Central AC not Working Properly?

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Call_Me_Op
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Central AC not Working Properly?

Post by Call_Me_Op » Sun May 26, 2019 5:29 pm

I have an aging central A/C system. It is 14 years old. Recently, I had a refrigerant leak supposedly repaired and the system was recharged (with Puron - the newer stuff). Today it was 85 F-87 F (and sunny) outside and the AC would not reduce the 2nd floor temperature below 73 F when running constantly. This seems to be inadequate. Two questions:

1.) Does this seem like inadequate performance? My recollection is that it worked much better when system was younger.

2.) Should I dump more money into troubleshooting/repairing the existing system (paid ~$800 already this year) or should I spring for a new outside unit? It is a 3-ton Carrier system, 13 SEER.
Last edited by Call_Me_Op on Sun May 26, 2019 5:32 pm, edited 1 time in total.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

Broken Man 1999
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Re: Central AC not Working Properly?

Post by Broken Man 1999 » Sun May 26, 2019 5:32 pm

What temp are you shooting for?

We run at 74 and my daughters wear sweaters when they are at our casa for any length of time. They say we are hanging meat in the house!

Broken Man 1999

ETA: The current temp outside is 90, down from a high of 97.
Last edited by Broken Man 1999 on Sun May 26, 2019 5:36 pm, edited 1 time in total.
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Re: Central AC not Working Properly?

Post by Call_Me_Op » Sun May 26, 2019 5:33 pm

Broken Man 1999 wrote:
Sun May 26, 2019 5:32 pm
What temp are you shooting for?

We run at 74 and my daughter's wear sweaters when they are at our casa for any length of time. They say we are hanging meat in the house!

Broken Man 1999
I set it at 73, but it never shut off - which it would have done of temp has reached 72. In part, I was testing the system, since this is our first hot day of the year.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

Broken Man 1999
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Re: Central AC not Working Properly?

Post by Broken Man 1999 » Sun May 26, 2019 5:42 pm

How big is your home?

We have split system of 2 ton and 2.5 ton for 2800 sqft of heating/cooling. One Trane, one American Standard (same company). Heat pumps.

Broken Man 1999
“If I cannot drink Bourbon and smoke cigars in Heaven than I shall not go. " -Mark Twain

joe-kr
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Re: Central AC not Working Properly?

Post by joe-kr » Sun May 26, 2019 5:53 pm

I didn’t think you could just replace Freon (R-22)with Puron (R410-A), and I found this info on an HVAC website:

“You cannot just switch refrigerants because R410-A and R-22 have different chemical properties. R410-A operates at a higher pressure. If you put R410-A into an R-22 system, the parts will rupture due to the increased force.
You can convert your current system to one that runs on R-410A, but the cost will be high. You’ll need to replace the compressor, condenser and evaporator, and probably the refrigerant tubing, with equipment that can handle R410-A. It would be more cost effective to put that money toward a new system designed for R410-A.”

Broken Man 1999
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Re: Central AC not Working Properly?

Post by Broken Man 1999 » Sun May 26, 2019 6:01 pm

OP, if you are going to replace, I would try to limp along for the summer as you would be buying at peak season for AC work. You could probably do better in the fall.

Broken Man 1999
“If I cannot drink Bourbon and smoke cigars in Heaven than I shall not go. " -Mark Twain

student
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Re: Central AC not Working Properly?

Post by student » Sun May 26, 2019 6:23 pm

Have you tried measuring the temperature of the air coming out of the vent? This will help determine whether the AC is working properly.

Spirit Rider
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Re: Central AC not Working Properly?

Post by Spirit Rider » Sun May 26, 2019 6:36 pm

joe-kr wrote:
Sun May 26, 2019 5:53 pm
I didn’t think you could just replace Freon (R-22)with Puron (R410-A), and I found this info on an HVAC website:
This is correct, but Carrier was the first to offer R-410a residential systems more than 20 years ago under their Puron trademark. So it is entirely possible that the OP's system is designed for r-410a.

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TexasPE
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Re: Central AC not Working Properly?

Post by TexasPE » Sun May 26, 2019 6:38 pm

You can spend $15 on a laser temperature gun to determine whether the unit is cooling properly

https://georgebrazilhvac.com/blog/what- ... utting-out

https://www.amazon.com/HOLDPEAK-Non-Con ... pons&psc=1
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UpstateNY86
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Re: Central AC not Working Properly?

