Ask Me Help Desk

Ask Me Help Desk (https://www.askmehelpdesk.com/forum.php)
-   Heating & Air Conditioning (https://www.askmehelpdesk.com/forumdisplay.php?f=150)
-   -   Variable speed settings (https://www.askmehelpdesk.com/showthread.php?t=291141)

  • Dec 11, 2008, 05:37 PM
    Pvencius
    Variable speed settings
    New Goodman 95% V/S furnace s not cycling as the brochure stated. States it runs 90% of the time to circulate air. My contractor says to fun the fan on the ON position to achieve but that will make it run 100% of the time. When in the auto setting it seems to cycle similar to the old heater, on for a while then off, nowhere near the 90% like it is supposed to be engineered? Should it be set in manual vs auto and in auto should it run more often?
  • Dec 11, 2008, 05:40 PM
    MarkwithaK

    And here we go! VS motors are, in my opinion, more trouble then they are worth. I tend to shy my customers away from variable speed motors.
  • Dec 11, 2008, 08:42 PM
    KC13

    I'm a big fan of variable speed equipment myself, and my home is equipped with such. I have seen a few failures over the years, but they were usually attributable to something external (moisture, incorrect voltage, etc.). Automatic vs. continuous operation is a matter of personal preference-if comfort is improved with continuous operation, then go with it. I do and the comfort level is much more consistent throughout my home, but this is not always the case. If you use the auto selection, the blower only runs during heating and cooling cycles. In the continuous mode the speed will ramp up during a cycle, then ramp down to a lower speed in between cycles. Variable speed motors typically convert the AC power supplied to DC, and at low speed measurable power consumption is greatly reduced. When I say measurable, I am referring to your electric meter-it is designed to measure power consumption in the form of a wide-band elliptical sine wave. Conversion to DC narrows and squares the sine wave, hence the meter doesn't recognize as much power consumption. P.S. I do not wish to discredit MarkwithaK's statements-variable speed is not necessarily for everyone, and perhaps he has seen a high failure rate in his area. Strange as it is, some things work well in some areas, not so well in others.
  • Dec 12, 2008, 02:57 AM
    Pvencius

    So the brochure "runs 90% of the time" is not correct?
  • Dec 12, 2008, 04:34 AM
    KC13

    Well, I would hope that the manufacturer knows their own product. They may have some quirk that varies from others, but the operating scenario I described before is pretty typical of most variable speed units. Does the brochure give any specifics on the other 10% when the blower might not run?
  • Dec 12, 2008, 06:18 PM
    Pvencius

    No
  • Dec 12, 2008, 07:04 PM
    hvac1000
    Strange as it is, some things work well in some areas, not so well in others.

    It has to do with power conditioning by the utility. Factory variable speed is junk and the price of replacement parts is out through the roof when it is out of warranty. I prefer the add on type since you just use the same standard 3-4 speed motor. Been using variable speed of the add on type for over 30 years and never lost a unit or motor because of it but the factory GE/Regal-Beloit setup that is in the variable speed units now by all the manufactures is just to expensive to repair. There is NO reason to convert to DC just for variable speed.
  • Dec 13, 2008, 12:34 AM
    MarkwithaK

    My point wasn't about the quality of VS motors but more in line with the cost of replacement/repair. I have priced a replacement VS motor from my supplier and at my cost you can damn near buy a new furnace... without a variable speed motor lol. Factor in markup and labor and that supposedly money saving device just cost you a butt load of money.
  • Dec 13, 2008, 12:46 AM
    hvac1000
    Eventually there will be no savings with a factory variable speed setup. The replacement parts will take care of all that savings. LOL
  • Dec 13, 2008, 09:50 PM
    MarkwithaK

    I'm sure that sales reps will show a customer all the numbers outlining their potential energy savings but I would bet my last beer that nowhere in the companies literature do they layout the high repair costs of the units with variable speed motors.
  • Dec 14, 2008, 09:23 AM
    KC13

    Whoosh! What was that? Look! Up in the sky, it's.. it's... VARIABLE SPEED MAN! Yes, Variable Speed Man, defender of the virtues and benefits of variable speed HVAC equipment. Together with Bryantman, he battles the forces of skepticism and discomfort...
  • Dec 14, 2008, 10:15 AM
    Pvencius

    Guys, Thanks to all for your comments but the main questions have yet to be answered as with my contractor. Are these units that new that we really don't know how they are supposed work? If the 90% run time per the MFG is supposed the be achieved in the auto setting why can't that be without running in the ON mode which again is 100% run time? The point of repair costs is appreciated but I'm beyond that now and just want the unit to run the way it is engineered.
  • Dec 14, 2008, 10:24 AM
    hvac1000
    The difference between 90% and 100% is a no contest overview. Is the 10% really bothering you? The reason I say that is brochure's have been known to be wrong. Get the installers manual if you really want the strait story. Post the Real/Exact model number and I will see if I can find one on the main frame. I might get lucky and find one but no guarantee.
  • Dec 14, 2008, 06:14 PM
    Pvencius

    Thanks... GMV950704CX. Look forward to your reply.
  • Dec 14, 2008, 06:39 PM
    hvac1000
    Quote:

    Originally Posted by Pvencius View Post
    Thanks...GMV950704CX. Look forward to your reply.


    Goodman variable-speed furnace runs 90%
    of the time in the low-heat capacity on most days,
    but when the weather is very cold, ramps up to
    high-heat capacity so that your family stays
    warm and snug.
    QUIET OPERATION
    Your Goodman High-Efficiency Furnace uses
    a multi-speed induced draft blower motor and
    variable-speed circulating blower to reduce the
    noise levels common in other furnaces. Since this
    unit runs in low-heat stage 90% of the time, the
    impact of the normal high-fire sound is eliminated
    90% of the time. Add to that a fully insulated,
    heavy-gauge steel cabinet, and the result is…
    extra-quiet comfort.
    YEAR-ROUND
    ENERGY SAVINGS
    Energy efficiency

    All it states is when the unit runs it will be in the low stage heat mode 90% of the time. The blower is not to stay running 90% of the time just the furnace WHEN it has a call to run.

    Here is a link to the paper you were talking about.

    Your furnace is operating properly.

    https://www.acwholesalers.com/EasyEd...95brochure.pdf
  • Dec 16, 2008, 02:42 PM
    Pvencius

    Thanks to all!
  • Dec 16, 2008, 03:07 PM
    hvac1000
    Yep
  • Dec 16, 2008, 07:13 PM
    MarkwithaK

    So can we go back to VS motor bashing now? Lol
  • Dec 16, 2008, 07:17 PM
    KC13

    Perhaps an online roundtable debate... with mudslinging and everything!
  • Dec 16, 2008, 07:19 PM
    MarkwithaK

    No mud in NW Indiana. But w are getting a nice snow fall right about now. How about a snowball fight instead of the mudslinging?

  • All times are GMT -7. The time now is 12:43 AM.