What's New With Title 24 - Energy Design Resourcess New With Title 24 Introducing the 2005 Energy Efficiency Standards for Nonresidential Buildings 79 slides. ... º Formerly, T24

What's New With Title 24

What's New With Title 24

Introducing the 2005 Energy Efficiency Standards for Nonresidential Buildings

79 slides

Introducing the 2005 Energy Efficiency Standards for Nonresidential Buildings

79 slides

2005 © EDR 2005 Title 24 Changes Overview Module

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Welcome!Welcome!

This is an introductory online module, where you will :

Get a brief overview of the new energy-efficiency requirements for

Envelope LightingMechanicalAcceptance Testing

Receive references to specific code provisions and additional information sources

You can move through the module at your own paceYou can email the instructors for answers to your questions at [email protected]


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About the StandardsAbout the Standards

The “Building Energy Efficiency Standards” are Part 6 of the “California Building Standards Code”The “California Building Standards Code” is a 11 part code, and is also referred to as “Title 24 of the California Code of Regulations”For the purpose of this module, we will use the shorthand “Title 24” or “T24” to refer to the “Building Energy Efficiency Standards”


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Why the changes to Title 24 in 2005?Why the changes to Title 24 in 2005?

The California Energy Commission (CEC) adopted the 2005 changes to Title 24, for a number of compelling reasons*:

Respond to the recent Energy Crisis, promoting energy savingsTo respond to the AB 970 (Statutes of 2000) urgency legislation to adopt and implement updated and cost-effective building energy efficiency standardsTo respond to the SB 5X (Statutes of 2001) urgency legislation to adopt energy efficiency building standards for outdoor lighting; andTo emphasize energy efficiency measures that save energy at peak periods and seasons

* Information adapted from content on the CEC website


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2005 Title 24 Standards Adoption Schedule2005 Title 24 Standards Adoption Schedule

The Energy Commission adopted the 2005 Building Energy Efficiency Standards on November 5, 2003The Building Standards Commission adopted them on July 21, 2004The Standards became effective October 1, 2005The Standards are enforced as part of the California Building Code Enforcement Process


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Scope of the 2005 Title 24 Standards Scope of the 2005 Title 24 Standards

The provisions of the 2005 Title 24 standards apply to all residential, non-residential, hotel/motel and high-rise residential buildings:

That are of Occupancy Group A, B, E, F, H, M, R, S, or U of the California Building Code; andWhose application for approval or renewal is filed after October 1, 2005; andThat are:

Unconditioned, indirectly or directly conditioned by mechanical heating or mechanical cooling or process spaces; orLow-rise residential buildings that are heated with a wood heater or another non-mechanical heating systemOutdoor lighting function areas in residential and nonresidential buildings

This module concentrates on requirements for non-residential and high-rise residential buildings only.


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Compliance Options in Title 24Compliance Options in Title 24

Mandatory requirementsAs the name suggests, these measures have to be installed in buildings,

and sets minimum standards that all building components must meet (at least when they're being installed)

Prescriptive approachThe standards provide list of measures for each CA Climate ZoneApplies to individual systems and permits

e.g. Lighting requirements for stand-alone electrical permitsLimited tradeoff allowed between envelope measures in the Overall Envelope method

No Tradeoffs allowed between envelope and other measures Limited lighting power density trade-offs allowed between various spaces

No Tradeoffs allowed between lighting and other measures


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Compliance Options in Title 24… continuedCompliance Options in Title 24… continued

Performance ApproachAllows one to choose any combination of measures, provided they meet or exceed the mandatory requirements individuallyThe energy budget for the proposed building is calculated using Time Dependent Valuation (TDV)

Energy Budget refers to the total TDV energy usage estimated for heating, cooling, water heating, lighting, ventilation and other regulated loads in the building on an annual basis.

The building complies with the T24 requirements if the TDV energy usage of the proposed design is lower than the standard budget

The ‘standard budget’ is the energy usage calculated for a minimally code compliant design that shares the same geometry, location, orientation and equipment type as the building being permitted


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So what is Time Dependent Valuation (TDV)?So what is Time Dependent Valuation (TDV)?

TDV is the most significant concept underlying all the 2005 Title 24 code changes, although it will be transparent to most users

TDV affects the way energy trade-offs in the performance approach are valuedIt does that by changing the way energy is ‘valued’ based on the time of use of that energy

Formerly, T24 energy use estimates had a constant value regardless of whether the use was at night or dayTDV assigns higher value for on-peak savings, lower value for off-peak, and is neutral for savings that are both


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So how is TDV energy calculated?So how is TDV energy calculated?

The energy use values for the proposed and standard designs are estimated for each hourThe difference between these values are multiplied by the TDV value for that hour

TDV values vary for each hour of the year and by

Energy fuel type (electricity, natural gas or propane), California climate zone, and Building type (low-rise residential or nonresidential, high-rise residential or hotel/motel)

The TDV value for a hot summer weekday afternoon hour is worth many times the value of a nighttime hour


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Monday Friday

With flat energy value a kWh saved is valued the same for every hour of the day

With TDV value a kWh saved during a high-cost peak hour is valued more highly than a kWh saved during an off-peak hour

Flat Energy Value used in previous

standards

Time Dependent Energy Value in 2005 Standards

Ene

rgy

valu

e


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So why is TDV important to you?So why is TDV important to you?