Post by UpstateNY86 » Sun May 26, 2019 7:06 pm

A temperature check doesn’t mean that much, especially in your situation. You know the unit is working, just not up to snuff. You need someone to take the pressures of the system, airflow check, and enthalpy change. The system could have just been charged not to proper specs. I would call the company who did the repair and say you would like a courtesy check.

UpstateNY86
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Re: Central AC not Working Properly?

Post by UpstateNY86 » Sun May 26, 2019 7:08 pm

I would think your system has a piston in the evap coil, and would need to be charged to the proper superheat. It’s a formula and has be done correct. If you do have someone come out, make sure they check the numbers properly.

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Re: Central AC not Working Properly?

Post by Spirit Rider » Sun May 26, 2019 7:09 pm

student wrote:
Sun May 26, 2019 6:23 pm
Have you tried measuring the temperature of the air coming out of the vent? This will help determine whether the AC is working properly.
While not a detailed diagnostic, the DeltaT is a good indication of the operating efficiency of the overall system. DeltaT is the difference between the air coming out of the supply vents and the air entering the return vents. Nominally, this should be at least 15 - 20 degrees. You don't need an HVAC thermometer, a typical meat thermometer or any other similar probe based thermometer works just fine.

Also, at very low refrigerant levels you may get frost or ice on the refrigerant lines. Check the lines at both entry to the outside condensor and inside air handler/evaporator.

Note: Other causes can trigger these symptoms, so they are not a guarantee that the problem is low refrigerant. Some of the other simple things to check are; Is the air filter dirty restricting air flow, is the outside coil dirty or restricted by debris or vegetation restricting heat transfer of the condensor, is the inside evaporator dirty, are there leaks in the duct work, etc...

The air filter is a pretty simple fix. Checking and removing or obstructions at the outside condensor is relatively easy, just don't damage the coil/fins. Cleaning the coils may beyond a typical homeowner (especially the evaporator). However, there are cans of foaming coil cleaner available at Home Depot, Lowes, Walmart, etc... There is a reason it is called "duct tape". It is not the most elegant, but check for major leaks and at least temporarily patch with duct tape.

That's all I have for simple homeowner checks and maybe corrective actions, but maybe worthwhile before calling an HVAC contractor.

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Re: Central AC not Working Properly?

Post by Turbo29 » Sun May 26, 2019 7:50 pm

joe-kr wrote:
Sun May 26, 2019 5:53 pm
I didn’t think you could just replace Freon (R-22)with Puron (R410-A), and I found this info on an HVAC website:

“You cannot just switch refrigerants because R410-A and R-22 have different chemical properties. R410-A operates at a higher pressure. If you put R410-A into an R-22 system, the parts will rupture due to the increased force.
You can convert your current system to one that runs on R-410A, but the cost will be high. You’ll need to replace the compressor, condenser and evaporator, and probably the refrigerant tubing, with equipment that can handle R410-A. It would be more cost effective to put that money toward a new system designed for R410-A.”
I had a R-22 system replaced with a R410-a system 7 years ago. New compressor, new air handler and coil, but same refrigerant lines between the outdoor unit (compressor) and air handler unit (evaporator) in the attic. Haven't had any problems with the lines taking the higher pressure. It's my understanding that the lines are not usually changed.

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Re: Central AC not Working Properly?

Post by Call_Me_Op » Mon May 27, 2019 6:28 am

joe-kr wrote:
Sun May 26, 2019 5:53 pm
I didn’t think you could just replace Freon (R-22)with Puron (R410-A), and I found this info on an HVAC website:

“You cannot just switch refrigerants because R410-A and R-22 have different chemical properties. R410-A operates at a higher pressure. If you put R410-A into an R-22 system, the parts will rupture due to the increased force.
You can convert your current system to one that runs on R-410A, but the cost will be high. You’ll need to replace the compressor, condenser and evaporator, and probably the refrigerant tubing, with equipment that can handle R410-A. It would be more cost effective to put that money toward a new system designed for R410-A.”
Nobody swapped type of refrigerant. I have always had Puron in this system.

It is a 3 ton Carrier system servicing a 1700 sq foot 2-story home (single unit for entire house). For the first 12-13 years, it did work great - so no fundamental issues.

Filter is brand new.

