Compressorless Comfort Homes Residential HVAC …h-m-g.com/T24/Res_Topics/2011.05.13Meeting... · Compressorless Comfort Homes Residential HVAC Baseline ... ASHRAE Standard 55-2004

California Statewide Utility Codes and Standards Program

Compressorless Comfort HomesResidential HVAC BaselineResidential Stakeholder Meeting

Abhijeet PandeHeschong Mahone Group, Inc.

Buehler Alumni Center, UC DavisMay 13, 2011

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05/13/2011

CALIFORNIA STATEWIDE UTILITIES CODES AND STANDARDS PROGRAM

Compressorless Comfort Homes/Res HVAC Baseline

Presentation Overview

● Summary of current code requirements

● Typical practice

● Summary of potential code change proposals

● Initial data/findings

● Potential code change proposals

● Next Steps

05/13/2011CA Utilities 2013 Title 24 Stakeholder Meeting for Proposed Code Changes

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Potential Code Change Proposals

● Prescriptive Requirements ● In coastal climate zones*, baseline building without

air conditioning in package D● Alternate prescriptive package with high efficiency air

conditioners for inland climates● Trade-off options between package D and path with high-

efficiency AC

● Performance Method● Standard building without AC in coastal climates● Proposed building can have AC but meets total TDV

energy use of package D (without AC)● Thermal comfort modeling in compliance calculations

* Areas with no or low cooling energy needs


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Current Code Requirements

● HVAC baseline efficiency set by Federal Standards● Currently at SEER 13 for residential air

conditioning

● Table 151-C (Package D)● Includes minimum efficiency (SEER 13) air

conditioning● Sets the basis for the performance approach

● Both standard and proposed designs assumed to have air conditioning even if none present in proposed design


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Typical Practice

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Source: 2004 RASS Database




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Typical Practice

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Typical Practice

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Typical Practice

● HVAC energy projected to be 45% of total peak consumption in the coming years

● Reducing or eliminating this peak consumption ● While still maintaining occupant comfort

therefore needs to be addressed

● If we are to meet the energy challenges of the (near) future



COMPRESSORLESS COMFORT HOMES


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● Prescriptive Requirements● Compressorless Comfort Homes

● In coastal climate zones*, baseline building without air conditioning in package D

● Performance Method● Standard building without AC

● Thermal comfort modeling in compliance calculations

* Areas with no or low cooling energy needs


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CA Utilities 2013 Title 24 Stakeholder Meeting for Proposed Code Changes

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Initial Data / Findings

● High efficiency projects increasingly looking at reducing HVAC loads ● Through better construction practices and

innovative whole-building solutions

● PIER Compressorless Home Study● PassivHaus● Building America● SMUD Home of the Future● Related CASE Topics● ASHRAE Standard 55 Comfort Metrics

05/13/2011




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● PIER Compressorless Comfort Homes● Multi-stage project conducted between 1998 to

2004● Key findings include:

● Compressorless technologies have potential to maintain comfort in some California climates

● A downsized compressor coupled with night ventilation and house design strategies will do in all climate zones but the hottest ones




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● Several regional, national, international efforts to define zero net energy home designs● PassivHaus Institute and Standard

● Annual source energy budgets

● High efficiency airtight envelope with heat recovery ventilation systems

● Building America● Whole building “system engineering” approach to residential

building design and construction

● SMUD Home of the Future● Advanced framing and innovative HVAC, ventilation systems




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www.eceee.org/buildings/MazeGuide2-NetzeroEnergyBldgs.pdf




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● ASHRAE Standard 55-2004“Thermal Environmental Conditions for Human Occupancy”● Specifies conditions in which majority of

occupants in the space will find the space thermally comfortable

● Based on “Predicted Mean Vote (PMV)” and “Predicted Percent of Dissatisfied (PPD)” ● PMV-PPD based on field evaluations and meta-analysis

● Two personal variables: Activity, Clothing● Four environmental variables: Temperature,

Thermal Radiation, Humidity and Air Speed




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● ASHRAE Standard 55-2004● PMV and PPD

● PMV is an index that predicts the mean value of votes of a large group of persons on a 7-point thermal sensation scale

● PPD is an index of percentage of people thermally dissatisfied based on the PMV

● Comfort defined as -0.5<PMV<0.5 and PPD <= 10%

-3 -2 -1 0 1 2 3

Cold CoolSlightly

CoolNeutral

Slightly Warm

Warm Hot




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Methodology

● Energy Modeling● Use new modeling capabilities in development

version of CALRES for 2013 Title 24 code● Current Package D requirements as baseline for

analysis● Parametric analysis to evaluate packages of

measures● Coordinated across other residential CASE topics

● Life Cycle Costing Analysis● Compare measure savings for packages of

measures against costs● Account for cost savings due to absence of

HVAC system



Comfort Simulations

● CALRES 2013 includes hourly comfort model based on ASHRAE Std 55● Software hourly outputs