TDV favors technologies that save more energy on-peak than off-peak

So there is greater credit than before for measures such as:

Better EER air conditionersBetter duct insulation (in unconditioned spaces)Daylighting controls for lighting

Greater penalties than before for measures such as:West-facing glassOversized windows/skylights

Generally neutral or lower credits for measures such as:

EconomizersEnvelope insulation

These will affect your trade-off choices under the performance approach


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2005 Title 24 Code Change Specifics2005 Title 24 Code Change Specifics

Now that we have reviewed the basics, let us look at the specific code changes in the following categories

Envelope MeasuresLighting MeasuresMechanical MeasuresAcceptance Testing RequirementsField Verification of Measures

Envelope MeasuresEnvelope Measures

Changes to compliance requirements for envelope measures in the 2005 Title 24

Standards

Changes to compliance requirements for envelope measures in the 2005 Title 24

Standards


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Construction Assembly SpecificationConstruction Assembly Specification

Rule-sets for construction assemblies have been simplified in the 2005 standards

Default U-factors for various wall, floor and roof construction assemblies have been specified in the

Joint Appendix IV of the Alternative Compliance Manual (Tables IV-1 through IV-27)

These default values must be used for all prescriptive, overall envelope and performance method compliance options

If a given assembly for your building is not adequately represented in the appendix tables, choose an assembly that has similar energy performance,

and be prepared to justify your choice to the local building department

OR, seek permission from the CEC for approval to use the assembly

For more information call the CEC Energy Efficiency Hotline 1-800-772-3300 (toll free in California)


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Sample Envelope U-Factor tableSample Envelope U-Factor table

• Here is an excerpt from the table for U-factors of wood framed attic roofs in the Joint Appendix IV document

• Choose your assembly U-factor based on the rated R-value of continuous insulation, and the R-value of the attic insulation


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Construction Assembly: Mandatory MeasuresConstruction Assembly: Mandatory Measures

Overall, the new values for U-factors in the appendix tables are more stringent than the equivalent 2001 requirements.

Assumption of framing percentage increased from 15% to 25%, thus decreasing assembly R-value and increasing overall U-factors for the assemblies

Metal Framed RoofsRoofs with metal framing will have to meet an insulation level of an equivalent wood framed roof

Based on overall U-factor of the assemblyAnd not on the R-value of insulation alone

Slab-on-grade FloorsHeated slab-on-grade floors must be insulated both

Vertically at the slab edge, andHorizontally between the heated slab and foundation wall


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Construction Assembly: Prescriptive MeasuresConstruction Assembly: Prescriptive Measures

The U-factor of your construction assembly must be equal to or lower than the values specified in:

Table 143-A: For Nonresidential buildings, and Relocatable Classrooms rated for specific climate zonesTable 143-B: For Hotel/Motel and High-rise Residential buildingsTable 143-C: For Relocatable Classrooms rated for all CA climate zones

Calculate the U-factor of your assembly in accordance with the Joint Appendix IV proceduresA good description of the procedure is found in the Nonresidential Compliance Manual section 3.3


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Construction Assembly: Excerpt from Table 143-AConstruction Assembly: Excerpt from Table 143-A

Below is an excerpt of the prescriptive requirements by climate zone for roof, wall, and floor/soffit

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0.1390.071

11

0.0900.071

11

0.1390.071

11

0.1390.071

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0.0900.048

Floor/SoffitR-value orU-factor

Mass/7.0≤HCOther

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0.1020.2170.1130.4300.4100.102

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0.10240.2170.1130.4300.6500.102

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0.1100.2240.1230.4300.6900.110

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0.1100.2240.1230.4300.6500.110

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0.1020.2170.1130.3300.3600.102

WallR-value orU-factor

Wood FrameMetal FrameMetal BuildingMass/7.0≤HC<15.0Mass/15.0≤HCOther

0.051 19

0.051 19

0.076 11

0.051 19

0.051 19

Roof/CeilingU-factorR-value

14, 152, 10-136-93-51, 16

Climate Zones


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NFRC LabelNFRC Label

NFRC stands for the National Fenestration Rating Council

A non-profit organizationAdministers the uniform, independent rating and labeling system for energy performance of windows, doors, and skylights

Graphic Courtesy: NFRC website


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Fenestration: Mandatory RequirementsFenestration: Mandatory Requirements

For all fenestration products except site-fabricated windows:

The manufacturer needs to certify the product, to meet U-factor and SHGC requirements set in Section 116

U-factor: Either use default value in Table 116-A or be rated in accordance with NFRC 100SHGC: Either use default value in Table 116-B or be rated in accordance with NFRC 200 or NFRC 100


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Fenestration: Mandatory Labeling RequirementsFenestration: Mandatory Labeling Requirements

