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  1. #14
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,638
    When cooling at normal/outdoor indoor temps, the cooling coil should be 30^F below the return temp for a 50%RH interior humidity. That means 78^F, 50%RH is a 57^F dew point. A 48^F coil temp will provide significant moisture removal, you get a long run cycle. It takes 30 mins. to start removing moisture down the drain. When cooling runs are less than 30 mins., minimal moisture will be removed. During low/no cooling loads and outdoor dew points +60^F, a whole house dehumidifier is an easy fix to mainatin <50%RH. Check out the Ultra-Aire xt105H to control the home. This unit control the entire home.
    If the coil temps are right, the cooling runs long, and the 50%RH is not achieved, check for duct leaks and structure air leaks.
    Regards TB
    Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
    Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
    Use +Merv 10 air filter. -Don't forget the "Golden Rule"

  2. #15
    Join Date
    Jun 2001
    Location
    Moore, Oklahoma, United States
    Posts
    4,505
    Quote Originally Posted by beenthere View Post
    10.5 tons on 2006 construction. Wow, oversized a lot.
    6,000/10.5 = 571 sqft per ton. Yup typical over-sizing using rule of thumb

  3. #16
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    4,877
    the 19i unit runs at 50 percent capacity on 1st stage . what thermostat do you have is it the 900 series or the 803 thermostat .
    We really need change now

  4. #17
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    4,877
    after looking closer at the pics you do not have the communicating 900 tstat .the 803 thermostat does not have dehumidify on demand all it an does is under cool, first thing to ask is comfort r turned on and are the units set at 350 cfm per ton and are the dip switches set up for the correct tonnage of the outdoor unit . is your service provider a trane comfort specialist
    We really need change now

  5. #18
    Join Date
    May 2004
    Location
    south louisiana
    Posts
    3,318
    so far everyone agrees that your units are oversized.
    options set dip switches to low speed
    make sure that fan cuts off when unit shuts down
    (fan not on continously)
    check tstat set up
    install whole house dehumidifier

    when tech shows up to adjust dip switches & check fan
    setup ask if they have installed whole house dehumidifiers.
    you'll want someone with experience to do this.

    as for sealing air leaks & duct leaks..this is always a good idea.
    people think they own/build tight houses..but it often isn't the case.
    trying to dehumidify to 50% in summer with outside air leaking
    into the house and conditioned air leaking out of ducts makes it
    almost impossible to do so, even with correctly sized equipment.
    seal the house, seal the ducts.
    Resnet, Bpi, Comfort Inst all have people to do blower door
    testing, duct testing & provide info as to where & how to seal
    these leaks.

    I can keep house @ 50-55% RH here in La. in the summer
    but to lower the RH to 45% makes a world of difference in comfort.
    to get this added dehumidification..it takes whole house dehumidifier.
    my unit isn't nearly as oversized as yours, and the variable speed air handler
    of the heat pump unit is what I planned on using for dehumidification.
    so even the best of plans...don't always achieve the RH% that is
    the healthiest.

    while the whole house dehumidifier is kind of expensive..it is a
    GREAT investment in comfort.

    teddy bear can give you the best of information on these units.

    best of luck.

    and Merry Christmas everyone!
    The cure of the part should not be attempted without the cure of the whole. ~Plato

  6. #19
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    4,877
    5 tons on 6000 square should be able to keep the humidity in check if working properly .
    We really need change now

  7. #20
    Join Date
    Feb 2009
    Location
    Tallahassee, FL
    Posts
    6,051
    Coil temp will be key to good dehum if locked in 1st stage like Teddy bear said

  8. #21
    Join Date
    Dec 2012
    Posts
    7
    Guys, your are greatest community here! Really.
    I did not expect anybody to answer these days (holidays) and got so many comments..
    Many Thanks again too all of you.

    My lammer questions after reading your comments.

    1. Am i right that first thing to be tried should be make all units working on lowest possible speed (jumpers and switches)? So they will be working longer and taking out more humidity as result? I do remember decision of last service company to put units on highest level to make them work harder and in their heads making less humidity. If i am right now they got opposite result - right?

    2. Whole house dehumidifier. If i have 3 separate units do i need only one or 3? Can you give me fair idea baout cost of unit and installation? Teddy Bear (thanks!) recommended model Ultra-Aire xt105H but i checked their website and this model is for 2500 sq. f. If i need this one for each unit then i understand. But if one works for whole house somehow then i think i need biggest model which is Ultra-Aire XT205H (5000 sq f). Please explain this in details if possible.

    3. And guys - are any of you by any chance works in Florida?
    I am really sick and tired from our local "pros" - i think you understand from my descriptions why.
    Today i checked Trane website, there is one company presented there as Trane comfort professionals. From your knowledge does it mean anything in real? I mean will there be any real pros in Trane units or it will be same as 3 other tries?

    Thanks Guys!
    Kir

  9. #22
    Join Date
    Jan 2004
    Location
    PA
    Posts
    68,769
    Use the link in my sig to see if anyone from this site is in your area.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  10. #23
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,428
    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

  11. #24
    Join Date
    Jun 2003
    Location
    Madison, WI/Cape Coral, FL
    Posts
    6,638
    Quote Originally Posted by Kirka777 View Post
    Guys, your are greatest community here! Really.
    I did not expect anybody to answer these days (holidays) and got so many comments..
    Many Thanks again too all of you.

    My lammer questions after reading your comments.

    1. Am i right that first thing to be tried should be make all units working on lowest possible speed (jumpers and switches)? So they will be working longer and taking out more humidity as result? I do remember decision of last service company to put units on highest level to make them work harder and in their heads making less humidity. If i am right now they got opposite result - right?

    2. Whole house dehumidifier. If i have 3 separate units do i need only one or 3? Can you give me fair idea baout cost of unit and installation? Teddy Bear (thanks!) recommended model Ultra-Aire xt105H but i checked their website and this model is for 2500 sq. f. If i need this one for each unit then i understand. But if one works for whole house somehow then i think i need biggest model which is Ultra-Aire XT205H (5000 sq f). Please explain this in details if possible.

    3. And guys - are any of you by any chance works in Florida?
    I am really sick and tired from our local "pros" - i think you understand from my descriptions why.
    Today i checked Trane website, there is one company presented there as Trane comfort professionals. From your knowledge does it mean anything in real? I mean will there be any real pros in Trane units or it will be same as 3 other tries?

    Thanks Guys!
    Kir
    Operate a enough speed to provide a 45-50^F cooling cool with normal indoor outdoor temperatures. This will get you <50%RH when you are in peak cooling loads.
    Depending on how your home is layed out and how well you a/cs operate, One dehumdifier may do the job. After getting your a/c optimized, pick the most occupied and wetted area, add one dehumidifier like the Ultra-Aire xt105 H to the a/c serving the area. If you can leave the door open to the rest of the areas and they have air movement, should work. If the areas are isolated, suggest a small dehu to the two most critical areas. like the UA 75H connected to the each a/c.
    Regards TB
    Bear Rules: Keep our home <50% RH summer, controls mites/mold and very comfortable.
    Provide 60-100 cfm of fresh air when occupied to purge indoor pollutants and keep window dry during cold weather. T-stat setup/setback +8 hrs. saves energy
    Use +Merv 10 air filter. -Don't forget the "Golden Rule"

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