Return to the Heating & Air Conditioning Forum | Post a Follow-Up

 o
Best A/C option for Sotuh FL?

Posted by fauguy (My Page) on
Thu, Mar 20, 14 at 18:31

We live in a 2 bedroom townhouse in Ft Lauderdale, 2-story, 1200 sq/ft total under air.
The outside and inside unit was replaced in 2000 with a Rheem 2.5 Ton 10 SEER.
Since one of us is usually here, we keep the temp around 72-74 when home. Anything lower than 71 the A/C will not turn off, and higher than 75 it hardly ever turns on and the house is too warm.

Our electric bill use to be around $100-$120 in Dec-March, and up to $250 in the summer. But for the last 2 years it has been running us $290-350 each month.

We had a local Lennox dealer over last week for them to do a system check (free tune-up) and also give us prices on their system. The service tech said there was several problems with our system: the outside unit is pulling 50 Amps, when it should be at 40, and the pressure is to high at 375 PSI, the inside unit only has a 14 degree temp difference between the air in and out, when it should be 20 degree difference or more.

These were the three systems the sales man put together:

Option 1: $3676
Outside Unit: 13ACX030 (15 SEER Effective)
Inside Unit: CBX27UH030 (2.5 TON)

Option 2: $3912
Outside Unit:14ACX030 (16 SEER Effective)
Inside Unit: CBX27UH036 (3 TON)

Option 3: $4028
Outside Unit: 14ACX030 (14.5 SEER Effective)
Inside Unit: CBX25UHV030 Variable Speed Motor (2.5 TON)

Out of them, Option 1 is the least amount.
Option 2 he said is the most energy efficient, since its 16 SEER.
But Option 3 has Variable Speed Motor for the inside unit.

Between them, not sure which is the best option. All of them use the Merit line for the outside unit, but #1 and #2 an Elite for the inside, but #3 uses the new variable speed, but it a Merit. I not sure if variable speed makes much of a difference.

But I've read in here that Lennox isn't as good as they use to be, and most people prefer Trane or Carrier. Between those, what do you guys think would be a good solution for us? We wanted to keep the cost under $3500, but I guess a good system is going to run us over $4? I'd like to get some feedback before I have other estimates done for Trane and Carrier.


Follow-Up Postings:

 o
RE: Best A/C option for Sotuh FL?

Fauguy

You made the identical post two days ago.

Reposting is not good forum etiquette.

What are you looking for? These are low end systems better suited for rental property. I believe these condensers are made South of the Border. Your price expectations are not exactly reasonable for a quality system. The prices quoted are better than the equipment. I would not have them. But if intent on Lennox, I would move up to Elite series, XC 14.

Are you in a coastal environment or inland?

IMO

Here is a link that might be useful: Two Day Old Thread


 o
RE: Best A/C option for Sotuh FL?

So far I have only had that one quote, and it turns out that place only really deals with Lennox. That is what I have two other places coming out next week that do Trane and Carrier. But I wanted to do some research first and get some opinions about what system may be best for the townhouse.

We live about 7-8 miles inland from the beach, so don't really have any issues with salt water.

From what I've seen online, it does seem that Trane is the better brand, just not sure how much they will cost, such as with the XR13/15/16/17 compressor and a 2.5 ton air handler XB TEM3 or Hyperion XB.

This post was edited by fauguy on Fri, Mar 21, 14 at 17:15


 o
RE: Best A/C option for Sotuh FL?

There is no way your 2.5-Ton A/C could be pulling 50 amps; should be more like around 16-Amps.

Your existing system has major problems that needed resolving...


 o
RE: Best A/C option for Sotuh FL?

They said it was the outside unit that was pulling 50 amps, when the max is 40. But then when I looked at the breaker outside,it says 30, so if it was pulling 40-50 wouldn't that be tripping the breaker all the time? The breaker on the inside air handler unit is 20amp.

This post was edited by fauguy on Sun, Mar 23, 14 at 14:07


 o
RE: Best A/C option for Sotuh FL?

That would have to be locked-rotor amps on start-up; that was not indicated by the post.

Those breakers are time-delay & allow a higher quick start-up amperage without tripping.

If it was a Run amp-draw the breaker would trip.


 o
RE: Best A/C option for Sotuh FL?

Regardless, the $350 month electric bill is killing us, and since this Rheem is 14 years old, it's probably best to replace it.
We have one place coming Monday that does Trane and Carrier to see how much those would be, then another dealer later in the week that also sells them. But if they are like $5000+ then we couldn't do those.


 o
RE: Best A/C option for Sotuh FL?

Something sounds fishy with that first dealer's diagnosis and recommendations. You need to get a more reliable diagnosis of why your system is running so inefficiently.


 o
RE: Best A/C option for Sotuh FL?

We had another place out today, since they do Trane and Carrier. They said we can't get use a Trane Hyperion air handler because they are too tall to fit in the space, so would have to go with a Carrier.

He then looked at the inside circuit breaker, and saw that it is a 30 amp. He said that the wiring is most likely a 10 gauge and this would have to be changed to an 8 gauge/50 amp because of the 5Kw heater in the air handler. Just this is $500. He then quoted us on the Carrier systems (including the $500 electrical):
$4600, outside unit ca16na030 + FV4 inside
$4900, 24ABC6 + FV4
$5200, 24ACC6 + FV4
He said those prices would have been $500 less, but this is due to changing out the electrical wiring and breaker.