I suspect that the system was not recharged properly. I plan to get the AC company back out here to check. It was charged on a fairly cold day, which may have affected ability to properly charge.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

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Re: Central AC not Working Properly?

Post by Call_Me_Op » Mon May 27, 2019 6:41 am

Broken Man 1999 wrote:
Sun May 26, 2019 6:01 pm
OP, if you are going to replace, I would try to limp along for the summer as you would be buying at peak season for AC work. You could probably do better in the fall.

Broken Man 1999
Thanks for the tip. I could possible limp along, but not with it in its current state. First heat wave would drive me out of my home.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

Broken Man 1999
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Re: Central AC not Working Properly?

Post by Broken Man 1999 » Mon May 27, 2019 10:01 am

Call_Me_Op wrote:
Mon May 27, 2019 6:41 am
Broken Man 1999 wrote:
Sun May 26, 2019 6:01 pm
OP, if you are going to replace, I would try to limp along for the summer as you would be buying at peak season for AC work. You could probably do better in the fall.

Broken Man 1999
Thanks for the tip. I could possible limp along, but not with it in its current state. First heat wave would drive me out of my home.
Living in the Sunshine State, I completely understand. Summers can be brutal.

Broken Man 1999
“If I cannot drink Bourbon and smoke cigars in Heaven than I shall not go. " -Mark Twain

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Re: Central AC not Working Properly?

Post by neilpilot » Mon May 27, 2019 11:11 am

Turbo29 wrote:
Sun May 26, 2019 7:50 pm


I had a R-22 system replaced with a R410-a system 7 years ago. New compressor, new air handler and coil, but same refrigerant lines between the outdoor unit (compressor) and air handler unit (evaporator) in the attic. Haven't had any problems with the lines taking the higher pressure. It's my understanding that the lines are not usually changed.
...and in 2010 I had a R22 compressor replaced with a new R410A outdoor unit and furnace/air handler in attic, and had to replace the tubing from attic to outdoor unit. Not specifically because it would not handle pressure, but because the old tubing was undersized for the newer unit (although no change in tonnage).

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Re: Central AC not Working Properly?

Post by Call_Me_Op » Mon May 27, 2019 11:20 am

Retracted
Last edited by Call_Me_Op on Mon May 27, 2019 1:24 pm, edited 1 time in total.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

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Re: Central AC not Working Properly?

Post by Grt2bOutdoors » Mon May 27, 2019 11:30 am

Call_Me_Op wrote:
Mon May 27, 2019 11:20 am
Update: the company that supposedly repaired my leak and re-charged my refrigerant about 6 weeks ago is playing games - and has essentially blown me off.* I find that this type of unprofessional behavior is all too common.

* When I called today to set-up an appointment, the guy who answered the phone told me "I am not at the computer. Let me call you back in 10 minutes." 45 minutes later, I had not received a call and called him back. He said "I got distracted. I will call you back in 2 minutes." He never called me back.

Interestingly, they have a 30 day guarantee on labor, and it has been 40 days.
You may have a slow leak in the system. First, find yourself a reputable HVAC company, then have them check for leaks including at the compressor where the freon is added. Then, if no leaks, add more freon. Perhaps, if your local utility offers it, consider signing up for a monthly maintenance plan of A/C unit.
"One should invest based on their need, ability and willingness to take risk - Larry Swedroe" Asking Portfolio Questions

cherijoh
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Re: Central AC not Working Properly?

Post by cherijoh » Mon May 27, 2019 11:31 am

Call_Me_Op wrote:
Sun May 26, 2019 5:29 pm
I have an aging central A/C system. It is 14 years old. Recently, I had a refrigerant leak supposedly repaired and the system was recharged (with Puron - the newer stuff). Today it was 85 F-87 F (and sunny) outside and the AC would not reduce the 2nd floor temperature below 73 F when running constantly. This seems to be inadequate. Two questions:

1.) Does this seem like inadequate performance? My recollection is that it worked much better when system was younger.

2.) Should I dump more money into troubleshooting/repairing the existing system (paid ~$800 already this year) or should I spring for a new outside unit? It is a 3-ton Carrier system, 13 SEER.
I had the HVAC company come out and do some kind of leak test. They added something to the refrigerant that could be picked up by an instrument to pinpoint where the refrigerant was leaking. I ended up with leakage in a place that couldn't be easily or cheaply fixed. The HVAC company did credit the charge for the leak test against a new system.