Every manufactured and site-built fenestration product is required to have

A clearly visible temporary label that lists the U-factor, the solar heat gain coefficient (SHGC) of that product, and the method used to derive those values

Fenestration products rated using the NFRC rating procedure are required to have

A permanent label stating the U-factor and SHGC of the productSite-fabricated products are exempted from this requirement


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Fenestration: Prescriptive RequirementsFenestration: Prescriptive Requirements

2005 Title 24 limits the maximum window area for

West-facing windows to no greater than 40% of the gross west-facing exterior wall area, orSix feet times the west-facing display perimeter, whichever is greater; and

Combined total of window area on all orientations to no greater than

40% of the total gross exterior wall area for all orientations, orSix feet times the display perimeter on all orientations, whichever is greater

– Display perimeter is the length of an exterior wall used for displaying merchandise that immediately abuts a public sidewalk


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Fenestration: Prescriptive Requirements contd…Fenestration: Prescriptive Requirements contd…

The standards also limit the window U-factor and SHGC values to those specified in Tables 143-A, 143-B, and 143-C

The U-factors have been reduced slightly from the 2001 standards to account for a revised NFRC rating procedure –

There is no change to the type of windows that comply

Remember these are Prescriptive requirementsYou may decide to choose a higher U-factor or SHGC or greater window areaHowever, you will have to make up the lost energy savings by using greater efficiencies in other building components


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Relocatable ClassroomsRelocatable Classrooms

Relocatable classrooms must meet building envelope requirements the same as other buildings

If they are moved, they must still meet the requirements of the new location

Relocatable classrooms can be rated forThe whole State using the values in Table 143-C,

Or For a specific climate zone, using values in Table 143-A

Manufacturers will need to label each unit with a identification label stating whether

Unit is rated for all California climate zones, orList the climate zones it is rated for


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Ceiling Insulation PlacementCeiling Insulation Placement

Title 24 no longer recognizes insulation placed on top of suspended ceilings (Lay-on insulation)Instead, Title 24 requires that insulation be always placed in contact with a continuous roof deck or ceiling,

Either above or below the roof deck, or Above a drywall ceiling

Small conditioned spaces within bigger unconditioned spaces

Small space ceilings exempted if:A combined area no greater than 2,000 sf enclosed within a larger unconditioned space; and The distance from ceiling to roof more than 12’


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Ceiling Insulation PlacementCeiling Insulation Placement

SPACE

PLENUM

Suspended Ceiling

= Insulation

Lay-onInsulation:

NOT ALLOWED

Insulationat roof deck:

OK


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Skylighting in “Big-Box” SpacesSkylighting in “Big-Box” Spaces

New prescriptive requirement:At least half of the area of big-box spaces to be lit with skylights [Section 143 (c)]The conditions that trigger this requirement are spaces that are

Large, single story, conditioned or unconditioned, enclosed spaces, with

Greater than 25,000 sq.ft of area enclosed under a roofGreater than 15 feet high, and whereThe installed lighting power density is greater than or equal to 0.5W/sq.ft

Requires at least 3.0-3.6% Skylight Area to Daylit Floor Area Requires diffusing glazing in skylights, andRequires Multi-level Automatic Daylighting Controls in the Daylit Area


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Skylighting in “Big-Box” Spaces: Daylit AreaSkylighting in “Big-Box” Spaces: Daylit Area

Daylit Area is defined as the floor area that is illuminated through skylights as specified in Section 131 (c)

The daylit area under skylights shall be the rough opening of the skylight plus, In each of the lateral and longitudinal dimensions of the skylight, the lesser of

70% of the floor-to-ceiling height, orThe distance to the nearest 60-inch or higher permanent partition, orOne half the horizontal distance to the edge of the closest skylight or vertical glazingWhichever is least


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35° 35°

Height = 20’

H x 0.7 20’ x 0.7 = 14’

Daylit Area Width = 14’+4’+14’ =32’Daylit Area Length = 14’+8’+14’ = 36’

Daylit area= 32’x36’ = 1,152 ft2

Skylight Length = 8’Skylight Width = 4’

Daylit Area under the skylight

Daylit Area IllustrationDaylit Area Illustration


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Skylighting in Conditioned “Big-Box” SpacesSkylighting in Conditioned “Big-Box” Spaces

If the space is conditioned, the skylights must meet the requirements of Section 146 (a) 6 or 143(b), which state:

Skylight U-factors and SHGC not to exceed prescriptive values in tables 143-A, 143-B or 143-C depending on occupancy typeSkylight area to total gross roof area not to exceed 5%

Remember, all these requirements are Prescriptive requirements

So they only apply if you plan to use the Prescriptive or Overall Envelope methods of compliance

In the Performance method, you may choose not to use skylights,

But the standard budget will assume skylights and daylighting controlsAnd you would need to use higher efficiencies in your lighting, envelope or HVAC systems to make up for the loss of lighting savings due to skylights


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Cool Roof RequirementsCool Roof Requirements

Title 24 encourages the use of Cool Roof technologies that reflect heat, and lower cooling loads in the space