After he left, I called another company that I was going to have come out this week and asked them. The man there said that for a 5KW heater in the air handler, that our current 10 gauge/30 amp is all that is needed and would pass code & permit inspection. I then had him price it, and he said it would run:
$3500 ca16na030 + FV4
up to $4500 24ACB7 dual compressor + FV4

Do you agree with this, that for a 5Kw heater, our current 10 gauge/30 amp is OK, or would need to be change out to 8ga/50amp?

From looking online, this Carrier "builders grade" CA16NA model is listed that it is made in Mexico, so I guess I'll cross that off my list. I may have to call Carrier and find out if their other models in the Comfort and Performance line are made in US or Mexico.

Here is a link that might be useful: http://www.peirce.com/images/pdf/Product Bulletins/101-11-10.pdf

This post was edited by fauguy on Tue, Mar 25, 14 at 2:16


 o
RE: Best A/C option for Sotuh FL?

I called Carrier today and couldn't get any of my questions answered.
What wire gauge and breaker is required for the Air Handler FV4 with the 5KW heater. Where are the units made, since the CA16 is made in Mexico?

All he could say was the dealer would have to answer that.

I have another one coming out today.


 o
RE: Best A/C option for Sotuh FL?

The second Carrier dealer was out today, and said that our 10 gauge / 30amp is fine with the FV4 air handler with 5KW heater.

Here is their prices:
1) $3514, CA16NA030 outside + FV4CNF002 inside (2.5 ton)
2) $3954, 24ABC630 outside + FV4CNF002 inside (2.5 ton)
3) $4443, 24ACB724 outside dual stage + FV4CNF002 inside (2 ton).

He said that he wouldn't recommend option 2 since it is $440 more for that 24ABC6 outside unit, and there really is no quality or performance difference over the CA16 unit, expect that it may "look nicer" and is somewhat quieter. So he said Option 1 or 3 would be best, though #3 is about $1000 more since it is a dual-stage compressor, and he said would take about 5 years to recover that cost.

To do the duck-cleaning they charge a flat $299.
For the UV is $395 (single bulb), but he said there is something that works better called RGF Guardian that is $795.

These prices this this Carrier dealer are coming up around $1000 less than the first Carrier dealer that was here yesterday, as they wanted to charge $500 for electrical that is not needed.

Here is a link that might be useful: http://www.rgfairpurification.com/solutions.html#guardian


 o
RE: Best A/C option for Sotuh FL?

I had a few other Carrier dealers out this week, and below are the quotes that I got.

But there is one thing that is contradictory between two of the dealers: when doing the 2-stage compressor model 24ACB7 one of them "Dealer A" says that I all need is the 2 ton unit (24ACB724), but " Dealer B" says I should go to the 3 ton (24ACB736). Their reasoning is "Dealer A" says that since I'm 1200sq/ft and my current system is 2.5 ton with only 3 vents (one for each of the two bedrooms upstairs and one 12"x12" multi-directional in the ceiling downstairs) that a 2 ton dual-stage is fine, and that a 3 ton would be too much since we only have those three vents. But "Dealer B" says that since we have a 2.5 ton right now, that we would need to go to a 3 ton dual stage because when it drops to the smaller compressor, it would still have the proper BTU, and if we only had the 2-ton dual compressor unit, that it's lower speed would not be enough.
So between that, I'm not really sure who is correct.

Prices for "Dealer A" is a bottom line price that includes everything (even permits), expect FL 6% tax.
1) $3514, Builder CA16NA030 outside + Performance FV4CNF002 inside (2.5 ton).
2) $3954, Comfort 24ABC630 outside + Performance FV4CNF002 inside (2.5 ton).
3) $4443, Performance 24ACB724 outside dual stage + Performance FV4CNF002 inside (2 ton).
They have an option to pre-buy a 10 year labor warranty for $895.

Prices for "Dealer B" includes a 5-year labor warranty (but can be removed for $215 less), but does not include permits.
1) $3475, Comfort 24ABC630 outside + Performance FV4CNF002 inside (2.5 ton).
2) $4798, Performance 24ACB736 outside dual stage + Performance FV4CNF002 inside (3 ton).
3) $5629, Infinity 24ANB136 outside dual stage + Infinity FE4A002 inside (3 ton).
Keep in mind that "Dealer B" does not include in their price any of the permits and said we are charged by them whatever our City charges them, which could be $150-$300.

So between the Dealer A and B, the best price for the Performance 24ACB7 dual-stage compressor + FV4 air handler is Dealer A, though I'm not sure if it is OK to be a 2 ton, since Dealer B says I need a 3 ton. I even called Dealer A back about this to double-check today, and he assured me that the 2 ton 24ACB724 is all I need and the 3 ton 24ACB736 would be too much for our townhouse.

Which of these options do you guys think are best?

Lastly, what is your opinion on UV lights inside the air handler? They are between $400-700 for a single or dual UV system. Our current Rheem is 14 years old, and the inside raw insulation is completely covered with mold. I was told the UV helps to prevent mold from growing inside the unit.

-Thank you!

This post was edited by fauguy on Fri, Mar 28, 14 at 1:32


 o
RE: Best A/C option for Sotuh FL?

