When to replace 30 year old A/C

[Todd.Brock]

Hey all,

We bought our house two years ago and the Trane split system is original. PO had a furnace done in 2014. It is still plugging along. I had the coils cleaned and 1 lb freon added this summer. Tech said pressures were high and running at FLA. cleaned the coils and amps came down down as well as pressures. He didn't try to sell me anything, but I'm sure this thing is inefficient as all hell.

Is the payback enough that I replace it and it starts paying for itself or just run till it dies??

I figure I have to pay someone - either electric company or HVAC company. Cincinnati Ohio- 2500 sq ft 2 story house. Low to medium insulation level, spent about $320 /month on electric in July aug sept - keep house at 72.

 

[sms1974]

As a HVAC contractor I'd tell you to run it till it dies, spend money this year on insulation and any bad windows and doors... Next year look at replacing it... Yes a new unit will be more energy efficent but its not going to cut your bill as much as insulating will help

 

[theoldwizard1]

As a HVAC contractor I'd tell you to run it till it dies, spend money this year on insulation and any bad windows and doors... Next year look at replacing it... Yes a new unit will be more energy efficent but its not going to cut your bill as much as insulating will help

For folks with older A/C units, the older refrigerant is going to go out of production in the next 5 - 10 years, so the cost will go up !!

 

[Corndoggeh]

I believe you and I have nearly identical Trane units, if its running R-22 the production of it in the US will be banned within the next 10 years, but until then, run it until it dies or freon gets far too expensive. Considering your home is about the same as mine being 2 stories and about the same square footage, it will be an expensive replacement considering needing a big crane and all to get it up there so just start putting cash away for a new one over the next couple of years.

 

[EdT]

The simple payback might be something like this. You're in OHIO where I'd guess you have about 3 months of heavy AC use a year and let's say that $200 of your $320 bill is AC operating cost. Now let's assume that your current system is X efficient and that a new system is 2X. That is, the new system will only cost you $100 a month to run for 3 months each year so you'll save $300 a year on power to run the system. Now let's assume that you fall for all the fancy bells and whistles and get a system that costs you $6000. The money saved on power will break even in only 20 years. Of course it's not quite that simple taking maintenance and repair costs into account, but the 2X efficiency is pretty unlikely as well and the higher the SEER, the more complex the system becomes and the reliability drops and the circuit boards become more expensive. So, as suggested above, run it 'til it drops, but figure out what you want to replace it with before you have the catastrophic failure in the hottest month of the year. That way you can already know what the next step needs to be w/o making a poor decision in the "heat" of the moment. IMHO, the extra cost for the high SEER units does not pay back in a reasonable time frame and the likelihood of failure of high end systems is not a great deal either. In addition the more complex the system the lower the chance that it'll get fixed correctly. My neighbor had a very complex system installed in a very fancy house and it took about ten years before it ever worked properly. Bad payback there.

 

[danski0224]

Hey all,

We bought our house two years ago and the Trane split system is original. PO had a furnace done in 2014. It is still plugging along. I had the coils cleaned and 1 lb freon added this summer. Tech said pressures were high and running at FLA. cleaned the coils and amps came down down as well as pressures. He didn't try to sell me anything, but I'm sure this thing is inefficient as all hell.

Is the payback enough that I replace it and it starts paying for itself or just run till it dies??

I figure I have to pay someone - either electric company or HVAC company. Cincinnati Ohio- 2500 sq ft 2 story house. Low to medium insulation level, spent about $320 /month on electric in July aug sept - keep house at 72.

I would never suggest evaluating HVAC equipment based upon "payback" scenarios.

Very efficient equipment must be installed properly and the ductwork must be sized properly to get the airflow that the high SEER (over 13) equipment requires and 14+ SEER requires a variable speed furnace blower motor, so if the PO cheeped out there, you'll never get it...

There are 2 major things to keep in mind about HVAC equipment:

(1) The furnace will never fail in July
(2) The air conditioner will never fail in January

You are at least 10 years beyond what is considered to be a normal service life expectancy given approximately 6 months or less usage per year. Some would say 15.

Running it until it breaks could leave you in a position to be taken advantage of or even an emergency like freezing pipes. Installation of a preferred system requiring major changes could be shelved due to timing.

Approximately 50% of your annual energy usage is for heating and cooling, yet very few people make smart decisions with respect to HVAC.