Approved Cool Roofs have eitherHigh thermal emittance, and high solar reflectance; ORLow thermal emittance, and exceptionally high solar reflectance

The 2005 T24 standards require Cool Roofs for low-slope roofs (defined as roofs with slope of 2:12 or less)

This requirement applies to re-roofing tooThis is a prescriptive requirement, and can be traded-off if not desired

However, Cool Roof will be included in the standard energy budget, andYou will have to make up for the lost energy savings through other measures

Lighting MeasuresLighting Measures

Changes to compliance requirements for lighting measures in the 2005 Title 24

Standards

Changes to compliance requirements for lighting measures in the 2005 Title 24

Standards


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Changes to Lighting Measures: OverviewChanges to Lighting Measures: Overview

Lighting requirements in Title 24 are in two forms:Limits on Lighting Power Density (LPD in Watts/sf)Lighting Controls Requirements and Credits

Allowable Lighting Power Density limits are set three different ways:

Whole Building Method: LPD is specified for the whole buildings, and depends on the building type

Can use only where the whole building has the same occupancy type

Area Category Method: LPD requirements vary by type of space within a given building

Used where the type of occupancy varies by spaceTailored Method: A special method that sets different LPDs for general and display lighting by space, depending on the task in the space

Used mostly for unusual applications that require special lighting considerationsTailored allowances are ‘use-it-or-lose-it’ and cannot be traded with the area category method


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Whole Building MethodWhole Building Method

The lighting standards add new building types to the Whole Building MethodThe method is applicable to buildings where

More than 90% of the total area has the same type-of-use occupancyFor retail and wholesale buildings, method can be applied only to

Single tenant buildings, or Buildings with multiple tenants if 100% of space is used for retail and wholesale at time of permit, and

– Only if merchandise sales function area is ≥70%Hotel/Motel and High-rise residential buildings cannot use Whole Building Method

2005 Title24 reduces the allowable LPD for a number of spacesThe new LPD limits are in Table 146-B of the standards


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Whole Building Method Revised LPDsWhole Building Method Revised LPDs

Complete Building LPDs (W/sf)

1.21.4Schools

1.51.7Retail and Wholesale

1.61.8Religious Facilities

0.4 (new)n/aParking Garages

1.11.2Office Buildings

1.11.2Medical Buildings & Clinics

1.11.2General Commercial – High Bay

1.1 (new)n/aFinancial Institutions

1.3 (new)n/aConvention Centers

1.5 (new)n/aAuditorium

2005 Stds2001 Stds

Building Type


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Area Category MethodArea Category Method

The Area Category method can be used when there are multiple type-of-use occupancies in a building

The total allowed lighting power for the building is the sum of all allowed lighting powers for all areas of the buildingThe “area” is defined as a contiguous space occupied with one of the primary functions listed in Table 146-C

The 2005 revisions add a number of primary function areas to the listThe new standards also lower the allowable LPD’s for a number of primary function areas


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Area Category Method Revised LPDsArea Category Method Revised LPDs

Excerpts from Table 146-C compared to values in 2001 Standards

Area Category Method LPDs (W/sf)

1.52.2Hotel Function Areas

1.5 (new)n/aSenior Housing Common Areas

1.0 (new)n/aMultifamily Common Areas

1.11.2General Commercial High Bay

1.21.4Financial Institution

1.41.5Convention

1.3 (new)n/aCivic Meeting Place

1.11.2Auto Repair

1.52.0Auditorium

2005 Stds2001 Stds.

Primary Function Types


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Area Category Method Revised LPDsArea Category Method Revised LPDs

Excerpts from Table 146-C compared to values in 2001 Stds. Continued

Area Category Method LPDs (W/sf)

1.2 (new)n/aTransportation

1.0 (new)n/aTenant Lease Space

1.72.0Retail and Wholesale

1.52.1Religious Worship

1.21.3Office

1.21.4Medical and Clinical

1.11.7Hotel Lobby

1.71.6Kitchen

2005 Stds2001 Stds.

Primary Function Types


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Tailored MethodTailored Method

Requirements for the Tailored Method have been simplified and thoroughly re-written

The method can be used for a maximum of 30% area of the building area that is otherwise using the Area Category Method

Exception: Retail Merchandise Sales and Museums can use the tailored method for up to 100% of building areaException: If a single function area exceeds 30% of building area, then the tailored method can be used for that entire function area alone

Tailored and Area Category methods cannot be used for same floor areaNo trade-offs are allowed between the Tailored Method and Area Category MethodThe Tailored Method allowances are ‘use-it-or-lose-it’allowances that cannot be traded off against other allowances


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Tailored Method LPD AllocationsTailored Method LPD AllocationsThe revised Tailored Method Special Lighting Power Allowances are presented in Table 146-D. The table sets lighting power allowances for

General IlluminationSets the IESNA illumination category for the primary function area; corresponding LPD values are in Table 146-F

Wall DisplayQualified wall display lighting must be mounted within 6 feet of the display wall

