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  1. #1
    Join Date
    Dec 2004
    Location
    New Jersey / New York
    Posts
    10
    We recently installed an XL16i system with variable speed ahu and all new ductwork.The condenser has a two stage compressor. We did a manual J. and wired it to manufactuers specs. The humidity levels in the home are between 60 and 70% ! The tstat is in the auto mode. We noticed that there is more water left on the coil after the tstat is satisfied than we would like. Why is there residual water left and is that the problem? The ahu is pitched correctly.

    Please help

  2. #2
    Join Date
    Aug 2004
    Location
    MO
    Posts
    62
    What cfm is a/h set to? Do you have enhanced mode set?

    I have a 16i and 4TEE3F37A, cfm set to 350, with enhanced mode. I leave fan switched to "ON", and humidity stays below 53 percent.

  3. #3
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,390

    Lightbulb %R.H.

    Originally posted by iyaayas
    What cfm is a/h set to? Do you have enhanced mode set?

    I have a 16i and 4TEE3F37A, cfm set to 350, with enhanced mode. I leave fan switched to "ON", and humidity stays below 53 percent.
    WHY do you run the fan Continously?

    Try fan set on AUTO
    and see if the R.H. is reduced ~7%?
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

  4. #4
    Join Date
    Aug 2004
    Location
    MO
    Posts
    62
    I tried the fan on "auto", and wife didn't like it. She would rather have the constant circulation, and just run the temp down to feel comfortable.

  5. #5
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,596
    Originally posted by icssales
    We The humidity levels in the home are between 60 and 70% ! The tstat is in the auto mode. We noticed that there is more water left on the coil after the tstat is satisfied than we would like. Why is there residual water left and is that the problem? The ahu is pitched correctly.

    Please help
    The water covered coil is normal. That is the reason for not operating the fan in the "on" mode. The water on the coil is evaporated back into the home after each cooling cycle. You need a lot of supplemental dehumidification to maintain 50%RH using the "on" fan. "Auto" fan with a cold a/c coil should get you 50%RH on the hottest days of the year. During the damp cool times of the year with little or no cooling load, you need supplemental dehumidification. Suggest 100 pints per day per 2,500 sqft. The simplest high eff dehu is the Santa Fe Advance and the most sofisticated is the Ultra-Aire that deals with filtering fresh air , distributing the dry fresh air throughout the home.

  6. #6
    Join Date
    Aug 2002
    Location
    Office and warehouse in both Crystal River & New Port Richey ,FL
    Posts
    18,836
    With that system ,you shoul be able to do a lot better,something is wrong,have the contractor check it out.If they can't find it call the factory rep.,give them some time first.


    After finding and correcting the root cause,IF you still desire lower humidity,then and only then consider a dehumidifier,and yes the one "teddy" sells is likely the best.

  7. #7
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,474
    Analyzing the ratings, the 3 ton with 40 air handler had a sensible heat ratio of .78 on low cool. That doesn't leave much room for humidity removal. Doesn't the air handler run at 80% on low with that system while the compressor is at 67%? I don't leave the fan on constantly with my VS unit in humid weather either. My single stage system keeps lower 50s. As iyaayas says, slow the blower down and you may see some improvement. Switching to a stat with on demand dehumidification or putting a simple humidistat on the system could help too.

  8. #8
    have the charge rechecked.

  9. #9
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,596
    Originally posted by dash
    With that system ,you shoul be able to do a lot better,something is wrong,have the contractor check it out.If they can't find it call the factory rep.,give them some time first.


    After finding and correcting the root cause,IF you still desire lower humidity,then and only then consider a dehumidifier,and yes the one "teddy" sells is likely the best.
    I must admit, I got choke-up when I read your post. I agree that during hot weather, the system should do ok. Our difference is during low/no load or if the house is unoccupied for extended time, dehumidification makes more sense to me, sorry. We can still be friends. TB

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