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Posted by Jean on February 19, 2009, 10:13 pm
wrote:
>>On Thu, 19 Feb 2009 13:56:03 -0800 (PST), HateThatHeatPump
>>>I compared 13 seer and 14 seer and here what I've got
>>>It should be at 308/90 HI/Low
>>>But I might be wrong also
>>>Just check data for 14 seer here
>>>http://www.goodmanmfg.com/Portals/0/pdf/ss-SSz14.pdf
>>Thanks for input.
>>My HVAC tech says it should be about 350/100 or so for my heat pump.
>>He has stated to throw out Goodman sheets. I'm awaiting his return
>>right now to troubleshoot problem. He thinks unit was factory
>>overcharge as only 6 oz was added for additional line length.
>>Here's the response from Alpine when I questioned the strange specs in
>>three emails:
>>"The manufacturer's spec sheet is based of of ARI industry testing and
>>should be correct. You have to note that your pressures will vary
>>depending on your outdoor and indoor humidity along with the amount of
>>air flow and the and charge the system has. These specs indicate what
>>the correct pressures should be based on the delta T (or temperature
>>drop across the evaporator coil) and the outdoor temperature. If your
>>pressure seem off based on the outdoor temp, I would first look at
>>delta T to see if it's correct."
>>and
>>"The manufacturer's specs are to be used as a reference for what the
>>system pressures should be operating at. The difference in values
>>will not change how the system should be charged. According to the
>>install manual, the contractor will need to add 0.6 ounces of
>>refrigerant for every foot of liquid line further than 15 feet. Once
>>the additional refrigerant is added, the contractor will need to
>>perform a superheat or subcooling calculation to verify the unit is
>>operating and charged properly."
>>I gotta repeat this phrase:
>>" to be used as a reference for what the system pressures should be
>>operating at"
>>What the hell did he think I was using it for, except to do just that!
>>BTW, Alpine says the only way to add refrigerant is by weight in heat
>>mode. Tech says he has done superheat/subcooling check at 60 F but
>>would prefer 70 F.
>>It's 40 F here.....
>>I'm beginning to think the only solution to the noisy machine is to
>>sell tickets to a "heat pump bash".
>>$100 for the first swing with a baseball bat at the thing
>>$95 for the second
>>$90 for the third
>>etc etc
>>The person who puts it completely out of it's misery will get their
>>ticket money back.
>>Afterwords we'll take it out to the country and roast it on a huge
>>bonfire.
>>I know quite a few people who would just love to get their
>>frustrations out.
>Ok,
>Jean, Im probably going to hate myself for doing this, ESPECIALLY
>since it seems you purchased it from alpine home air but here goes.
Mea culpa. You won't beat on a guy when he's down, will you? ;)
>Since I wasnt completly paying attention and Im not going to search
>back for it..............tell me again
>What is the EXACT model and serial of the outdoor unit AND the indoor
>unit.
Goodman:
GSZ130241A heat pump - 2 Ton R410A w/ piston flowrator and aux heat
thermostat set at 25 F. (I added crankcase heater to prevent migration
and help with cold starts. Lowest recorded temp here was 15 F in 1955.
It got down to 20 or so for a week this winter.)
ARUF182416 air handler w/ piston flowrator - 3 speed fan w/ 5KW heat
strip.
(Don't have serial numbers handy but can get them tomorrow if
necessary)
>When, approximately, was it installed.
Oct 2008 - commissioned Nov 2008
>Then I take it that your problem is noise during the defrost cycle?
>Bubba
It sounded like this but is getting WORSE. I'm afraid it may be
slugging.
http://www.youtube.com/watch?v=9gfnmVB5q3c
The unit ran fairly quiet until recently. I'll take a video tomorrow
and upload to youtube.
Here's what I've checked out:
Airflow check using 5 KW aux heater strip w/o heat pump:
Air handler tested w/ ACTUAL measured voltage/current to strip:
237 VAC / 20.0 A = 4.74 KW
CFM = KW X 3514 X 1.08 / TR
Hi speed: 19 F temp rise 74 to 93 = 947 CFM
Mid speed: 21 F temp rise 72 to 93 = 857 CFM
I haven't measured static pressure but have provided a hole for HVAC
tech if he wanted to check. Hard to get at with downdraft unit. He
looked at my figures and install and seems satisfied.
These match figures I did at install time. I had the unit running good
on auxiliary heat for several weeks while waiting for HVAC guy to do
the brazing (used nitrogen), purge (500 micron) and 6 oz top up for
line length. He added filter w/o refrigerant addition.
Heat pump (about 40 F outdoor temp) w/o heat strip:
BTU = CFM x TR / 1.08
Using 856 CFM I came to 20,631 BTU for temp rise 72 to 98
New HVAC tech came and did a quick check several days ago. I'm
waiting for him to come back and start a full diagnoses. His first
plan of attack is to remove refrigerant.
Outside temp 40 - inside temp 72
Hi PR 410 / Lo PR 96
Discharge temp 158 and current 7.9 (these are from memory - might not
be correct - I didn't write them down).
The Hi PR dropped a bit when we upped fan speed.
This fellow is different from original installer who insists initial
unit pressures were OK and the current noise is "normal".
Unfortunately, I have no record of these. :(
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>It should be at 308/90 HI/Low
>But I might be wrong also
>Just check data for 14 seer here
>http://www.goodmanmfg.com/Portals/0/pdf/ss-SSz14.pdf