This would be the minimum system I would recommend. You do want a Carrier Edge Thermidistat that will give you independent dehumidify on demand feature for AC cooling.

6937512 Active Systems CARRIER AIR CONDITIONING PERFORMANCE SERIES PURON AC CARRIER AIR CONDITIONING 24ACB330A30 FV4CN(B,F)005L 875 28800 12.00 15.00 1 RCU-A-CB 232

Pay attention to L suffix on air handler. This has the aluminum coil.

IMO


 o
RE: Best A/C option for South FL?

The summer design temperature for Fort Lauderdale is 90 degrees which happens to be the same as mine in central NJ. Given that information it would seem a 2 ton condenser would be sufficient for a 1200 sq. foot townhouse. I assume the area is split evenly between each floor and you are attached on both sides. I would feel better if the contractor did a load calculation to confirm the sizes.

I have more confidence in Dealer A since he does not want to over size the unit and he correctly points out your duct work cannot handle the air flow for a 3 ton condenser.

I don't recommend spending money on UV lights. If your unit is properly installed you should not have mold problems.


 o
RE: Best A/C option for Sotuh FL?

I posted a thread about this over on hvac-talk.com and got to replies there as well, I also have some pictures showing the current layout on page 2.

Here is a link that might be useful: http://hvac-talk.com/vbb/showthread.php?1532231-Which-one-of-these-Carrier-units-is-best-for-our-townhouse-in-South-FL


 o
RE: Best A/C option for Sotuh FL?

------------------------------------
Posted by mike_home (My Page) on
Fri, Mar 28, 14 at 12:20

The summer design temperature for Fort Lauderdale is 90 degrees which happens to be the same as mine in central NJ. Given that information it would seem a 2 ton condenser would be sufficient for a 1200 sq. foot townhouse. I assume the area is split evenly between each floor and you are attached on both sides. I would feel better if the contractor did a load calculation to confirm the sizes.

I have more confidence in Dealer A since he does not want to over size the unit and he correctly points out your duct work cannot handle the air flow for a 3 ton condenser.

I don't recommend spending money on UV lights. If your unit is properly installed you should not have mold problems.
-------------------------------------

Mike,

In the summer is mid-90s here (with heat index over 100), and even in "winter" it is usually 75-82 most days. We do get so cooler 40-60s in winter but only lasts a day or two then back to 75-82.

The townhouse building is like a giant square, with each corner being a unit. Each unit is 1200 sq/ft, 600 upstairs and 600 downstairs. Two walls are shared with the other units.


 o
RE: Best A/C option for Sotuh FL?

The design temperature is meant to be the typical high temperature, not the absolute high.

I read the other posts. I am confident the the 2 ton condenser is the correct size. If you can get the humidity down to 40% you will feel comfortable at 75 degrees. This will also eliminate the mold problem.


 o
RE: Best A/C option for Sotuh FL?

I did read the HVAC Talk AOP pst.

Not necessarily disagreeing with Mike but I would want to see a professionally performed load calc in writing.on software letterhead. And for Florida, you don't want to be borderline correct. Insist on matching thermidistat. That's a must for comfort and controlling humidity.

IMO


 o
RE: Best A/C option for Sotuh FL?

After talking to a half-dozen of the "larger" Carrier dealers in my area, they all said that they don't do a Manual J load Calculation, but if you want it, then they have to come in with their special PC Program, take all the measurements, and do the calculations and reports, which costs a few hundred...which is why they say no one does it any more.

But I did talk to one other Carrier dealer today (will be coming out next week) and he did make a suggestion, see link, post # 26.

Here is a link that might be useful: http://hvac-talk.com/vbb/showthread.php?1532231-Which-one-of-these-Carrier-units-is-best-for-our-townhouse-in-South-FL/page2

This post was edited by fauguy on Sat, Mar 29, 14 at 2:43


 o
RE: Best A/C option for Sotuh FL?

1) If I follow correctly, you've been advised that (an oversized) " 4 ton air handler with blower set to 2/3 ton speeds will give MASSIVE humidity removal by lowering the temp of the coil, and raising the surface area of the coil to allow significant moisture collection."

2) You run the inside fan essentially around the clock.

I believe these two factors have been frequently suggested here to be huge negatives as far as humidity reduction.

Possibly one of the pros here could elaborate?

This post was edited by saltidawg on Sat, Mar 29, 14 at 9:07


 o
RE: Best A/C option for Sotuh FL?

Do your own FREE Whole House load-calc.

Print all the instructions & follow them.

After U have the calc properly performed print it; then click on the SIZING link; print it.

You can also use the 'snipping tool' to capture an image of the calc that U can save; then do the same with the sizing results; both could be uploaded to this forum thread..

Here is a link that might be useful: FREE Whole House load-calc


 o
RE: Best A/C option for Sotuh FL?

You can also do your own calculation for $49 using HVAC-Calc. It should be more accurate than the free version.

Is the thermostat on the first floor near a register? From piecing together your two sets of postings it sounds to me your current system is short cycling when you set the thermostat to 75 and you are not getting enough air to the second floor. You also have a bad humidity problem.

