Should I proactively replace my central AC unit?

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Hockey10
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Should I proactively replace my central AC unit?

Post by Hockey10 » Mon Mar 26, 2018 3:06 pm

My central AC unit is 22 years old. The last time we used it in September, it was still working perfectly. I have read some articles that say that the life expectancy of central AC units is approximately 15 years. It is a Trane, 4 ton, 13 SEER unit. My fear is that it is going to die in the middle of July when the temp is 94 and the HVAC contractors are deluged with calls.

So, should I count myself as lucky that it lasted 22 years and buy a new one before it breaks?

Thanks

bloom2708
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Re: Should I proactively replace my central AC unit?

Post by bloom2708 » Mon Mar 26, 2018 3:17 pm

A two stage unit, properly sized with a higher SEER rating will be a nice upgrade. Will it pay for itself? Likely not.

We upgraded a similar unit. The unit running in the first stage is virtually silent. The old unit would run short cycles at turbo fan mode. It didn't run enough to remove humidity.

The higher SEER unit will likely be much quieter outside if sound is an issue.

We did the furnace at the same time. Heating is the same. Stage 1 is silent. We run "fan only" more to keep warm/cool are mixing. More stable temps and less pooling of different air temps.

I am a "don't wait for it to break to fix it" person, but I also like the value of the new technology. Our units are Lennox.
"We are not here to please, but to provoke thoughtfulness." --Unknown Boglehead

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flamesabers
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Re: Should I proactively replace my central AC unit?

Post by flamesabers » Mon Mar 26, 2018 3:18 pm

I think it depends:

* Will a new AC unit be much more energy efficient then your current one?
* How tolerant are you of high temperatures without having the A/C running?
* How was the average life expectancy for central AC units calculated? (I imagine it varies on your climate, usage and how diligent you are with performing routine cleaning/maintenance.)

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goingup
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Re: Should I proactively replace my central AC unit?

Post by goingup » Mon Mar 26, 2018 3:27 pm

I don't proactively replace appliances. Sometimes they last much longer than expected. Sometimes they underachieve.

Maybe you could get a few quotes on replacing the unit, with the knowledge that you'll need to replace it soon. Decide on the contractor and the model. It's nice to have a plan in place.

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wageoghe
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Re: Should I proactively replace my central AC unit?

Post by wageoghe » Mon Mar 26, 2018 3:31 pm

bloom2708 wrote:
Mon Mar 26, 2018 3:17 pm
A two stage unit, properly sized with a higher SEER rating will be a nice upgrade. Will it pay for itself? Likely not.

We upgraded a similar unit. The unit running in the first stage is virtually silent. The old unit would run short cycles at turbo fan mode. It didn't run enough to remove humidity.

The higher SEER unit will likely be much quieter outside if sound is an issue.

We did the furnace at the same time. Heating is the same. Stage 1 is silent. We run "fan only" more to keep warm/cool are mixing. More stable temps and less pooling of different air temps.

I am a "don't wait for it to break to fix it" person, but I also like the value of the new technology. Our units are Lennox.
I agree 100%. 22 years is pretty old. It might last for a few more years or it might give out this summer. Personally, I would not want to wait for it to fail, as you might not have the luxury of a longish shopping process it fails during a heat wave.

We replaced a 20+ year old heat pump a few years ago (had a few repairs over a couple of seasons) with a Carrier Infinity two stage heat pump and have been completely satisfied.

Hockey10
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Re: Should I proactively replace my central AC unit?

Post by Hockey10 » Mon Mar 26, 2018 3:34 pm

flamesabers wrote:
Mon Mar 26, 2018 3:18 pm
I think it depends:

* Will a new AC unit be much more energy efficient then your current one?
* How tolerant are you of high temperatures without having the A/C running?
* How was the average life expectancy for central AC units calculated? (I imagine it varies on your climate, usage and how diligent you are with performing routine cleaning/maintenance.)
- The energy bills with the existing unit are not that bad, but I would expect a new unit to be a higher SEER and save us some money on future usage.