If it were late in the season I'd try to limp through to get a better price on a new system. But not for the first hot day of the year.

Housedoc
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Re: Central AC not Working Properly?

Post by Housedoc » Mon May 27, 2019 11:40 am

The coil above air handler/ furnace usually is the issue not outside coil. Hard to find tiny leaks. Maybe try a service guy who will add some leak stop when he adds freon. May get you through till bargain time in the fall. Top dollar this time of year, no year end model closeouts. Not worth being miserable all summer so you may have to unload some investment dollars to save your sanity, possibly marriage too!

msk
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Re: Central AC not Working Properly?

Post by msk » Mon May 27, 2019 1:45 pm

Call_Me_Op wrote:
Sun May 26, 2019 5:29 pm
I have an aging central A/C system. It is 14 years old. Recently, I had a refrigerant leak supposedly repaired and the system was recharged (with Puron - the newer stuff). Today it was 85 F-87 F (and sunny) outside and the AC would not reduce the 2nd floor temperature below 73 F when running constantly. This seems to be inadequate. Two questions:

1.) Does this seem like inadequate performance? My recollection is that it worked much better when system was younger.

2.) Should I dump more money into troubleshooting/repairing the existing system (paid ~$800 already this year) or should I spring for a new outside unit? It is a 3-ton Carrier system, 13 SEER.
I would be happy with the 14 years delivered. Just change the system, indoor and outdoor units and be happy for another 10 years. Not worth the fight. Also make sure that the new system is adequately sized for your desires. Somebody who wants 68 degrees (hotel rooms with electricity bill paid by somebody else) on the hottest days will require a bigger system than somebody who is happy with 75. Of course it also depends on how hot your local climate gets. For 1700 sq ft I would normally use 5 tons but we get 105 degree days going on and on...

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Re: Central AC not Working Properly?

Post by Call_Me_Op » Mon May 27, 2019 3:53 pm

msk wrote:
Mon May 27, 2019 1:45 pm
Call_Me_Op wrote:
Sun May 26, 2019 5:29 pm
I have an aging central A/C system. It is 14 years old. Recently, I had a refrigerant leak supposedly repaired and the system was recharged (with Puron - the newer stuff). Today it was 85 F-87 F (and sunny) outside and the AC would not reduce the 2nd floor temperature below 73 F when running constantly. This seems to be inadequate. Two questions:

1.) Does this seem like inadequate performance? My recollection is that it worked much better when system was younger.

2.) Should I dump more money into troubleshooting/repairing the existing system (paid ~$800 already this year) or should I spring for a new outside unit? It is a 3-ton Carrier system, 13 SEER.
I would be happy with the 14 years delivered. Just change the system, indoor and outdoor units and be happy for another 10 years. Not worth the fight. Also make sure that the new system is adequately sized for your desires. Somebody who wants 68 degrees (hotel rooms with electricity bill paid by somebody else) on the hottest days will require a bigger system than somebody who is happy with 75. Of course it also depends on how hot your local climate gets. For 1700 sq ft I would normally use 5 tons but we get 105 degree days going on and on...
Maybe I should opt for 4 ton. We sometimes get close to 100 for several days.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

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Re: Central AC not Working Properly?

Post by Grt2bOutdoors » Mon May 27, 2019 8:18 pm

Call_Me_Op wrote:
Mon May 27, 2019 3:53 pm
msk wrote:
Mon May 27, 2019 1:45 pm
Call_Me_Op wrote:
Sun May 26, 2019 5:29 pm
I have an aging central A/C system. It is 14 years old. Recently, I had a refrigerant leak supposedly repaired and the system was recharged (with Puron - the newer stuff). Today it was 85 F-87 F (and sunny) outside and the AC would not reduce the 2nd floor temperature below 73 F when running constantly. This seems to be inadequate. Two questions:

1.) Does this seem like inadequate performance? My recollection is that it worked much better when system was younger.