Yes, you will likely see a fairly significant reduction in monthly operating costs if your existing equipment is oversized and if the replacement is properly sized.

Variable speed furnace motors (also used when the AC is on ) will only deliver the claimed energy efficiency if the total external static pressure is kept to design limits of 0.50" of water column- which is extraordinarily difficult to do. Some savings could be realized at a TESP of 0.80" of water column compared to a regular permanent split capacitor motor. However, variable speed blower motors will use more energy than a traditional split capacitor motor as the TESP climbs over 0.80" wc and the motor life will be shortened.

Those 1" pleated filters are actually costing you money to use- and are worse when people leave them in for 90+ days because the package says so

 

[bonneyman]

Lots of good advice here.

 

[mygarageone]

I have never been an advocate of replacing equipment because it's old . If it's working and doing what it was designed to do , can be repaired . Leave it be . Ok. So in 5-7 yrs it is no longer reasonable to repair . Then replace but in the mean time sock some money away for replacement .
And besides technoligy is changing so fast when you do have to replace it , you be into the latest there is .

 

[Git]

Any rebates from your power company?

I just checked ours and they will pay $750 - that would help ease the pain a little bit

https://www.sce.com/wps/portal/home...0FBIS9nQSEh/?from=residential/rebates-savings

 

[danski0224]

I have never been an advocate of replacing equipment because it's old . If it's working and doing what it was designed to do , can be repaired . Leave it be . Ok. So in 5-7 yrs it is no longer reasonable to repair . Then replace but in the mean time sock some money away for replacement .
And besides technoligy is changing so fast when you do have to replace it , you be into the latest there is .

Repair/replacement of the compressor or refrigerant coils would not be economically viable.

Sort of using a Megger and an established history of check-ups, evaluation of the compressor beyond an amp draw reading is impossible.

Virtually no one socks away money for major components of a home. Failure of 30 year old HVAC equipment is almost always a surprise, as is the failure of 30 year old asphalt shingles (the second layer)...

Air conditioning is a proven technology but as more features/technology are added, cost goes up and the inability to repair in a cost effective manner also starts to creep in.

High-SEER equipment absolutely must be sized properly, installed properly and the ductwork must move enough air at design static pressure. I can guarantee you that most residential ductwork systems are undersized and I can guarantee you that any ductwork system predating the installation of air conditioning is (1) undersized for air conditioning and (2) undersized for 90%+ AFUE furnaces.

I have yet to encounter a person experiencing an AC failure that does not treat it as a life threatening emergency.

I would tell the OP to proactively replace the equipment (including the lineset) *before* it fails.

 

[JJThrasher]

Does it still cool? My dad has his 25+ year old system recharged every few years and they always recommend a replacement because they can't find the leak. He still hasn't replaced it and probably won't until something major happens.

 

[dsimatt]

Like others have said don't replace something like that just because of "savings" since it will take a very long time to recoup your investment.

The thing I look at is it owes you nothing and could completely fail tomorrow due to its age and like someone else said its not gonna fail at the very end of summer but probably during the hottest week of the year. You can keep running it till it fails or talk with a shop and get prices and then see about what kind of discounts they give if you do it during their slow time and see if the savings justify doing it then.

 

[LS6 Tommy]

Run it until it dies, then replace the whole system.

On a side note, unless the system was undercharged from day one, you shouldn't need any refrigerant. You have a leak.

Tommy

 

[zmaxmotorsports]

For folks with older A/C units, the older refrigerant is going to go out of production in the next 5 - 10 years, so the cost will go up !!

Theres plenty of different replacement refrigerants that are a drop in replacement for r22,they don't cost much more than 410a.

 

[sms1974]

For folks with older A/C units, the older refrigerant is going to go out of production in the next 5 - 10 years, so the cost will go up !!

The U.S. Environmental Protection Agency (EPA) announced its final phasedown schedule regarding production and importation of HCFC-22 on Oct. 16 2014. The order calls for an immediate drop from 51 million pounds allowed in 2014 to 22 million pounds beginning Jan. 1, 2015. Subsequently, 18 million pounds of new and imported R-22 will be allowed in 2016, 13 million pounds in 2017, 9 million pounds in 2018, and 4 million pounds in 2019. No new or imported R-22 will be allowed in the U.S. on or after Jan. 1, 2020.