- I would not be very tolerant of high temps if the AC was broken - that is my main concern for posting this question today. A few years ago, we had an electrical outage in our neighborhood on a very hot night. Even with the windows open, it was very uncomfortable. Plus the birds chirping at 0500 in the tree outside my bedroom did not help (I don't hear them with the windows closed).

- I got the average life expectancy from reading a bunch of internet articles. Although some were saying only a 10 year life was normal (but I suspect they were in the business of selling new ones as often as possible).

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dm200
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Re: Should I proactively replace my central AC unit?

Post by dm200 » Mon Mar 26, 2018 3:36 pm

Suppose it fails - how big a "sacrifice" will you have in waiting for it to be replaced in the heat of summer. Not a good time to negotiate a replacement.

Maybe see what you can "negotiate" AFTER this season's need for AC

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Re: Should I proactively replace my central AC unit?

Post by mhadden1 » Mon Mar 26, 2018 3:40 pm

goingup wrote:
Mon Mar 26, 2018 3:27 pm
I don't proactively replace appliances. Sometimes they last much longer than expected. Sometimes they underachieve.

Maybe you could get a few quotes on replacing the unit, with the knowledge that you'll need to replace it soon. Decide on the contractor and the model. It's nice to have a plan in place.
+1 Be aware that ancient hvac, roof, etc.will likely be seen as a negotiating levers at selling time. Otherwise I would be on my own schedule which for me involves not paying until needed. I have obtained replacements for my current house within 2-3 days which I think is typical for the medium-sized city where I live. Admittedly, the urgency for me is reduced since my house has 2 units.
Oh I can't, can I? That's what they said to Thomas Edison, mighty inventor, Thomas Lindberg, mighty flyer,and Thomas Shefsky, mighty like a rose.

tomd37
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Re: Should I proactively replace my central AC unit?

Post by tomd37 » Mon Mar 26, 2018 3:42 pm

You are living on borrowed time! At that age I would very seriously consider replacing it with an appropriately sized and type of unit. HVAC dealers are not that busy yet and are offering some good deals as are the manufacturers. You will "pay through the nose" if it happens to go out in the late spring, summer, or early fall. :dollar
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Re: Should I proactively replace my central AC unit?

Post by Spirit Rider » Mon Mar 26, 2018 3:57 pm

I would not be proactively replacing a unit not matter how onld unless it is exhibiting indications that a failure is likely.

If you have been having more problems or doing more repairs. For example, you made it the first 18 years on two run capacitor replacements and you had to replace the third last year after only three years, it is intermittently tripping the breaker or you had to install a hard start capacitor. You are having to add refrigerant every 1-2 years and so on.

health teacher
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Re: Should I proactively replace my central AC unit?

Post by health teacher » Mon Mar 26, 2018 4:14 pm

When I had a part replaced on my unit I asked my HVAC guy this question and he said to let it ride. He said AC units outlast furnace significantly as long as debris (grass clippings, leaves, etc) is cleared from the unit.


So, I will not be proactively changing my AC unit. Both my AC and furnace are Lennox.

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lthenderson
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Re: Should I proactively replace my central AC unit?

Post by lthenderson » Mon Mar 26, 2018 4:52 pm

Hockey10 wrote:
Mon Mar 26, 2018 3:06 pm
My fear is that it is going to die in the middle of July when the temp is 94 and the HVAC contractors are deluged with calls.

So, should I count myself as lucky that it lasted 22 years and buy a new one before it breaks?
Generally the silly season among HVAC contractors is late spring and late fall when folks are turning their systems on for the first time. By the middle of the season, things have settled down dramatically.

A/C units are very simple machines with few moving parts and thus generally aren't prone to breaking down as often as central heating. Generally you replace them to get efficiency gains or because they can't hold a charge anymore.

