Difference between revisions of "2011 11 11 CFR004"

Latest revision as of 18:03, 31 March 2012

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DRAFT IN PROGRESS - Cx Field Report 004 - 11/11/2011

Cx Activity & General Progress

• Unit Checks (Installation and Start-Up Checks)
  • Check Sheets
  • Start-up Checks
  • Mfg. start-up reports on ERV, booster fan, and Earthroom fan.
  • Heat exchanger appears to be adequate for slowly charging the tanks by the Altherma in heating mode. Raised tank temperature about 1.5 degrees per day when heating not required. Recommend checking heat transfer of exchanger in heating and cooling mode.
  • Check water flows for radiant floor zones. Document for the record.

• Technical Integration Testing (System Verification)
• Back-checking resolved Cx issues
• Sensor & Device Checkouts: The following items or questions still remain:
  • Check zone sensors in final locations. SENSORS REPLACED WITH SPINWAVE SENSORS. CHECKED CALIBRATION OKAY ON 1/27/2012.
  • If Altherma working, set dehumidifcation setpoints for correct range. DEHUMIDIFICATION SET FOR
  • Storage tank cooling low limit is 68F. Should this actually be high limit?
  • Earth room temp setpoints and deadbands corrected? YES; OPTIMIZE USING ALTHERMA EFFICIENCY VS. FAN POWER
  • T-6 domestic hot water temp, pick up in DDC? NO; NOT AVAILABLE.
  • T-7 radiant floor return temp appears out of calibration or not sensing pipe temp well. Approx. 4.8F off.
  • T-8 radiant floor supply temp effective setpoint meaning? PICKS UP SETPOINT WHETHER IT IS IN COOLING OR HEATING MODE. Supply temperature reset? If so, it it based on outside air temp or zone loads? NO; CONSTANT 90F TO GET ENOUGH HEAT THROUGH WOOD FLOORS. MAY NEED TO SET WATER TEMP HIGHER TO GET FLOORS TO 90F.
• 1.1 ERV SVT
  • Final fan readings
  • Building pressurization in each of 3 modes (ERV low/high, Booster F-3 low/high)
  • Safeties (wheel defrost)
  • Fan manual operation
  • Fan alarms (F-1, F-2)
• 1.2 Booster Fan SVT
  • Final fan readings
  • Safeties
  • Fan manual operation
  • Fan alarms (F-3, F-4)
  • Earth Room Fan (F-3)
    • Determine optimal airflow through Earth Tubes for best heat transfer; set speed of Earth Room fan (1/27/2012)
      • Outside air temp: 40.6F TSI Outside air temp by Weather Service: 38.0F
      • Ground temp at Earth Tubes: 55.0F (read in wine cellar (3 walls); Earth Room wall temp: 33.6F
      • Fan Speed: 7 volts Earth Room Temp: 45.7F Earth Tube Air Speed: 298fpm Earth Tube Outlet Air Temp: 38.8F-40.2F Altherma: ON
      • Fan Speed: 6 volts Earth Room Temp: 45.7F Earth Tube Air Speed: 260fpm Earth Tube Outlet Air Temp: 37.0F Altherma: ON
      • Fan Speed: 4.5 volts Earth Room Temp: 45.1F Earth Tube Air Speed: 135fpm Earth Tube Outlet Air Temp: 38.0F Altherma: ON
      • Fan Speed: 6 volts Earth Room Temp: 44.6F Earth Tube Air Speed: 260fpm Earth Tube Outlet Air Temp: 37.0F Altherma: ON
      • Fan Speed: 10 volts Earth Room Temp: 45.0 Earth Tube Air Speed: 450fpm Earth Tube Outlet Air Temp: 36.0F- Altherma: ON
    • Results: Indications are that because the Altherma has been running continuously for a long period time, the near Earth Tube heat has already been extracted from the ground and the outside air during testing was actually being cooled rather than heated.
    • Review temp Earth room with Altherma off vs. temp of air coming through Earth Tubes with Altherma on and determine fan set points
      • Unable to turn Altherma off at this time due to lack of solar production. Consider running Altherma with fan off to see what happens to the room temp.

• System Testing (Functional Performance Testing)
• Fall Shoulder Season mode - charging tanks for heating
• Winter Season mode - charging tanks for heating
• Spring Shoulder Season mode - maintain tanks for heating until April 15, then drift down to cooling mode temps

Cx Issues Update

• Please see linked documents for Cx Issues found.
  • Cx Issues Log (sorted by Status) is a short summary of issues in PDF format for tracking purposes with active items listed first.
  • Cx Issues is the full description of issues in PDF for record purposes.
  • Cx Issues Resolutions is an interactive Google Docs version of the issues with space for the resolution to be recorded along with name and date of responsible party taking care of the issue. Yellow highlights indicate spaces that should be completed as issues are completed or as questions get answered. J. Gallagher coordinating resolutions.

