IECC – International Energy Conservation Code • IGCC – International Green Construction Code


US Standards and Codes Development Process

State and Local Codes

(CA Title 24)

ICC (3 groups) Codes and Tech Committees*

Standards And

Codes Working

Committees

State and local code committees

ASME UL CSA NEMA

ICC Code Group

Revision Year/Release

Codes

A 2012 - 2013 IBC (fire, general, egress, structural) IFGC (fuel gas) IMC (Mechanical) IPC (plumbing) IPC (private sewage)

B 2013 -2014 IECC (energy new buildings Res & Comm) IEBC (energy existing buildings) IFC (fire) ICCPC (performance) IPMC (property maintenance) IZC (zoning) IWUIC (Wildland & Urban Interface) IRC (Residential) ISPCS (Swim pool & spa)

C 2014 - 2015 IgCC (new building green code)

ASHRAE standards

ANSI standards

ISO standards

Products and services must meet codes

3 year cycle

3 – 5 year cycle


ASHRAE Standards

•ASHRAE 62.1-20xx Ventilation for Acceptable Indoor Air Quality

- The purpose of this standard is to specify minimum ventilation rates and indoor air quality that is acceptable to human occupants

•ASHRAE 90.1-20xx Energy Standard for Buildings Except Low-Rise Residential Buildings

-The purpose of this standard is to provide minimum requirements for the energy- efficient design of buildings except low-rise residential

25 File Number

Where does CO2 come from in buildings?

Where indoor concentrations are elevated (compared to the outside air) the source is usually due to the building’s occupants. People exhale carbon dioxide—the average adult’s breath contains between 10 and 100 times the ppm of CO2 found in outdoor air.

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•Outdoors: 390-450 ppm

•Offices: 800 – 1000 ppm

•Stuffiness: 1000-2500 ppm

•OSHA: 5000 ppm

•Extreme/ Dangerous: 30,000-50,000 ppm

CO2 concentration Vs. Air flow

27 File Number

US National Library of Medicine National Institutes of Health Carbon dioxide is a physiologically important gas, produced by the body as a result of cellular metabolism. Its main mode of action is as an asphyxiant, although it also exerts toxic effects at cellular level.

At low concentrations, gaseous carbon dioxide appears to have little toxicological effect.

At higher concentrations it leads to an increased respiratory rate, tachycardia, cardiac arrhythmias and impaired consciousness. Concentrations >10% may cause convulsions, coma and death.

http://www.nlm.nih.gov/

http://www.nih.gov/

http://www.nih.gov/

28 File Number

How much CO2 is too much?

individuals in schools and offices with elevated CO2 concentrations tend to report drowsiness, lethargy and a general sense that the air is stale.

29 File Number

Potentially Adverse Outcomes of Prolonged Low-Level CO2

Source: HUMAN HEALTH RISK ASSESSMENT OF CO2: SURVIVORS OF ACUTE HIGH-LEVEL EXPOSURE AND POPULATIONS SENSITIVE TO PROLONGED LOW-LEVEL EXPOSURE by Susan A. Rice, Ph.D., D.A.B.T. www.netl.doe.gov/publications

Exposure % Duration of

Exposure Potentially Adverse Outcome •0.85 20 days ↑ Lung dead space volume [31] •1.2 3 days 35% ↓ Cerebral blood flow [32] •1.2 5 days ~20% ↑ Blood pressure [33]

•1.2 25 days Significant ↓ Biomarkers of bone formation Slight ↑ bone resorption [34]

•1.5 42 days ↑ Urine volume & Na, K, Cl excretion Slight ↑ Hct, RBC count, Hemoglobin [35]

•1.5 42 days Significant ↑ Lung dead space volume [36-39]

•2.0 30 days Slight ↑ Lung dead space volume [10]

•3.0 8 days Significant performance decrements Erratic, abnormal behavior [41]


• Demand Control Ventilation (DCV) is growing rapidly in popularity and required by codes in many locations