Floor DisplayQualified floor display lighting must be mounted more than 6 feet from the walls

Ornamental/Special Effects LightingThese are special purpose light sources, and cannot be the only light source in the space

Very Valuable DisplayFor lighting of display cases that carry highly valuable merchandise only


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Tailored Method LPD AllocationsTailored Method LPD Allocations

Apart from General Illumination, all other allowances are use-it-or-lose-it allowances and cannot be traded off

e.g. If you do not plan to have ‘Very Valuable Display’ lighting, the LPD limits for that usage type do not apply to you, and you will not be able to use the LPD for that usage in the ‘general illumination or other use’

All the LPD allocations are also dependent on ceiling height of the space being 12’ or less

Table 146-E gives adjustments to the LPD requirements when the mounting height of light fixtures is higher than 12 feet


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Mandatory Lighting ControlsMandatory Lighting Controls

The 2005 standards require multi-level lighting controls in spaces:

Over 100 square feet in area, andUsing at least 0.8 w/sf of lighting energyi.e., Most spaces

Multi-level lighting controls reduce the lighting power by either dimming or switching the lamps so that there is

At least one level with 50-70% of maximum lighting power consumption, andAt least one level with less than 35% of maximum lighting power consumption (including completely off for a bi-level control)


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Mandatory Daylighting ControlsMandatory Daylighting Controls

For daylit areas under skylights, the standards also require the use of daylighting controls

For daylit areas greater than 250 sf, half the lighting in the daylit area is required to be on a separate dimming or switching control

These controls can be manual controls (switches, sliders etc)

For daylit areas greater than 2,500 sf, the general lighting in the daylit area is required to be automatically controlled by

Automatic multi-level daylighting controls, ORAutomatic multi-level astronomical time switchManual controls do not qualify


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Lighting Control Credits – What are they?Lighting Control Credits – What are they?

In order to encourage the use of automated lighting controls such as occupancy sensors, and daylight sensors, the standards also provide

Lighting Control Credits in the form of Power Adjustment Factors (PAF) to the general lighting allowable LPD limits

The PAF is not a Mandatory requirement but is intended as an optional incentive for an exemplary control systemThe PAF reduces the total installed lighting wattage value used for compliance calculations

equal to the product of the PAF credit and the total controlled lighting wattage

i.e. [installed wattage for compliance calculations] = [actual installed wattage] - [PAF x controlled wattage].

Savings are recovered through the operation of the automatic controls, providing cost savings and power reductions to the building owner and the California electricity grid.


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Changes to Lighting Control CreditsChanges to Lighting Control Credits

Table 146-A lists the various lighting Power Adjustment Factors (PAF), and a number of changes have been made to the type of controls eligible for PAFs:

The 2005 Standards no longer provide PAFs for regular occupancy sensors

Instead, the standards give PAFs for occupancy sensors that have built-in multi-level control capabilities.

The standards no longer give PAFs for automatic time switch control devicesThe PAFs for combined controls, i.e. controls that have both occupancy and daylight based controls, have been updated to reflect the changes aboveThe PAFs for combined occupancy and programmable multiscene dimming controls are no longer offered

Instead, PAFs are offered for combining bi-level enabled occupancy sensor with manual dimming with electronic ballasts


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New PAF: Multi-level Occupancy SensorsNew PAF: Multi-level Occupancy Sensors

A new PAF of 0.20, for a newly defined Multi-level enabled occupancy sensor, for

Any space less than or equal to 250 sf enclosed by ceiling height partitions, Any size classrooms, Corridors,Conference or Waiting rooms

To be eligible for this credit, the qualifying sensor must be capable of providing either

‘Manual On’ or Automated ON for the first level (50% or less) of the installed fixtures,A separate user action (like pressing a switch) to get full light outputAutomatic shut-off of all lighting when the occupants leave the space


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New Lighting Control Credits in 2005New Lighting Control Credits in 2005

New PAF: Bi-level Occupancy Sensor PAF of 0.25 for Hallways of Hotels/MotelsPAF of 0.15 for Commercial & Industrial Storage Stacks (max. 2 aisles per sensor)PAF of 0.15 for Library Stacks (max. 2 aisles per sensor)

To be eligible for this credit, the qualifying sensor must be capable of providing either

Automated reduction of lighting power to no more than 50% of maximum output when no persons are presentAutomated full light output when persons enter the space


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New Lighting Control Credits in 2005New Lighting Control Credits in 2005

New PAF: Manual dimming with automatic load control of dimmable electronic ballasts

PAF of 0.25 for all building typesAutomatic load control refers to the ability to reduce lighting power consumption for peak demand savings

New PAF: Combined CreditsAdditional credits are available if either daylighting controls or manual dimming controls are also used on the same circuits that have multi-level occupancy sensorsRefer to Table 146-A of the standards for more details


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Outdoor Lighting StandardsOutdoor Lighting Standards

Responding to a legislative mandate, the Title 24 Standards have been modified to include

Lighting in unconditioned buildings and Lighting for particular outdoor function areas

No tradeoffs are allowed between indoor lighting and outdoor lightingOutdoor lighting requirements are Prescriptive requirements only, and are NOT included in the Performance methodFor more detailed information, please refer to the module on outdoor lighting standards on the EDR website.

