Advice needed on new hvac system in NC

mwredeMay 29, 2012

We are planning to replace our upstairs heating and cooling system.

We currently have a 3.5 ton ac and 100,000 btu furnace - the ac parts have been replaced over the years with mismatched parts by AHS but we are still having issues and the heating system is the original from 1992. It's a split system most of it is in the attic and the ac compressor is outside. We are in NC so we have typically hot and humid summers and relatively mild winters. The ac has been failing for the last 4 yrs since we bought the house and can't seem to keep the house cool without breaking down a couple times a season. Our first floor is heated/cooled by an American Standard gas pack the previous owner put in 2004.

The upstairs is about 2000 sq feet. We are also thinking of finishing the 3rd level (attic) in the next year or two which might add 500-600 square feet up there- with a separate bedroom, bathroom and the rest being open area. When getting prices for the 2nd floor unit we'd like to take into account the 3rd floor as we would hate to have to spend more than a couple thousand dollars down the road to heat/cool the 3rd floor. There is currently very minimal insulation in the attic and we are thinking of adding insulation up there.

I have just started getting quotes and want to hear people's opinion on the different brands and what your recommendations would be to us as far as efficiency, heat pump vs furnace/ac, replacing the 20 yr old ducts vs keeping them etc. We would like to add some kind of filter probably media filter and possibly something to increase humidity in the air in the winter time. So far we have a quote for the trane XV80 furnace (tdd2c100a9v5va + 4txcc044bc3hcb) and XL16i (4ttx6048e1000b). I also have a price for American standard and goodman equipment. Please let me know your recommendations. Thanks in advance.

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Where in NC?

20 year old ducts in vented attic? - it would be tempting to replace.

When was house built? 20 years ago (a guess) would still have decent attic insulation.

I assume you have NG?

You will want a third system for the attic. Code basically requires it or zoning but it would be hard to get zoning to work well in your scenario.

Goodman is not thought of highly here.

    Bookmark   May 30, 2012 at 4:54AM
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David thanks for your response. I would normally be doing a ton of research but have little time with a 17 mo old running around. We are in Durham. As far as the ducts yes I probably should get quotes to replace them but I had one reputable company here (as well as 2 others through American home shield) and no one mentioned replacing them. I have 2 more companies coming today so we'll see what they say.

I have heard than new ducts would have a lot more insulation by code and would actually be sealed properly. We would have to add a return in one of the bedrooms anyway (we sleep with doors closed and current system only has returns in hallway and bonus room) and probably run a bigger duct to the master bath ( its freezing in the winter even after adding in floor heat) .

Yes the house was built in 1992-93 and we do have NG. There is insulation under the floor of the attic but none on the ceiling or walls from what I can see. We also have new wiring ready to be used up there. I was hoping zoning might work as I've asked about a separate system for the attic and was given prices over $5000 which would be more than we hoped to spend.

As far as brands I see trane and carrier are popular on here. What's interesting is I have had a few companies that are longer trane dealers tell me they had a ton of problems with their equipment. Now these companies were send by American Home Shield ( typically does not use the most reputable companies) so not sure whether to believe them or not.

So what equipment would you recommend in our case? Thanks again.

    Bookmark   May 30, 2012 at 8:26AM
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I would not have Goodman for a dog house.

I would size for 2nd floor only and put in a separate system for future addition/expansion.

I would not use any recommended company from a third party warranty company like AHS. If this is warranty work, ask for a settlement and get a qualified dealer with a good reputation.

Ductwork for new system should have a thorough evaluation including size of lines adequate return, leak test, insulation qualities. If you have any existing hot/cold spots, these are usually associated with bad ductwork design/sizing and should be addressed. You want R8 insulation for attic.

I doubt you require a 100 KBTU furnace. Insist on load calc both for cooling and heating. Both Trane and AmStd offer a 4 ton rated 80 KBTU 80% eff VS furnace.