2.) Should I dump more money into troubleshooting/repairing the existing system (paid ~$800 already this year) or should I spring for a new outside unit? It is a 3-ton Carrier system, 13 SEER.
I would be happy with the 14 years delivered. Just change the system, indoor and outdoor units and be happy for another 10 years. Not worth the fight. Also make sure that the new system is adequately sized for your desires. Somebody who wants 68 degrees (hotel rooms with electricity bill paid by somebody else) on the hottest days will require a bigger system than somebody who is happy with 75. Of course it also depends on how hot your local climate gets. For 1700 sq ft I would normally use 5 tons but we get 105 degree days going on and on...
Maybe I should opt for 4 ton. We sometimes get close to 100 for several days.
No, you should opt for a qualified HVAC company to do the correct calculation on how much tonnage you actually need to efficiently cool down your home. Has such a calculation been done already?
"One should invest based on their need, ability and willingness to take risk - Larry Swedroe" Asking Portfolio Questions

6Pack
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Re: Central AC not Working Properly?

Post by 6Pack » Mon May 27, 2019 8:49 pm

If you are comfortable with doing some work on your system, get a manifold gauge set (they are specific to each type of refrigerant, such as R-12, R-22, R-134a, R-410a, etc...) off Amazon, hook it up to your high side and low side, which will be near your outdoor unit and do some troubleshooting.

If I had to guess, I’d say you have a minor leak and your refrigerant lines are iced up too.

Don’t guess on the tonnage - too low and you’ll run nonstop, too much and you’ll be cycling too often, which will burn out your compressor.

If you are trying to limp along, get some box fans and open up all of your doors so your returns will be working 100%.

FWIW, I’m a government employee and a side hustle lawyer, not an HVAC person. I also replaced my system last spring and asked a lot of questions while I was getting my quotes.
Last edited by 6Pack on Tue May 28, 2019 6:34 am, edited 1 time in total.

msk
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Re: Central AC not Working Properly?

Post by msk » Tue May 28, 2019 4:05 am

Grt2bOutdoors wrote:
Mon May 27, 2019 8:18 pm
Call_Me_Op wrote:
Mon May 27, 2019 3:53 pm
msk wrote:
Mon May 27, 2019 1:45 pm
Call_Me_Op wrote:
Sun May 26, 2019 5:29 pm
I have an aging central A/C system. It is 14 years old. Recently, I had a refrigerant leak supposedly repaired and the system was recharged (with Puron - the newer stuff). Today it was 85 F-87 F (and sunny) outside and the AC would not reduce the 2nd floor temperature below 73 F when running constantly. This seems to be inadequate. Two questions:

1.) Does this seem like inadequate performance? My recollection is that it worked much better when system was younger.

2.) Should I dump more money into troubleshooting/repairing the existing system (paid ~$800 already this year) or should I spring for a new outside unit? It is a 3-ton Carrier system, 13 SEER.
I would be happy with the 14 years delivered. Just change the system, indoor and outdoor units and be happy for another 10 years. Not worth the fight. Also make sure that the new system is adequately sized for your desires. Somebody who wants 68 degrees (hotel rooms with electricity bill paid by somebody else) on the hottest days will require a bigger system than somebody who is happy with 75. Of course it also depends on how hot your local climate gets. For 1700 sq ft I would normally use 5 tons but we get 105 degree days going on and on...
Maybe I should opt for 4 ton. We sometimes get close to 100 for several days.
No, you should opt for a qualified HVAC company to do the correct calculation on how much tonnage you actually need to efficiently cool down your home. Has such a calculation been done already?
A good HVAC engineer would try to size the unit to match precisely what HE thinks you want. E.g a temperature of 72 degrees with a couple of occupants in a small dwelling. But since many of us cannot even agree with the spouse exactly what temperature to set in which room... I have built many houses and apartments over the decades and I have come to the conclusion that a "correctly" sized unit can be extremely annoying when you have a lot of guests for that birthday party/funeral, etc. Hence I have grown to prefer some over-sizing rather than accurate sizing. Discuss with your HVAC engineer. Last summer we've been having a large family group dinner weekly at my mother's house. The HVAC was well matched all week but disastrously under-sized for the family dinner with the kids constantly hopping in and out letting in hot air. Solution: added a 2 ton split unit that gets used on those weekends that are especially hot. Nirvana! If you wish to battle on with the 14 year-old HVAC, adding a 1 ton split unit (does not matter in which room since the central HVAC system circulates air around anyway) ought to take care of the super hot spells (or parties).

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Re: Central AC not Working Properly?