R-22 will be available for a long time to come, after the virgin supply is gone there will be reclaimed and cleaned R-22. the problem will be the cost of it. I see companies selling it any where from $65 to $125 a pound now next year i expect to see atleast a 50% rise in cost next year and even more in the following years. some of us will try to stock pile it to be able service equipment at reasonable cost...

that said I dropped $8000 on R-22 2 months ago, the same amount bought today would cost me over $11,000. I'm not planning to purchase any more when its gone its gone the cost will drive repairs in to replacements.

 

[ford33]

Why replace it when it is working unless you have a medical need for AC or just want peace of mind.

Maintain it and put the money aside for a new AC unit later.

 

[James-W]

The opening poster said he had to have a pound of Freon added to the system. Where did the Freon go? There must be a leak in the system someplace. I would think the first step is to find the leak and fix it.

My thinking on the subject is this, all appliances have an average lifespan. Once you get past that point, you can (and usually will) start to have issues with it. Keep in mind, appliances are not a fine wine, they don't get better with age. That's why if there is a problem with an older appliance I am a firm believer in replacing that appliance. That is, unless the appliance can be repaired for a very low cost in which case I may repair it once, but not more than once. If I continue to have problems I figure it is time to buy a new one.

 

[EdT]

Just curious Danski0224, if not a payback analysis what would you use?

 

[Todd.Brock]

Guys- thanks for all the great feedback ! We bought in 2014. I assumed it was services at the time the furnace was installed. I did not do it last year. This was the first year for a tune up. I do not know how long it had been. I should have done it in 2014 and 2015. It was an lb. low. I have no reference point to figure out how big of a leak I do have. It was 180bucks for the tune up, coil cleaning and 1lb of freon. I will keep at that until it dies or the leak becomes a bigger issue. I forgot to have them put dye in to track the leak.

 

[HAP]

I would plan to replace it when its convenient for you. Spring time would be an option where it would not be missed during the replacement effort. ***** to wait until it fails, then try to get someone to meet your needs.

 

[James-W]

I would plan to replace it when its convenient for you. Spring time would be an option where it would not be missed during the replacement effort. ***** to wait until it fails, then try to get someone to meet your needs.

Also, many times you can get a much better deal on a furnace or an air-conditioner if you buy it off-season. Manufacturers don't like to keep a large inventory for long periods of time so if they find themselves overstocked many times they will give reduced prices to dealers who in turn will generally give a discount to customers. You may or may not get a better deal off-season, but it certainly pays to check it out.

 

[dave*99]

The old unit will die at an inconvenient time for sure. Either at the spring start up or during the cooling season, when all the contractors are busy. And it's 30 years old, so it's not justifiable to put significant funds into it.
As others have said the energy savings alone will not justify replacement. So we are left with a convenience / timing question.
Just decide if you prefer to be proactive, do your research ahead of time and contract for the job in the off peak season, or do you prefer to deal with it on it's terms rather than your own.

Ultimately it boils down to how you want to handle the inevitable.

 

[brownbagg]

every year you go pass the lifespan of the unit, you are making money

 

[James-W]

every year you go pass the lifespan of the unit, you are making money

I don't understand how it "makes" you money, please explain.

My position on this issue is as follows.

Appliances have an average lifespan. It is called an "average" lifespan because some items last longer than the norm and some die an early death. But when you add them all up, you get an "average" lifespan. If you have an appliance that lasts beyond the average lifespan, then you are one of the lucky owners. If you have an appliance that dies prematurely, you will probably be upset, but that is the luck of the draw.

If you happen to have an older appliance, and many of us do, I would say that as long as the appliance is working OK, keep using it. If it breaks down and you can repair it for a relatively cheap price, then do so, ONCE. If you continue to have problems, get a new one.

My explanation is the way I look at it, others may and probably will, disagree with me. That's OK, this is America, a place where we can disagree and still be friends.

 

[Marctrees]

Stick with the old existing unit till dead, BUT, have a backup replacement plan , as said before. Marc

 

[Marctrees]

"Making money" could be maybe better restated as "not spending unnecessary new money" Marc

 

[Showkey]

They said the samething about R12.......and.........it is still available. Yes.....sometimes it can expensive depending location.

 

[dave*99]

They said the samething about R12.......and.........it is still available. Yes.....sometimes it can expensive depending location.

Yup and since the demand had dropped, the prices have stabilized.

