| B-Hate-Me 2005-07-24, 9:13 pm |
|
"Derek Mark Edding" <dreq@earthlink.net> wrote in message
news:HZ6Ee.2826$6f.1880@newsread3.news.atl.earthlink.net...
> Hi Folks,
Why didn't you listen to the dude that TOLD you
the ductwork was too small ?
Fucking people never cease to amaze me.
>
> It looks like our 3 yo 12 seer Goodman combined AC/heat outdoor unit has
> an installation problem. The compressor works great, but the variable
> speed blower barely spins. When set to heat it blows just fine - very
> powerfully. But set on AC, it feels like someone's waving a newspaper.
>
> According to the HVAC Tech who visited this week, the refrigerant is fully
> charged and the temperature measures 55 degrees F at the output vents,
> 82-83 at the two intake vents.
>
> Our digital thermostat shows that the compressor is running between 12 and
> 14 hours a day. We've had temperatures in the nineties for the last three
> weeks, and this system is running hard enough to power a whole-house
> refrigerator. We keep the thermostat at 78-79, but the best it can do is
> four degrees above that.
>
> The 12 seer unit is a replacement the original Goodman Comfortmaker
> gaspack. When our installer removed the old one, he remarked that the
> intake and output hoses were too small, and had been reduced in size to 12
> inches which did not meet building code.
>
> To the best of my knowledge, all of the homes in our neighborhood were
> equipped this way. The original builder installed systems were
> inefficient but functioned adequately. The replacement unit is physically
> much larger, but at 3.5 tons is probably the same capacity (we have no
> records for the original unit).
>
> He removed the original "main trunk" of the ducting under the house -
> plenum? Manifold? And replaced it with a much larger one that had 18"
> pipes running to the outdoor gaspack. There was no change other than
> that.
>
> After installing and powering on the new system in August three years ago,
> we had the same problem we have now. The variable speed fan barely ran
> when set to AC, but ran powerfully when set to heat. Our installer had
> not installed this model before and had to consult with Goodman repeatedly
> to fix the problem. He replaced the variable speed blower unit, but this
> did not fix it.
>
> What eventually did make a difference was this: he said that there was an
> Air Mass Detector built into the variable speed blower, which is like a
> humidity detector. He said that the air flow returning to the unit was
> not sufficient, and this detector was keeping the fan from ramping up to
> its full speed. He pointed to the intake duct inside the unit and said
> that there was (and here my memory is sketchy) something like an air flow
> restrictor, that he had needed to adjust to increase the velocity of the
> air returning to the unit.
>
> After he made this change, the blower began functioning normally and we
> had decent cooling. However, this was towards the end of the Summer. We
> had to call him back again last Summer for a similar problem, which he
> said was "just needed a few pounds of refrigerant".
>
> That brings us to this year, where we have unusually high heat and
> humidity and again, the blower is back to barely running. The HVAC tech
> who visited this week said that the unit appeared to be fully operational
> and was not reporting any failure codes. He said he would need to send an
> expert to examine our installation and determine if it needs to be redone.
>
> If anyone has any clues that might help us get this unit to run properly
> I'd be very grateful. The fellow who did our installation did an
> excellent job of taking care of our old system for ten years, but he seems
> out of his depth with its replacement.
>
> Thanks,
>
> -dreq
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