Post by Call_Me_Op » Tue May 28, 2019 6:40 am

Grt2bOutdoors wrote:
Mon May 27, 2019 8:18 pm
Call_Me_Op wrote:
Mon May 27, 2019 3:53 pm
msk wrote:
Mon May 27, 2019 1:45 pm
Call_Me_Op wrote:
Sun May 26, 2019 5:29 pm
I have an aging central A/C system. It is 14 years old. Recently, I had a refrigerant leak supposedly repaired and the system was recharged (with Puron - the newer stuff). Today it was 85 F-87 F (and sunny) outside and the AC would not reduce the 2nd floor temperature below 73 F when running constantly. This seems to be inadequate. Two questions:

1.) Does this seem like inadequate performance? My recollection is that it worked much better when system was younger.

2.) Should I dump more money into troubleshooting/repairing the existing system (paid ~$800 already this year) or should I spring for a new outside unit? It is a 3-ton Carrier system, 13 SEER.
I would be happy with the 14 years delivered. Just change the system, indoor and outdoor units and be happy for another 10 years. Not worth the fight. Also make sure that the new system is adequately sized for your desires. Somebody who wants 68 degrees (hotel rooms with electricity bill paid by somebody else) on the hottest days will require a bigger system than somebody who is happy with 75. Of course it also depends on how hot your local climate gets. For 1700 sq ft I would normally use 5 tons but we get 105 degree days going on and on...
Maybe I should opt for 4 ton. We sometimes get close to 100 for several days.
No, you should opt for a qualified HVAC company to do the correct calculation on how much tonnage you actually need to efficiently cool down your home. Has such a calculation been done already?
When the system was first installed, I assume that the installer did that calculation. The system worked well until last year, when it developed a leak. Leak was supposedly fixed last month and system re-charged, but still not functioning well. My guess is it was not properly charged or leak was not properly fixed.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

criticalmass
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Re: Central AC not Working Properly?

Post by criticalmass » Tue May 28, 2019 11:10 pm

joe-kr wrote:
Sun May 26, 2019 5:53 pm
I didn’t think you could just replace Freon (R-22)with Puron (R410-A), and I found this info on an HVAC website:

“You cannot just switch refrigerants because R410-A and R-22 have different chemical properties. R410-A operates at a higher pressure. If you put R410-A into an R-22 system, the parts will rupture due to the increased force.
You can convert your current system to one that runs on R-410A, but the cost will be high. You’ll need to replace the compressor, condenser and evaporator, and probably the refrigerant tubing, with equipment that can handle R410-A. It would be more cost effective to put that money toward a new system designed for R410-A.”
Where did you see that anyone replaced r22 with r410a? I only saw that additional 410a was added. Issue with 410a is that to get the charge right, you can’t just add more (like a r22 system), you need to evacuate and meter carefully due to the properties of 410a, which contains more than one compound.

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Re: Central AC not Working Properly?

Post by Call_Me_Op » Wed May 29, 2019 7:37 am

criticalmass wrote:
Tue May 28, 2019 11:10 pm
joe-kr wrote:
Sun May 26, 2019 5:53 pm
I didn’t think you could just replace Freon (R-22)with Puron (R410-A), and I found this info on an HVAC website:

“You cannot just switch refrigerants because R410-A and R-22 have different chemical properties. R410-A operates at a higher pressure. If you put R410-A into an R-22 system, the parts will rupture due to the increased force.
You can convert your current system to one that runs on R-410A, but the cost will be high. You’ll need to replace the compressor, condenser and evaporator, and probably the refrigerant tubing, with equipment that can handle R410-A. It would be more cost effective to put that money toward a new system designed for R410-A.”
Where did you see that anyone replaced r22 with r410a? I only saw that additional 410a was added. Issue with 410a is that to get the charge right, you can’t just add more (like a r22 system), you need to evacuate and meter carefully due to the properties of 410a, which contains more than one compound.
My system was drained and refilled, but it was done on a fairly cold day (upper 50's), maybe 60. Not sure if that affects how well the system can be charged. In any case, not working well now, and having HVAC company back on Friday.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

Spirit Rider
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Re: Central AC not Working Properly?

Post by Spirit Rider » Wed May 29, 2019 8:24 am

If the charge was weighed in properly, the temp that day should not have mattered. However, to assess the balance of the charge, you really need a load on the system. Preferably at least 80 - 90 degrees.

Everybody including you are focusing on the refrigerant charge. While that may be the problem, as I already pointed out, their are many other factors that could be a contributing cause.