I don't understand the logic of over sizing the air handler. It seems like a waste of money. I think the 2-stage 2 ton AC with a variable speed air handler would be a good choice. I own the Carrier Infinity AC so I know it will do a great job of removing humidity. I would also recommend a properly sized 4 inch media filter with the largest matched coil.

I also think your duct work needs to be inspected for mold and cleaned. I would feel better if you could find some own who could inspect with a remote camera. You don't want to be breathing mold spores.

Here is a link that might be useful: HVAC Calc


 o
RE: Best A/C option for Sotuh FL?

Saltidawg:
That is what one of the people on the HVAC forum and what "Dealer C" told me. To go with a 4 ton unit but have the DIP Switches set for it to run at a lower CFM so it will better dehumidifier.

See my bottom post #26 on page 2

Here is a link that might be useful: http://hvac-talk.com/vbb/showthread.php?1532231-Which-one-of-these-Carrier-units-is-best-for-our-townhouse-in-South-FL/page2


 o
RE: Best A/C option for Sotuh FL?

Mike:
The thermostat is right next to the AC closet on the 2nd floor between the two bedrooms, you can see the pictures of the layout on Page 2 of the HVAC post.

There is a lot of mold inside the air handler and duct work. We want the duct work cleaned, and will cost between $300-500 depending on the place.

One of the other members Dan did a Load Calculation based on my info and drawings and posted the results on page 2. He also says that I need a 2 ton with 780 CFM.

Here is a link that might be useful: http://hvac-talk.com/vbb/showthread.php?1532231-Which-one-of-these-Carrier-units-is-best-for-our-townhouse-in-South-FL/page3


 o
RE: Best A/C option for Sotuh FL?

So from what I've been reading on that HVAC site, most people are saying NOT to "oversize" the system with a 3-4 ton that "dealer c" was suggesting to remove the extra humidity. But instead to keep it with a 2 ton and properly set up, that should remove the humidity just fine. Unfortunately, the AC closet isn't big enough for a whole home dehumidifier to be connected to the duct work, so I may still end up having to get a stand-alone dehumidifier to see if that helps out some.


 o
RE: Best A/C option for Sotuh FL?

Two things and then I will be done here.

1. I don't want to be borderline sized for Florida.

2. And for Florida, I would want a system to have var speed air handler and a thermidistat for independent dehumidify on demand feature.

Good Luck!


 o
RE: Best A/C option for Sotuh FL?

You probably will not need a dehumidfier if you purchase a properly sized AC with a variable speed air handler. I would put the money towards a 2-stage condenser. The stand alone dehumidifer could be add later if needed.


 o
RE: Best A/C option for Sotuh FL?

I will just add.

I don't think a dehumidifier is necessary standalone or not if you follow the guidelines for correct sizing, var speed air handler, and thermidistat with dehumidify on demand feature.

As far as 2 stage condenser, I suspect from what you have said, a two stage might be borderline undersized in 2 ton while a 3 ton two stage would be oversized. Not to mention the added cost.

IMO


 o
RE: Best A/C option for Sotuh FL?

This person (teddy bear) seams to think that I should get a variable speed air handler with a single-stage compressor, not a 2-stage compressor.
Because of the air flow could be too low to maintain a cool enough temp upstairs.

It just seems that everyone in these forums, and all the dealers have different opinions. Just makes me unsure what to go with.

Here is a link that might be useful: http://hvac-talk.com/vbb/showthread.php?1532231-Which-one-of-these-Carrier-units-is-best-for-our-townhouse-in-South-FL&p=18089621#post18089621


 o
RE: Best A/C option for Sotuh FL?

As you know, everyone has an opinion. The other HVAC site is a good one too. I am a member of that forum. They don't like to talk price, DIY, or brand bashing.

If you follow my advice, you will be just fine.

Correct sizing
Var speed air handler
Thermidistat that has independent dehumidify on demand feature.

That's my opinion.

Good Luck

This post was edited by tigerdunes on Wed, Apr 9, 14 at 6:52


 o
RE: Best A/C option for Sotuh FL?

"Because of the air flow could be too low to maintain a cool enough temp upstairs."

I am not sure I agree with this statement. What floor is the the thermostat located? In you current set up what is the temperature difference between the two floors?


 o
RE: Best A/C option for Sotuh FL?

The AC closet is upstairs between the two bedrooms, with the thermostat on the wall next to it. The master bedroom is the warmest room of the house, since it is on the 2nd floor, and has eastern exposure with a large sliding glass window (with vertical blinds). I haven't done any type of temp reading room-to-room to see what the actual temp difference is.
You can see the layout here:

Here is a link that might be useful: http://hvac-talk.com/vbb/showthread.php?1532231-Which-one-of-these-Carrier-units-is-best-for-our-townhouse-in-South-FL&p=18022281#post18022281


 o
RE: Best A/C option for South FL?

Since you own the townhouse, I'd do a load-calc using tight construction & a tight duct system in conditioned area; if it is.

Then you tighten up the home's envelope to reduce air infiltration & insulate to appropriate R-values & do all the many other 'Cost-Effective' things that reduce summer heat-gain/winter heat-loss.

The way U reduce energy consumption bills is to make everything more energy efficient & reduce the Btu/hr size of the equipment; that allows it to work more efficiently with a properly sealed & if needed insulated duct system.

The options you mentioned may not reduce your utility bills.(?) Working on these other critical design engineered factors make saving on energy usage possible.