Demand Control Ventilation


• A sensor in the space or duct senses how much CO2 (in parts per million) is in the air, and an economizer motor opens the outside air damper when levels exceed the setpoint (typically 1000-1200 ppm)


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Vbz = Ventilation in breathing zone (CFM) = Vp = Ventilation for people + Va = Ventilation for building sources

33 File Number

Rp = Occupant Component factor Pz = Max. number of occupants Ra = Building Component factor Az = Area of space


Vbz = Rp Pz + Ra Az Ventilation required in the breathing zone:

Vp Va

Result expressed in CFM



Occupant Component

Category Rp Discussion

0 0 CFM per person Applies to spaces where the ventilation requirements are dominated by building related sources, e.g., storage rooms and warehouses

1 5 CFM per person Applies to spaces where primarily adults involved in passive activities, e.g., office work

2 7.5 CFM per person Applies to spaces where occupants involved in higher levels of activities but not strenuous, e.g., lobbies and retail stores.

3 10 CFM per person Applies to spaces where occupants involved in more strenuous activities but not exercise level, e.g., most classrooms and other school occupancies.

4 20 CFM per person Applies to spaces where occupants involved in very high levels of activities or high contaminant generation, e.g. beauty salons, dance floors and exercise rooms.

Building Component Ra Discussion

1 0.06 cfm/ft2 Applies to spaces where building related contaminants are generated at rates similar to office spaces, e.g., conference rooms and lobbies.

2 0.12 cfm/ft2 Applies to spaces where building related contaminants are generated at rates significantly higher than office spaces, e.g., class rooms and museums.

3 0.18 cfm/ft2 Applies to spaces where building related contaminants are generated at even higher rates, e.g., laboratories and art classrooms.

4 0.30 cfm/ft2 Last two are for sports and entertainment category where there is no people based ventilation requirement, all building ventilation.

5 0.48 cfm/ft2

Source for data: ASHRAE Standard 62.1-2004 User’s manual 2005 edition


Classroom Example

Vbz = Rp Pz + Ra Az

Vbz = (10 CFM/person) (15 persons)+(0.12 CFM/ft2 )(1024 ft2)

Vbz = 150 CFM + 123 CFM

Vbz = 273 CFM


Built-Up Unit


DCV Example, built-up unit


Packaged Rooftop Unit


A

Packaged Unit with Economizer

OA and RA Sensors Damper Actuator 2-stage Room Thermostat or controller Mixed Air Sensor Modulating Dampers OA and RA OA Hood

B

C

D

E

F

A B

C

D

E

F

A

39

Need 2-stage thermostat for integrated economizing


Damper Position

CO2 Level

100% Open

Ventilation Limit (max occupancy, “old” min position)

0% Open 450 ppm 1000 ppm 2000 ppm

Normal Operation w/o DCV

Ventilation vs. Demand Control Ventilation (DCV)

CO2 Sensor only

• Minimum Ventilation Code - When space occupied,

damper opens to minimum position to ventilate for maximum occupancy

- CO2 sensor with modulating or two position damper opens damper 100%

- No limits, may bring in cold or hot/humid air

New Min Pos


Demand Control Ventilation (DCV)

Damper Position

CO2 Level

100% Open economizing

Vent Limit (“Old” min Pos)

New Min Pos

0% Open 450 ppm 1000 ppm 2000 ppm

DCV Economizer full occupancy Normal Operation w/o DCV

• DCV Ventilation Code - When space occupied damper

opens to new minimum position to ventilate for lower occupancy

- CO2 sensor with modulating damper opens to new Ventilation limit (old min pos)

- Limits induction of cold or hot/humid air

- Dampers can go 100% open for economizing

Open further when free cooling available


Demand Control Ventilation (DCV)

• Demand Control Ventilation - changes ventilation in

response to occupancy - Minimum pos and DCV Max

position varies based on building type

- Min Pos ventilates for building effluents and low occupancy

- New DCV Max is “old” min pos for maximum occupancy

Damper Position

CO2 Level

100% Open Economizing

Vent limit “Old” min Pos

Min Pos

0% Open 450 ppm 800 ppm 2000 ppm

DCV Economizer full occupancy DCV Economizer


Potential Savings of CO2 based DCV

• Some estimation for $.05 to more than $1 per sq. foot annually

• Highest payback in high-density spaces with variable and unpredictable occupancy - Auditoriums - School buildings - Meeting areas - Retail establishments


Energy


Energy Code Adoption – Where are they Now?