Mechanical Measures

Mechanical Measures

Changes to compliance requirements for mechanical measures in the 2005 Title

24 Standards

Changes to compliance requirements for mechanical measures in the 2005 Title

24 Standards


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Changes to Mechanical MeasuresChanges to Mechanical Measures

A number of significant changes have been made to

Modeling of mechanical equipment, andRequired efficiencies

In the following slides, we will look at the following changes

More credit for EER improvementsCooling tower certification Ventilation changesDuctsAirside measures Hydronic measures


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Modeling Cooling EfficiencyModeling Cooling Efficiency

There are two metrics for modeling cooling efficiency Seasonal Energy Efficiency Ratio (SEER)

SEER is an efficiency at 82 degrees – Approximates the average efficiency of the unit over the entire

cooling period– Includes losses at part load due to compressor cycling

Energy Efficiency Ratio (EER)EER is efficiency at 95 degree outdoor temperature

– This is the ARI test condition– A steady-state value at full load

For small air conditioning systems (less than 65,000 Btu cooling capacity)

Both the SEER and EER values can be specifiedNo change here from the previous standards

For large air conditioning systemsOnly the EER value is specified (SEER value not used)

Same as in the previous standardsIn addition, now you can specify custom efficiency curves

More on this on the next slide


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Improvements to the EER Modeling RulesImprovements to the EER Modeling Rules

For large air conditioners (greater than 130,000 Btu cooling capacity), in addition to the EER value at ARI rated conditions,you can now enter:

A series of manufacturer supplied kW vs capacity values for various outdoor air and indoor air temperature and humidity conditions in the Performance Method

This allows one to model the true efficiency of the unit at various temperature conditionsPotentially resulting in greater compliance margins

– If the true efficiency of the unit is higher than the EER valueWhy is this going to result in compliance improvements?

The air conditioner efficiency modeled in the compliance software is temperature dependent

If only the EER value is used, at temperatures greater than the ARI test conditions, the modeled efficiency of the unit is lowerBy specifying custom curves, one can force the software to model the real (greater) efficiency for that unit

Combined with the TDV regimen this will result in greater compliance credits than those for just EER improvements

Of course, if the real efficiency of the unit is lower than the EER value, you will take a compliance penalty!


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Cooling Tower CertificationCooling Tower Certification

Factory assembled cooling towers are now required to be tested and certified per the Cooling Tower Institute test proceduresTable 112-G specifies the following certification requirements:

Propeller or Axial Fan Cooling TowersRequire greater than or equal to 38.2 gpm/hp performance rating perCTI ATC-105 and CTI STD-201 test procedures

Centrifugal Fan Cooling TowersRequire greater than or equal to 20.0 gpm/hp performance rating perCTI ATC-105 and CTI STD-201 test procedures

Air Cooled CondensersRequire greater than or equal to 176,000 Btu/h·hpperformance rating per ARI 460 test procedure


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Cooling Tower Requirements: [Section 144 (h)]Cooling Tower Requirements: [Section 144 (h)]

Fan Speed Control Each fan powered by a motor of 7.5 hp (5.6 kW) or larger shall have the capability to control fan speed based on water temperature or refrigerant pressure. This would include:

Two speed fan motors,Smaller “pony motor”Variable Frequency Drive Adjustable blade pitch for axial (propeller) fans

Tower Flow Turndown Open cooling towers configured with multiple condenser water pumps shall be designed so that all cells can be run in parallel with the larger of:

The flow that’s produced by the smallest pump, or33% of the design flow for the cell.

Centrifugal Fan Cooling Towers Restricts the use of centrifugal fans to cooling towers with less than 300 Ton capacity


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Variable Volume Systems [Section 144 (c) ]Variable Volume Systems [Section 144 (c) ]

Total Fan Power Index (FPI) at design conditions of each fan system with total horsepower over 25 horsepower

Shall not exceed 1.25 watts per cfm of supply air

Individual Variable Air Volume (VAV) fans with motors 10 horsepower or larger are required to have:

Variable speed drive;Vane-axial fan with variable pitch blades; orControls that limit the fan motor demand to no more than 30% of rated power at 50% of flow


58

Variable Volume Systems contd…Variable Volume Systems contd…

Static Pressure Sensor to be located such thatController set point is no greater than one-third the total design fan static pressure

Set Point ResetIf there are DDC controls with communication to individual zone boxes, thenStatic pressure set point to be reset based on the zone requiring the most pressure

Series fan powered VAV boxes now are required to have electronically commutated motors or

Minimum motor efficiency of 70%


59

Demand Control Ventilation RequirementsDemand Control Ventilation Requirements

Demand Control Ventilation (DCV) saves ventilation energy by

Cutting back ventilation automatically when space is unoccupiedIt uses CO2 sensor technology to maintain indoor air quality