Whether or not I replaced it would be dependent on how long I was planning on continuing to live at the residence. If it was going to be a long while before I would even think of moving, I would probably opt to replace it with a new more efficient system if the payback period was shorter than my foreseen move.

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Sandtrap
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Re: Should I proactively replace my central AC unit?

Post by Sandtrap » Mon Mar 26, 2018 5:03 pm

Unless you have a reason to "upgrade" and "modernize", run it till it dies. You may get another 5 years out of it, or more.
j :D

il0kin
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Re: Should I proactively replace my central AC unit?

Post by il0kin » Mon Mar 26, 2018 5:12 pm

I had a 34 year old unit replaced in our current home that was still ticking! Incredible, really. It was about a 5-6 SEER unit, or so the replacement company guessed based on old HVAC records they dug up. Top of the line in '84! We upsized from 3.5 ton to 4 ton as our air handler was rated for up to 4 tons. We got a 13 SEER Lennox unit and our home is much more comfortable now. I think 3.5 was undersized from the start, or maybe in '84 people just tolerated warmer temps. With young kids in the home, I did not want to gamble on it dying in the heat of summer. I calculated the savings for 14 and 15 SEER but did not find that it would be very beneficial in energy savings, and SEER doesn't make the house cooler, so 13 worked for me.

A tip - if you replace it, ONLY employ a company that pulls permits. I did a lot of research and talked extensively with a friend who is a city inspector, and that was his main advice. The units tend to be less important than a proper install, and he said he rarely saw issues with permitted work, but frequently saw issues with fly by night, unpermitted companies when doing other inspections.

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FrugalInvestor
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Re: Should I proactively replace my central AC unit?

Post by FrugalInvestor » Mon Mar 26, 2018 5:29 pm

bloom2708 wrote:
Mon Mar 26, 2018 3:17 pm
A two stage unit, properly sized with a higher SEER rating will be a nice upgrade. Will it pay for itself? Likely not.

We upgraded a similar unit. The unit running in the first stage is virtually silent. The old unit would run short cycles at turbo fan mode. It didn't run enough to remove humidity.

The higher SEER unit will likely be much quieter outside if sound is an issue.

We did the furnace at the same time. Heating is the same. Stage 1 is silent. We run "fan only" more to keep warm/cool are mixing. More stable temps and less pooling of different air temps.

I am a "don't wait for it to break to fix it" person, but I also like the value of the new technology. Our units are Lennox.
Our experience was similar with two units being on their last legs. Since we we're going to be in the house a few more years we bit the bullet and replaced. Major advantages included increased efficiency/reduced energy cost, much quieter operation, and more even temperature throughout the house. The old units were so noisy that my wife couldn't sleep. That is now a non-issue.

Along with contracting the replacement we had an energy audit performed which was subsidized by our electric utility company. The result was that we added some insulation and went from two units (total 6-tons) to one 5-ton unit. In the process we combined the air intakes which made for much more efficient air-flow.

What a difference! Had we known how much of a difference it would make we would have done it much sooner.
IGNORE the noise! | Our life is frittered away by detail... simplify, simplify. - Henry David Thoreau

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Watty
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Re: Should I proactively replace my central AC unit?

Post by Watty » Mon Mar 26, 2018 5:31 pm

I once had to pay for an emergency replacement of a hot water heater and after having to pay top dollar for that I have always replaced my appliances before they actually failed.

I replaced both my furnace and AC at about that age a few years ago when they were working fine but the AC had needed a few maintenance calls.

I live in a humid part of the country and I got a mid range AC system which was a step up from my old system and the AC system monitors and manages the humidity a LOT better than the old AC. It makes the house noticeably more comfortable and that alone makes me glad that I replaced it sooner rather than later.

I did this in September which was the lull between the heating and cooling season here and I got a very good price. When I was asking for bids I made it clear that I was only looking to buy it if I got a good price and I was flexible on when to schedule it so they could install it on a slow day. I think that also helped me get a better price. I also had the time to get five or six bids and the prices for similar systems were significantly different.