• 2013-2014 4 additional states have adopted ASHRAE 90.1- 2010/2012/ IECC equivalent or more energy efficient • Only 8 states with no energy code


US DOE Climate Zones Source: https://www.google.com/search?q=us+department+of+energy+climate+zones


ASHRAE Standard 90.1

The Committee’s unanimously approved work plan goal for the 2010 edition was to reduce energy cost by 30% compared to the 2004 version of the standard. Toward that goal, 109 addenda were processed by the committee and approved by the ASHRAE and IES Boards of Directors and are included in the 2010 edition. Most equipment efficiencies are higher, energy recovery is required in more applications, economizers are required in more climates, and more energy conserving controls are required. 6.5.1 Economizers. Each cooling system that has a fan shall include either an air or water economizer meeting the requirements of Sections 6.5.1.1 through 6.5.1.4.

Exceptions: Economizers are not required for the some systems listed in section

TABLE 6.3.2 Eliminates required economizer for comfort cooling by increasing the cooling efficiency of the equipment. The efficiency improvement is listed by climate zone. 6.4.3.9 Demand control ventilation (DCV) is required for spaces larger than 500 ft2 and with a design occupancy for ventilation of greater than 40 people per 1000 ft2 of floor area and served by systems with one or more of the following:

a. an air side economizer, b. automatic modulating control of the outdoor air damper, or c. a design outdoor airflow greater than 3000 cfm.

Exceptions: DCV is not required for the some systems listed in section


New Mexico Codes Commercial Code: 2009 IECC Enforcement Status: All residential and commercial structures, as defined in the IECC are required to comply with the New Mexico energy code. Compliance and plan review requirements are those specified in the 2009 IECC. Mandatory Without Amendments Commercial Code Notes: All Executive Branch state agencies & Higher Ed Dept to adopt LEED rating system. Plan review and enforcement is regulated by the local jurisdiction (when they elect to enforce the code) as required in the MEC. If the local jurisdiction does not elect to, or does not have personnel qualified to, enforce the code provisions, the Construction Industries Division provides the necessary reviews and inspections for residential buildings. Link to NM Code: http://164.64.110.239/nmregister/xxii/xxii12/14.7.6.htm TITLE 14 HOUSING AND CONSTRUCTION CHAPTER 7 BUILDING CODES GENERAL PART 6 2009 NEW MEXICO ENERGY CONSERVATION CODE

14.7.6.8 ADOPTION OF THE 2009 NEW MEXICO ENERGY CONSERVATION CODE: A. This rule adopts by reference the 2009 international energy conservation code (IECC), as amended by this rule. B. In this rule, each provision is numbered to correspond with the numbering of the 2009 international energy conservation code. C. This rule is to be applied in conjunction with each of the other 2009 New Mexico building codes, including the NMCBC, NMRBC, NMPC, NMMC and the NMEC. [14.7.6.8 NMAC - Rp, 14.7.6.8 NMAC, 8-1-11]

http://164.64.110.239/nmregister/xxii/xxii12/14.7.6.htm

Commercial Mechanical Requirements

U.S. Department of Energy Building Energy Codes Program

PNNL-SA-66171

50 HONEYWELL - CONFIDENTIAL File Number 50

Introduction to the Energy Code Compliance Process

Must the Project Comply with the

IECC?

Comply with the Envelope

Requirements

Comply with the Mechanical /SWH

Requirements

Comply with the Power & Lighting

Requirements

Section 502 90.1 Section 5 Sections 503 and 504 90.1 Section 6 Section 505 90.1 Section 9

Document Compliance with the

IECC

Plan Review

Inspection


Does My Project Need to Comply with the IECC?