On a 14 year old system, at a minimum they should be checking not only the filter, but the cleanliness of both the indoor and outdoor coils. Often the indoor coil is overlooked.

An A/C system is a heat transfer system. Restricted irflow and any buildup on the coils will reduce system efficiency. Sometimes significantly. Not to mention that there could be other causes (blocked or malfunctioning refrigerant metering device, compressor issues, etc...).

Broken Man 1999
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Re: Central AC not Working Properly?

Post by Broken Man 1999 » Wed May 29, 2019 12:26 pm

Prior to replacing one of my heat pumps, the A.C. tech found a partially clogged drain line that would sometimes trip a control that shut down the unit until the catch pan no longer was in danger of overflowing. Unit was in the attic.

When the techs looked at the exit point, they would see it draining, so things looked OK. He blew out the line, fixed the problem, worked fine a few more years.

Any chance your A.C. is turning off occasionally?


Broken Man 1999
“If I cannot drink Bourbon and smoke cigars in Heaven than I shall not go. " -Mark Twain

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Call_Me_Op
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Re: Central AC not Working Properly?

Post by Call_Me_Op » Wed May 29, 2019 5:19 pm

Broken Man 1999 wrote:
Wed May 29, 2019 12:26 pm
Prior to replacing one of my heat pumps, the A.C. tech found a partially clogged drain line that would sometimes trip a control that shut down the unit until the catch pan no longer was in danger of overflowing. Unit was in the attic.

When the techs looked at the exit point, they would see it draining, so things looked OK. He blew out the line, fixed the problem, worked fine a few more years.

Any chance your A.C. is turning off occasionally?


Broken Man 1999
No, both the blower and compressor run constantly unless/until the temperature falls below the set-point.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

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Call_Me_Op
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Re: Central AC not Working Properly?

Post by Call_Me_Op » Wed May 29, 2019 5:21 pm

Spirit Rider wrote:
Wed May 29, 2019 8:24 am
If the charge was weighed in properly, the temp that day should not have mattered. However, to assess the balance of the charge, you really need a load on the system. Preferably at least 80 - 90 degrees.

Everybody including you are focusing on the refrigerant charge. While that may be the problem, as I already pointed out, their are many other factors that could be a contributing cause.

On a 14 year old system, at a minimum they should be checking not only the filter, but the cleanliness of both the indoor and outdoor coils. Often the indoor coil is overlooked.

An A/C system is a heat transfer system. Restricted irflow and any buildup on the coils will reduce system efficiency. Sometimes significantly. Not to mention that there could be other causes (blocked or malfunctioning refrigerant metering device, compressor issues, etc...).
You are correct - the problem could be elsewhere, but I definitely had a refrigerant leak in the system recently. Perhaps the leak was fixed and there is still something wrong, but Occam's razor suggests that it is more likely that the leak was not actually fixed or the system was not properly re-charged after the leak was addressed (or both).
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

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Call_Me_Op
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Re: Central AC not Working Properly?

Post by Call_Me_Op » Sat Jun 01, 2019 5:46 am

Update: Technician returned yesterday and found that refigerant was low. He felt that I do not currently have a leak, but that he did not charge the system completely back 6 weeks ago because it was getting cold outside. He added some R410A and the system is now cooling like it did when it was new. Time will tell if it is fixed.

Delta T between return and supply is now 21F.

He did not charge me any additional money for the visit.

Thanks for your interest.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

student
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Re: Central AC not Working Properly?

Post by student » Sat Jun 01, 2019 5:52 am

Thanks for the update.

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Re: Central AC not Working Properly?

Post by Call_Me_Op » Sat Jun 01, 2019 5:55 am

student wrote:
Sat Jun 01, 2019 5:52 am
Thanks for the update.
Thanks student. To answer your earlier question, temp of air coming out of vent was 64F before adding R410A, 49F after.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

UpstateNY86
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Re: Central AC not Working Properly?

Post by UpstateNY86 » Sat Jun 01, 2019 6:28 am

Thats what I figured. Glad to hear you are all set now.

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Re: Central AC not Working Properly?

Post by Call_Me_Op » Sun Jun 02, 2019 6:27 am

UpstateNY86 wrote:
Sat Jun 01, 2019 6:28 am
Thats what I figured. Glad to hear you are all set now.

Thanks Upstate.
Best regards, -Op | | "In the middle of difficulty lies opportunity." Einstein

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