Good Luck

    Bookmark   May 30, 2012 at 10:16AM
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tigerdunes thanks so much for your input. We are doing exactly what you are recommending and getting a cash-out from AHS so we can go out and use whomever we want for this install. We just had to get two of their companies to come in in order to confirm the issues with our system (upstairs coil is leaking) and they gave us estimates while they were here even though we are not planning to use them.

As far as a separate unit for the 3rd story it doesn't sound like we could afford it. I have asked all the companies that came by for estimates (I have had 5 reputable companies come in) and they gave me an approximate cost of $5500-7000 to install a separate unit up there for just 500-600 sq feet of space (assuming 3 rooms, at least one return and at least 5 vents) vs. around $2000+ for adding a zone system to 2nd floor unit adding dampers etc. and new ductwork for 3rd lever. Everyone agreed that we could do a 4 ton 2 stage AC (vs. a 3.5) that with proper attic insulation it could handle the aprox. 500 sq feet up there. They felt heat would not be an issue as heat rises especially with a 2 stage furnace.

Out of the 5 companies only one sort of did a load calculation (measured windows) and he seemed the least experienced of the people I met with. He said the AC load was 3.3 tons. I forget what he said about the furnace. A few of the other companies said that we could get away with a 70 or 80k btu furnace but said that if we did a 100k btu 80% efficient would be like getting 80k btu. The rest asked for square footage of the house and if there were any cold hot spots etc. I asked one specifically why they don't do a load calculation and he said he used to do them and the AC units they put in ended up not being able to deal with the 100+ degree days during the middle of the summer. No one asked or offered the option to replace our ducts until I brought it up. Our ducts are R4.2 and sealed with tape probably leaking in places and the new ducts would be R8. We were quoted a price of $2500+ to replace the ducts (they are in the attic so pretty accessible). Many of the companies offered to test and seal the existing duct system with tape/mastic during the new system installation.

Can you please let me know your thoughts on the following equipment/prices? I believe they are all flushing and reusing the existing refrigerant line. They pretty much all recommended an 80% efficient furnace installation in an unconditioned attic due to possibility of lines freezing in the winter and cost of having to vent the 90% and up units. They all basically recommended a split ac gas furnace system and not a heat pump due to the higher cost of equipment and increasing electricity prices (they did not feel we would save money). All systems qualify for $200 Duke energy rebate for 15 seer and up. Furnaces with 90% and higher efficiency qualify for $100 off from PSNC.

Company a:
Trane XR15 $6628 after Trane rebates and discounts
TDD2C100A9V5VA 80% efficient
4TTR5042E1000A 3.5 ton 15 SEER
Warranties: 10 year compressor, 10 year parts, lifetime heat exchanger and 2 year labor

Trane XL16i $8212 after Trane rebates and discounts
TDD2C100A9V5VA 80% efficient
4TTX6048E1000B 4 ton 16 SEER
Warranties: 12 year compressor, 10 year parts, lifetime heat exchanger and 2 year labor

Both options include increasing duct size to master bath and adding return in master bedroom
Add media filter $350
Add Clean effects $1350

Company B:
Trane XL16i $8616 after trane rebate
16 SEER 4 ton (2) Stage Air Conditioning Unit and matching Trane 80% (2) Stage VS Gas Furnace
A/C 4TTX6048
Furnace TUD2C080A9V4VB
Warranties: 12 year compressor, 10 year parts, lifetime heat exchanger and 1 year labor

Trane XR15 $7737 after trane rebate
15 SEER 4 ton Air Conditioning Unit and matching Trane 80% (2) Stage VS Gas Furnace
A/C 4TTR5048
Furnace TUD2C080A9V4VB
Warranties: 10 year compressor, 10 year parts, lifetime heat exchanger and 1 year labor

