A/C runs constantly

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Originally Posted By: ctrcbob
I see your unit is a "Goodman". I had new AC put in back in 2010. They installed a Goodman. Did not work right. (The Air Handler was good but the outside compressor was junk). After a couple days, they removed the outside unit and replaced it with another Goodman. Went through FOUR Goodmans. Air never came out cold enough plus they did not dehumidify the house. They then replaced the outside unit with an Amana. No more problems. The Amana works great. As far as I'm concerned, Goodman is another word for junk. Thank
god my AC contractor is great and stands behind his work.



[/quote] When we got an all new system 3 years ago, I asked the guy (family friend with 30+ years of HVAC experience) about Goodman. I had to duck when he tried to smack me. He installed a Rheem for me. He all but refuses to work on them as he said they are junk. His comment was that they use dissimilar metals in their coils and cheap compressors. [/quote]

All 350 some units in my complex have Goodman everything, furnaces, condensers, air handlers. They have good reviews on goodmans website but so far I can say I'm not impressed with the equipment in my unit. I've always heard Trane and Rheem were the way to go.
 
"The supply line from the condenser reads at about 56 degrees right before it enters the a-coil."

Nope, that's the suction (return) line.

"Slowing the air should allow the air more time to have heat removed and increase dehumidification"

You have already said you feel there is not enough airflow.... and now you lowered it. Put it back.



If you want it diagnosed you need to know:
Outside ambient temperature
Head pressure
Suction pressure
Return air temperature
 
"More notes: The system seems to have a hard time getting enough air flow into the supply. The indoor part of the system is in a small closet with the hot water tank. The blower is trying to pull so much air it literally sucks the door closed when it's on. So I don't think the supply vent provides enough."



I re-read this this morning.... if you have a gas water heater you have a potentially dangerous situation here.
This needs immediate attention.
If you can't get any action call your local city building inspector.

[color:#FF0000][/COLOR]

Where is your filter located.... is it clean?
 
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Originally Posted By: Throt
I use a Filtrate Allergen filter. I have no doubts that it slows air flow but I also have absolutely terrible allergies year round. Allergist told me she's never seen such bad allergies in her career. So needless to say, the filter is staying for now until my immunotherapy fully kicks in.

This is one major problem: Your filter is too restrictive.

Many people confuse this issue. All the filter does is keep the coil clean. That's it. It's not meant to prevent/reduce your personal allergies, nor prevent dust from settling on furniture, nor clean your house. These are common misconceptions and marketing bravo sierra.

Too much pressure drop across the filter will cause poor airflow, increased current draw, & bowing of the filter. I'd suggest the minimum 3M pleated filter that comes encased in plastic wrap. I've discovered Purolator pleated filters to be far more restrictive than 3M, based on test data.

I suspect you're experiencing poor humidity removal because the evap coil isn't cold enough to lower the air temp below the dew point, despite the system running for hours on end.
 
Second photo from the bottom of your equipment:

1. The small dia uninsulated copper line is the liquid or high pressure line. It should be quite hot all the way up to where the metering device is, which may be inside the equipment case itself. Not sure if your unit uses a flow rater (cap tube) to TXV to meter refrigerant.

2. The large dia insulated line is the suction (vapor) line. It should be cool. This line has vapor flowing out of the evap coil that is returning to the compressor.

3. You're correct your system is restricted. The filter you're using is too restrictive. Further, why does the blower attempt to pull the door closed when your return air is in the ceiling? Doesn't make sense. You may have a leak then.

4. You state this system was installed three years ago. Has it always had a cooling/airflow problem?
 
Originally Posted By: KJSmith
"The supply line from the condenser reads at about 56 degrees right before it enters the a-coil."

Nope, that's the suction (return) line.

"Slowing the air should allow the air more time to have heat removed and increase dehumidification"

You have already said you feel there is not enough airflow.... and now you lowered it. Put it back.



If you want it diagnosed you need to know:
Outside ambient temperature
Head pressure
Suction pressure
Return air temperature


I discovered that the suggested CFM per ton of cooling is 400CFM. With the blower set to high it was moving 1,584CFM. Nearly double the required 800CFM based on my 2 ton system. The result was the air moving so quickly that it never had a chance to cool or have the humidity pulled out of it. Lowering the speed to Med-Lo moves about 900CFM according to Goodman. With the filter being restrictive it should move about 850CFM. On high it was attempting to move double the air over the coil. I've already noticed a huge improvement in cooling, run times and dehumidification. Dehumidifier has been unplugged for 12 hours and the humidity hasn't crossed 50%. A drastic improvement over the 68% it used to maintain. The door is no longer sucked shut either.

The wiring diagram even has a note on that the installer needs to adjust blower speed based on equipment. The apartment HVAC guy clearly did not do this.

I appreciate everyone's input. I think the problem is corrected!
 
That looks like a bad install job, the cap on the suction line is missing, which could lead to refrigerant leaking down the road. On the furnace the liquid line loops around and looks like poop ( wont affect the performance ). Just looking from installers point of view based on the 2 pictures you posted i'd say that somebody just slapped that system together and Got outta there in a hurry. Im glad u corrected the problem.
If they had pulled a permit for that install i would have failed them on numerous things based on just those pictures if i was the inspector.
 
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Originally Posted By: Merkava_4
If you stick a thermometer into the air vent register, what's it say ?