All Buildings Other Than: • One- and two-family

residential • R-2, R-3 three stories or

less in height


Section 503 Building Mechanical Systems

Simplified to Include Only Four Sections: • What Provisions of the

Code Apply (503.1) • Mandatory Provisions

(503.2) • Simple HVAC Systems and

Equipment (503.3) • Complex HVAC Systems

and Equipment (503.4)


What Provision of the Code Apply? (503.1) Mandatory Provisions – Section 503.2 PLUS

- Section 503.3 (Simple Systems) or - Section 503.4 (Complex Systems)


Simple Versus Complex Systems

Simple systems - Unitary or packaged

HVAC equipment - Serves one zone and

controlled by a single thermostat

Buildings served by unitary or packaged HVAC each

serving 1 zone controlled by 1 thermostat. Two-pipe

heating systems serving multiple zones are included if no cooling system is installed

[Tables 503.2.3(1) through 503.2.3(5)]

Section 503.3 Simple

Systems


Simple HVAC Systems and Equipment (503.3)

Unitary or packaged, single zone controlled by a single thermostat in the zone served. Includes:

Simple Systems • Unitary packaged cooling

system • Split system cooling • Packaged terminal A/C • Heat pump cooling • Unitary packaged heating • Split system heating • Packaged terminal heat pump • Fuel-fired furnace • Electrical resistance heating • Two-pipe heating systems w/o

cooling • Economizers


Simple Versus Complex Systems

Complex systems • All equipment not

covered under Section 503.3 Simple Systems Section 503.4

Complex Systems

All buildings served by HVAC systems not

covered under 503.3


Complex HVAC Systems and Equipment (503.4)

Complex Systems • Packaged VAV reheat • Built-up VAV reheat • Built-up single-fan, dual-duct

VAV • Built-up or packaged dual-fan,

dual-duct VAV • Four-pipe fan coil system with

central plant • Hydronic heat pump with central

plant • Any other multiple-zone system • Hydronic space heating system • Economizers

This section applies to all HVAC equipment and systems not included in Section 503.3


Mandatory Provisions (503.2)

Provisions Applicable to ALL Mechanical Systems

• HVAC Load Calculations • Equipment and System Sizing • HVAC Equipment Performance

Requirements • HVAC System Controls

• Ventilation • Energy Recovery Ventilation Systems • Duct and Plenum Insulation and Sealing • Piping Insulation • HVAC System Completion • Air System Design and Control • Motor Nameplate Horsepower • Heating Outside a Building


HVAC Load Calculations (503.2.1)

Heating and cooling load sizing calculations required

• ASHRAE/ACCA Standard 183 • Other approved computation procedures – defined

in Chapter 3 • Exterior design conditions

• Specified by ASHRAE

• Interior design conditions • Specified by Section 302 of the IECC

• ≤ 72oF for heating load • ≥ 75oF for cooling load


Equipment and System Sizing (503.2.2)

Output capacity SHALL NOT exceed sizing –

• Select the system which serves the greater load, heating or cooling - Exceptions Standby Equipment with Required

Controls Multiple Units with Combined

Capacities Exceeding Loads • Sequencing Controls Required


HVAC Performance (Minimum Efficiency) Requirements (503.2.3) • Applies to all equipment used in heating and cooling of

buildings • Must comply with all listed efficiencies • Exception

- Water-cooled centrifugal water-chilling packages


Table 503.2.3(2)


Table 503.2.3(3)


System Controls (503.2.4)

One temperature and humidity (when applicable) controller per zone


System Controls

Heat pump systems - Heat pump thermostat

required


Duct and Plenum Insulation and Sealing (503.2.7)

Required for supply and return ducts and plenums

• Insulating ducts and plenums: • Located in unconditioned

space - R5 • Located outside the building -

R8


Low and Medium Pressure Duct Systems • Ducts designed to operate at static pressures ≤ 2 in. wg • Securely fastened and sealed