Trane XL16i heat pump $9287 after trane rebate
16 SEER 4 ton (2) Stage Heat Pump and matching Trane 80% (2) Stage VS Gas Furnace
Heat Pump 4TWX6048
Furnace TUD2C080A9V4VB
Warranties: 12 year compressor, 10 year parts, lifetime heat exchanger and 1 year labor

Trane XR15 heat pump $8187 after trane rebate
15 SEER 4 ton Heat Pump and matching Trane 80% (2) Stage Variable Speed Gas Furnace
Heat Pump 4TWR5048
Furnace TUD2C080A9V4VB
Warranties: 10 year compressor, 10 year parts, lifetime heat exchanger and 1 year labor

All options include increasing duct size to master bath and adding return in master bedroom
Add new duct system: $2650
Add 5" media filter: $286
Add Trane clean effects: $925 after rebate from trane
Add UV light (ultramax) $223

Company c:

Rheem 16 Seer $8976
16 seer two stage AC with two stage 80% gas furnace & high efficiency evaporator coil
Ac: rarl049-jec
Furnace: rgpe10ebrmr
Coil: hm4821cc

Add new ductwork: $2823
New return in master bedroom: $325

They also gave an option for a 13 seer single stage unit with 70k btu 80% furnace for $6783 that we are not considering.

Waiting for final estimates from companies 4 and 5 later today. Company 4 is quoting York/Trane/Carrier (they are pushing York though) and company 5 Amana and Carrier (they said Carrier starts at 19 SEER for 2 stage so they were recommending Amana).

    Bookmark   June 5, 2012 at 3:47PM
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I like company B best.

On the options, I see no reason for the UV light and not a fan of Clean Effects. Go with media filter. Make certain there is a pan for the furnace. I assume this will be attic location.

If you expect good comfort operating one system for second floor and future expansion, then I would want zoning controls. However if you don't want that added cost, then definitely manual damper controls for the supply trunk line both for second floor and the small expansion.

Also by all means insist on a true two stage thermostat that controls the furnace, not the timer on the furnace control board. This is a must. You will probably need a new and correctly sized refrigerant lineset.


    Bookmark   June 6, 2012 at 10:35AM
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Thanks tigerdunes.Which of the options by company 2 do you think is best for our circumstances?

Also can you explain the difference between manual damper controls and the zoning controls?

I am wondering if it would make sense to add the zoning controls now vs when we add the 3rd level. We only use 2 of the 4 bedrooms and one of the bathrooms at night (there is also a bonus room, 2 other bathrooms and a laundry room on the 2nd floor) 99% of the time and would love to just heat and cool the rooms we need between 10pm and 7am since we close the doors at night.

So as I mentioned above no one is really bringing up heat pumps and only company 2 actually gave me a quote for heat pumps. Should I really be considering them based on our energy rates?

Electricity has been going up from 8.7 cents per kwh 2 years ago to 10.1 cents per kwh this month.
Natural gas is going down from 99.5 cents per therm (3.4 cents per kwh) to 89 cents this spring (3.04 cents per kwh) to 81.7 cents this month (2.79 cents per kwh)

Average temperatures: Average high in the peak of the summer 87 degrees (record high 105), average low in Jan 27 and average high 48. Record low 2 degrees.

Any thoughts?

Also how much would we save in efficiency by spending upwards of $2500 for new ducts at this point?

Here are some of the other quotes:

Company 4:
York 15.5 SEER $8452 before possible utility company rebates of $300
4 ton coil 80,000 btu 96% AFUE 2 stage furnace with variable speed blower
Coil: mc48c3xh1
AC: ycjf48s41s1
Furnace: tm9v080c16mp11

Warranties: 10 year compressor, 10 year parts, 20 year heat exchanger and 10 year labor

Includes Focus Pro 6000 thermostat

Upgrade to WIRELESS FOCUS PRO 6320 THERMOSTAT: $376.80
Add 20x25 Merv 10 media filter $173.68
Add new duct work: $2554
Does not include added return in master bedroom or enlarging master bath duct. Will also send me the same quote with a 80% AFUE furnace and how much adding a return in master bedroom and enlarging master bath duct will cost.