 

[Todd.Brock]

A lady has a family HVac business and r-22 is 79 a pound. My guy was $99 so I thought that was reasonable enough.
I am not planning for a high dollar fancy shmancy unit, but I am really interested in multi zone. Our upstairs is hot or cold -season dependent- and our basement is unfinished. I would really like to be able to equalize the upstairs and downstairs. I know it takes motorized dampers and such, but it may be worth looking into

 

[Wizzard]

Our unit is 16 years old and is losing ~2-3lbs of r22 a year. Techs could not pinpoint a leak, even after using dye. We are now slowly planning for a change out since r22 is $80/lb and getting more expensive each year...I'd rather sink that money into a new system.

 

[danski0224]

Just curious Danski0224, if not a payback analysis what would you use?

Payback is hocus pocus mumbo jumbo.

A HVAC system will never fail when you don't need it. Never. I always recommend replacing an older functioning system in an off season when it is not needed, whenever possible.

I have NEVER seen a customer with a failed AC unit NOT act like they are experiencing a life threatening emergency. Never. Never. Never. I wonder how homo sapiens made it through the 80,000 or so years before 1950....

Running it until it's broke is epic bad advice.

It will fail when everyone else's unit fails, then you are stuck rushing for a replacement, dealing with possible price adjustments and even shoddier work because the boss sez "Git 'er Done, NOW".

The HVAC system is a major capital investment that uses 50% or more of your energy dollars and it should be proactively planned and executed. Home inspectors routinely fail "old" HVAC equipment and the buyer demands either a new system or a credit, so you are paying for it either way you slice it.

A lady has a family HVac business and r-22 is 79 a pound. My guy was $99 so I thought that was reasonable enough.
I am not planning for a high dollar fancy shmancy unit, but I am really interested in multi zone. Our upstairs is hot or cold -season dependent- and our basement is unfinished. I would really like to be able to equalize the upstairs and downstairs. I know it takes motorized dampers and such, but it may be worth looking into

More Tom Foolery.

Uneven temperatures are the result of two things, maybe 3.

(1) Shoddy ductwork design and installation. This includes not only the main trunk and branch ductwork, but also the fittings used at the air handling equipment
(2) Shoddy building construction- including an improperly defined thermal barrier, shoddy insulation installation, massive air leakage through things like can lights and attic access hatches, building cavities used for return air and more
(3) Poor equipment sizing/selection

Zone dampers require a duct system designed for their use.

Unlike a commercial HVAC system with a medium pressure loop and individual VAV boxes with thermostats for each defined space, your residential system cannot throttle capacity (BTU and fan) up and down. The only (partial) exception to this that I am aware of is the Carrier Infinity system, which is a top tier high dollar system.

With zone dampers, you are taking a percentage of total system capacity and using it, and dumping the rest in a dump zone or through a barometric bypass damper.

Residential zone dampers are a band-aid applied to a hacked-in system that doesn't work right.

You would be far better off splitting what you have into two separate systems, if the ductwork isn't ****.

 

[danski0224]

Our unit is 16 years old and is losing ~2-3lbs of r22 a year. Techs could not pinpoint a leak, even after using dye. We are now slowly planning for a change out since r22 is $80/lb and getting more expensive each year...I'd rather sink that money into a new system.

That big of a leak should stand out easily with dye. It may take a couple of months of operation to see it, but you will see it.

I'd put money on the evaporator coil being bad.

I'd also put money on being able to see it without dye.

 

[Gila Monster]

I know my example is probably not typical, but I "pre-emptively" replaced my perfectly working, 30 year old AC unit and the new one promptly died a year in service. It was a Trane unit (fwiw) supposedly a board failure took out the compressor. Everything was covered under warranty, but it took a week for them to repair it. The outfit was well established and legit.

So I'm very skeptical about the idea of preemptively replacing things if they are not broken.

I honestly think the "old" AC units are simply better built. Even though some are still assembled here, there's still a LOT of Chinese parts on the new ones and corners are cut. I really don't believe for a minute your going to see a lot of 30 year life spans on currently made heat pumps. It reminds me a lot of appliances. I've "preemptively" replaced old appliances and watched them quickly fail.

Also, the cost savings of a new heat pump are typically pretty low, I could see MAYBE $50 a month in the summer will be saved just because your unit is so old. So like 25-30 years it will break even on replacement cost, in which case you've probably already replaced it several times.