When I called to schedule it they wanted to do it the next day because they had people available with no work to do. Two people showed up at about 8:00 AM and they basically spent all day working on it and did a very good job since they didn't have to hurry to get to their next job.

If your furnace is older also get a quote on replacing that at the same time. When I did mine at the same time it did not add a lot of labor costs and getting a well matched A/C, Furnace, and air handler has some advantages.

In some parts of the country the same people can also install hot water heaters so you should also ask how much it would cost to have them replace that at the same time too since that might be much less expensive than replacing it in a few more years.

Hockey10 wrote:
Mon Mar 26, 2018 3:06 pm
13 SEER unit.
That is what it was rated at when it was brand new, it is likely lower now.

Goal33
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Re: Should I proactively replace my central AC unit?

Post by Goal33 » Mon Mar 26, 2018 5:43 pm

I wouldn't. Had a similar situation and just got a window unit until I could get it repaired.
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Re: Should I proactively replace my central AC unit?

Post by Mudpuppy » Mon Mar 26, 2018 6:02 pm

Hockey10 wrote:
Mon Mar 26, 2018 3:06 pm
My central AC unit is 22 years old. The last time we used it in September, it was still working perfectly. I have read some articles that say that the life expectancy of central AC units is approximately 15 years. It is a Trane, 4 ton, 13 SEER unit. My fear is that it is going to die in the middle of July when the temp is 94 and the HVAC contractors are deluged with calls.
It is unlikely that a 22 year old Trane AC unit will die in such a way that it can't be repaired. I don't think you need to worry about suddenly having to replace it in the middle of July. You might need to repair it, but that should only take a day or two.

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Artful Dodger
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Re: Should I proactively replace my central AC unit?

Post by Artful Dodger » Mon Mar 26, 2018 6:06 pm

I would not. We have two units both going on 24 years. Using the 15 year average life theory, if I had replaced at year 16 or 17, I would already be half way through the assumed life of the new unit. :oops:

I do have the luxury of having two units, so if one goes out, we can always move sleeping arrangements to downstairs if the upstairs unit goes out. If the main goes out, we'll suffer through it or head upstairs to cool, or basement family room which will be cooler. We are also both more tolerant of higher temps, and usually run our downstairs main unit at 78 - 80, usually aiming to reduce humidity as much as temp.

We built our current home, and we did install higher quality / higher efficiency units at the get go, so that probably has helped.

Maybe you would get a better deal now, I don't know. We had our water heater give out recently, checked with a number of sources, and had no problem getting a quick install with standard pricing. Now, if I had called, and said i wanted it immediately, and they had to pay extra overtime labor, then I could see some up charge. But, we were fine waiting a couple of days.

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Re: Should I proactively replace my central AC unit?

Post by Spirit Rider » Mon Mar 26, 2018 6:12 pm

il0kin wrote:
Mon Mar 26, 2018 5:12 pm
We up sized from 3.5 ton to 4 ton as our air handler was rated for up to 4 tons. We got a 13 SEER Lennox unit and our home is much more comfortable now. I think 3.5 was undersized from the start, or maybe in '84 people just tolerated warmer temps.
It is more likely that the 3.5 ton from 84 was properly sized. They might have even done a Manual J back then. The 4 ton is probably over sized but not enough to cause real problems.

A properly sized system should run continuously at the 98% point of local ambient operating temperatures. This means there should be some small number of hours, maybe not even every year, where the A/C will drift a little above design temperature.

When it is a few degrees above the 98% ambient point, when the hottest temps of the decade cause the internal temp to rise a few degrees from 72 to 75, it is not a catastrophe. Yet many people will call their HVAC contractor and berate them. "Why is my A/C running continuously at 105?", "So it will run enough at 78 to remove humidity".