Also can install Trane and Carrier equipment but their trane quote was a higher than companies 1 and 2.

Company 5:
Amana 16 SEER $8320
Two stage 16 SEER 4ton AC w/ 90,000 btu 80% 5 ton furnace - 2 stage variable speed with ComfortNet Communication System
AC: ASXC160481B
Furnace: AMVC80905CXA
Warranties: lifetime compressor, 10 year parts, lifetime heat exchanger 10 year coil and 10 year labor

Includes adding dampers on master bedroom and baby room distribution box to regulate airflow.
Add Honeywell thermostat with averaging sensors on existing returns and relocate thermostat from hallway to master bedroom $430

I am waiting on a Carrier Infinity quote from them as well.

    Bookmark   June 6, 2012 at 3:22PM
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More quotes from company 4:

$7841 + $405 to add return in master bedroom and enlarging master bath vent duct to 8"
Coil: MC48C3XH1
Furnace: TM8V080C16MP11

Carrier: $9045 no mention of carrier cool cash rebates * + $405 to add return in master bedroom and enlarging master bath vent to 8"
Described as 16 SEER two stage AC and 90,000 btu 80 AFUE 2 stage furnace
Furnace: 58CVA090116
AC: 24ANA148A003 21 SEER Infinity
Coil: CNPHP6124ATA
Not including infinity thermostat
(* They will install Carrier but they are not on the Carrier dealer website)

Still waiting for the Carrier Infinity quote from company 5 who is a factory authorised Carrier dealer.

tigerdunes you seem to like the Trane equipment best can you explain what makes it better. I would also be really interested in learning more about the manual dampers vs zoning controls.

    Bookmark   June 6, 2012 at 7:39PM
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I have Carrier Infinity because I wanted zoning. Carrier does not have demand defrost which is okay because I have dual fuel and set the balance point above freezing anyway.

Infinity zoning is pretty slick. Stat for each zone. Either one can call for cooling(or heating) and direct all the airflow to that area. If the pressure climbs because of inadequate ducts, the fan speed is slowed. The stats sense humidity also and will drive the temp down to keep the humidity lower when needed.

Zoning to do 2 bedrooms out of four doesn't help much particularly on the cooling side. Cooling at night is actually a good idea because it is more efficient than daytime. By zoning you would tend to have shorter run cycles which is less efficient. You would also have more pressure in your ducts (even if you had the Infinity to limit it) and so you would leak more. All these hits make zoning not a very efficient thing to do in general despite what seems like a good idea.

Now with a really leaky house on the heating side, zoning would probably help. At night, heating is harder (with a heat pump) and also the leakiness "costs" more so the inefficencies are overwhelmed by the savings of having those rooms cooler. But - most of the time you aren't saving enough to be useful.

We use zoning to sleep in the 60s while our toddler sleeps in the 70s. So it is a comfort thing rather than an efficiency one.

With our setup, 5000 sqft is about $1000 a year to HVAC. It is a pretty even split between heating and cooling. But this is a new house.

    Bookmark   June 7, 2012 at 2:09AM
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David the infinity system sounds great. Is there a central remote that controls/monitors all the thermostats? I really need to learn more about it and zoning in general. If we did zoning we would still heat/cool the rest of the spaces but to a lesser degree. Is there a way to make zones flexible meaning could we at a future date add/subtract rooms from a zone as we expand our family?

My husband definitely likes the room cool - he used to sleep with the thermostat at 70-71 in the summer but recently we've had to keep it at 73 at night (and 75 during the day) because we have a toddler and her small bedroom get's much colder with the door closed than our large bedroom.