Otherwise the amount of Btu/hr to heat & cool your home under identical conditions will be relatively the same; SEER level mfg'ers Rating (is only potential) the Rating has no power on its own to reduce energy use; the other factors do have that power!.

When they show you a chart where an 18-SEER unit will cut your electric bill in half over a 10-SEER; they are pulling your leg; on many installs there will be little if any savings over a 10-SEER unit, because the other factors won't support the 18-SEER potential.

Everyone has been encouraged to sell equipment using the SEER Savings Charts; well that is NOT being fair to your customers; instead TEST the Installed Btu/hr performance Results!.

The higher the SEER the more perfect all the supporting factors have to be...

Return-Air filter area sizing needs to be sized for under 300-fpm velocity through a media filter, a 1'' inch deep pleated filter on most filter sizing, will considerably lower SEER performance; Vetted PRO David R who does a lot of testing says; On some installations it can reduce a 14-SEER down to an 8-SEER operating performance.

Print the instructions for the load-calc & follow them; print final results of the calc; then click the SIZING LINK & print those results. Tell us the results; or copy an image of the results & upload it to this forum.

Here is a link that might be useful: Online Free whole house load-calc


 o
RE: Best A/C option for Sotuh FL?

So the air handler and thermostat are on the second floor which in the summer will have the higher cooling load. The location works in your favor. The second floor will get the better air flow, and the thermostat will not shut off the AC until the second floor temperature is achieved. The first floor will also be cool since the colder air tends to sink to the lower level. Therefore based on what you have described, the concern about a 2-stage AC not being able to cool the second floor is not valid in my opinion.

In summary the single stage AC with the variable speed is a good option. If you want to spend a little more money, then go for the 2-stage AC. All the data I have seen so far suggests the 2 ton condenser is the right size.


 o
RE: Best A/C option for Sotuh FL?

A handful of observations:

1. You've been getting some good advice from HVAC-talk.

2. Your current system is oversized. That's why you have to set it at 71-72 to be comfortable. If you dehumidified the air more, you would be comfortable at a higher temperature. (An oversized system doesn't dehumidify as well because it doesn't run long enough).

3. A two ton (single or dual stage) AC condenser should be more than adequate for your townhome.

4. DON'T run the fan continuously - that increases indoor humidity.

5. Get a variable speed air handler with a humidity-controlling thermostat (like the Carrier Edge). The larger capacity air handler WILL be better at humidity removal (for the reasons stated on HVAC-talk).

6. Don't obsess over brands - they're all pretty much equivalent. You've spent most of your time researching Carrier so why not stick with that brand.

7. I know that you have looked into this but look further - see if there is any way you can replace or renovate the ductwork. If necessary, hire an HVAC consultant/engineer for $500 to do a Manual J, Manual D and envelope test to evaluate your home and if necessary andvise on any changes that are needed/can be done separate from the actual equipment. This will be money well spent - an installing company probably won't do this properly (as you have already found out).

Good luck!


 o
RE: Best A/C option for Sotuh FL?

Udarrell:
Unfortunately there are no other "energy saving" methods that can be done, as there is no attic to add or replace insulation. It's a flat cement roof with Johns Manville white tile roofing on it. So whatever "insulation" there is, it's just from that. The only other thing is the windows could be tinted, which would run $600, or $300 for the top floor....or replace them with energy efficient windows, but talking several thousand. Our electric bill is now averaging $350/month with AC set to 71 during the day and 72-73 at night. Anything above that gets too warm.

Sktn77a:
The current system Rheem installed in 2010 is a 10 seer, 2-ton, 30K BTU, 1000 CFM.
Most of the dealers that came over want to "sell me" the Carrier FV4 variable speed air handler (2 ton) with the 2-stage 24K BTU condenser. But one of them said to go with the larger 3 ton FV4 air handler with 36K BTU, and use the DIP Switches on the air handler to lower the CFM. He said the larger coils in the 3 ton unit would dehumidify better than the 2 ton.
That is one thing I'm not sure about, and different people in the HVAC Talk forum don't think that is a good idea.


 o
RE: Best A/C option for Sotuh FL?

This was a Manual J that was done on the other HVAC site by Dan SW FL based on my townhouse layout and sq/ft. Just not sure if its 100% accurate, but can be used as a gauge.

Here is a link that might be useful: http://hvac-talk.com/vbb/showthread.php?1532231-Which-one-of-these-Carrier-units-is-best-for-our-townhouse-in-South-FL&p=18028321#post18028321


 o
RE: Best A/C option for Sotuh FL?

"one of them said to go with the larger 3 ton FV4 air handler and use the DIP Switches on the air handler to lower the CFM. He said the larger coils in the 3 ton unit would dehumidify better than the 2 ton"

This is correct, and it will also provide a higher system efficiency (SEER/HPF). Note I said "system efficiency" but this is not the same as "delivered efficiency" as we know nothing about the ductwork.


 o
RE: Best A/C option for Sotuh FL?

sktn77a,

Below is the link, that I went into detail on the HVAC site.

