Poor Installations Undermine the Benefits of High Efficiency HVAC Equipment

Transcription

1 Poor Installations Undermine the Benefits of High Efficiency HVAC Equipment Glenn C. Hourahan, P.E. Sr. Vice President Air Conditioning Contractors of America Baltimore, MD ACEEE 2014 National Symposium on Market Transformation 1 April 2014 Session A4

2 Topical Areas Energy losses associated with poor QI ( and, by extension, to QM) Resources in support of QI Fault diagnostics & detection thoughts

3 Generally Accepted Wisdom Impact of Improper QI / QM 30% is lost out of the Box!! Commonly-noted field problems Refrigerant charge Incorrect airflow over the coil Equipment size Duct sizing (airside) Duct Leakage Out-of-Tolerance Up to 30% off of OEM design Up to 50% off of design Routinely, % too big Routinely, ½ the requirements Up to 50% of airflow

4 Generally Accepted Wisdom Impact of Improper QI / QM

5 IEA Annex 36 QI / QM Sensitivity Studies Avoiding Efficiency Degradation due to Poor Installations and Maintenance International collaboration based on QI and QM Quantify impacts on system performance (e.g., capacity, energy utilization, etc.) related to varying QI and QM practices / attributes for varied equipment applications. IEA Participants: France (EdF) Sweden (KTH, SP, SVEP) United Kingdom (DECC) US (ACCA, NIST, ORNL) ACCA / NIST / ORNL are co-operating Agents 3 year effort: Oct 2010 Nov 2013 Final report available by Aug 2014

6 IECC Climate Zone Map Zone Climate Location Slab-on-grade house House with basement 2 Hot and humid Houston, TX Yes No 3 Hot and dry Las Vegas, NV Yes Yes climate 4 Mixed climate Washington, Yes Yes DC 5 Heating Chicago, IL Yes Yes dominated 6 Heating dominated Minneapolis, MN Yes Yes

7 Examples: Single-Fault Effects Duct leakage The most influential fault on performance Impact: 10-30% energy penalty Refrigerant charge The 2 nd most influential fault 30% undercharge: 20% energy penalty 30 % overcharge: 10 to 15% energy penalty 10% undercharge: 2 to 3% energy penalty. Undersized cooling TXV most pronounced in localities with a high number of cooling mode operating hours 14 % more energy used in Houston (40 % undersize) 3 % energy penalty in Chicago. Non-condensables / improper voltage / equipment size Energy penalty is under 4% (for the studied ranges). [Obviously, these faults have a substantial impact on 1 st cost, equipment durability, and degraded moisture control capability.]

8 Examples: Double-Fault Effects Multi-fault Set: 3 (Houston) 15% Undercharge 5% 30% Undercharge 21% Multi-fault Set: 10 (Houston) 15% Undercharge 5% 30% Undercharge 21% 20% Duct Leakage 40% Duct Leakage 9% 28% 15% 36% 32% 56% - 15% Airflow - 36% Airflow 4% 12% 7% 11% 23% 27%

9 Obviously, without an emphasis on ensuring quality installations (QI) HVAC Systems do not properly perform and You Don t Get What you Paid For!!

10 Design Manuals Resources QI / QM Standards

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12 ACCA 5 QI / ACCA 9 QIvp / ACCA 12 QH Basis for QA Contractor Accreditations New Homes Started in accredited contractors nationwide Residential Service and Installation Started in (and growing) contractors nationwide Home Performance Coming late-2014

13 EPA EnergyStar TM Programs New Homes EnergyStar Certified New Homes (v3; eff. Jan2012) Aligned with ACCA s QA New Homes Program Existing Homes EnergyStar Quality Installation (ESQI) Energy Star Verified HVAC Installation (ESVI; 2014) Aligned with ACCA s RSI Program + + =

14 Can FD&D Reduce the Costs for Efficiency Programs Implementing QI? Relative Costs ($) Instrumentation costs (FD&D) Labor Costs (verifiers) Timeframe (years)

15 Opportunities & Challenges for Fault Detection and Diagnostics (Automating the QI Elements Cx and Re-Cx) Easy Temperature / humidity Voltage / amps Airflow thru evaporator Equip. ESP / duct SP More Challenging Duct leakage Room airflow balance On-rate (combustion) Refrigerant charge/comp. Quite Difficult Equipment sizing / selection to load calculations Ventilation CFMs to design requirements Systems controls are correct and properly set-up Fossil-fuel venting is to code Owner aspects: education and documentation

16 Discussion to Follow