"-58CVA135-22 Carrier 80%/135Kbtu Infinity 2 stage VS gas furnace 24";
-25HNA660 Carrier 5 ton 15+Seer Infinity HP as hybrid;
-CNPVP6024ATA Carrier Coil 24"

That combinaton is ARI# 882105:
59,500 btu cooling, 10.8 EER, 14.5 SEER, 58,500 btu heating at 47F, 8.8 HSPF.

I would bump the parts and labor warranty to 10 years for such a high-end system with a lot of bells & whistles.

Best to you.

Here is a link that might be useful: Air Conditioning, Heating, and Refrigeration Institute

goddi

I would change the lineset out.

what are cooling and heating load calculations? that's a lot of heating BTUS...

IMO

I am kind of surprised that the EER is only 10.8 and the SEER is only 14.5 for this Hybrid setup. (The Trane (non-hybrid) 15i had an EER of 12.00 and a SEER of 14.5.) I figured this Infinity Hybrid setup would be a bit higher. Am I missing something here??? Is this still a good combination or is there a better match-up of equipment??? Does this mean it is better not to go Hybrid?

He wants $675 to install a new 1 1/8" and 3/8" lineset. He talked me out of doing it. "Never had a problem." I understand that it would be nice to do this. What are your concerns and is it worth $675???

He said he would do a Manual J if we went with him and make adjustments later. No one else even offered to do it. But I think the next level down from 135K is 100K. Not sure. And that would be a bit too low. And with a 2-stage furnace, it should mostly in the first stage.

Thanks...confused...Gary

Gary, new linesets aren't always necessary provided the size is correct and they are properly flushed to remove oil. Lineset replacement is good, but it doesn't always happen due to cost and physical restrictions. I wouldn't worry about reusing it, and he reaffirms the fact that he hasn't had any problems. From others I've talked with, no problems with reusing old linesets correctly.

"That combinaton is ARI# 882105:
59,500 btu cooling, 10.8 EER, 14.5 SEER, 58,500 btu heating at 47F, 8.8 HSPF."

I've tried to enter data into the ARI site but the only model number I can get results from is the '24ANA760', and that gives me an EER of 11.60 and SEER of 15.50. And that is not the Hybrid setup that I'm looking at. I can not get any result with the other numbers. I am just not sure where to put them. Can you point me in the right direction????

goddi,

I have always believed it is best to change out and replace lineset. If changeout is straifgrforward without any obstacles, then I recommend the lineset be replaced especially when going to the new refrigerant. $350 is a reasonable price not $675. If there are installation issues, then lineset should be flushed out and correct size must be verified to achieve best efficiency of new system.

and youdo need a load calc preferably before you sign the dotted line. If your dealer won't comply with this request, there are sites such as HVAC-CALC that you can run the numbers yourself. Not a bad odea. I still believe thatfurnace is oversized unless that's the smallest available with a 5 ton rated blower.

as far as question regarding the AHRI directory, I believe you accessed the AC directory rather than the HP directory. The matching number is in the HP directory.

IMO

tigerdunes...
Yes...I was in the wrong directory...I got it. Thanks.
So now my concern is that, even though the SEER rating (14.50) for the Carrier hybrid system is the same as the straight Trane A/C and furnace combo, the EERs are lower for the Carrier hybrid (10.80) then the Trane (12.00). This reflects that operating costs will be HIGHER for the hybrid. Is this an incorrect conclusion? If the EER is worse for the Carrier hybrid, why go for it??? The EER for the Carrier's straight A/C unit is 11.60 (and SEER=15.50). What is all this supposed to tell me???
Still confused... Gary

goddi

I think you are making a mountain out of a molehill.

check the AHRI HP directory and compare the hybrid systems for Carrier Infinity 16, Lennox XP16, and Trane XL16i. I think you will find the EER eff rather poor on all two stg HP condensers. Can't explain why but that's the case. I personally think these two stg condensers are overkill for 99.9% of homes unless they are used in conjunction with zoning controls for several zones running off one system. You will get better humidity control and less electric consumption from a two stg properly sized Infinity HP or AC but of course that comes with a cost.And you already know that you don't reach these great eff numbers listed in the glossy brochures from a five ton condenser. Note these stats that have "dehumidify on demand" like the Infinity controller and HW VisionPro IAQ will give you superior comfort in the summer whether two stg or sgl stg condenser.