● Space air temperature

● Mean radiant temperature

● PMV

● PPD

● Custom software inputs – fixed values for all runs● Clothing value

● Metabolic rate

● Air velocity


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Comfort Simulations● CALRES 2013 custom software inputs*

● Clothing value● Range of 0.5 (summer casual wear during day) to 2.0 (winter

night with thick blanket)● 24 hour schedule – winter versus summer

– Vary within range based on clothing value equation developed by Richard De Dear based on field data in ASHRAE comfort database

● Metabolic rate● Resting at night to medium activity during day● 24 hour schedule

● Air velocity● 24 hour schedule – winter versus summer● Summer – fan ON during day● Winter – fan OFF

* Inputs being validated against ASHRAE comfort dataset. Subject to change before final recommendations.


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Comfort Simulations


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‐ 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

"Clo" Va

lue

Climate Zone

Clothing Value Inputs

Winter Min Clo Winter Avg CloWinter Max Clo

‐

0.5

1.0

1.5

2.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

"Clo" Va

lue

Climate Zone

Clothing Value Inputs

Summer Min Clo Summer Avg Clo

Summer Max Clo

Winter and Summer max Clo values for night-time with blankets/sheetsWinter and Summer min Clo values for day-time



Measure Analysis

● Proposed 2013 Envelope Efficiency Measures Modeled● Roof Specs

● R-13 under deck insulation● Cool roof with 0.25 reflectance● Attic insulation per 2008 T24 package D

● Wall Insulation● R-21 cavity insulation with R4 exterior insulation

● Envelope Infiltration● 4.0 ACH50

● Windows● U-factor 0.32 all CZs● SHGC 0.25 all CZs except CZ 1, 3, 5 with SHGC 0.60


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Analysis – 2008 Package D


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60.0 65.0 70.0 75.0 80.0 85.0 90.0 95.0

100.0 105.0 110.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Air Tem

perature (D

eg F)

Climate Zone

Space Air Temperature with Cooling ‐ 2008 Package DWinter Min Tair Winter Avg Tair Winter Max Tair

Summer Min Tair Summer Avg Tair Summer Max Tair



Analysis – 2008 Package D


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60.0 65.0 70.0 75.0 80.0 85.0 90.0 95.0

100.0 105.0 110.0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

Air Tem

perature (D

eg F)

Climate Zone

Space Air Temperature No Cooling ‐ 2008 Package DWinter Min Tair Winter Avg Tair Winter Max Tair

Summer Min Tair Summer Avg Tair Summer Max Tair



Analysis – 2013 Proposed Envelope Measures


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Analysis – 2013 Proposed Envelope Measures


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Comfort – 2008 Package D


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Comfort – 2013 Proposed Envelope Measures


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Comfort – 2008 Package D


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Note: Hours outside comfort zone includes false positives for space being too cold/warm. Needs further investigation



Comfort – 2013 Proposed Envelope Measures


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Note: Hours outside comfort zone includes false positives for space being too cold/warm. Needs further investigation



Strawman - Proposed Code Language● Update Package D (Table 151-C)

● Change Space Cooling Requirement from Minimum Efficiency AC to Not Allowed (NA)

● Sets the budget for Performance Approach● Proposed building can have AC as long as total energy use

matches or less than standard design ● Standard design without AC (zero cooling energy)● Show equal or less number of hours outside comfort zone

compared to standard design


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Climate Zone

1 2 3 4 5 6 7 8

SPACE-COOLING

SEER = MIN NA

MIN NA

MIN NA

MIN NA

MIN NA

MIN NA

MIN NA

MIN



Proposed Code Requirements

● Proposed requirements apply only to new construction

● Need to address issues with addition of AC at a later date in these homes● Proposal - House shows equal energy

performance to package D at time of AC addition

● Needs further stakeholder feedback and analysis


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Next Steps

● Complete energy and comfort analysis● Finalize comfort inputs

● Eliminate false positives for space being too cold/warm

● Re-run analysis with all proposed 2013 envelope measures

● Complete cost-effectiveness analysis

● Develop compliance rule-set for comfort reporting


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ALTERNATIVE HVAC BASELINE


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● Residential HVAC baseline efficiency● Alternate prescriptive package using

● SEER 15/EER 12.2 based on recent negotiations between AHRI/CEC/ACEEE

● Alternative to 2013 prescriptive package D requirements


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AHRI High Efficiency Agreement

● Agreement between ● Air Conditioning, Heating and Refrigeration Institute (AHRI) ● American Council for and Energy-Efficient Economy (ACEEE) ● Alliance to Save Energy (Alliance)● Natural Resources Defense Council (NRDC)● Northeast Energy Efficiency Partnership (NEEP)● Appliance Standards Awareness Project (ASAP)● California Energy Commission (CEC)