But basically it is that the first two dealers that came out said to go with a 24ACB724 (24K BTU) 2-stage condenser with a FV4CNF002 2-ton variable speed air handler for around $4500.
The third dealer recommended 24ACB736 (36K BTU) 2-stage condenser, with the larger FV4CNF005 3-to-4-ton variable speed air handler, but said to "set the DIP Switches" on the air handler for it to run at a lower speed. His price was $4700.

If you look at the link below, you can see the CFM for the 2-ton setup would be 450-700 CFM. But the larger FV4CNF005 is 670-1050. Then if you change the dip switches for "super dehumidifying" it will lower the CFM by 10%. So that would give the FV4CNF005 a lower CFM of 603-945.

I just wasn't sure which option is the better choice for dehumidifying and overall comfort, while lowering our electric bill. My concern is the larger system (24ACB736 / FV4CNF005) is going to use more KW/Hr and cost more to run than the 2-ton system?

Here is a link that might be useful: http://hvac-talk.com/vbb/showthread.php?1532231-Which-one-of-these-Carrier-units-is-best-for-our-townhouse-in-South-FL&p=18026181#post18026181

This post was edited by fauguy on Wed, Apr 16, 14 at 1:01


 o
RE: Best A/C option for Sotuh FL?

FWIW, I have essentially that same townhouse, western exposure, and a bottom of the line Goodman replacement unit the then-owner put in back in 2007 when I was still a renter here. It's noisy and it clunks on and off in a way that took a lot of getting used to, but my electric bill last year (in Stuart) varied from $34 in the winter to a high of $67 in September. And that's with bottom of the line appliances throughout the house and sliders that leak so much there's a perceptible draft when you stand between them and the blinds. My neighbors with better quality units who keep the thermostat set pretty low run five to twenty dollars a month higher. Friends who live in another complex with the same mansard roof fourplex buildings have bills similar to these.

If you have FPL, I can't imagine how your bill can be so high. I would have to say that something more than just the AC is wrong. Have you had an FPL energy usage audit?


 o
RE: Best A/C option for Sotuh FL?

I haven't had FPL come out yet. I've only done their online energy survey that asks what type of house/appliances/usage you have and then gives an estimate. But it isn't very accurate.


 o
RE: Best A/C option for Sotuh FL?

Had another Carrier dealer out today, and awaiting one on Monday (though he did a "ball-park estimate" and emailed it that I got two weeks ago - wanting to go with the larger FV4CNF005).

So as of now, they basically run down like this:

Dealer A: $4443 (includes permits).
24ACB724 2-stage condenser 24K BTU, FV4CNF002 variable speed air handler.

Dealer B: $4798 (PLUS permits).
24ACB736 2-stage condenser 36K BTU, FV4CNF002 variable speed air handler.

Out this week was Dealer C: $4690 (includes permits).
24ACB736 2-stage condenser 36K BTU, FV4CNF002 variable speed air handler. He said that Dealer A was wrong in sizing the condenser at 24, when it should be a 36. That if they put in a 24 condenser, it would not cool enough for the upstairs rooms that get warm.

Coming next week is Dealer D, but he did do an E-Mail ball-park estimate of $4721 (includes permits).
24ACB736 2-stage condenser 36K BTU, FV4CNF005 variable speed air handler. He wants to remove the original dry-wall shelf and put in a metal air-handler stand. And also use the larger 005 air handler model, since he said it will provide better humidity control because of the larger surface area of the coils and set the DIP Switches for it to run at a 10% reduced speed.

Out of everyone that's been here, I like Dealer C the best. His prices was fair, and seemed to be the most knowledgeable. Though Dealer D that I've talked to on the phone is as well, and will be here next week.

Regarding duct cleaning, only Dealer A and C does it, for $300 and $200. But Dealer B recommended a place called Air Quality Control in Coral Springs FL since they specialize in duct cleaning and have been there for 25 years. I called them up, and they said they do a full cleaning, and spry a special white coating on the fiberglass duct-board that seals it and also prevents mold from growing with a 10 year warranty. In order to get an accurate price, they would want to come out and see the layout, but said based on my description it would be around $350 for the cleaning and $420 for the sealant/anti-microbial coating = $770, and would also include the driver-vent cleaning (a $135 value). Here's a link to their site:

Here is a link that might be useful: http://www.airqualitycontrolenv.com/air_ducts

This post was edited by fauguy on Sat, Apr 19, 14 at 1:51


 o
RE: Best A/C option for Sotuh FL?

Should You Get Your Ducts Cleaned per the EPA:

Here is a link that might be useful: Sumary of EPA's Position


 o
RE: Best A/C option for Sotuh FL?

Thanks for the EPA info. I looked on the NADCA site, and the one place I called yesterday (Air Quality Control) is on their list. But there's a few other ones in my area that I'll check with next week and see what type of duct cleaning they do and the price. Personally, I'd like to have all this fiberglass duct board removed and have the insulated flexible type installed, which that EPA site says is best, but the only way to do that is to remove sections of cceiling that lead into the 2 bedrooms, and may not be able to get to the duct that leads down stairs...plus the cost of all that would be a few thousand I'm sure.


 o
RE: Best A/C option for Sotuh FL?

Since it has been a month since Dealer A was here, I had them come back out to go over a few things, since they seem to be the most reputable and have good reviews on many site and Angies List.
This was their original quote:
Dealer A: $4443 (includes permits).
24ACB724 2-stage condenser 24K BTU, FV4CNF002 variable speed air handler.

