Might be time to replace AC unit

[msweig]

So the compressor motor on my AC unit is going bad/bearings are going out.  Had the tech come out to verify I was correct, and he agreed, along with mentioning the start capacitor (IIRC) is also staring to go, and there is a coolant leak and the levels are low (I have someone come out and check the system 2x/year, and the low coolant level was mentioned in the fall).  System is a Lennox (XC16-048-230, which is a 4 ton 16 SEER 2 stage), and about 11 years old.  I'm in a gated community where the builder used basically the same systems for all of the houses, and I think 3-4 other people have had to replace theirs in the last year.  

Considering age of system, and the fact that I'm going straight into the worst/most stressful part of the year in Houston, I'm really tempted to not sink money into a repair and just replace the whole thing, as my understanding is these systems typically only last 10-12 years generally, or maybe a bit longer.   And as the system is still functional this gives me a bit of breathing room to get quotes, etc.

Any suggestions on what I should generally look out for, or avoid?  This is the first time I've had to replace a system and I've heard stories that run the gamut.  And even looking at brands some people say some are great, and others say they suck. 

If it helps the house is ~2500 square feet and three stories, with three zones (one for each floor).  And the outside unit is close to a bedroom, so a quieter system would be nice (but it doesn't need to be the quietest model out there).  And the furnace is in the attic. (My understanding is that it is generally best to just replace both at the same time, but I don't really know).

[sweensdv2]

Three years ago my 11 year old, at that time, A/C failed and I replaced it with a RUUD unit.  The furnace was also 11 years old and working just fine so I didn't replace that, it's still working fine today.  The RUUD unit is fairly quiet but as all the windows are closed when using the A/C the noise issue is really not an issue anyways.

[joe1086]

FWIW

I can share my neigbor's experience who just went through the same thing. Old unit was a five ton Goodman, and good Lord that thing was so noisy we could barely have a discussion on our porch. She replaced it with a Bosch 4.5 ton AC and gas furnace for about $12K installed. She got quotes for Tranes and Carriers and said those were near the $20K range. I don't know much about the Bosch brand but do see a upward trend in installs on the neighborhood chat pages.

BTW her outside compressor is about 50' from our porch and you can barely hear it when running. Super quiet.

[rwe2156]

I don't know if they carry them out there, but I've had 2 Goodman units at my office, one was installed in 1999 the other in 2001.

Since then, I've had both units at my house changed over to Goodman. No they are not the quietest in the world, that's a separate decision.

That said, IMO the service after the install is more important than the brand.

[MKepke]

No real insight, but if it's a slow leak I'd be inclined to limp along for another year or two:

- motor bearings and the start cap are DIY'able. But you'll need a tech for the refrigerant.

- industry is in the process of phasing out the R410a Puron used in your current system and replacing it with something else. There seem to be competing alternatives, depending on the manuf.

I don't buy cars in the first few years after a significant change either...

- you *may* get a better deal on a system at any other time than the start of the cooling/heating season. Esp. if the economy contracts.

-Mark

[JDuke]

No real insight, but if it's a slow leak I'd be inclined to limp along for another year or two:

- motor bearings and the start cap are DIY'able.  But you'll need a tech for the refrigerant.

- industry is in the process of phasing out the R410a Puron used in your current system and replacing it with something else.  There seem to be competing alternatives, depending on the manuf. 

I don't buy cars in the first few years after a significant change either...

- you *may* get a better deal on a system at any other time than the start of the cooling/heating season.  Esp. if the economy contracts.

-Mark

I’d be inclined to limp along on what you have until the spring rush has subsided a little bit. 

there are lots of options at wide price points these days, single speed, 2 stage variable speed etc. are escalating efficiency and comfort but also escalating price as well. 

We put a Trane variable speed in a previous house very specifically for lower noise air handler due to its location right next to the room we watched TV in.  It was a huge upgrade over the old single speed, but it was also a few thousand more than a single or 2 stage. 

We also replaced one of the units in current house right before move in with variable speed Trane and are happy with it.  We have another unit on the other side of house that’s over 20 years old and don’t plan to replace it until it starts having more problems.  

We like the variable speed units, as they run much longer at lower speed, keeping air moving and temps more consistent rather than the all or nothing you get with single stage. 

you also have to consider resale, as a new unit of any type has essentially the same value to a buyer. 
So if you have any plans to sell in next several years then the upcharge for variable speed may not be worth it.  But if your willing to spend extra for a little more comfort then it MIGHT be worth it to you. 

And the installer you go with is more important than the brand of equipment. 
A mediocre installer can do more to degrade the efficiency of an install than any engineer can outsmart.

[ShopStud]

So the compressor motor on my AC unit is going bad/bearings are going out.  Had the tech come out to verify I was correct, and he agreed, along with mentioning the start capacitor (IIRC) is also staring to go, and there is a coolant leak and the levels are low (I have someone come out and check the system 2x/year, and the low coolant level was mentioned in the fall).  System is a Lennox (XC16-048-230, which is a 4 ton 16 SEER 2 stage), and about 11 years old.  I'm in a gated community where the builder used basically the same systems for all of the houses, and I think 3-4 other people have had to replace theirs in the last year.  