● Multi-prong strategy● Amend Energy Policy and Conservation Act● Advocate DOE to adopt proposed requirements into national

standards● Provide path for regional standards to exceed federal

minimum efficiencies


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● Agreement covers:● Energy efficiency standards, test procedures,

metrics and building code provisions for ● Residential central air conditioners, heat pumps, and

weatherized and non-weatherized furnaces

● Agreement also addresses issues involving preemption of building codes and multiple metrics

● Agreement divides country into three regions● North – population weighted Heating Degree Days

(HDD) ≥ 5000● South – population weighted HDD ≤ 5000● Southwest – Arizona, California, Nevada and New

Mexico


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● Allows California to have higher efficiencies than federal standards for new construction and significant upsizing

● Potential adoption by DOE in effect by 2016


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Methodology

● Energy Modeling● Use new modeling capabilities in development version of

CALRES for 2013 Title 24 code

● Compare to 2008 package D requirements

● Compare to proposed 2013 envelope efficiency requirements

● Compare energy savings

● Life Cycle Costing Analysis● System cost data based on market surveys

● Compare measure savings against costs using CEC LCC criteria


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Strawman Energy Analysis

● Proposed 2013 Envelope Efficiency Measures Modeled● Roof Specs

● R-13 under deck insulation● Cool roof with 0.25 reflectance● Attic insulation per 2008 T24 package D

● Wall Insulation● R-21 cavity insulation with R4 exterior insulation

● Envelope Infiltration● 4.0 ACH50

● Windows● U-factor 0.32 all CZs● SHGC 0.25 all CZs except CZ 1, 3, 5 with SHGC 0.60


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Energy Analysis


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Clim

ate Zone

A B C D E

TOTAL kTDV/sf/year2008 Package D 2013 Envelope

Measures2013 Envelope Measures

+ 2% west glass

2008 Package D+ SEER 15 EER 12.2

2013 Envelope Measures

+ SEER 15 EER 12.21 45.2 35.2 35.0 45.2 35.22 55.8 40.1 38.9 53.9 39.33 39.0 30.0 27.8 38.1 29.24 57.0 40.3 38.6 54.2 38.95 37.2 24.3 22.6 37.2 23.96 41.5 28.6 27.3 39.0 27.47 32.7 23.9 22.6 30.8 23.08 52.9 40.6 38.9 48.5 37.79 75.4 56.2 54.3 67.4 50.710 82.2 63.4 61.5 72.5 53.511 124.0 101.6 99.8 107.8 84.112 87.3 72.3 70.1 78.6 62.613 122.3 100.3 98.4 106.6 83.114 112.1 95.3 92.9 98.7 80.015 163.4 144.1 141.4 134.2 110.716 97.3 67.9 66.1 92.1 66.6



Energy Analysis


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Energy AnalysisClim

ate Zone

A‐B (A‐B)/A A‐C (A‐C)/A A‐E (A‐E)/A

TOTAL kTDV/sf/yr and % savings relative to 2008 Package D

2013 Package D 2013 Package D+ 2% west glass

2013 Package D + SEER 15 EER 12.2

1 10.0 22% 10.3 23% 10.0 22%2 15.7 28% 16.9 30% 16.6 30%3 9.0 23% 11.2 29% 9.8 25%4 16.6 29% 18.4 32% 18.1 32%5 12.8 35% 14.6 39% 13.3 36%6 12.9 31% 14.2 34% 14.1 34%7 8.7 27% 10.1 31% 9.6 30%8 12.2 23% 14.0 26% 15.2 29%9 19.2 25% 21.1 28% 24.7 33%10 18.8 23% 20.7 25% 28.7 35%11 22.4 18% 24.2 19% 39.8 32%12 15.0 17% 17.2 20% 24.7 28%13 22.1 18% 23.9 20% 39.3 32%14 16.8 15% 19.3 17% 32.2 29%15 19.3 12% 22.0 13% 52.7 32%16 29.4 30% 31.2 32% 30.7 32%


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Energy Savings


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Example Trade-off between PackagesSEER 15 Package vs. Package with 2% windows on west


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Cost Data Collection

● Interviews with distributors● System sizes from 1.5 to 5 tons

● Representative locations – San Francisco Bay Area, Riverside, San Diego, Sacramento

● System costs on average● SEER 14 - $516* increase over SEER 13

● SEER 15 - $1019* increase over SEER 13* numbers represent the mid to high-end of cost data collected


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Next Steps

● Complete energy analysis of trade-off options with high-efficiency AC package

● Complete LCC analysis of alternate package

● Develop alternate prescriptive package table


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Abhijeet [email protected]

916-213-9150

QUESTIONS & COMMENTS


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Documents

Compressorless Comfort Homes Residential HVAC …h-m-g.com/T24/Res_Topics/2011.05.13Meeting... · Compressorless Comfort Homes Residential HVAC Baseline ... ASHRAE Standard 55-2004