But now since we're talking about taking out the restrictive shelf that is in the A/C closet and use a metal air handler stand with secondary drain pan, the quotes from Dealer A are now:
$4661 (includes permits). 24ACB724 2-stage condenser 24K BTU, FV4CNF002 variable speed air handler.

$4702 (includes permits). 24ACB736 2-stage condenser 36K BTU, FV4CNF005 variable speed air handler.

The reason the price is almost the same is because the FPL power company rebate goes from $405 to $770.

I spoke with their head service/install tech and he said between them, the 24ACB736/FV4CNF005 would probably be better choice, having it run at lower speed for the "super dehumidification" function via the DIP switches. That running it longer at a lower CFM speed would dehumidify better than running shorter at faster CFM speed.

But with taking out the restrictive shelf and using an air handler stand, it now gives us an option of installing an air cleaner/purifier such as the Carrier Performance PGAP. The price is $700, which is a bit much for us. But the dealer said it would have to be done at the time of install; that if we wanted it later on, the price would be around $1100 since we're paying extra for labor to remove the air handler and stand then re-install it with the filter.

Even though the Carrier Performance PGAP is a bit pricy for me, it still would be a better cost to do it at install ($700) than later on ($1100). But I would of thought there are air handler stands that could accommodate a filter like this being added on later without everything having to be removed and reinstalled?

But I'm still not 100% sure about the unit, since some have commented about the "ozone" effect/scent that it gives off.

Are there any other brands/models that are recommended?


 o
RE: Best A/C option for Sotuh FL?

I am not an expert on electronic air filters, but from everything I have read they seem to create more problems then they solve. In my opinion I think you are better served by installing a 4 inch media filter. Once you clean out the duct work they will stay clean as long you change the filter when it is dirty. You should be able to go 6-12 months between filter changes. I pay $33 for a 16X25X4 inch Carrier filter from my HVAC contractor.


 o
RE: Best A/C option for Sotuh FL?

Mike,
I wasn't aware that Carrier had a regular 4" media filter. I thought they only had the Performance and Infinity electrostatic units.
Can you provide me with some more info about what filter you use, if it fits inside the unit or has a special filter box under the unit?


 o
RE: Best A/C option for Sotuh FL?

The one I have uses the rigid 4 inch filter. It is basically a rectangular box that has a door with a thumb screw to open it. I believe it is referred to as the FILCAB air cleaner. Here is a link.

http://dms.hvacpartners.com/docs/1010/public/0e/01-iaq-053-25.pdf

Another type uses a filter that you expand like a flexible accordion. Same idea but a little different design. Is the EZCAB air cleaner. Here is another link.

http://www.carrier.com/homecomfort/en/us/products/indoor-air-quality/air-cleaners/product---air-cleaners---ezxcab/

Aprilaire also makes a similar product. I suggest starting with a MERV 8 filter in order to keep the resistance as low as possible. You can always move up to more restrictive filter if necessary.


 o
RE: Best A/C option for Sotuh FL?

Is this the one you have?
It says the model is FCCCAB.

Here is a link that might be useful: http://xpedio.carrier.com/idc/groups/public/documents/techlit/fncb-02pd~1.pdf


 o
RE: Best A/C option for Sotuh FL?

Is this the one you have?
It says the model is FCCCAB.

Here is a link that might be useful: http://xpedio.carrier.com/idc/groups/public/documents/techlit/fncb-02pd~1.pdf


 o
RE: Best A/C option for Sotuh FL?

I believe the one I have is made for furnaces. The one you are showing is for air handlers. Same concept with different applications.


 o
RE: Best A/C option for Sotuh FL?

Oh OK. Do you happen to know the model # of the replacement filter you're using?
From what I'm seeing, the carrier media filter box that I linked to above is running about $300, compared to $700 for the electronic Performance model.


 o
RE: Best A/C option for Sotuh FL?

I wouldn't get the 3 ton outdoor unit - its oversized and will not dehumidify the home - you'll be back to square 1. Cutting the air handler airflow down too much will cause the indoor coil to freeze over.

Unfortunately, the smallest outdoor condenser that you can pair with the FV4CNF005 is a 2.5 ton unit - still oversized for your townhome. You could use the 003 air handler with a 2 ton outdoor condenser. See if Tigerdunes has any more insights - he's a Carrier expert.


 o
RE: Best A/C option for Sotuh FL?

sktn77a,
Your post on April 10th seems the opposite from what posted today? Or am I misreading it?
----------------------------
"one of them said to go with the larger 3 ton FV4 air handler and use the DIP Switches on the air handler to lower the CFM. He said the larger coils in the 3 ton unit would dehumidify better than the 2 ton"
This is correct, and it will also provide a higher system efficiency (SEER/HPF). Note I said "system efficiency" but this is not the same as "delivered efficiency" as we know nothing about the ductwork.
-----------------------

The 3 options this dealer had was
1) $4661 (includes permits). 24ACB724 2-stage condenser 24K BTU, FV4CNF002 variable speed air handler.

2) $4702 (includes permits). 24ACB736 2-stage condenser 36K BTU, FV4CNF005 variable speed air handler.

3) $5198(includes permits). 24ACB736 2-stage condenser 36K BTU, FV4CNF002 variable speed air handler.

