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WebRam
20-06-2001, 10:56 PM
email recieved from this lady

Dear Sir,
I was sold a five ten, 10 SEER heat Pump Frigidaire for my 2,000 square foot
home.
It does not move air The Plentem are 14", 12", 12", and 8" there are no
baffles to direct air. The feed on the supply is 12" and return house is 20"
The blower motor is 1/2 horsepower, fan motor 1/4 horse power, compressor LRA
1750. The voltage Hertz is 60. the model is Q3RA-O6OK, series Q3R0050087.
The ducts are wrapped and intack. Can you give me any idea what is wrong.
Obviously I am not an engineer, but I really need help.
Sue Daniel

Brian_UK
21-06-2001, 08:26 PM
Whilst not familiar with this make or model of equipment it sounds like the lady should approach the person who sold it to her or the people who installed it.

If it is not moving air then indications are that there is a lack of power to the motors or that the controls are incorrectly connected.

subzero*psia
24-06-2001, 12:05 AM
Interesting... is the blower wheel and motor correct... no obstructions in the return line(s)?

Possibility that the air is moving only so softly that you don't really notice it. With large ducts the volume is there but the velocity is very low so you may not "sense" the air movement. That begs another question... does the room seem to be warm up above and cool lower to the floor?

One more question... was there any wrapping, paper or plastic inside the air handler that may not have been removed??? You will probably have to check with the installer on those things. Don't give him a hard time... he probably had a busy day and had to work in an attic that was all of 140 degrees to install some of your components. :cool:

One more thing... this is a heat pump... is your control (thermostat) setting in the proper position COOLING or AUTO? Does the outdoor system come on when you set your thermostat to a LOW setting of say 60 degrees Fahrenhiet?

Andy
24-06-2001, 11:30 AM
Hi. I would start with the simple things. Is this a new system or is it fitted a while. Anyway check for an air filter and remove it to test your air flow if it is blocked replace it do not run the system without an air filter. Again go back to the supplier, he should help you. I would say that judging from where you are the installer may be a franchise check you equipment for the company name and after consulting with the installer contact head office for assistance.
Regards. Andy.

TAB TECH
04-07-2002, 01:33 PM
Is there some sort of blockage causing excessive restrictions at fan intake or discharge? Actual (tested) external and fan total static pressures referenced against manufacturers' specs could indicate where to look (return or supply system).
Is the rotation of the fan correct? Even single phase motors can be wired to change rotation. If rotation is backwards you could find very low air delivery and very high amp draw.
Subzero*psia has a viable point, first check the simple things first-
If T'stat is set to auto; the unit comes on only in responce to setpoint temperature (typically used in unoccupied modes for energy management. During occupied modes selector switch at T'stat should be set to "cooling" or "heating" depending on the the season. This would run the fan side continuously, to maintain air changes in the spaces served, and cycle the heating/cooling modes accordingly to setpoint demand.

billthomas
04-07-2002, 07:40 PM
I agree with "subzero". It is possible the system is operating as it should. ie: room or home is being cooled, but no air flow is felt. A properly engineered system will remove the heat from the room without feeling actual air blowing on you. Put your hand directly on a supply vent and see if there is cool air coming out. If not, then check for restrictions to the air flow.

frank
04-07-2002, 08:24 PM
You Guys in the US know about 10 SEERS equipment and stuff but we here in the UK we do it differently and have to really think and research this stuff.

Here is a lady that has either been sold or had installed a system that was or was not properly sized to match her installation (home). The lady is asking for help but all I see so far is techno speak which this lady will not understand.

Being professionals here on the forum, I think we should offer the "Gal" some common sense advice, i.e. Go back to whoever sold you the thing and tell them that it does not work for your situation!!

herefishy
05-07-2002, 02:08 PM
Well, 5-ton for 2,000 sq ft. seems fine. The lady says, "no air flow", but is it cooling the house adequately?

Inquiring minds want to know. :)

abcdefg1675
16-07-2002, 01:56 AM
with a lighter and incense, an average person could tell if there is air flow.

Dan
16-07-2002, 02:25 AM
If I recall, heat pumps use a slower speed on the blower to move the air in heat mode. That could be something to look at too. A suction pressure reading would be of benefit. Hence get a technician to sort it out. I have a smaller Fridgedaire with an 1800 sq ft house and it works just dandy. I must further confess that I once installed a blower fan backwards and it did manage to move air..... just not nearly as much as it shoulc have.:)

Gibson
31-10-2002, 03:46 AM
Five tons in a 2000 square foot house sounds like overkill from a North American perspective. Sounds to me like there is inadequate airflow from the air handler, not to mention inadequate ductwork for the cooling capacity. Five tons of cooling on two tons of ductwork! See what I mean?