High Pressure Duct Systems

• Ducts designed to operate at static pressures ≥ 3 in. wg to be leak tested in accordance with SMACNA HVAC Air Duct Leakage Test Manual - Air leakage rate < 6.0

• Must test ≥ 25% of the duct area and meet the requirements


(Duct Repairs – For Air Leakage)


Demand Controlled Ventilation (503.2.5.1)

• DCV must be provided for each zone with spaces > 500 ft² and the average occupant load > 40 people/1000 ft² of floor area where the HVAC system has: - An air-side economizer, - Automatic modulating control of the outdoor air damper, or - A design outdoor airflow > 3,000 cfm

Demand control ventilation (DCV): a ventilation system capability that provides for the automatic reduction of outdoor air intake below design rates when the actual occupancy of spaces served by the system is less than design occupancy.


Demand Controlled Ventilation (503.2.5.1) - Exceptions

• Systems with energy recovery per 503.2.6 • Multiple zone systems without direct digital control of

single zones communicating with central control panel • Systems with design outdoor airflow < 1,200 cfm • Spaces where supply airflow rate minus any makeup or

outgoing transfer air requirement < 1,200 cfm


Economizers (503.3.1)

• Air side economizer requirements and equipment performance -exceptions in Tables 503.3.1(1) and 503.3.1(2)

• Water side economizer requirements - Capable of providing 100%

of the cooling system load at 50o F dry bulb/ 45oF wet bulb


Climate Zones—2009 IECC

New Mexico includes Climate Zones 3,4,5



CLIMATE ZONES ECONOMIZER REQUIREMENT

1A, 1B, 2A, 7, 8 No requirement

2B, 3A, 3B, 3C, 4A, 4B, 4C, 5A, 5B, 5C, 6A, 6B

Economizers on cooling systems ≥ 54,000 Btu/ha

a The total capacity of all systems without economizers shall not exceed 480,000 Btu/h per building, or 20 percent of its air economizer capacity, whichever is greater

Table 503.3.1(1)

New Mexico

12,000 BTU/HR = 1 Ton of cooling; 54,000 BTU/Hr = 4.5 Tons of cooling All cooling systems ≥ 4.5 Tons require economizers



Trade-off high cooling efficiency for economizer

CLIMATE ZONES COOLING EQUIPMENT PERFORMANCE IMPROVEMENT (EER OR IPLV)

2B 10% Efficiency Improvement



Table 503.3.1(2)


Efficiency tradeoff vs. Economizer with DCV

Example from IECC Table 502.2.3 (3)

Equipment Type Size Category Minimum Efficiency + 15% + 20%Split System and Single Package

< 65,000 BTU (5.42 Tons) 13 SEER 15 SEER 16 SEER> 65,000, <135,000

(11.25 Tons) 11 SEER 13 SEER 13.5 SEER>135,000, <240,000 (20 Tons) 10.6 SEER 12.2 SEER 13 SEER> 240,000 9.5 SEER 11 SEER 11.5 SEER

3B 4B


Energy Recovery Ventilation Systems (503.2.6)

• Applies to individual fan systems with - Design supply air capacity ≥ 5,000 CFM - Minimum outside air supply of ≥ 70% of design supply air quantity

• Exhaust air recovery efficiency must be ≥ 50%


Energy Recovery Ventilation Systems (503.2.6) - Exceptions • Where energy recovery ventilation systems prohibited by the IMC • Lab fume hood system with at least one of the following:

- VAV hood exhaust and room supply systems capable of reducing exhaust and makeup air volume to ≤ 50% of design values

- Direct makeup (auxiliary) air supply equal to at least 75% of exhaust rate, heated no warmer than 2ºF below room setpoint, cooled to no cooler than 3ºF above room setpoint, no humidification added, and no simultaneous heating and cooling use for dehumidification control