Yep....The typical Delta T as the pros call it is usually around
a 25 F degree difference between the ambient temp at the air inlet, and the just after the condenser where the cooled air vents into the rest of the vents for the home.
 
My mother-in-law was visiting at our home and offered to watch the kids so my wife and I could have a day to run some errands and see a movie. It was a very humid day with dew point at 71 degrees with a temperature of 92. The house was set at 76 degrees and everything was fine when we left.

We returned to a house that was 83 degrees and getting warmer. I asked my mother-in-law if she changed anything with the air conditioning and her reply was she only tried turning down the temperature (she set the thermostat to 60 degrees!). When I asked her why she turned it down so low, her response was it wasn't keeping cool at 76 so she kept turning it down lower and lower. (I didn't bother trying to explain that it didn't matter how low she turned the thermostat down- if it's calling for cooling, it will cool until it reaches the set temperature.)

I called a buddy who works in the heating business and he came over and immediately saw the problem- condensation was draining very slowly and the A-coil was frozen over. He said that her action of turning down the thermostat so low caused the compressor to run constantly causing excess condensation to eventually freeze up around the coil and restrict the airflow through the A-coil. After letting the coil "thaw", everything worked fine. My buddy further explained, that it takes a rare combination of high humidity and low airflow for that to happen. I have had that happen in a car before, but never in my household system.

Maybe that's what happened in this case.
 
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Originally Posted By: ctrcbob
I see your unit is a "Goodman". I had new AC put in back in 2010. They installed a Goodman. Did not work right. (The Air Handler was good but the outside compressor was junk). After a couple days, they removed the outside unit and replaced it with another Goodman. Went through FOUR Goodmans. Air never came out cold enough plus they did not dehumidify the house. They then replaced the outside unit with an Amana. No more problems. The Amana works great. As far as I'm concerned, Goodman is another word for junk. Thank
god my AC contractor is great and stands behind his work.


Amana and Goodman are the same company same assembly line.
 
Haven't read the whole thread, but is there a chance your evap coil is icing up? Low charge or wrong orifice can cause this - which results in little cooling and restricted air flow.
 
PROBLEM SOLVED FINALLY.

Well I was wrong, the problem wasn't solved before. While slowing the blower definitely helped something else was still clearly going on.

So after guy came out this morning he tried to tell me the flowrator in the evap coil was wrong the size. Well within three seconds online I found that to be a load of bull. So I took it upon myself to take the return apart and take a peak in the attic.

And all of our problems are caused by.....drum roll please.....

yqSkXIr.png



The whole freaking supply line has fallen off! So the blower has been sucking in roof heat and humidity! I called them and was just like yeaaaa I busted into the attic and found the problem. Now come fix it.

They'll be here in the morning.
 
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Originally Posted By: Throt
The whole freaking supply line has fallen off! So the blower has been sucking in roof heat and humidity! I called them and was just like yeaaaa I busted into the attic and found the problem. Now come fix it.

The supply side is pressurized and carries air from the dist. box to the air supply vents in the rooms.

The return side sucks air from the return air grille, through the filter and supplies it to the evap. coil.

So which is it?

Curious that your unit is only three yrs old and yet they used a flowrater. Must be a low SEER unit as most, if not all, high SEER units use TXV's.
 
That's awesome you found that Throt! I was going to say it might be undersized by a half ton also since that's a 2 ton. We had the same issues and had to go up a 1/2 ton and now the house is beyond comfortable even on the triple digit days! Before our unit did exactly like yours...Ran 24/7 and would maybe cool the house down to 80 during the days. If the return line doesn't fix it then that's the next step and not sure they would upsize that for you though.
 
Originally Posted By: sleddriver
Originally Posted By: Throt
The whole freaking supply line has fallen off! So the blower has been sucking in roof heat and humidity! I called them and was just like yeaaaa I busted into the attic and found the problem. Now come fix it.

The supply side is pressurized and carries air from the dist. box to the air supply vents in the rooms.

The return side sucks air from the return air grille, through the filter and supplies it to the evap. coil.

So which is it?


Curious that your unit is only three yrs old and yet they used a flowrater. Must be a low SEER unit as most, if not all, high SEER units use TXV's.





It was the return supply line. Sorry should've been more precise.

The condenser outside is approx. 6 years old, the a-coil is 3 weeks old. But this system definitely doesn't have a TXV. It's 13 SEER.
 
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Originally Posted By: Rtstrider
That's awesome you found that Throt! I was going to say it might be undersized by a half ton also since that's a 2 ton. We had the same issues and had to go up a 1/2 ton and now the house is beyond comfortable even on the triple digit days! Before our unit did exactly like yours...Ran 24/7 and would maybe cool the house down to 80 during the days. If the return line doesn't fix it then that's the next step and not sure they would upsize that for you though.


It crossed my mind that we might be undersized so I went and checked some of the neighbors and we actually have the biggest one! Everyone else has a 1.5 ton, we have a 2. They probably did that because of all the complaints that I'm sure this unit has gotten about it's HVAC over the years.

But, finally, it is fixed for good.

It got up to about 82 here today, system ran 4.5 hours, down from 12 on days like this before. And on hot days I was getting air coming out at about 66, today it was a chilly 52. An awesome 20 degree split from return and supply!
 
Originally Posted By: Throt
It was the return supply line. Sorry should've been more precise.

lol.gif
You're still confusing me....oh well. Good to hear you've got it fixed!
 
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