WaterFurnace Envision Dehumidification Settings

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

  1. mokanman

    mokanman New Member

    Where are these humidity settings made?

    This is my first summer with my Envision system and I'm not happy with the humidity levels that my Honeywell thermostat shows. After reading this thread I have now changed the fan setting from ON to AUTO (a little more than an hour ago) so I'll see how much that helps. How many days should that take to level out?

    We have been freezing at night as the system keeps running down to about 3 to 5 degrees below where it is set (78F). I'm assuming it is because the humidity levels are still high (up to mid 60% in the day and in the mid 50% at night - it is set to 45%) and the system is trying to get it down to our setting. In the daytime we can feel the high humidity levels but at night we just freeze.

    Anyway, Hunter said that he had his dip switch set for dehumidify. I've looked at several of the PDF's and the closest I can find is IM1585 which shows DIP settings for various models as well as a table for Operation Logic Data which references ECM2 Dehumidify. I think I'm close here but could use some help in obtaining the correct understanding on first, how to determine what setting my system is currently at, and second (if necessary) what DIP setting I need to reduce my fan speed to 85%.

    One more question on this subject. Several posts mentioned that the 85% setting only occurs during cooling and not during heating. Can anyone reference some documentation that verifies that?

    By the way, my system was installed in November, replacing an air source heat pump. I was very pleased with operation and kwh usage this last winter (based on outside monthly average mean temperatures as compared to previous years). Several of the bidding contractors told me that the first year is not as good as subsequent years because the complete cycle of storing heat in the ground takes at least a year. If that's true (and we can resolve this summer humidity issue) then I'm a happy camper!
  2. Looby

    Looby Member Forum Leader

  3. Bergy

    Bergy Member Industry Professional Forum Leader

    Be careful of warranty issues. You need to have your installing contractor adjust the dip switch settings.

  4. geome

    geome Member Forum Leader


    If you are interested in changing the number of degrees your Honeywell thermostat will over-cool, (and if you don't already know how to adjust it) let us know the model number.

    It may also help to keep the system in 1st stage longer and to reduce the cycles per hour on the thermostat. Again, the thermostat model number is needed. We did some tweaking and are very happy with the results.
  5. mokanman

    mokanman New Member

    Looby - Thanks for the links. Good stuff!

    Bergy - Point taken. Can I look to see what they are set at or is there some kind of seal that "if broken" voids the warranty? If I can look and find that it's set for dehumidify then there is no need for a visit from the installer for that.

    geome - I have a Honeywell VisionPRO® IAQ thermostat and equipment interface module. I have the installation guides for each as well as the thermostat operating manual (all in PDF as well as printed copies) if you can point out the information in any of those.
  6. geome

    geome Member Forum Leader

    I agree with Bergy that you should involve your installer with all of this.

    IF the installer tells you that it is ok for you to adjust the DIP switch, then make sure ALL power is off to the units before beginning.

    I'm looking at the VisionPro IAQ (thermostat) Installation Guide. See page 2 to get into installer setup. These are some settings that we have adjusted on our Honeywell Prestige. You may or may not like the results. Record the original settings so you can go back to them later if you want. I would make no more than 1 change every few days to see if you like the results. If you change everything at once, you won't know what change did what. :)

    173 - Air to air or geothermal heat pump: Where is yours set? I haven't seen this before, but heard Honeywell was coming out with it. This may make other setup options available, but not positive.

    220 & 230 - Cycle rate: Set as low as possible consistent with your comfort. We have ours set to 1. Lower cycle rates may increase overall temperature swing. Ours holds +/- 1f around the set point. Benefits can include better dehumidification (in cooling mode) and better unit and DSH efficiency (all due to longer run times), and possible longer unit life due to less start and stop cycles.

    383 - (Dehumidification ) Over-cooling limit: 1f, 2f, or 3f.

    Have to run. I'll check the manual again later.

    Edit - That's all I see right now that may help with dehumidification. Your thermostat has a lot of customizable options. It's worth looking at the setup instructions and discussing any changes you are thinking of making with your installer and asking here. Before you change anything, you may want to wait several days to see how not running your fan constantly may help with your indoor humidity.

    Does your system bring in outside air at all (ERV/HRV)?
    Last edited: Jul 17, 2010
  7. WF_Inc

    WF_Inc Member


    Unfortunately, we are unable to provide technical support to homeowner’s for liability reasons. We would suggest contacting your contractor to discuss your concerns. If they are unable to provide you with a resolution, please have them contact our technical support staff, as we will be more than happy to offer our assistance.
  8. Jamie

    Jamie New Member

    Sounds like infiltration is defiantly the problem. Do you have an attic exhaust fan? An oversized attic fan can make the whole house negative pressure pulling in outside air and moisture from any air leak. If you have a fan turn it to 120 to make sure it is not running too often. I'm not sure where you are but in my market I try to shoot for below 50% humidity. I would also suggest a blower door test to look for infiltration. Look fora BPI auditor to determine where your problems are. It sounds like the equipment is doing it's job to me.
    Good luck
  9. Skmad

    Skmad New Member


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