HVAC Advice Sought

[infotech]

Hey all,

As big as this place is, I'm sure there are some HVAC experts around and I need some help.

To make a long story short, I have a home warranty that covers part of central ac replacement. My central AC stopped cooling Saturday so they sent a tech out. My AC is cooling again, but for a couple of reasons the tech recommended that I change out the outside compressor. The warranty covers $1150 of the cost and I have to pick up $850. If I go through with it they are installing a Fedders 3.5 ton 13 SEER efficiency. My current AC is a Trane 3.5 Ton 10 efficiency which is about 10 years old.

They are replacing my compressor with an R22 because that's what my coil is and the warranty company won't cover the replacement of the coil because it's still working. Being that it's about 10 years old the tech said I might get a couple of more years out of it. This is where I'm starting to get concerned.

I just read up about the R22 phase out.

If my coil goes out in 2 years will I stilll be able to get it replaced or serviced with R22, or will I have to upgrade my entire system to an R410A?

Thanks!

 

[biomesh]

I'm no expert, but if you are going to spend money on replacing part of an AC system, I'd look at something with a higher SEER rating. My house is six years old and 13 seer was the norm back then. Now there are 21-23 SEER systems that will save you lots of money in just a few years on electricity costs (especially in Houston). You might spend a bit more now, but you will reap the savings over the long run.

 

[porterhaus]

I believe that you should be able to still get it repaired. R-22 is becoming scarcer (and much more expensive). There is a huge base of existing R-22 equipment that will continue to need repairs.

Newly manufactured equipment will have to use non-hcfc refrigerants beginning in 2010. So, if you really needed or wanted to replace the entire system I would recommend going ahead and getting the alternative refrigerant equipment now. However, your equipment may last quite a while (or not). It is impossible for me to know. My parent's system was still running after 30+ years when it was replaced.

I can understand why a service technician would recommend upgrading the outside condensing unit. (They usually get some sort of sales commission.) And higher efficiency equipment will save $ on power bills. The most efficient equipment is typically priced pretty high though; it would take more than a few years of savings on power bills to pay for the difference.

Hope this helps.

 

[AdrianR]

My central AC stopped cooling Saturday so they sent a tech out. My AC is cooling again, but for a couple of reasons the tech recommended that I change out the outside compressor.

Hmmm...10 years old isn't that much...IMHO the unit should be good for a few more years. What, exactly, was the problem? Did the tech tell you? What does his service sheet say? Why are they saying to change the compressor if there's nothing wrong with it?

In 6 years of sub-tropical Mexico (where the AC mini-split units get punished harshly by heavy use in 100% humidity) we have only ever had a start capacitor go out on one compressor and a control board on another. The apartment has a 3 ton, a 2 ton, a 1 ton and a double fan 1.5 ton Samsung units. And yes, I dread receiving the power bill in summer!

 

[infotech]

Hmmm...10 years old isn't that much...IMHO the unit should be good for a few more years. What, exactly, was the problem? Did the tech tell you? What does his service sheet say? Why are they saying to change the compressor if there's nothing wrong with it?

In 6 years of sub-tropical Mexico (where the AC mini-split units get punished harshly by heavy use in 100% humidity) we have only ever had a start capacitor go out on one compressor and a control board on another. The apartment has a 3 ton, a 2 ton, a 1 ton and a double fan 1.5 ton Samsung units. And yes, I dread receiving the power bill in summer!

Well, Houston is pretty hot and humid year round. From what I understand AC units have about half life around here. However, I have seen some pretty old ones still in commission. I may look into the warranty on my current compressor.

Here is what he said about it:
Found AC not cooling due to compressor over amping and not pumping properly.

He mentioned that it was pulling more amps than it was rated for until he cleaned the coil and then it went back down to the rated amps, which is around 20. I felt the system begin cooling after he closed the door to the coil and turned it back on.

Turns out there's a nice tax credit for going to the new coolant. If you get a 16 SEER R410 system you can get $1500 from Uncle Sam. On top of that, our home warranty covers $1150 so I'm really considering upgrading.

However, that's still quite a bit of money and I don't want to throw out a good system that can be repaired and last another 10 years...

 

[biomesh]

My only other comment is to deal with someone you trust.

AC problems during the summmer in Houston are not fun.

