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Farias Early Childhood Center
Farias Early Childhood Center

Showcase Project: Farias Early Childhood Center Retrocommissioning

Sector Type

Education

Location

Houston, Texas

Project Size

40,150 Square Feet

Financial Overview

Project Cost $21,800

Annual Energy Use

(Source EUI)
Baseline (2015)
578 kBtu/sq.ft.
Expected (2017)
243 kBtu/sq.ft.
Actual (2017)
Coming in 2017

Energy Savings:

58%

Annual Energy Cost

Baseline (2015)
$145,000
Expected (2017)
$57,000
Actual (2017)
Coming in 2017

Cost Savings:

$88,000
Background

Farias Early Childhood Center (FECC) is one of the 238 schools that are part of the Houston Independent School District (HISD). In 2015, the district developed an Energy Master Plan to implement retrocommissioning across 20 targeted campuses. FECC was identified as having the highest energy use index amongst school buildings based on energy consumption, square footage and occupancy.

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FECC is a dual-language facility serving over 430 children in pre-kindergarten.  The building was constructed in 2005 using several energy efficient design elements including corridor skylights, energy efficient windows, and VAV HVAC systems. However, in recent years, this facility realized atypical electrical loads attributed to a fault in the direct digital control (DDC) programming and skill deficiencies of the maintenance staff. The DDC programming allowed for the building to operate on a 24/7 schedule.

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Solutions

Energy efficiency measures included adjustments to set points and building system controls, repair to damaged sensors, de-lamping and cleaning of equipment. Implementation began in October of 2015 and is expected to result in an annual energy savings of 58% and $88,000 at the project’s conclusion.

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Below is a list of energy efficiency measures implemented at FECC including the cost per measure and savings achieved:

 

Savings Measure

Project

Cost

Cost Savings Achieved

Notes

Reduce air handling unit (AHU) run time

$3,040

$32,000

  • Repaired conflicts causing systems to run continuously 
  • Adjusted night setback points to eliminate night-time operation

Space temperature set point control

$0

$12,000

  • Adjusted space temperature heating (HSP) and cooling set points (CSP) so that CSP – HSP > 4 degrees Fahrenheit (F)
  • Repaired damaged space temperature sensors

Variable air volume (VAV) box minimum air flow set point

$0

$8,000

  • Reduce minimum airflow set point from 40% of max to 10% of max to reduce reheat in unoccupied classrooms

VAV AHU air flow control

$500

$8,000

  • Repaired two AHU variable fan drive’s (VFD) running at full speed
  • Repaired one static pressure sensor controlling the VFD speed for one AHU

Chilled water coil discharge air temperature control

$0

$2,400

  • Established chilled water coil discharge air temperature set points at design value
  • Repaired one damaged CHW valve

Preheat coil discharge air temperature control

$0

$2,400

  • Reduced preheat discharge air temperature set points from 55 to 40 degrees F (previously at or above chilled water coil discharge air temperature set points)

Reduce central plant equipment run time

$4,505

$2,400

  • Repaired start/stop relay controlling the chiller operation
  • Replaced failed chilled water pump starter with new VFD

Open throttled isolation valves

$0

$2,400

  • Opened new chilled water pump VFD chiller isolation valves to 100%
  • Reduced VFD speed to provide design chiller flow with final max speed set to 50Hz.

Reduce domestic hot water set point

$0

$2,400

  • Reduced electric water heater set point from 130 degrees F to 120 degrees F in the building automation system (BAS)

De-lamp corridor lighting fixtures

$871

$2,400

  • Reduced over-lit corridors by removing one lamp per light fixture

Central Plant Maintenance

EST. $500

$2,400

  • Verified chiller flow switch
  • Cleaned condenser coils
  • Replaced chilled water supply and return sensors

Perform air-side equipment maintenance

EST. $500

$3,200

  • Verified valve and fan operations
  • Replaced bad temperature sensors and fuses
  • Modified set points to eliminate unnecessary reheat

 

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Other Benefits

In addition to the energy savings above, the measures are expected to increase overall building comfort, therefore improving the learning environment for the kids and the teachers by eliminating over-cooling of classrooms.  The reduced equipment run times will also improve system reliability and increase equipment life, as well as reduce maintenance cost over the life of the building.

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The district benchmarks Farias using the EPA’s ENERGY STAR® Portfolio Manager tool and expects these savings to result in an improved ENERGY STAR Portfolio Manager score with the potential for certification in the future. In addition, HISD plans to reinvest cost savings achieved district-wide to fund additional efficiency measures and academic support needs.

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