Requirements for DCV have been greatly enhanced by requiring DCV for

Single Zone HVAC systems Having outside air economizers, and servingHeavily occupied spaces e.g. auditorium, theater With occupant densities in excess of 25 persons/1000 sf

Exceptions to the requirements includeAll classroom spacesSpaces with high exhaust needsSpaces that generate hazardous fumes and do not have local exhaust systems


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Demand Control Ventilation RequirementsDemand Control Ventilation Requirements

Section 121 (c) 4 of the standards requires CO2 sensorsIn each room where the system uses DCVThe CO2 sensor must be mounted between 1’-6’from the floor

Section 121 (c) 4 requires the DCV strategy to Maintain CO2 levels less than or equal to 600 ppm plus the outside air CO2 levelsOutside air CO2 ppm can either be

Assumed to be 400 ppm without any direct measurement, orMeasured with a outdoor CO2 sensor near the outdoor air intake

CO2 sensors need to be certified by the manufacturer for

Accuracy not less than 75 ppm, andFactory calibrated or calibrated at start-up, and Certified to maintain calibration for 5 years


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Natural Ventilation RequirementsNatural Ventilation Requirements

Section 121(b)1 specifies that spaces that use natural ventilation in lieu of mechanical ventilation

Must be permanently open to and within 20 feet of operable windows or skylights open to the outdoors

It further sets a minimum requirement on the operable area in such windows or skylights to be

At least 5% of the conditioned floor area of the naturally ventilated spaceWhen louvers or blinds cover the openings, the operable area includes only the portion of the opening that is unobstructed

The means for opening windows or skylights should be within easy reach of the occupants at all times of occupancy


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Mandatory Duct Insulation MeasuresMandatory Duct Insulation Measures

For portions of supply and return ducts in unconditioned or indirectly conditioned spaces

Section 124 (a) mandates a minimum insulation of R-8 for ducts located:

Outdoors, orSpace between the roof and an insulated ceiling, orSpace directly under a roof with fixed vents or openings to the outside or unconditioned spaces, or Unconditioned crawlspace; or Any other unconditioned space

For portions of supply and return ducts in all other spaces except above

Section 124 (a) mandates a minimum insulation of R-4.2, orRequire these portions to be completed enclosed in a directly conditioned space


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Prescriptive Duct Sealing MeasuresPrescriptive Duct Sealing Measures

Section 144 (k) requires all duct systems to be tested and sealed to a leakage rate not to exceed 6% of the fan flow rate if the duct system:

Is connected to constant volume, single zone, air conditioners, heat pumps or furnaces, andServing less than 5,000 square feet of floor area; andHaving more than 25% duct surface area located

Outdoors, or Directly underneath a roof where the ceiling insulation is greater than the roof insulation

The leakage rate is required to be confirmed through field verification and diagnostic testing

In accordance with procedures set forth in the Nonresidential Manual

This is a Prescriptive requirement and can be traded off in the Performance method

Though the lost energy efficiency would need to be recovered through other measures


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Hydronic System MeasuresHydronic System Measures

HVAC chilled and hot water pumping with more than 3 valves requires fluid flow control so that

Flows are reduced by at least 50% or to manufacturer's minimum recommended flow rate. [Section (144(j)1]

Water loop heat pump systems require variable speed pumps when pump power exceeds 5hp [Section 144(j)5]Similar requirement for variable speed pumps exists for all variable flow systems that have pump power exceeding 5hp [Section 144(j)6]


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Multiple Chillers or BoilersMultiple Chillers or Boilers

When a hydronic system has more than one chiller or boiler, it is required to have controls that

Shut down water flow through a chiller or boiler that is shutoffWhile maintaining supply through the chillers or boilers that are operational. [Section 144(j)2 and 144(j)3]

Large capacity (>500,000 Btu/h) chilled and hot water systems also require

Automated controls that reset supply water temperatures based on building loads or outside temperature. [Section 144(j)4]


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Domestic Hot Water MeasuresDomestic Hot Water Measures

High-rise residential buildings fall under the preview of the non-residential standards for Envelope and HVAC measuresHowever, the Domestic Hot Water (DHW) measures are governed by the residential standards [Section 151(f)8]For units having individual water heaters,

The water heaters need to meet efficiency requirements of sections 111 and 113, andNo recirculation pumps are allowed

For units having a central recirculating DHW system,The water heaters need to meet efficiency requirements of sections 111 and 113, andAutomatic controls that shut-off the circulating pump when there is no need for hot water are requiredThe Performance Method also uses a recirculatingcentral DHW system with time-based automatic shut-off controls as the basis for standard DHW budget

Acceptance Testing

Requirements

Acceptance Testing

Requirements


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Acceptance Testing RequirementsAcceptance Testing Requirements

The 2005 Standards introduce a new set of mandatoryperformance verification criteria called Acceptance Testing RequirementsAcceptance testing is required for lighting and HVAC controls that are prone to miscalibration and failure

A “responsible person” performs the test and certifies on the compliance test forms that the equipment passesA responsible person is a licensed architect, engineer, contractor or other person certified to inspect buildings under the Business and Professions CodeMost of these tests do not require third party verification

