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  1. #1
    Join Date
    Jul 2012
    Posts
    11

    Goodman ASPF AH; selecting fan speeds on the fly

    Howdy;

    Just had a ASZ 14 2.5 ton Condenser, and ASPF 2.5 ton AH w\ Expansion Valve installed.
    Local dealer turned out to be a broker; not a full featured dealer. He has one full timer; but he's busy chasing bad installs and warrenty work.
    So; after a call and a face to face I have parts only warranty; not the 10 year labor he told me befor I agreed to his work. He's a slippery fellow, and he sounds like he's been doing this for years and getting away with it. If I had not already know how a AC and a heat pump worked, he would have waltzed out pocketing the extra $$ for the TXV and hard start kit. I held the install team untill he sent a fellow over witth the TXV and HS kit
    My next action is When I locate another dealer, and sweet talk him with a yearly maintenance contract to take over warranty claims if I need one.

    I have 5 years in the HVAC buisiness, but that was when I was 14-19. Riding with my Dad on service calls; and the last year taking calls solo.
    I own 2 sets of Robinair gauges, a vac pump and my Dads old school charging cylinder and micron gauge. These day I am an Engineer for a computer company based in Round Rock Texas.

    I corrected all the install errors myself, as the broker never seemed to have time to come back out.

    No TXV installed (Fixed by the installer)
    TXV sensing bulb installed at 12-o-clock'
    No hard dtart kit as I specced a TXV (Fixed by the installer)
    condensate drain running up hill
    Condensate "t" opening higher than the mid level of the water level in the drain
    AH fan on default of 4 out of 5; and way overspeed per duct size.




    My question is: can I have a single throw double pole relay installed to the high \ low cool on my thermostat to toggle the fan speeds on the fly?
    Not toggling compressor stroke here, just slowing the AH speeds when the TS wants to shift from High to Low automatically for Humidity control.

    Evaporator relay - STDP relay - Fan

    Thanks in advance for assistance; and if you are shopping for a dealer..please make sure you select a contractor from this site; or do your homework. The fellow talked a good game but assumed I was "Talking".
    You can imaging his surprise actually knew what the frac I saw talking about.
    The bastage even offered me a job...

  2. #2
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
    Posts
    11,334
    Seems if your thermostat is set up to slow the blower when it calls for extra dehumidification, the electronic board on the air handler should handle the fan speed switching vs. the old school SPDT relay (single pole, double throw). Lots has changed in the residential side of HVAC since those days you ran service calls for your dad. Not tremendously so, but enough that with the now near universal inclusion of electronic boards in the indoor and outdoor sections of a split system, you need to read the installation instructions to see what those boards are for and are capable of doing. Your installer should have read them as well, but alas, seems like our industry suffers from ITATRTFM...I'm Too Arrogant To Read The F****** Manual.
    • Electricity makes refrigeration happen.
    • Refrigeration makes the HVAC psychrometric process happen.
    • HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.


    A building is NOT beautiful unless it is also comfortable.

  3. #3
    Join Date
    Jul 2012
    Posts
    11
    Quote Originally Posted by Shophound View Post
    the electronic board on the air handler should handle the fan speed switching vs. the old school SPDT relay (single pole, double throw). Lots has changed in the residential side of HVAC since those days you ran service calls for your dad....


    ....you need to read the installation instructions to see what those boards are for and are capable of doing. Your installer should have read them as well, but alas, seems like our industry suffers from ITATRTFM...I'm Too Arrogant To Read The F****** Manual.
    Yes; I agree fully. The manuals tell you how they operate.
    The Goodman based ASPF handler is actually quite a bit simpler than the Carrier I removed (And re-installed in my shop with a new Evap core)

    The AH uses a simple time delay relay for the fan. See page 19 here.

    http://www.goodmanmfg.com/Portals/0/...Os/IO-A-PF.pdf

    I miss those days, lunch at A&W.. Buck Owens on the AM ..

  4. #4
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
    Posts
    11,334
    A & W? Buck Owens on AM? Man, it HAS been awhile since you were in a service truck....

    (as it has for me...still in the trade but not in a truck)

    That air handler has an ECM motor, best I can tell. A delay-on and delay-off for pre-cooling and post compressor shutdown cooling, respectively. Pretty bare bones unit. On your thermostat, is it set up to both read and signal for dehumidification?
    • Electricity makes refrigeration happen.
    • Refrigeration makes the HVAC psychrometric process happen.
    • HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.


    A building is NOT beautiful unless it is also comfortable.

  5. #5
    Join Date
    Jul 2012
    Posts
    11
    A & W? Buck Owens on AM? Man, it HAS been awhile since you were in a service truck....
    Yea; I suppose so. We live rural; so the local AM station was tru to it's roots.

    Dad taught HVAC at the local Ag collage, so he had his summers off. When we wasent engineering systems he took service calls. Very blue collar fellow..
    I envy those days. What I see now in this large market is behavior I am ashamed of.


    That air handler has an ECM motor, best I can tell.

    Yes; looks like Goodman calls it a EMM; and it's probably the GE X13; or a China variant.

    A delay-on and delay-off for pre-cooling and post compressor shutdown cooling, respectively. Pretty bare bones unit.

    Yes, Us Engineers like "KISS" : Keep It Simple, Stupid

    On your thermostat, is it set up to both read and signal for dehumidification

    No; That sounds like prework I need to do. My current non programmable does 2 stage heat and cool; but no humodity.

    Suggestions for a TS? Installer grade does not scare me off...

    Thanx

  6. #6
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
    Posts
    11,334
    Honeywell VisionPro 8321 is a rock solid thermostat with dehumidification ability. Mainly an "overcool" strategy vs. vary fan speed.

    Honeywell IAQ is more spendy but may have the blower speed option for dehu. The Prestige stat is slicker n' greased lightnin' and also has dehu, I believe. But I'm partial to the VisionPro. Digital version of the T87 series, in my book.
    • Electricity makes refrigeration happen.
    • Refrigeration makes the HVAC psychrometric process happen.
    • HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.


    A building is NOT beautiful unless it is also comfortable.

  7. #7
    Join Date
    Jul 2012
    Posts
    11
    Quote Originally Posted by Shophound View Post

    • Honeywell VisionPro 8321
    • Honeywell IAQ
    • Prestige

    I'm partial to the VisionPro.
    OK; researched all of these.

    Don't really need the programing features; but they are very pretty to look at
    Do you have suggestions for a TS of any reputable brand that allows setting the fan to run for at least 2 mins after cool setpoint is reached; and\or a random fax cycle every few hours?

    1. I want to assure the Evap coil stays dry in cool mode. This is what triggered me to replace the entire system; mold growth and particulate contamination (OK, I wanted a unit in my shop, and this was enough reason to get it past the "boss")
    2. Random fan; or fan running between cool \ heat cycles to filter air and even hot rooms VS cool central room.

    I see units from LuxPro, AprilAir, CTC, Pro1, Braeburn, Venstar ECT..

    Too many vendors to be in business long... I thing a few of them will dry up as the market has sagged..

    Thanx for you assistance

  8. #8
    Join Date
    Jun 2001
    Location
    Moore, Oklahoma, United States
    Posts
    4,265
    Instead of a fancy thermostat I just used an old school mechanical humidistat to control the connection from the "G" terminal to the "Y" on the furnace board. Low cost and does the job. The SPDT relay trick will work also.
    http://www.fluke.com/Fluke/usen/comm...h+Humidity.htm

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