We would probably keep the other zones at 75-76 during ac season ( our house feels so stuffy when the themperature goes over 76 whereas my inlaws in Chapel hill have a new house and new systems and they keep their house around 77-78 and that feels fine) and in the mid sixties in the winter.

Would you send me an email through my page with the company that you used to install your system? Thanks again.

    Bookmark   June 7, 2012 at 3:33PM
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Ok so our AC is acting up again and I am trying to finalize a decision ASAP.

I have another quote for carrier infinity:
$10,150 minus $1,100 carrier mail in rebate = $9050
Ac:24anb748a003 4 ton 2 stage 17 SEER
Furnace: 58CVA110-20 80% 110 btu 2 stage ( they claim we need 110 btu to have a matched system)

To add all new ducts and 4 zone zoning system add $3240

We would use the 3 zones for the second floor to improve comfort now and then add a fourth zone when attic is finished.

Aprilaire 2210 Media Filter included for free if we do the zoning system.
Add Carrier 10 year labor warranty $500

Same installation but with 25hnb648a003 heat pump $340 more. The heat pump would give us 3 stages of heating : heat pump at 48k btu (stage 1 heat), furnace low at 59k btu (stage 2 heat) and furnace high at 85k btu.

We also have a $200 Duke energy rebate and $629 AHS cash out reimbursement.

Bottom line... it's a lot of money. Do you think we should do the zoning/ new ducts now or do it when we finish the attic? Any thoughts David_cary, tigerdunes? I am still considering the Trane equipment too. Thanks again.

    Bookmark   June 13, 2012 at 10:59PM
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"Furnace: 58CVA110-20 80% 110 btu 2 stage ( they claim we need 110 btu to have a matched system)"

I disagree with this statement. The 58CVA90-16 (90,000 BTU) can be used with a 4 ton AC. Find out the Carrier coil model and someone can verify if it is a matched system on the AHRI web site.

In my opinion it is a better investment to get a 95% AFUE furnance rather than spending the money on a heat pump. You need to compare your current gas and electricity rates before considering a heat pump.

If you know you will be finishing the attic, then it makes sense to do everything now.

    Bookmark   June 14, 2012 at 7:58AM
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Just to be clear.

Your dealer's assertion that the 110 K Infinity furnace is required to get an AHRI match is factually incorrect. Your dealer is mistaken and the 090 would be your best choice.

I personally think the HP upgrade is a poor idea. You do not need 4 stages of heat for your location/climate.

Zoning is an excellent idea for a further expansion down the road. Probably is cost effective as well versus adding a small system later. You
do lose some redundancy though if a breakdown occurred.

I think you need toqualify your dealer's experience using zoning controls. Get some of his prior customers names and contact them. You might even consider a visit if homeowner would allow you to look at their setup.

The zoning, ductwork, and controls should be done now as long as you are certain addition will definitely occur.

You do want some type of filter cabinet for both indoor air quality and protection of furnace blower and evap coil.

Carrier Infinity controls are generally regarded as the best integrated sgl source zoning in the residential market.

Finally, pay attention to comment about the furnace size.


    Bookmark   June 14, 2012 at 8:29AM
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What mdl evap coil was quoted?

And you want adequate return(s) for all zones, strategically located for best air flow and overall comfort.


    Bookmark   June 14, 2012 at 8:34AM
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Thanks Mike and tigerdunes. Coil is CNPV6124A for ac or CNPH6124A for dual fuel. He send me the AHRI certificates. This is company 5. I feel their pricing is fair and i think i prefer the carrier infinity over the trane xl16i.

My only concern with company 5 is that the guy i have been talking with seems to be stretched too thin and had initially taken a long time to get back to me with the additional options I asked for.

I still like Company B a lot because i have actually talked with the owner and not a salesperson and he really knows what he is talking about. I just talked to them and even though they are mainly a Trane dealer they also install Carrier so they will send me their prices for Carrier Infinity. I will wait to see what they come up with. Thanks again.