Acceptance testing must be completed before the building official issues the certificate of occupancy


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Acceptance Testing RequirementsAcceptance Testing Requirements

The requirements are embedded in various sections of the 2005 standards documentAn handy reference is Section 8.0 of the Nonresidential Compliance Manual that:

Explains the standards provisions and their intent in simple termsProvides detailed instructions on the procedures required for the Acceptance TestingProvides a handy list of forms and associated code sections

– Table 8-1 which we have included in the following slidesProvides sample test procedures with time and labor estimates

The actual test procedures are found in the Nonresidential Alternative Compliance Manual (NACM) Appendix NJ


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Measures Requiring Acceptance TestingMeasures Requiring Acceptance Testing

NJ 4.1§121(b)2MECH-3-A-05 Packaged HVAC Systems

NJ 3.1 and 3.2

§121(b)2MECH-2-A-05 Ventilation Systems – Variable and Constant Volume

N/A§10-103MECH-1-A-05 Certificate of Acceptance

Mechanical

NJ 6.1§119(e)LTG-3-A-05 Automatic Daylighting

NJ 6.2, 6.3 and 6.4

§119(d) and §131(d)

LTG-2-A-05 Lighting Controls

N/A§10-103LTG-1-A-05 Certificate of Acceptance

Lighting

ACM Manual Appendix #

Standards Reference

Form NameSectionTable 8-1 - Acceptance Forms of the Nonresidential Compliance Manual


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Measures Requiring Acceptance TestingMeasures Requiring Acceptance Testing

NJ 10.1 –10.5

§144(j)6MECH-8-A-05 Hydronic Systems Control

NJ 9.1§144(c)MECH-7-A-05 Supply Fan VFD

NJ 8.1§121(c)4.E. MECH-6-A-05 Demand Control Ventilation

NJ 7.1§144(e)MECH-4-A-05 Economizer

NJ 5.1§144(I)MECH-5-A-05 Air Distribution SystemsMechanical

ACM Manual Appendix #

Standards Reference

Form NameSection

Table 8-1 - Acceptance Forms of the Nonresidential Compliance Manual.. Contd.


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Field Verification of MeasuresField Verification of Measures

New duct systems in unconditioned spaces are prescriptively required to have tested and field verified sealed ducts.

Typically the installer will test the tightness of ducts and fill out the MECH-5-A acceptance testing formMust be third-party verified by a certified HERS rater who may sample 1 out of 7 systems

One could bypass duct sealing by using the performance method

But you would have to make up for the lost energy savings through other efficiency measures


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Field Verification of Measures (continued)Field Verification of Measures (continued)

Thermostatic Expansion Valve (TXV) and airflow

Performance method credit is given to air conditioners that have a TXV installed, and have sufficient airflow

TXV is a precision component in the refrigeration system that controls the rate of refrigerant flow into the evaporator

Credit requires correct airflow and TXV verification by a third party certified HERS (Home Energy Rating Service) rater

SummarySummary


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So what’s the big picture?So what’s the big picture?

More insulation required in metal constructionSkylights and automatic daylighting controls required in large open spaces like warehouses and big box retail spaces.“Cool roofs” required for low slope roofsAllowable LPD’s have been reduced – this reflects more efficient lighting sourcesIncreased control requirements for mechanical and lighting systemsAcceptance tests required for many automated mechanical and lighting controls


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Where can you read the Requirements?Where can you read the Requirements?

There are three main documents that collectively specify the standards and explain all the details

2005 Building Energy Efficiency StandardsThis is the official code language for all the provisions of the 2005 Title 24 standards

2005 Nonresidential Energy Standards Compliance Manual

This is a very useful reference guide that explains the code provisions, implementation procedures and compliance procedures

2005 Nonresidential Alternative Calculation Method (ACM) Approval Manual and related Appendices

These documents contain instructions for the compliance software vendors on how to implement the code provisions in the compliance software

– It is also very useful to understand details of each of the code provision


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Where to Find DocumentsWhere to Find Documents

All the three documents are available for free on the California Energy Commission (CEC) website at:

www.energy.ca.gov/title24You can also call the CEC Energy Efficiency Hotline at:

E-mail: [email protected]: 916-654-5106 orPhone: 1-800-772-3300 (toll free in California)


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Additional ResourcesAdditional Resources

The Energy Design Resources website has various other resources for Title 24 information, including:

Module on Outdoor Lighting Provisions in the 2005 California Title 24 StandardsCase Study illustrating the impact of the 2005 California Title 24 standards on a nonresidential buildingEDR Lights – an online course on energy efficient lighting and lighting controlsLinks to Energy Code websites

The California Investor Owned Utilities that sponsor EDR also provide Title 24 training at their respective Energy Centers

For more information, visit: http://www.energydesignresources.com/resource/151/

So that’s a summary of the 2005 CA Title 24

Standards

So that’s a summary of the 2005 CA Title 24

StandardsGood luck, make better buildings, and

save a lot of energy!Good luck, make better buildings, and

save a lot of energy!