 

[infotech]

My only other comment is to deal with someone you trust.

AC problems during the summmer in Houston are not fun.

I agree.

Right now, I can tell you they are trying to rake me over the coals and it really... makes me mad. It has only taken me about 4 hours to read enough information to know just how bad they were trying to screw me over.

 

[missnu]

First if, they are going to recommend changing the condensing unit, they also need to change the air handler. It makes no sense to me stick a supposedly higher seer condensing unit with a lower seer air handler also by different manufacturers.

The tech said that the compressor was running high amps which could mean an overcharge of refrigerant, bad condenser fan motor, restriction in the refrigerant cycle or dirty condenser coil. Sounds like you just had a dirty condenser coil. Did he give you an amperage reading after he cleaned the coils?

Then he proceeds to tell you that it is not pumping correctly. This sounds like he is trying to say the compressor has bad valves. You have a 10 year old Trane unit which should have the orange compressor with roto-locks. There are other checks he could have done to check the pistons and discharge valve operation inside the compressor instead of saying that it is not pumping correctly.

Basically he is trying to make a sell. If your system is cooling fine after the cleaning I bet that was the only problem, a dirty condenser coil which is a common occurrence if the unit has not been routinely serviced. There is no way to definitely determine the longevity of a unit. Here in Florida, I have seen some units running after 35 years of operation and some last only seven over on the coast because of the corrosion that occurs from the salt in the ocean.

The aforementioned R-22 will be phased out and will become more expensive but it will still be available. At this point if I were you I would stay with your current system. When and if it does crap out then look at getting the 410a system and please get it from another company.

 

[infotech]

Thanks for your thoughts missnu and everyone.

I read up a bit more and came across the same thing you said. I called back the warranty company and needless to say they're going to cover the cost of the coil replacement.

I am tempted to stay with the current system, however having a warranty cover nearly half of the replacement, plus the tax rebate at the end of the year, I might just pull the trigger on the new 410A system and get it out of the way.

It would be my luck that if I stay with the current system it would flake out in two months when the home warranty expires.

I'm a lot happier now that they're going to cover the coil replacement.

 

[porterhaus]

I would suggest getting something in writing from the warranty company before you actually pull the trigger. Sometimes people will just tell you what you want to hear. Then when it comes to actually making good on their promise, they get amnesia.

 

[infotech]

Here's how this story ends for now.

A friend of a friend owns an AC business and came out and looked at my AC Sunday. He walked me through the whole system, showed me where it was leaking, and left me with some duct sealant. He said after I get the system sealed to call him back out and he's going to charge it with R22 coolant.

Later that day my brother in law and I ripped out the degraded sheet rock that made up the walls of the air in take and replaced it with plywood, installed another 20x20x1 air intake grill and sealed the whole thing up with silicone and expanding foam. That evening I sealed one of the ducts. My goal is to seal two an evening until I'm finished. There were also some leaks around the coil housing. That sheet rock was the same age as the house. The reason I know that for a fact is because I found two Schlitz beer cans in the wall dated 1973! One was a "Tall Boy" 3/4 of a Quart (that's how it was labeled) and the other was a regular sized can. Those cans were put together like spray paint cans are today. I don't think you'd want to try and crush one on your head...

I went home at 3 PM today, which is normally the hottest part of the day around here and my AC was running, but the temperature inside was equal to what I set the thermostat to (80). Within 5 minutes of being there the AC turned off as it had caught up to the set temperature.

 

[skankpile]

I live in Houston, and a couple of things on AC units I've found.

- If you have a decent (newer) unit I'll bet that your air handler is a variable speed blower, and regardless of your outside compressor you CAN take advantage of this with the correct settings and humidistat. In Houston have the blower high cool speed set to low (helps control humidity), and have the shutoff setting to full stop (no slow down for 90/60/30 secs as it will pump the humid air back into your house.)

-make sure not to have a humidistat that cools by supercooling. The humidistat MUST be able to detect humidity and output to the DH pin on the handler controller board to slow down the blower to dehumidify.

Download the technical manuals and read them yourself. AC units are not rocket science as every installer would have you believe. After dealing with local AC contractors I've rewired mine myself and am finally happy. You must get a knowledgeable AC specialist, as most people pass the test, but don’t know squat about configuring the units.

If you want it done right...