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  1. #1
    Join Date
    Jul 2008
    Posts
    551

    VisionPRO IAQ and some other ?'s.....

    System:
    OD = Amana ASZ16 3.0 ton
    Furnace = Amana AMV8090
    Coil = Lennox C33 (4 ton, I think)
    T-stat = VisionPRO IAQ
    Location = Kansas City
    1400sq ft house

    The system was just installed yesterday. I was told to keep the fan setting on the thermostat set to "ON". In this setting, the VFD controlled fan never slows down from 100%. Even if the inside temp is below the set point, the fan is still cruising along at full speed, but the cooling coils are turned off. If I set the t-stat to "auto" it will shut the fan off when below the set point. I thought the idea behind the VFD fan was that it would run at 20% w/ no cooling if the temp was below the set point? Do I need to check one of the installation settings? The techs tested both stages of heating and cooling before they left.

    Another question. On my old heat pump system (1995 lennox, 2.5 ton), I couldn't set the A/C back in the summer more than 2 degrees or it would take it 4+ hours to recover. With this newer unit, should I be able to set it back farther during the day when I'm not home? I used to set it at 79F for when the house is occupied and 81F for the daytime setting when no one is home. The preset energy star settings set it back to 85F. That seems a bit much to me.

    I appreciate any help anyone can provide.

  2. #2
    Join Date
    May 2007
    Location
    DC Metro Area (MD)
    Posts
    3,371
    Why did they install a Lennox coil instead of an Amana coil for a complete matched system? Especially with a heat pump, it's important that it's matched for efficiency and capacity as well as to get the manufacturer's warranty. The setback that comes with the VisionPRO thermostats are a bit far in my opinion. You can change them. How was the unit sized? Going from 2.5 tons to 4 tons is a pretty big leap. I hope they adjusted the ductwork to work with it and did a Manual J load calculation to determine correct sizing. As far as recovery goes, to go 3 degrees in 4 hours doesn't seem out way off if it's hot out and the system has to remove a lot of heat and humidity. I once lost power and had to recover 4-5 degrees, and it took at least 4 hours, maybe around 5. To say if it's right or not for your situation would require a load calculation. You'll have to test it with your new system to see how well it responds. The VisionPRO will learn your house and then be able to recover earlier to meet the setpoint by your return if you have Adaptive Recovery enabled.

  3. #3

    Smile Test

    Check the back presure it should be at 60 psig on R22, If it is at 70 psig or higher, Then the unit is to small for the aplication.

  4. #4
    Join Date
    Jul 2008
    Posts
    551
    Thanks for the replies. The designer wanted to go with the oversized Lennox coil. I didn't grill him for specific reasons. The calculations showed the duct work big enough to handle 4 tons. The heat pump itself is only 3ton. The Amana lifetime warranty says it is valid as long as the heat pump is matched and designed to the coil by a certified installer/designer.

    Let me clarify, the new system is cooling properly. No problems at all cooling right now. My main concern is whether to set the fan to "ON" or "AUTO." I want the fan to always operate but throttle back to 20% if the temp is at or below the setpoint. Can the VP IAQ do that?

  5. #5
    Join Date
    May 2007
    Location
    DC Metro Area (MD)
    Posts
    3,371
    Sorry, I was thinking it was a 4 ton for some reason. I still don't agree with the Lennox coil and would ask him what his reasons were, and the coil is not a certified match. I assume it has a R410A TXV installed? Setting the fan to ON can increase humidity but provide for more even temperatures. Setting the fan to AUTO would be better for humidity control but wouldn't provide circulation except when the system is running. The CIRC fan mode is a nice feature that runs the fan around 35% of the time when there is no call for cooling. On your furnace, the continuous fan speed is adjustable. On your thermostat, did the installer set it up to dehumidify on demand by slowing the blower down? That's one of the key features on this thermostat.

  6. #6
    Join Date
    Jul 2008
    Posts
    551
    No. The dehumidification setting has not been enabled. Enabling that would allow the fan to run slower/longer?

  7. #7
    Join Date
    May 2007
    Location
    DC Metro Area (MD)
    Posts
    3,371
    It would allow the blower to slow down to remove more humidity if the humidity setpoint isn't reached. That furnace also has a dehumidification ramp profile that can be set up to remove humidity at the start of the cooling cycle.

  8. #8
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,928
    Thats just BS!
    Contractor locator map

    How-to-apply-for-Professional

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

  9. #9
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,928
    Quote Originally Posted by badtlc View Post
    The Amana lifetime warranty says it is valid as long as the heat pump is matched and designed to the coil by a certified installer/designer.

    Call Amana, You don't have a life time warranty with an unrated coil.
    And if you can't find an ARI rating for that coil, its not a match.

    Something is wrong wire your install besides the indoor coil mismatch.
    It sounds like its not wired right.
    The blower doesn't slow to 20%, it slows to 50%.
    Also, don't run the fan 24/7, set the fan to circ.

    Get your contractor back out to fix the wiring problem, and set the blower settings correctly.

    And get the right coil installed.
    Contractor locator map

    How-to-apply-for-Professional

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

  10. #10
    Join Date
    Jul 2008
    Posts
    551
    Quote Originally Posted by beenthere View Post
    Call Amana, You don't have a life time warranty with an unrated coil.
    And if you can't find an ARI rating for that coil, its not a match.

    Something is wrong wire your install besides the indoor coil mismatch.
    It sounds like its not wired right.
    The blower doesn't slow to 20%, it slows to 50%.
    Also, don't run the fan 24/7, set the fan to circ.

    Get your contractor back out to fix the wiring problem, and set the blower settings correctly.

    And get the right coil installed.
    Amana gave it the OK.

    I'll try the "circ" setting and see what happens. My blower will slow down to 20% on my furnace. It is 80% variable speed VFD driven fan. I wasn't sure if the the VisionPRO IAQ could control a VFD that precisely or not.

    Is there any way to check and see how many stages are currently running and what speed level the fan is running at?

  11. #11
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,928
    No easy way.

    You do NOT have a VFD.

    You have a VS ECM motor.

    Look in the install manual. More like your blower slows down by 20% when it receives a high humidity signal.

    Amana ok'ed it, or a loacal distributor ok'ed it?
    Contractor locator map

    How-to-apply-for-Professional

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

  12. #12

    Smile The Fan Speed

    Quote Originally Posted by badtlc View Post
    Thanks for the replies. The designer wanted to go with the oversized Lennox coil. I didn't grill him for specific reasons. The calculations showed the duct work big enough to handle 4 tons. The heat pump itself is only 3ton. The Amana lifetime warranty says it is valid as long as the heat pump is matched and designed to the coil by a certified installer/designer.

    Let me clarify, the new system is cooling properly. No problems at all cooling right now. My main concern is whether to set the fan to "ON" or "AUTO." I want the fan to always operate but throttle back to 20% if the temp is at or below the setpoint. Can the VP IAQ do that?
    O n the relay or energize the Y2 termininal this will bring on the high speed when the cooling starts. I have a four ton unit split system when I hooked up Y1 it began to freez up I fixed this by hooking up Y2 with a jumper wire.

  13. #13
    Join Date
    Dec 2006
    Location
    Middle Tennessee
    Posts
    11,347

    *

    i/d controls need to be set to enhanced!



    .

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