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  1. #14
    also ecm tech is here to stay i love them there so easy to check plus i believe moisture is a primary cuase air passing thru the motor on a unit iss about 48 to 59 degrees constant on a lil circuit board attached to the motor i beileve in tiime this constant moisture build up over time will cuase the electronicspackage give out

  2. #15
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    Quote Originally Posted by ferd1942 View Post
    I've done some math indicating high SP loses a SEER point or so due to increased blower power:
    Please share this with us. I would like to see your numbers.

  3. #16
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    All furnace nameplates are marked 0.5" ESP. That's an AGA certification, never learned what that's about. I believe it dates back to when people designed duct systems at 0.5", to include the coil: 0.5" furnace less 0.25" for the coil left 0.25" for ducts, duct fittings, registers, grilles and exotic air cleaners. Today, it's quite common for national builders and others to select coils at 0.4", so the 0.5" marking must be ignored.

    That 0.5" marking is not to be confused with the manufacturer's product data. York, for instance, permits its TM9V furnaces to be operated at 1.0".

  4. #17
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    I'm away, don't have the info with me. Here's the gist.

    SEER is BTU/W-H (BTU per watt-hour). On that basis, you'd expect a 16 SEER 2 ton unit to have a 1,500 watt power input (24,000/16 = 1,500). That includes blower power input at some (0.5"??? - be interested to hear from someone about that) SP. Operating an ECM at a higher SP (as in poor coil selection, 0.10" duct design, etc.) increases blower power input.

    Add 100 W of blower power and the 16 becomes a 15 (24,000/1,600 = 15).

  5. #18
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    Quote Originally Posted by ferd1942 View Post
    All furnace nameplates are marked 0.5" ESP. That's an AGA certification, never learned what that's about. I believe it dates back to when people designed duct systems at 0.5", to include the coil: 0.5" furnace less 0.25" for the coil left 0.25" for ducts, duct fittings, registers, grilles and exotic air cleaners. Today, it's quite common for national builders and others to select coils at 0.4", so the 0.5" marking must be ignored.

    That 0.5" marking is not to be confused with the manufacturer's product data. York, for instance, permits its TM9V furnaces to be operated at 1.0".
    The Maximum rated ESP is usually .5 for a cooling ready unit and .2 for heat only.
    Most mobile home units such as Intertherm and Coleman that are approved for that application max out at .3".
    You can purchase a high static RTU @ 1.0" and many York RTU's @ 5 and 5 6.5 tons are rated to .7"
    The certification is basically stating that at the "X" amount of static pressure or below this rating the equipment will operate as it is supposed to.

    Anything above this rating there may be performance concerns.

    This does not mean that you can't design a system @ .6"wc (thats rated .5) if @ .6" it delivers the rated cfm you need as outlined on the fan curve chart.

  6. #19
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    Quote Originally Posted by ferd1942 View Post
    I'm away, don't have the info with me. Here's the gist.

    SEER is BTU/W-H (BTU per watt-hour). On that basis, you'd expect a 16 SEER 2 ton unit to have a 1,500 watt power input (24,000/16 = 1,500). That includes blower power input at some (0.5"??? - be interested to hear from someone about that) SP. Operating an ECM at a higher SP (as in poor coil selection, 0.10" duct design, etc.) increases blower power input.

    Add 100 W of blower power and the 16 becomes a 15 (24,000/1,600 = 15).
    Actually, BTU/W_H is EER, not to be confused with SEER. EER is "at that instant" where as SEER is "Seasonal" and not easily computed.
    SEER is defined by AHRI and has a standard (ARI 210/240) and is not easily calculated.
    This is why I asked as how you felt you can determine a gain or loss of a point on your own. You would need to know the amount of cooling days, operating cost of the air handler and other factors to compute the SEER.

  7. #20
    Join Date
    May 2007
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    Central NJ Area
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    i thought that the module failure in the older model GE modules was due to high static pressure and the lack of limiting the motors rpms like the new modules do at 1400 rpms max. We had alot of capacitor failures in the modules from poor duct systems that had high static pressure. The issue had been rectified by the 1400 rpm limit on the new modules. Now duct repairs are needed to drop down the static pressure.

    I've seen very high static pressure systems that have ECM motors cause the blower wheel to deform to an egg shape due to the high motor speed and high static pressure! CRAZY!!

  8. #21
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    Apr 2012
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    Millsboro, DE
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    So you agree with the premise that a bad duct system increases power and reduces SEER, right?

  9. #22
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    Apr 2012
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    Millsboro, DE
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  10. #23
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    SEER is BTU/W-H (BTU per watt-hour). On that basis, you'd expect a 16 SEER 2 ton unit to have a 1,500 watt average power input over the cooling season (24,000/16 = 1,500). That includes blower power input at some (0.5"??? - be interested to hear from someone about that) SP. Operating an ECM at a higher SP (as in poor coil selection, 0.10" duct design, etc.) increases blower power input.
    Last edited by ferd1942; 05-25-2012 at 07:49 AM. Reason: move "average"

  11. #24
    Join Date
    Dec 2002
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    in a house, Appomattox, Va.
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    3,249
    Was at a Trane meeting and they had a chart relating seer to the static pressure on a system. high esp can drop a 16 seer to below 14 seer, killer on seer rating.

    Also, put the plug on the bottom side of the motor (horizontal shaft), and a drip loop on the harness to ensure moisture doesn't run into motor off wire harness.

    Some of the motor bearings failed due to static electricity across the shaft bearings (mico welds). I think they include a static dissipating brush in the motors now. That's what those Aeon? rings are for that are advertised in the trade magazines.
    Col 3:23


    questions asked, answers received, ignorance abated

  12. #25
    Join Date
    Apr 2012
    Location
    Millsboro, DE
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    100
    Just downloaded Florida Heat Pump/Bosch geothermal heat pump specs for a job. They're showing SP's up to 1.2".

  13. #26
    Join Date
    Sep 2007
    Location
    TX
    Posts
    206
    Check again UPG's are almost all .3esp max now Even the coleman MH units

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