WaterFurnace Envision Dehumidification Settings

Discussion in 'General Discussions' started by Hunter, Jun 14, 2010.

  1. Hunter

    Hunter New Member

    I have Envision dip switch set to dehumidify yet it doesn't seem to help. Are there other settings that need changed besides SW2-4 looking at the switch 2-4 is to the left. no water comes out the drain line. Yet my portable dehumidifier runs constant with water pouring outs its drain. I have an digital Accurite temp/humidity gage ant stays about 74% which indicates high. I would like to turn off the portable as its old and noisy!
     
  2. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader

    Cooling

    Cooling is what dehumidifies. The switch just sets blower speed to 85%. This aids in dehumidification but the unit still needs to be cooling.
     
  3. Michael

    Michael New Member

    All that dip switch does is set the fan speed one setting lower in cooling. For example if you have your unit in First Stage Cooling in normal operation the WaterFurnace runs in Medium Speed. With a Second stage call the WaterFurnace runs high speed fan.

    With dehumidification turned on the fan speed stays in LOW with a First Stage call and Medium Speed with a Second stage call in cooling.
     
  4. WF_Inc

    WF_Inc Member

    Hunter,

    Urthboy is correct. The fan speed will be reduced by 15% when set to dehumidification mode. This should assist in removing moisture from the air when in cooling. Humidity comes from three places; cooking, showering, and outside. It is not likely that the humidity you are experiencing is coming from cooking or showering. In an effort to maintain the desired humidity level, we would suggest locating the place of infiltration, and taking preventative measures to keep the humidity out.
     
  5. geome

    geome Member Forum Leader

    Hunter, is the unit not even dripping a little bit when cooling? Is the system cooling your house?
     
  6. Michael

    Michael New Member

    credit where its due. turns out WaterFurnace made a change on the E-Series and on that changed from what I said to the new 15% rule. Your post is 100% right.
     
  7. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    There are a few more sources of indoor humidity than...

    ...just cooking, showering, and "outside" (more accurately known as "infiltration")

    Other significant sources include house plants and human respiration

    Unwanted humidity is sometimes called "latent load" To make an airconditioner of any description - geo, central air, heat pump, or even a window unit deal better with humidity requires reducing the airflow across its evaporator coil. Setting the Envision's dehumidify dipswitch does in fact reduce airflow by 15% resulting in a typical system's sensible heat ratio shifting toward latent load by 5% or so.

    A portable dehumidifier won't make much water if relative humidity is 50% or less. 74% RH is way high and leads to all manner of problems.

    I find it very hard to believe that a WF Envision configured to dehumidify results in RH much above 50 unless the system is way way oversized or the home includes a waterfall, indoor pool, or a gazillion house plants.

    In an odd coincidence I just deselected my Envision Intellizone dehumidification dip switch in an effort to increase overall efficiency. Relative humidity rose from the lower to upper 40s as a result of that change, but the system is better able to handle outdoor temps in the upper 90s while staying in low stage.

    I'd really like to see the next generation of Intellizone firmware able to dynamically deal with dehumidification calls from individual thermostats by dynamically reducing CFM per ton during such calls. Having to flip a dip switch is 'so 1990s'
     
  8. geome

    geome Member Forum Leader

    DIP switch -

    I believe the blower speed in heating mode will remain at 100% even though the blower speed in cooling mode will be at 85% with the dehumidification DIP swithch engaged. This is convenient for people that like this setting since they don't have to flip the switch in heating mode to restore 100% blower speed.

    I would turn off the system circuit breakers before changing any DIP switch settings.
     
  9. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    That's correct

    dehu switch cuts airflow in cooling only
     
  10. Hunter

    Hunter New Member

    Thanks everyone!

    Now I am very concerned. I have my temp set to 70 degrees year round. It cools fine but my humidity remains high around 70% when I set my digital gage on the register the humidity actually rises to 100% during cycles. Its like the condensation on the coils doesn't fall down to drain pan, rather it re-evaporates. Could my fan still be too fast?
     