Considering age of system, and the fact that I'm going straight into the worst/most stressful part of the year in Houston, I'm really tempted to not sink money into a repair and just replace the whole thing, as my understanding is these systems typically only last 10-12 years generally, or maybe a bit longer.   And as the system is still functional this gives me a bit of breathing room to get quotes, etc.

Any suggestions on what I should generally look out for, or avoid?  This is the first time I've had to replace a system and I've heard stories that run the gamut.  And even looking at brands some people say some are great, and others say they suck. 

If it helps the house is ~2500 square feet and three stories, with three zones (one for each floor).  And the outside unit is close to a bedroom, so a quieter system would be nice (but it doesn't need to be the quietest model out there).  And the furnace is in the attic. (My understanding is that it is generally best to just replace both at the same time, but I don't really know).

I went through the same analysis, as my HVAC systems are 24 years old (both Carriers) and are running OK for now, but will soon require replacement.  I live in Arizona.

Given that technology has come some way since it was first installed, you have a few options available.  Before I go into them, let me just say that you should choose a reverse cycle system (i.e., without gas furnace) as Houston doesn't get cold enough to justify it.  You will be fine with a heat pump only model.  With regard to the options you have, here's may take:


Option 1 - Select the cheapest/simplest version of a good brand, where the compressor runs at just one speed and fit it out with a thermostat accessible from the Internet.


Option 2 - Install a system that has a 2-speed compressor, also of a good brand, and fit it out with a thermostat accessible from the Internet.


Option 3 - Install it with a system that has a continuously variable compressor.


Avoid #3 like the plague.  My immediate neighbor just had two systems installed 3 years ago (3,500 sq ft home) and they have already had 2 major breakdowns so far.  The technology is not quite there from a reliability standpoint.  In theory it sounds good, but from a practical standpoint, the design complexity has not been backed by adequately reliable components.  It is also quite noisy.


You stand to gain some benefits from going with Option 2, but you have to weigh that against the cost.  If I were you, I would go with Option 1 and have the simplest and most reliable system.


While going through your analysis, you might also like to think of whether having individual split-systems for specific rooms would provide you with additional convenience and value.  I did this analysis and found that I would be better of splitting about 330sq ft of space (single room) away from the rest of the house and installing a dedicated split system for this area.  There are a number of brands available (Mitsubishi, Daikin, LG, Samsung and Mr Cool).  Mr Cool has a "do it yourself" kit available and offers a 7-yr compressor warranty.  Another neighbor of mine installed a 2-ton Mr Cool unit in his triple garage (he's a woodworker and would like to work in the summer months as well) and is very happy with it.


https://mrcool.com/warranty/




All the best !

[msweig]

I ended up swapping the compressor motor. Right when I was about to give it a shot myself it failed. So had a local company do it that I heard about from a friend. Liked them better than the one I had been using. Then got to use them again when one of the zoning motors broke a week later ?

And I've also heard bad things about the continuously variable compressor. My understanding is those systems also have a tendency to be brand specific for many of the components, so of something goes out and it is on backorder you just get to wait.

I do like the two speed system as it seems like they work better in my zoned, three story, zero lot line house (which also takes out the split system option).

I do need to look into the heat pumps as an option down the road. I know they supposedly work well in warmer climates where it doesn't get particularly cold. I don't know how much of an issue humidity is with them. I haven't really seen them being advertised as an option around here, but not sure if that is just because companies don't want to install something cheaper.

[ShopStud]

I ended up swapping the compressor motor. Right when I was about to give it a shot myself it failed. So had a local company do it that I heard about from a friend. Liked them better than the one I had been using. Then got to use them again when one of the zoning motors broke a week later ?

And I've also heard bad things about the continuously variable compressor. My understanding is those systems also have a tendency to be brand specific for many of the components, so of something goes out and it is on backorder you just get to wait.

I do like the two speed system as it seems like they work better in my zoned, three story, zero lot line house (which also takes out the split system option).

I do need to look into the heat pumps as an option down the road. I know they supposedly work well in warmer climates where it doesn't get particularly cold. I don't know how much of an issue humidity is with them. I haven't really seen them being advertised as an option around here, but not sure if that is just because companies don't want to install something cheaper.

I live in Phoenix and during winter temperatures go down to about 45F during the peak.  My heat pump works just fine.

[Roly]

I live in Phoenix and during winter temperatures go down to about 45F during the peak.  My heat pump works just fine.

I live near St. Louis and the heat pump can carry the house down to just below 20F then aux heat kicks in just to assist the heat pump to maintain the temp.    The aux heat is only on for several minutes before the house is up to temp then the heat pump will keep running until the inside temp drops 3 degrees again.
The air discharge from the vents is a lot cooler than gas or some lower than resistance heat.    You will swear it won't keep the house warm but it does, even in below zero and cheaper that just resistance heat.     I had them size my aux heat to be able to carry the full heating load for the house.  
 As far as humidity, heat pumps have a defrost cycle to remove frost when outside temps are low.    I don't know if all heat pumps have a defrost cycle or just one where the climate needs it.      Roly