• Additional description of Cx Issues found.
  • Please explain solar panel descriptions on enable/disable setpoints. Especially need to understand enable/disable vs. start/stop. ANSWER: T1B/T2 comparison takes over once the first two conditions are met.
  • Unoccupied mode, Altherma is enabled but Altherma pump P-8 says it is off. ANSWER: THERE IS NO STATUS FOR PUMP P-8 CURRENTLY. WOULD NEED TO BE ADDED THRU DDC.
  • All zones set for 68.5F occupied except annex is 67F. All zones set for 68.5F unoccupied mode. What is reason for difference in annex? ANSWER: ANNEX CANNOT KEEP UP, SO DROPPED SETPOINT TO KEEP FROM TAKING ALL HEAT.
  • Wired stat appears a couple of degrees warmer than wireless. Check calibration and location for external influences. ANSWER: CHECKED CALIBRATION.
  • Zones 2 and 4 running at night. What makes them different? Check history; do they always come on when 1 and 3 don't? ANSWER: ANNEX NEVER SEEMS TO CATCH UP. ZONE 2 HAS MORE EXPOSURE THAN ZONE 3 AND LESS HEATING TUBING THAN ZONE 1. IT APPEARS TO OFTEN LEAD HTG ON AND LAG HTG OFF, DEPENDING ON SUN, WHICH AFFECTS ZONE 1 SIGNIFICANTLY.
  • Altherma trips on low flow. Appears to be related to two conditions:
    • When not in heating mode, V-25 closes and V-5 stays in space heating position. When the pump starts up in this mode, it is dead heading. V-5 does not appear to always switch over to DWH and even when it does, it is sometimes too late before the low flow activates.
    • When in space heating mode, pump P-8 has to pump through the heat exchanger. P-3 also pumps through the heat exchanger, but only as much water as is sent by the position of V-6 modulating. When all of the P-3 flow is going through the heat exchanger while P-8 is also on in that mode, it appears that there is too much pressure drop for P-8 to provide adequate flow. At other modulated positions, P-8 does appear to run successfully, but the range of measured flows does not always stay in the required range for the Altherma. Consider decoupling to reduce low flow trip risk. ANSWER: CHANGED V-25 TO STAY OPEN EXCEPT IN DEHUMID. MODE. LIMITED V-6 TO REDUCE FLOW THRU HEAT EXCHANGER TEMPORARILY TO PREVENT TRIP.
    • For now, V-6 limited to only open about 70% to keep Altherma flow above low flow cutout (about 8 gpm). Need to analyze impact to radiant floor heating since valve V-6 cannot go to 100% to give it heating required.
    • What happens to heat exchanger efficiency now that we have increased the flow on the radiant floor loop side by adding P-8 Altherma flow going through the heat exchanger as well as radiant floor loop from P-3?

Next Steps

• Plan for mixing return air upstream of dehumidification coil in freezing weather to protect the coil (Open D-2 to mix return air with ERV air upstream of coil when temperature upstream of dehumid. coil is below 35F; make sure booster fan is higher airflow than ERV at that point also).
• Solar panel storage tank bypass unwanted flow (Add manual shutoff valve in bypass).
• Revise secondary solar panel control to look at solar panel water in-out temperature differential to decide if stays running.
• Tank temperature sensor inadequate with stratification in tank above 110 deg F. Replace with in-tank sensor.
• Filter Considerations
  • Pre-filter (1") Koch info MERV 8, initial PD 0.26"; final PD 1.0"
  • Consider adding magnehelic gauge to determine when to change filters (add only on OA filter and change both at that time; take independent reading on return air filter periodically).
  • Consider eliminating 5" filter in return duct above tank town (redundant; unnecessary pressure drop/energy usage).
• Plan for control of energy recovery wheel (frost control, economizer conditions).
  • Turn wheel off when outside air temp is between 50F (adj.) and 70F (adj.).
  • Turn wheel off below 5F (adj.) outside air for frost protection.
  • Have the ability to override the wheel on and off from the DDC.
• During tank switchover, determine controls for running Altherma to loop directly (without tank storage part of sequence) for heating in the late Spring and early Fall; no cooling anticipated or provided during tank heating Spring and Fall, just let building drift and use natural ventilation if space temp exceeds acceptable range.

Look Ahead

• Prioritize basic cooling testing before weather too cold.
• Need to understand plan for system/equipment alarms - priority, where alarm routed to, what action is required when alarm received (messaging).
• Schedule submission of O&Ms manuals for review - completeness, specific to project.
• Substantial completion and warranty start date - coordinate with warranty review session scheduling.