So many contractors have just given up and oversize units so they don't get call backs. "Its only 95 outside, I have been back from vacation for an hour, why hasn't my A/C reduced the temperature from 84 to 68 in an hour." "Sigh."

I'm amazed at how cold people run their A/C. I usually run mine around 75 sometimes 77, but know different people who run theirs continuously at 66 - 70.

ddurrett896
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Re: Should I proactively replace my central AC unit?

Post by ddurrett896 » Mon Mar 26, 2018 6:48 pm

Hockey10 wrote:
Mon Mar 26, 2018 3:06 pm
So, should I count myself as lucky that it lasted 22 years and buy a new one before it breaks?

Yes, but I wouldn't replace because...

1) 13 SEER is still pretty efficient.
2) You live in Philly, not FL/TX/etc. where summer can be impossible without AV.

boglegirl
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Re: Should I proactively replace my central AC unit?

Post by boglegirl » Mon Mar 26, 2018 6:48 pm

I wouldn't buy a new system in anticipation of failure of the current one. But I'd buy one if the old one wasn't doing a good job, which ours wasn't. Our old system ran around the clock during the summer just to keep the house below 80 (and we live in a moderate climate). And the upstairs was about 4 degrees hotter than the downstairs...so we'd keep running it to get the upstairs comfortable, and the downstairs would then be too cool. And don't get me started on the noise...it sounded like an airplane taking off when it cranked up. Very loud inside, and the compressor outside was so loud it was hard to have normal conversations on our back patio.

We love love love our new Lennox system. It's zoned so that the upstairs and downstairs can be whatever temp we choose! And so quiet that we wonder if it's running sometimes. It's got a high SEER (I don't remember what, offhand, it's been about 18 months) so we are saving maybe $1000/year on electricity costs, but we are actually COMFORTABLE in our home even though we use less electricity.

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Re: Should I proactively replace my central AC unit?

Post by Bengineer » Mon Mar 26, 2018 7:27 pm

This:
Goal33 wrote:
Mon Mar 26, 2018 5:43 pm
I wouldn't. Had a similar situation and just got a window unit until I could get it repaired.
A few hundred to keep life tolerable, resell on CL.

Do some reading up and shopping around in the meantime so that you know what you want, get some quotes. then when it breaks, you have a plan.

Maybe do some air-sealing and insulating in the meantime as well. Get a load calculation (Manual J) done after the upgrades. You'll likely need a smaller unit.

IMO, the sweet spot for residential split AC or Heat pumps is a single speed compressor with a variable speed, efficent ECM blower air handler. Sizing is crucial with two or variable speed compressor units in terms of getting the stated efficiency. Not so much with single speed compressors.

Good duct design is the key to (nearly) silent HVAC.

jminv
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Re: Should I proactively replace my central AC unit?

Post by jminv » Mon Mar 26, 2018 8:36 pm

I wouldn't replace it.

You could check if a local HVAC company offers a good deal on a twice yearly service program that also includes free same day/next day visits outside this whenever you have a problem to 1.) diagnose the problem and 2.) provide a quote to fix a problem (they'll often fix minor problems free of charge). You can often get these plans for around $100 per year. Companies offer them because it drives high margin repair business, increases customer stickiness, and reduces the number of customers comparing prices. They'll often couple it with some sort of 10% off anything outside the package (like evaporative coil replacement, etc). The nice part about these plans, particularly if you have old HVAC equipment that's likely to break, is that you can use their quotation to shop around to multiple other HVAC contractors and get a good price. I have a relative that uses this and the precise quote which they then used to get multiple additional quotes saved them around 2k in August while getting the contractor out the next day.

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Re: Should I proactively replace my central AC unit?

