Unformatted text preview:

SCC systems analysisSCC systems analysisJohn Basbagill, Sarah Russell-Smith, Cris WiseCEE 243June 2, 2010June 2, 2010Big IdeasFunctional intents are based on set points given in SCC Facility Data Manual. When data does not match functional intent, consultation with building manager is needed to determine whether functionalwith building manager is needed to determine whether functional intent values are correct.Air handlers maintain space air temperatures with minimal fl t tifluctuations.For AH42, 52, 62, 72, 82 & 92, space air temperatures are consistently lower than functional intent:consistently lower than functional intent:-verify 74±2°F set point for AH42-82-verify 75±2°F set point for AH92-determine whether cooling coil is functioning as intendedUnexpected positive correlations exist between space air temperatures and OAT.2Basbagill, Russell-Smith, WiseLegends Used on GraphsFunctional Status LegendNeeds immediate attention; little consistency with functional intent; major issue(s)System working but a few issues to be addressed; some consistency with yg ; yfunctional intent; moderate issue(s)System is performing as intended; much consistency with functional intent; no/very minor issue(s)Annotations Used in GraphsFunctional Intent Green line(s) indicate functional intent.Inconsistent Red highlights anomalies or patterns inconsistent with functional intent.Consistent Black highlights patterns consistent with functional intent.3Basbagill, Russell-Smith, WiseSystems SummarySystemFunctional StatusArea Served Major Problem(s)AH01BasementSpace air temperatures 2-4°F below Manual set AH01BasementpointAH02 BasementSpace air temperatures 2-4°F below Manual set pointAH42 4thfloor day room & multi-purpose room Space air temperatures 4°F below Manual set pointAH525thfloor day room & multi-purpose room Space air temperatures 2-4°F below Manual set pointAH626thfloor day room & multi-purpose room Space air temperatures 3-5°F below Manual set point.thAH727thfloor day room & multi-purpose room High fluctuation in space air temperature. Damper valve closes.AH828thfloor day room & multi-purpose roomSpace air temperatures 2°F below Manual set point. Heating/cooling coil valve position always 50%.AH929thfloor day room & multi-purpose roomSpace air temperatures 2-3°F below Manual set point. Mixed air and supply air positively correlate with OAT for colder temperatures.Small ChilledSupply water temperature 35°F belowManualsetSmall Chilled Water LoopGround floor server roomSupply water temperature 3-5F below Manual set point.4Basbagill, Russell-Smith, WiseAir Temperature (44)AH42Air Temperature (44)AH42POD A/B/CDay RoomAH42POD A/B/CDay RoomPOD A/B/CDay RoomAH42POD A/B/CMulti PurposeValve Position (47)POD A/B/CMulti PurposePOD A/B/CMulti PurposeValve Position (47)Air Temperature (46)()On/Off Status(272)Mixed Air Temperature (45)Supply Air Temperature (245)Air Temperature (46)()On/Off Status(272)Mixed Air Temperature (45)Supply Air Temperature (245)EconomizerCooling CoilSupply Fan Return FanEconomizerEconomizerCooling CoilSupply Fan Return FanCombined Valve Position (43)Outside AirDamper Position (244)Return FanOn/Off Status (246)Supply Air Temperature (243)Cooling CoilHeating CoilCombined Valve Position (43)Outside AirDamper Position (244)Return FanOn/Off Status (246)Supply Air Temperature (243)Cooling CoilHeating Coil5Basbagill, Russell-Smith, WiseSummary of the AH42 SystemFunctional StatusFunctional Intent Day room and multi-purpose rooms are maintained at 74±2°F.Patterns Consistent w/ Functional IntentDay room and multipurpose room temperatures stayPatterns Consistent w/ Functional IntentDay room and multi-purpose room temperatures stay fairly constant.Patterns Inconsistent w/ Functional Intent 1. Day room ranges from 69-73°F and averages72°F. Multi-purpose room ranges from 65-78°and averages 71°Fand averages 71F. 2. Supply air temperature is too cold and range is toolarge.Testable Hypothesis 1. Multi-purpose room space temperature is set 4 yppp p pdegrees below manual set point. 2. Cooling coil valve position causes supply air temperature to be too cold.Conclusions/Recommendations Space temperature does not align with Manualset point. Supply temperature and cooling coil position work together as expected. Cooling coil is open too much in cold weather. Determine whether cooling coil is malfunctioning Determine whether actual set pointBasbagill, Russell-Smith, Wise6is malfunctioning. Determine whether actual set point is correct or if manual gives correct set point. Rewrite manual set point if incorrect.AH42AH42DR S AiT OATMltiPRSAiT OATSpace temperature stays fairly constantAH42-Day Room SpaceAirTemperature (44) [Deg F] AH42-Multi-Purpose Room SpaceAirTemperature (46) [Deg F]Day Room Space Air Temp. vs. OATMulti-Purpose Room Space Air Temp. vs. OATDay room temperature slightly bl d db dpp yyMulti-purpose room temperature positively correlates with OATbelow deadbandpositively correlates with OATMulti purpose room temperature below deadband.7Basbagill, Russell-Smith, WiseAH42Day Room & Multi-Purpose Room Space Air Temp. vs. TimeAH42 D R S Ai T t (44) [D F]Both space air temperatures suddenly decrease by 2° in late September; change in set point?AH42 Day Room SpaceAirTemperature (44) [Deg F]AH42 Multi-Purpose Room SpaceAirTemperature (46) [Deg F]Mltiit t it tll(from 2/1/2009 12:00:00 AM to 12/31/2009 11:59:00 PM)Multi-purpose room air temperature consistently lower than functional intent and day room air temperature8Basbagill, Russell-Smith, WiseYes! TAH42Multi-Purpose Room Supply Air TempAH42Multi-Purpose Room Supply Air TempMulti-Purpose Room Supply Air Temp., Cooling Coil Valve Position vs. TimeMulti-Purpose Room Supply Air Temp., Cooling Coil Valve Position vs. OATConstant value agreeswith Building EQ pattern…but no data in warm weatherCooling coil and supply air temperature work together as expected(11/212009 from 7:15 PM to 8:15 PM)Cooling coil valve position open during cold weatherCooling coil valve position positively correlates with OAT9Basbagill, Russell-Smith, Wisegpositively correlates with OATAir Temperature (64)AH52POD A/B/CDay RoomPOD A/B/CDay RoomAH52POD A/B/CMulti PurposePOD A/B/CMulti PurposeAir Temperature (66)Valve Position (67)On/Off Status(260)EconomizerEconomizerMixed Air Temperature (65)Cooling CoilOutside AirCooling CoilHeating CoilSupply Fan Return FanReturn FanOn/Off Status (262)Combined Valve Position (63)Damper Position (261)Status


View Full Document

Stanford CEE 243 - SCC systems analysis

Download SCC systems analysis
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view SCC systems analysis and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view SCC systems analysis 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?