  11. WF_Inc

    WF_Inc Member

    Hunter,

    Have you measured the humidity at all registers, and if so, are they all the same? What is the relative humidity in the center of the room? Have you discussed this with your contractor, and have they made any suggestions? The answers to these questions may assist in facilitating a resolution.
     
  12. geome

    geome Member Forum Leader

    Need information to go on...

    Clogged drain line?
    What is the fan speed setting?
    Do you run the fan constantly (on vs automatic)?
    How long have you had the system for?
    Is it the unit grossly oversized? What size is the system, and what was the load calc?
     
  13. Hunter

    Hunter New Member

    Yes I have had my contractor who installed the system out to look.The tech wasn't much help.He said my digital gage I am using does not measure RH and is not a valid measurment tool.
    This all started after reading the manual and the "dehumid mode" option. The system does not operate as described in the book. The book says the system more or less runs normally with normal speeds but and the end of each cycle one room temp is met the fan slows to create condensation for a few minutes then compressor shuts off. In reality, it does not do this. Per reading the threads the fan stays at 85% all the time in dehumid mode. So, which is it, the book way or thread way? Is there a firmware update that will help?
     
  14. WF_Inc

    WF_Inc Member

    Hunter,

    Please provide your model number, serial number, and the name of your installing contractor so that we may look into your inquiry further.
     
  15. Hunter

    Hunter New Member

    The install contractor is Mark's Heating and Air, Decatur Indiana. I will get the other info when I get hjome after work. Thanks!
     
  16. geome

    geome Member Forum Leader

    Can you tell us what book you are looking at (page number and section would be great).
     
  17. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    constant fan is a big no-no for dehu

    Getting rid of constant fan dropped my RH 10%. Very high efficiency units have massive evaporators which capture lots of water between fins while operating. Constant fan causes much of this water to re-evaporate into the air before it gets a chance to drip into condensate tray.

    I was very frustrated with 55+% RH and was seriously considering adding a central whole house dehu before I figured this out.

    It is OK, indeed desirable for the blower to stay on a minute or so after compressor stops during each cycle. This wrings a bit more cool air out of the system before refrigerant and evaporator warm back up.

    A minute or two after the compressor quits, the blower should stop as well.

    The foregoing is not germane to winter operation, so if constant fan helps even out temps and keep air fresher in closed bedrooms all night, feel free to use it in winter.

    All that said, I think it would take a combination of low sensible load, grossly oversized unit, constant fan operation to raise RH to 70%.

    As for a condensate line clog that would either: 1)Stop the unit if it has a float switch on the tray or 2)create a big visible leak before it alone raised RH to 70%
     
  18. westsider

    westsider New Member

    I have an Envision also and in the winter, I keep my fan on all the time. However, when the AC starts running, I have to set the fan to only run when the unit is running. otherwise, the dehumidification does not work as well. This year, I forgot to change the fan to auto with unit and when the cooling started, I was only able to get my humidity level down to 62%. When I set the fan to auto - not running all the time - the humidity is now at 46%.
    Im not sure if this is what youve got happening, but I thought I would mention it. someone here could probably explain why that is. Im assuming that the constant air flow across the radiator was cooling the liquid down when the unit was sitting idle.
     
  19. geome

    geome Member Forum Leader

    I was -

    just doing some maintenance items around the house and had our all in one unit open. Although the unit was off, the coil and drain pan was wet. I believe engineer said that with the blower running, the water that did not drain off re-evaporates and is circulated throughout the house with the blower running. Not sure if humid basement air (if the unit is in the basement) could also add to this situation since units are not air tight?
     
  20. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Geome's got it.

    Envisions, especially package units, have humongous evaporators, and they trap lots of water. It takes awhile for the water to work its way down into the drain pan, and it is subject to re-evaporation if blower runs constantly.

    Humid basement air could play a role. Units are indeed not completely airtight.

    If the water makes it to the pan it should drain out the condensate line, though there is nearly always some in pan during cooling season. Constant blower will eventually pick that water back up as well, but that would take hours or days, not minutes.

    Westsider's experience matches mine.
     

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