Post by Epsilon Delta » Mon Mar 26, 2018 8:55 pm

Mudpuppy wrote:
Mon Mar 26, 2018 6:02 pm
It is unlikely that a 22 year old Trane AC unit will die in such a way that it can't be repaired. I don't think you need to worry about suddenly having to replace it in the middle of July. You might need to repair it, but that should only take a day or two.
I'm not sure what refrigerant a 22 year old AC is using, but it is likely to be one that is controlled by the Montreal Protocol and could be expensive to scavenge and replace. So while a simple leak may not be beyond repair it may be beyond economic repair when you factor in the cost of a recharge.

denovo
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Re: Should I proactively replace my central AC unit?

Post by denovo » Mon Mar 26, 2018 9:04 pm

Hockey10 wrote:
Mon Mar 26, 2018 3:06 pm
My central AC unit is 22 years old. The last time we used it in September, it was still working perfectly. I have read some articles that say that the life expectancy of central AC units is approximately 15 years. It is a Trane, 4 ton, 13 SEER unit. My fear is that it is going to die in the middle of July when the temp is 94 and the HVAC contractors are deluged with calls.

So, should I count myself as lucky that it lasted 22 years and buy a new one before it breaks?

Thanks
No, if you're lucky it would last 30 years. Just make it's properly tuned up/maintained. A service call can't hurt. Clean the coils, check the motors, etc.
"Don't trust everything you read on the Internet"- Abraham Lincoln

il0kin
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Re: Should I proactively replace my central AC unit?

Post by il0kin » Mon Mar 26, 2018 9:14 pm

Spirit Rider wrote:
Mon Mar 26, 2018 6:12 pm
il0kin wrote:
Mon Mar 26, 2018 5:12 pm
We up sized from 3.5 ton to 4 ton as our air handler was rated for up to 4 tons. We got a 13 SEER Lennox unit and our home is much more comfortable now. I think 3.5 was undersized from the start, or maybe in '84 people just tolerated warmer temps.
It is more likely that the 3.5 ton from 84 was properly sized. They might have even done a Manual J back then. The 4 ton is probably over sized but not enough to cause real problems.

A properly sized system should run continuously at the 98% point of local ambient operating temperatures. This means there should be some small number of hours, maybe not even every year, where the A/C will drift a little above design temperature.

When it is a few degrees above the 98% ambient point, when the hottest temps of the decade cause the internal temp to rise a few degrees from 72 to 75, it is not a catastrophe. Yet many people will call their HVAC contractor and berate them. "Why is my A/C running continuously at 105?", "So it will run enough at 78 to remove humidity".

So many contractors have just given up and oversize units so they don't get call backs. "Its only 95 outside, I have been back from vacation for an hour, why hasn't my A/C reduced the temperature from 84 to 68 in an hour." "Sigh."

I'm amazed at how cold people run their A/C. I usually run mine around 75 sometimes 77, but know different people who run theirs continuously at 66 - 70.
It may be oversized, I don't know. What I do know is that the 3.5 ton could not keep our upstairs where all our bedroom are comfortable even overnight. Maybe that was due to age/wear on the compressor, or maybe it was due to undersizing. The 4 ton has more coils for air to pass over and cool and is remarkably more comfortable. We set our thermostat at 78 during the day, 75 in the evening and 73 overnight. I definitely understand the real world limitations of AC and don't expect a 68* house when it is 100+ outside.

What does 98% local operation temperature mean? I don't understand that term.

il0kin
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Re: Should I proactively replace my central AC unit?

Post by il0kin » Mon Mar 26, 2018 9:15 pm

il0kin wrote:
Mon Mar 26, 2018 9:14 pm
Spirit Rider wrote:
Mon Mar 26, 2018 6:12 pm
il0kin wrote:
Mon Mar 26, 2018 5:12 pm
We up sized from 3.5 ton to 4 ton as our air handler was rated for up to 4 tons. We got a 13 SEER Lennox unit and our home is much more comfortable now. I think 3.5 was undersized from the start, or maybe in '84 people just tolerated warmer temps.
It is more likely that the 3.5 ton from 84 was properly sized. They might have even done a Manual J back then. The 4 ton is probably over sized but not enough to cause real problems.