Gibson
31-10-2002, 03:48 AM
Dan, it should also be mentioned with air cooled heat pumps, the airflow should be higher than for standard cooling applications.

frank
31-10-2002, 05:35 PM
gibson

what is the basis for that statement?

the way you guys size a/c is totally different from here in the uk

frank

Gibson
02-11-2002, 05:02 AM
frank,

We size A/C and heat pumps based primarily on cooling requirements for the building. Generally a Cooling Load form is filled out based on the buildings design. A 2000 square foot house here would require about three tons of cooling.

El Tel
13-11-2002, 06:18 AM
Dear Sue,

I'll go with Tab Tech - could be as simple as the blower running backwards.
However, could be the ductwork, too.

a) If you've got too many supply grilles (I'd guess no more than about 5 standard 144 square-inch ceiling diffusers), or
b) if they used miles of that crinkly, flexible, high-friction rubbish instead of proper smooth steel ducting, or
c) If the return-air grilles are too small (less than around 440 square inches of return grilles in total), or
d) If they strangled the duct to get past a beam or around a corner, or
e) If they didn't reduce the size of the ducting run after each supply-air takeoff...
that'll all help to cut down the airflow velocity.

Baffles? That's a term I'm not familiar with (we work in Spanish down here). Does it mean "grilles", "diffusers" or "registers"?
If the air is just coming straight out of the duct, with no diffuser, you'll get the right volume of air coming out, but it'll feel slow. Fit diffusers.

Here in South America they like "breezy" aircon systems - 1200 FPM or better, and complain like hell if the temperature's right, but they don't need to use paperweights to hold the Sunday Supplements on the table...

Whatever it is, you can't fix it yourself. I'd pay an independent aircon tech to come and look over the system. If he points out a fault in the design (easy to do on someone else's installation), or the equipment, and the installation is not brand new, have him put it right (but only pay when it works).
Good luck.

twcpipes
14-11-2002, 01:47 AM
I don't mean to complicate the situation with techno-talk, but I have a question rather than advising you, maam. Are you sure the indoor blower is 1/2 hp and not 3/4hp or 1hp?
thank you.

subzero*psia
29-12-2002, 04:36 PM
Originally posted by Gibson
Five tons in a 2000 square foot house sounds like overkill from a North American perspective. Sounds to me like there is inadequate airflow from the air handler, not to mention inadequate ductwork for the cooling capacity. Five tons of cooling on two tons of ductwork! See what I mean?


In my area Midwest Ohio, USA... a 5 ton AC/HP will do 4000 square feet. I just put one in this summer and it works wonderfully. But in the UK they may (probably do) have a higher grains of moisture / humidity level per their geographic location, so it could be possible that they need a larger system there... one would have to know the specifics of their area relative to load.... but 5 tons does sound like overkill.... "even at 60 grains of moisture" and a using a liberal building structure with only 2000 square feet, I only come up with 3.5 tons required for air conditioning using a high temp of 95F, low temp of 10F and a 15 temperature differential. Just my opinion ... can't really say as I don't know the specifics there.

Are they using this as their "only" source of heat or is it only a first stage... if it is the only heat source... that may be why they installed a 5 ton... but why not just add heat strips to the proper size system?

One more thought.... the supply is only a 12 inch.... is this square or round, rigid steel or flex pipe? I don't have my book in front of me but I'm not sure about a 12 inch supply being able to handle 2000 cfm for the cooling mode... may be the restriction was "designed into it" unknowingly by the installer? Another question was brought up by DAN... it made me wonder if possibly the blower speed connections are on the proper terminals.... I've seen them come wired wrong straight from the factory! ;) Still have a suspicious eye on that supply trunk though.... I wonder how many take off/supply lines are fed from it and what sizes they are too? Inefficient ductwork will cause liquid slugging and destroy the compressor....

I've been away for awhile.... has this particular problem been solved?????

Take Care,

angryk
01-01-2003, 06:08 PM
Reading through all the post's, I see a lot of excellent ideas and possible solutions to this situation. However, would'nt it be best to go to the job and see first hand what is actually going on with the system? Like a regular service call? Maybe I am missing something about the situation. I've found from experience to just listen to the basic complaint from the customer. Because once they start trying to get technical, all it does is cause confusion and misdirection on the technicians part.