The reason that option 3 was the most expensive was because it didn't quality for as much FPL rebate. That's why they were recommending option 1 or 2.

But between those, your saying that option 1 (24ACB724 / FV4CNF002) would be the best selection?

I'm not sure if they do the 003 air handler, since they only priced out the 002 and 005 (there is no 004). But I know the 003 is an N Slope coil, where the 002 and 005 is an A coil. I not sure if that makes a difference?

Looking at the product info linked below, the 002 and 003 air handler can use the 24 or 36 outside unit, but the 005 can only use the 36 or 48 unit. The 003 and 005 are both the same size cabinet, but the 003 is N coil and 005 is A coil. So maybe that is why the 003 can use the 24 condenser since it has a smaller N slope coil.

Here is a link that might be useful: http://dms.hvacpartners.com/docs/1009/public/00/fv4c-03pd.pdf

This post was edited by fauguy on Sun, Apr 27, 14 at 1:17


 o
RE: Best A/C option for Sotuh FL?

I use the FILCCCAROO16 16 x 25 filter.


 o
RE: Best A/C option for Sotuh FL?

So Dealer A called me back today, as they caught an error (in my favor) on their pricing for the option #3 I had listed above.

This makes it:
1) $4661. 24ACB724 2-stage condenser 24K BTU, FV4CNF002 variable speed air handler.

2) $4702. 24ACB736 2-stage condenser 36K BTU, FV4CNF005 variable speed air handler.

3) $4549. 24ACB736 2-stage condenser 36K BTU, FV4CNF002 variable speed air handler.

Now with the updated price, you can see it's only about $150 between lowest price (#3) and highest (#2). But not looking at price, I'm still not 100% sure which of these three combinations is the best for the townhouse. Keep in mind that even though the outside 24ACB736 unit is a 36K BTU, that is when it's operating at full speed. The lower stage speed would be under 30K.

They said the Carrier-branded media filter would be $385, but if I went with the "generic" brand, it would be $200 but has to be retro-fited to fit the unit.


 o
RE: Best A/C option for Sotuh FL?

Guys,

I'm looking to make the final decision by next week on the new Carrier A/C, but still trying to decided which is the best option:

$4661. 24ACB724 2-stage condenser 24K BTU, FV4CNF002 variable speed air handler.

$4549. 24ACB736 2-stage condenser 36K BTU, FV4CNF002 variable speed air handler.

The reason there is a price difference is because the FPL Rebate is $405 with the 2-ton 24ACB724, and $585 with the 3-ton 24ACB736.

I'm still not sure which is the best option, as the 24K BUT might be undersized, through the 36K is oversized. As the current Rheem is a 2.5-ton 30K BTU, but at 15 years old, I'm sure its not outputting that amount of cooling.


 o
RE: Best A/C option for Sotuh FL?

The two ton is undersized, the three ton oversized...

If my choice, here is my advice...

Both choices 2 1/2 ton systems...

This would be the minimum system I would recommend. You do want a Carrier Edge Thermidistat that will give you independent dehumidify on demand feature for AC cooling.

6937512 Active Systems CARRIER AIR CONDITIONING PERFORMANCE SERIES PURON AC CARRIER AIR CONDITIONING 24ACB330A30 FV4CN(B,F)005L 875 28800 12.00 15.00 1 RCU-A-CB 232

Better choice.

6937626 Active Systems CARRIER AIR CONDITIONING PERFORMANCE SERIES PURON AC CARRIER AIR CONDITIONING 24ACC630A**30 FV4CN(B,F)005L 875 28800 13.00 16.00 1 RCU-A-CB 223 Yes

Pay attention to L suffix on air handler. This has the aluminum coil.

IMO

This post was edited by tigerdunes on Tue, May 13, 14 at 19:15


 o
RE: Best A/C option for Sotuh FL?

Tiger,

Thanks for your help.
But would like to know why'd you recommend the larger FV4CNF005 air handler instead of the 002?


 o
RE: Best A/C option for Sotuh FL?

You get a few extra cooling BTUs with the 005. But I won't quibble over the 005,003,or even the 002 as long as it has the L suffix for aluminum coil and the Carrier Edge Thermidistat.

7019306 Active Systems CARRIER AIR CONDITIONING PERFORMANCE SERIES PURON AC CARRIER AIR CONDITIONING 24ACC630A**30 FV4CN(B,F)003L 875 28200 13.00 16.00 1 RCU-A-CB 219 Yes

6937626 Active Systems CARRIER AIR CONDITIONING PERFORMANCE SERIES PURON AC CARRIER AIR CONDITIONING 24ACC630A**30 FV4CN(B,F)005L 875 28800 13.00 16.00 1 RCU-A-CB 223 Yes

6937627 Active Systems CARRIER AIR CONDITIONING PERFORMANCE SERIES PURON AC CARRIER AIR CONDITIONING 24ACC630A**30 FV4CNF002L 875 28000 13.00 16.00 1 RCU-A-CB 217 Yes

IMO


 o
RE: Best A/C option for Sotuh FL?

Hi
WOW have lived in s. florida for 38 years and have never had a central air . Now i know why!!! ,lol My highest all time electric bill was 68 bucks . I easily paid for the house after all these years . good luck with whatever you decide
gary


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Heating & Air Conditioning Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here