A properly sized system should run continuously at the 98% point of local ambient operating temperatures. This means there should be some small number of hours, maybe not even every year, where the A/C will drift a little above design temperature.

When it is a few degrees above the 98% ambient point, when the hottest temps of the decade cause the internal temp to rise a few degrees from 72 to 75, it is not a catastrophe. Yet many people will call their HVAC contractor and berate them. "Why is my A/C running continuously at 105?", "So it will run enough at 78 to remove humidity".

So many contractors have just given up and oversize units so they don't get call backs. "Its only 95 outside, I have been back from vacation for an hour, why hasn't my A/C reduced the temperature from 84 to 68 in an hour." "Sigh."

I'm amazed at how cold people run their A/C. I usually run mine around 75 sometimes 77, but know different people who run theirs continuously at 66 - 70.
It may be oversized, I don't know. What I do know is that the 3.5 ton could not keep our upstairs where all our bedroom are comfortable even overnight. Maybe that was due to age/wear on the compressor, or maybe it was due to undersizing. The 4 ton has more coils for air to pass over and cool and is remarkably more comfortable. We set our thermostat at 78 during the day, 75 in the evening and 73 overnight. Humidity is also lower in the home by 5% or so as well, which indicates to me the size is correct. I definitely understand the real world limitations of AC and don't expect a 68* house when it is 100+ outside.

What does 98% local operation temperature mean? I don't understand that term.

Normchad
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Re: Should I proactively replace my central AC unit?

Post by Normchad » Mon Mar 26, 2018 9:21 pm

I actually just did this last fall with my 2 systems. My units were 17 years old.

My thinking was:
1. They still work, and probably will for a while. No repairs needed in the last 7 years.
2. I’ll move out in 6 years, and the new buyers are sure to hold the old units against me,
3. I might as well pay now, and enjoy the new units for the next 6 years, and
4. I didn’t want them dying in the summer, and having to make a rush decision.
5. Lots of the surrounding homes of the same age have been replacing them, so the end may be near.

Doing it this way, I was able to get several quotes and pick a slower time of year for install. I think I got a decent price, but probably not great.

I’ve only ever owned builder grade equipment; and always been satisfied. I live in the mid-atlantic where the summers are long, hot, and humid. Since I’ve been happy with the bottom of the line stuff, that’s what I bought again. Single stage, SEER 14. Of course it’s more effucent, quieter, etc. so it’s still an upgrade fir me.

On a tangent, I’ve never paid anybody to service my HVAC in any house. And I’ve never needed repairs. I swear my friends who pay for annual service have way more problems. I suspect just keeping the units clean and changing the filters is sufficient to keep them trouble-free indefinitely.

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Re: Should I proactively replace my central AC unit?

Post by Dottie57 » Mon Mar 26, 2018 9:36 pm

bloom2708 wrote:
Mon Mar 26, 2018 3:17 pm
A two stage unit, properly sized with a higher SEER rating will be a nice upgrade. Will it pay for itself? Likely not.

We upgraded a similar unit. The unit running in the first stage is virtually silent. The old unit would run short cycles at turbo fan mode. It didn't run enough to remove humidity.

The higher SEER unit will likely be much quieter outside if sound is an issue.

We did the furnace at the same time. Heating is the same. Stage 1 is silent. We run "fan only" more to keep warm/cool are mixing. More stable temps and less pooling of different air temps.

I am a "don't wait for it to break to fix it" person, but I also like the value of the new technology. Our units are Lennox.
I don’t wait either. Allergies galore - the A/C really helps.

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Sandtrap
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Re: Should I proactively replace my central AC unit?

Post by Sandtrap » Mon Mar 26, 2018 10:00 pm

Dottie57 wrote:
Mon Mar 26, 2018 9:36 pm
bloom2708 wrote:
Mon Mar 26, 2018 3:17 pm
A two stage unit, properly sized with a higher SEER rating will be a nice upgrade. Will it pay for itself? Likely not.

