HVAC 2.0 Diaries

From Green Garage Detroit
Revision as of 20:48, 26 September 2011 by Joeg (Talk | contribs) (→‎Sept 26 2011)

Jump to: navigation, search

Sept 26 2011

  • Heavy rains in AM. Broken clouds later, did get some heating.
  • Noticed zone 3 heat running at 4:30. Changed temperature setting and setback t, did not shut off loop. Changed space heat calendar to Oct, pump 2 and 3 went off, pump 6 continues to run. Noticed while 2 and 3 were running, valve 6 did not modulate to get loop temp to 90°.



Sept 25 2011

2011-09-26 0145 Zone stats temp dropping out.png
2011-09-26 0137 Zone FPT Z2 Unocc Htg.png
2011-09-26 0223 OAT RH Last 7 days B'ham.png
  • Mainly cloudy...small amounts of sun.
  • P5 on at 1:00, there should be no call. P2 and P3 also on, set to 'emergency auto' and they went off. P5 did not. ***[LLC COMMENT] Zone stat temps dropped out to zero degrees a few times, so it appears that pumps came on because they thought the zones required heat when the zone temps went below the unoccupied heating setpoint. Problem appears to be with stat signal, and pump logic for unoccupied heating mode appears to be correct. See images at right.
  • Tanks @ 92.8F
  • Why is the humidity in the building so steady. It's been in the low 60'sRH for some time even though the humidity outdoors has been very high...tonight it's 71RH. It's been 91RH last week. ***[LLC COMMENT] Wondering what you were thinking it should be? Looking at 7-day history, RH fluctuated between 55% and 65% per stats. Three weeks ago, it was 50%, but the indoor temp was also 75F then, and now is around 69F-70F, so about the same moisture content. OA RH doesn't mean too much without also knowing what the temperature is since it is so relative. See history from Birmingham for OA temp/RH to get feel for that magnitude over the last week. Building materials absorb/give up moisture as content in air changes also. So if temp pretty steady, then RH likely to also be steady unless introduce big load in space. Seasonal moisture content change is pretty slow.
  • Annex continues to be 1F higher than the historic building. Assume it is the tanks losing heat.
  • Earth room exhaust fan status point needs to be added to history trending.



Sept 24 2011

  • P9 was not coming on as scheduled...programmed. Determined to be the "mode" it was running in. Joe set it to "emergency auto" to get it running. Need instruction on how to set these parameters on the "Piping Diagram" when logged in as the "Admin".


Sept 23 2011

  • Solar Thermal Collectors (@ 6:34am) RAIN
    • P9 off
    • Array Out = 72F
    • Air Core = 49F
    • Tank 1 = 93.4F
    • BTU Production
      • Daily (Yesterday)
        • Partially Sunny day: 2.4F tank rise * 4800gal * 8.33lbs/gal / 400 sf = 240 BTU/sf/day
  • Ventilation
    • Mode was correct: Unoccupied
    • Booster fan and ERV all OFF
    • Dehumidification Setpoint raised to 70%...to avoid it coming on with doors opening during construction
  • Earth Room
    • 67.1F
  • Altherma
    • Off
  • Zones
    • Annex is slightly high 70.9F vs. 70.1F than the historic zones: reason believed to be heat from tank room.
  • Follow-up Points
    • Need to get trickle loop logic for solar panels defined and working for the cases where the panels are not hot enough for the tanks but could heat the ground.
    • Need blanket for hot water tank.


Sept 22 2011

  • Solar Thermal Collectors (@ 6:20am)
    • P9 went off last night
    • Array Out = 73F
    • Tank 1 = 91F (Passed 90F!!!)
    • BTU Production
      • Weekly
        • This is 880,000 BTU's in a week.
        • This is 314 BTU/sf/day...which is on the low side.
      • Daily (Yesterday)
        • Partially Sunny day: 7F tank rise * 4800gal * 8.33lbs/gal / 400 sf = 700 BTU/sf/day <<== planned 750BTU/sf/day
    • Air Core = 49F
  • Ventilation
    • Booster fan was on all night- this is in mode 7 which calls for dehumidification
    • ERV was off last night
    • Altherma shows On? Trying to dehumidify. unit was off do to low water pressure.
    • 10:43 AM solar panels start- air temp-58, panel air temp 120, tank temp 90.9


Sept 21 2011

2011-09-26 0330 Solar Tanks FPT Fall Htg Up.png
  • Solar (Lunar) Thermal Collectors
    • Ran all night!! ***[LLC COMMENT]Check array inlet/outlet temp sensors when under load. Check array bypass line short circuiting. Check logic that starts pump to see relationship between core temp, array inlet, and array outlet temp and how they were programmed to start/stop array.
    • Tank 1 = 84F (about 85F from graph)
    • Array Out = 88F? (about 93F from graph)
  • Ventilation
    • Dehumidification was on most of the day
      • It produced water in the drain line!!
      • Graphing Indoor RH showed it was slowly going down.
      • Some risk if this can't keep up with very high humidity (91%RH today!)
  • Earth Room
    • Looks like Earth room hits 90F within 30 minutes of running
    • Issue with the exhaust fan turning on and off rapidly because it turns on at 90F and turns off at 89F. ***[LLC COMMENT]Spread out the dead band on heating and cooling end of exhaust fan operation. Also need to match exhaust volume with Earth tube design so incoming air is cooled/heated by ground as designed. Volume may be too high.
    • Not providing value because outdoor temp is 70F and earth room gets to 90F within 30 minutes.
    • Opportunity to do some "thermal pumping" in the shoulder seasons...heating 30 mins, cooling (dehumid) 30 mins, cycles.
Retrieved from "http://wiki.greengaragedetroit.com/index.php?title=HVAC_2.0_Diaries&oldid=14457"