    Bookmark   June 14, 2012 at 4:16PM
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Seems like getting the heatpump for only an extra $340 might be nice just to have.

    Bookmark   June 15, 2012 at 11:51AM
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Thanks everyone for all the input. I think we are going with the heap pump option although not with the company above (they have not been returning my calls). We had another company do a detailed load calculation and I think we are narrowing it down to these two options below. I need to decide asap as we are going out of the country tomorrow and we have to sigh a contract in order to take advantage of the carrier rebates through 6/30.

Would you pay $660 more for this combination:

16.4 SEER 12.5 EER 9.5 HSPF
Carrier Infinity Heat pump 25HNB948A003 2 stage
Furnace 58CVA090-1-16 90k btu 80% AFUE 2 stage
Coil CNPHP6024ALA 5 ton

than this one

15.8 SEER 12.3 EER 9.2 HSPF
Carrier Infinity Heat pump 25HNB648A003 2 stage
Furnace 58CVA090-1-16 90k btu 80% AFUE 2 stage
Coil CNPHP6024ALA 5 ton

Both options include infinity control, Honeywell media filter and a 10 yr labor warranty.

    Bookmark   June 21, 2012 at 2:26PM
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Anyone have any thoughts as to whether the slightly higher SEER rating is worth $660 more?

    Bookmark   June 21, 2012 at 8:41PM
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I still believe the HP is a marginal choice.

I wanted to verify the performance/eff numbers of each system as well as that mdl evap coil was your best choice but the AHRI directory website was down.

But assuming the numbers and evap coil are correct, then my answer is no.


    Bookmark   June 22, 2012 at 6:28AM
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We are in the process of replacing a 1 year old...Yes,1 year old 4 ton ($12,400put in Aug.20,2011)
air conditioner:TraneXL16i seer:16.5
load calculation was done by 5 out of the 6 companies stating we needed a 4 ton unit. We just had a company come out and they said we are oversized by 1 ton and that was the reason for our whole problem?? We have what they call 'dirty sock' syndrome which started 2 weeks after it was installed!! 4 coil changes later still an issue. When we ran it in emergency heat over the winter,without a coil,no smell!!! With Tranes non responsiveness to all I would never get a Trane again!!!!!!!!!!!!
Now I've read about all the problems with all units and am more confused then ever,but I do know that I will not get a heatpump again!!! Our original Lennox furnace(19yrsold)began getting stuck/freezing(not turning on) no smell issues whatsoever.
Since we had just finished with our D.I.Y renovation of our home we decided to get a new unit,more energy efficient since it was the last thing that was needed to complete our home!
I cannot believe how each and every contractor differs on their load would think there would be some sort of protocol/procedure to do this accurately and come up with the same numbers?? More confused then ever~smile~Afraid to get that horrendous smell back in my house with another 'coil'...and Yes, we had one dipped and the procedure was done incorrectly , even the contractor said the chemical smell was making him was in the house for 1 hour and he had to take it out immediately after closing up the unit(took him an hour to install it).
We had to air out the house mid winter and sit outside...stress to say the least....Any comments advice would be appreciated~smile~ I too live in W.N.C.

    Bookmark   August 27, 2012 at 11:18AM
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An oversized condenser and dirty sock syndrome are not necessarily related. Keep in mind, you get about 66-70% of BTU output on first stage of the XL16i condenser.

What size condenser was the unit you replaced?

This load calc complaint gets a little old. If you are able to come on this forum, then you are able to perform the load calc yourself. The cost is

The HVAC equipment you mention is top of line. So I have to believe your issue may be install and dealer related.

Dirty sock syndrome can be difficult to identify and correct.

And BTW, it is bad forum etiquette to hyjack and piggy back onto an existing thread especially when your complaint has nothing to do with the thread itself.


    Bookmark   August 27, 2012 at 11:34AM
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    Bookmark   August 27, 2012 at 2:41PM
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