What it really comes down to is how much is your wife going to scream when the AC goes out.

I do agree when the AC goes out, its an "emergency" and many contractors will take advantage of that, which is unfortunate.

 

[JerryC]

Our unit is 16 years old and is losing ~2-3lbs of r22 a year. Techs could not pinpoint a leak, even after using dye. We are now slowly planning for a change out since r22 is $80/lb and getting more expensive each year...I'd rather sink that money into a new system.

That big of a leak should stand out easily with dye. It may take a couple of months of operation to see it, but you will see it.

I'd put money on the evaporator coil being bad.

I'd also put money on being able to see it without dye.

That was my case, went for years putting refrigerant in it twice a season. New system. The leak could not be found, not by visual, sniffer or dye. Finally the HVAC company replaced the evap coil, done. The speculation was that condensation washed the dye down the drain.

As for the 30 year old system my 2 cents... If you are thinking about then it is weighing on your mind and planning for a new system in the off season might be the thing to do. If you decide to run it until it dies, buy a couple of cheap/closeout window AC units at the big orange/blue stores to keep on hand so that when the central AC dies you'll have a couple of cool zones to sit/sleep in while you shop for a replacement.

 

[brewchief]

Unlike a commercial HVAC system with a medium pressure loop and individual VAV boxes with thermostats for each defined space, your residential system cannot throttle capacity (BTU and fan) up and down. The only (partial) exception to this that I am aware of is the Carrier Infinity system, which is a top tier high dollar system.

Lennox Harmony zone controls can vary the fan speed based on airflow needed in a zone, the furnace is controled by an output temp sensor and will either switch between 1st and 2nd stage(on the 2 stage units) or modulate input(on the modulating units) to maintain a constant output temp. A/C is operated the same way but can be either a single stage, two stage or modulating unit.

Duct design is still important but you don't waste energy dumping heated or cooled air into zones or spaces that you don't need it in.




My suggestion is to first look at the overall building and see if there are improvements to be made, better windows and doors and adding insulation can reduce the size of the equipment needed and should be done first so that the proper size equipment can be used.

Planned replacement is much better then waiting to it dies, the furnace you have may be new but that doesn't necessarily make it good, if someone is planning on moving they will be much more inclined to buy the cheapest from the lowest bidder so even if it's a good brand or model it may not be installed worth a dang.

 

[danski0224]

That was my case, went for years putting refrigerant in it twice a season. New system. The leak could not be found, not by visual, sniffer or dye. Finally the HVAC company replaced the evap coil, done. The speculation was that condensation washed the dye down the drain.

Spectroline dye for HVAC will not wash off with water. No way, no how.

 

[zmaxmotorsports]

That big of a leak should stand out easily with dye. It may take a couple of months of operation to see it, but you will see it.

I'd put money on the evaporator coil being bad.

I'd also put money on being able to see it without dye.

I'd put money on shader valves,nobody ever checks the simple stuff.

 

[danski0224]

Cool info on the Lennox.

 

[Cave Creek Ray]

I just passed three years on a massive renovation of a property here in Arizona. Seven months of major re-construction prior to move-in with replacement of every home system -except the new dishwasher.

I replaced an inoperative A/C system (squirrel cage sheared off motor that hard-seized) and another 20 year old system that was working but drawing 14.5 amps under load. The tech who checked out the unit said it was a miracle that motor hadn't fried under that load. We chose to replace both systems in the fall, prior to move in, which is off season here in AZ.

The Trane systems we chose were recommended by the sales tech that sized up our house. His theory was, don't buy leading edge on air conditioners/heat pumps because they run at a high premium. He suggested a slightly lower SEER (18) on a really nice unit with a matched air handler for both systems. He had installed the same systems in his home the year prior and loved them.

By buying off season we saved about $1500 off for both systems. By doing the install in late September, the weather was nice while our systems were shutdown and the installers could take their time and do a good job. That's harder to do when its 108 outside.

I am a big fan of proactive maintenance. I'd rather be inconvenienced on my schedule rather than the equipment's. Had these systems been three or four years old and operating, I would have kept them.

Just my $.02.

Ray

 

[yhprum]

What Ray said. You are in a much better position to negotiate when its cold outside! My AC guy said after 7 years to start putting some money away every year for the new one.