• Systems serving uncooled spaces and heated to < 60ºF • Where > 60% of outdoor heating energy is from site-recovered or site

solar energy • Heating systems in climates < 3,600 HDD • Cooling systems in climates with a 1% cooling design wet-bulb

temperature < 64ºF • Systems requiring dehumidification that employ series-style energy

recovery coils wrapped around the cooling coil

Commercial Mechanical Requirements Currently being adopted by many states

U.S. Department of Energy Building Energy Codes Program

PNNL-SA-66171


IECC 2012 - International Energy Conservation Code

Changes from 2009 code to 2012 code (R= Residential committee, A= All and C= Commercial Committee):

- Air system economizers are required in more climate zones and at a lower threshold (33K Btu/h instead of 54K Btu/h) – >2.75 Tons

Source: https://www.energycodes.gov/sites/default/files/documents/Comparison_2009to2012_IECC.pdf



C401.2 Application. Commercial buildings shall comply with one of the following: 1. The requirements of ANSI/ASHRAE/IESNA 90.1. 2. The requirements of Sections C402, C403, C404 and C405. In addition, commercial buildings shall comply with either Section C406.2, C406.3 or C406.4. 3. The requirements of Section C407, C402.4, C403.2, C404, C405.2, C405.3, C405.4, C405.6 and C405.7. The building energy cost shall be equal to or less than 85 percent of the standard reference design building.

C401.2.1 Application to existing buildings. Additions, alterations and repairs to existing buildings shall comply with one of the following:

1.Sections C402, C403, C404 and C405; or 2.ANSI/ASHRAE/IESNA 90.1.

Source: http://publicecodes.cyberregs.com/icod/iecc/2012/index.htm


IECC - International Energy Conservation Code












ASHRAE Standard 90.1 -2010

The Committee’s unanimously approved work plan goal for the 2010 edition was to reduce energy cost by 30% compared to the 2004 version of the standard. Toward that goal, 109 addenda were processed by the committee and approved by the ASHRAE and IES Boards of Directors and are included in the 2010 edition. Most equipment efficiencies are higher, energy recovery is required in more applications, economizers are required in more climates, and more energy conserving controls are required. 6.5.1 Economizers. Each cooling system that has a fan shall include either an air or water economizer meeting the requirements of Sections 6.5.1.1 through 6.5.1.4.

Exceptions: Economizers are not required for the some systems listed in section

TABLE 6.3.2 Eliminates required economizer for comfort cooling by increasing the cooling efficiency of the equipment. The efficiency improvement is listed by climate zone. 6.4.3.9 Demand control ventilation (DCV) is required for spaces larger than 500 ft2 and with a design occupancy for ventilation of greater than 40 people per 1000 ft2 of floor area and served by systems with one or more of the following:

a. an air side economizer, b. automatic modulating control of the outdoor air damper, or c. a design outdoor airflow greater than 3000 cfm.

Exceptions: DCV is not required for the some systems listed in section


Impact of Energy Issues

In the past the HVAC industry provided electro-mechanical and analog controls for saving energy

Controllers of the future • More complex control requirements for additional energy savings and

a healthier environment • Demand Control Ventilation

• Simplified diagnostics and verifiable operation • Traceable operation and maintenance • More profit per unit of labor


Emerging Economizer Trends Basic: Integrated Economizer Demand Control Ventilation CO2 sensor input Emerging (current in Title 24, and 2012 IECC): System FDD (Fault Detection & Diagnostics) Alarms FDD Sensors (3 – OA, RA, SA or MA) Damper Reliability Test Certification of the damper assembly with 60k damper open-close cycles Damper Leakage Test Maximum leakage rate of 10 cfm/sf at 1.0 in. w.g. Sensor Accuracy, Calibration Temperature accuracy +/- 2°F over range of 40°F to 80°F Enthalpy accurate to +/- 3 Btu/lb over the range of 20 Btu/lb to 36 Btu/lb Energy Saving Ventilation Fan Speed Pre-purge Damper position indication


THANK YOU!

QUESTIONS?

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