We upgraded a similar unit. The unit running in the first stage is virtually silent. The old unit would run short cycles at turbo fan mode. It didn't run enough to remove humidity.

The higher SEER unit will likely be much quieter outside if sound is an issue.

We did the furnace at the same time. Heating is the same. Stage 1 is silent. We run "fan only" more to keep warm/cool are mixing. More stable temps and less pooling of different air temps.

I am a "don't wait for it to break to fix it" person, but I also like the value of the new technology. Our units are Lennox.
I don’t wait either. Allergies galore - the A/C really helps.
Good point.
Hay fever/pollen season is anxious to get started soon after the first spring rains. :shock:
j

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Re: Should I proactively replace my central AC unit?

Post by Mudpuppy » Mon Mar 26, 2018 10:00 pm

Epsilon Delta wrote:
Mon Mar 26, 2018 8:55 pm
Mudpuppy wrote:
Mon Mar 26, 2018 6:02 pm
It is unlikely that a 22 year old Trane AC unit will die in such a way that it can't be repaired. I don't think you need to worry about suddenly having to replace it in the middle of July. You might need to repair it, but that should only take a day or two.
I'm not sure what refrigerant a 22 year old AC is using, but it is likely to be one that is controlled by the Montreal Protocol and could be expensive to scavenge and replace. So while a simple leak may not be beyond repair it may be beyond economic repair when you factor in the cost of a recharge.
It's likely this unit, being a mid-1990s Trane install, is using R22 refrigerant. R22 is still in the phase-out stage right now for new manufacturing of the refrigerant. New manufacturing of R22 won't be completely phased out until 2020. Even after it is phased out, there will be sources from refrigerant recovery programs (more expensive sources, but it won't disappear entirely). So it's getting more expensive, but it's still in the hundreds range, not the thousands range that a new unit would cost.

That being said, the OP should have the unit serviced soon and have the servicing company check the pressure of the refrigerant system to see if it is leaking. If there is no leak, there is no concern about the cost of refilling the refrigerant at this point in time. If there is a leak but the leak is easily fixed, fixing it now and topping off the refrigerant is perhaps the best path. If there's a large leak that is not easily fixed, then the OP can plan for a unit replacement.

But just replacing the unit because it might leak and the refrigerant is getting more expensive doesn't make much sense. Spend $200 on a service visit and see if there is a refrigerant leak before making any decisions.

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Re: Should I proactively replace my central AC unit?

Post by runner3081 » Tue Mar 27, 2018 8:27 pm

We were 19 years into our unit and just replaced it in Nov 2016.

It ran fine, but each year it seemed that there would be something new that needed replacing on startup. Also, having it go down once in 117 degree weather was not fun.

We didn't go with an ultra-efficient new unit (14 SEER), but man, what a cost savings over the summer. The bill was right around $100 per month cheaper.

Not having to worry about it breaking down for many years was worth it as well.

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Re: Should I proactively replace my central AC unit?

Post by SittingOnTheFence » Tue Mar 27, 2018 11:39 pm

I think the R22 issue is very important. I'm looking to replace my 22 yr machine (which is loud and does a poor job of cooling) that is tacked on to a system built in 1957. The ducting is 4" and according to one vendor it is undersized to handle newer refrigerant (R410A) which apparently needs larger ducts to keep coils from freezing up.

The quote for a 4 ton replacement 'dry charge' R22 unit is ~$6k. It's a dry unit because it's currently prohibited to manuf new units containing R22 but a loophole allows sale of units w/o R22, then you pay through the nose to fill with reclaimed R22. As said in earlier post, the reclaimed R22 is just going to get more costlier. I'm thinking that replacing with another R22 unit is a bad deal.

I'm now looking at a costlier system because I don't want to replace the ducting and furnace to accommodate R410A refrigerant. That would be a ductless system with individual 'heads' in each room. And not doing all the rooms do to the cost. I haven't convinced myself this is a good approach either.

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