Check the numbers with a Carrier five ton Performance 15 and Trane XL15i HP. I suspect they will be better.

Still I think you are concerned over nothing.

IMO

What State do you live in?

2 stage condensers are generally preferred in hot and high humid climates where they can run on low to reduce summer humidity and lower operating costs. 2-stage condensers have a higher EER on first stage than second stage (thus the high SEER#), however the overall EER rating is on 2nd stage. 2-stage systems save operating $$ as long as they run on first stage which also minimizes cycling to help with efficiency.

I agree with TD that 2-stage condensers are overkill on most houses. They are more for comfort than energy savings, especially when the application is a heat pump in a heating climate, and heating btu's outweigh 2-stage cooling.

Below the balance point of the home (around 32F ambient or so), the gas furnace will be providing heat.

Your decision depends on climate and condenser run times.

Pricing on that Carrier Infinity Hybrid looks great.

Good luck.

tigerdunes...
Yes, but at this point, the molehill looks pretty big to me. I am trying learn and understand all of this and it is really hard to dissect/understand the important points.

garyg...
I am in Northern Virginia (24 miles from DC). My bills last year for gas was $926 (.099/kwh) and electric was $1,214 ($1.61/ccf). At first, I thought it was a good idea to go with a hybrid system. However, with the comments that the 2-stage is 'overkill' makes me think maybe not. I have been satisfied with my A/C and gas furnace for 22 years.

I'd rather have something very reliable. The bid shows an "Infinity 16 HP, 25HNA660, 2-speed". However, the Carrier site shows the InfinityS (up to 19 SEER, 2 stage scroll) and the InfinityR (up to 17 SEER, 2 stage reciprocating). So I am now not sure which the bid is actually for. I don't see an "Infinity 16 HP" listed. Is a 'two speed' the same as a '2 stage'?

And now I see on the Carrier site that all the 'Infinity' HP and A/C models have 2-stage compressors. I'd have to step down to the 'Performance Series' to get a single stage. Does this sound right?

Never having had a HP before, I am a bit afraid of getting into one. I've heard lots of negatives--cold air, frequent repairs, etc. Perhaps, now they are unfounded. Also, I don't know how to judge the good/bad of the scroll vs. reciprocating compressor, and getting an HP vs. a straight A/C.

It's like a moving target... Not sure what to do.
Gary

goddi

First of al, you have been quoted the Infinity 16 Heat Pump-Mdl 25HNA660. The first 6 indicates the Infinity 16 and the 60 indicates the five ton size(12 x 5=60).

I would ask your dealer what the COP is for this heat pump configuration. Tell him you don't want a guesstimate that you want the true published Carrier number.

The Infinity 16 is the only two stg that I would consider.

However there are two additional factors that you need to be aware of.

1.It is a recip compressor-I prefer the scroll which is the way the market is moving.

2.The condensor actually stops and starts as it moves from
low to high stage, not on the fly so to speak.

I am not certain if this pump has timed defrost or the preferred electronic demand defrost-perhaps Ryan can answer.

So as you can see, all HVAC, even high end systems have trade-offs.

As far as HP heating, it is vastly different from 10 yrs ago as far as supply output temperature but still below gas furnace temps. I have a Trane dual fuel and was hesitant about the pump. I love it and my wife does not complain. In fact, I wish I had gotten an air handler as opposed to the backup gas furnace for better efficiency. My system is 3 1/2 yrs old. I did purchase the 10 yr ext warranty for parts/labor. I do have a once a yr service performed and change my 5" pleated media filter once a yr.

I still believe you have been quoted a very nice system with a good price that you will be happy with and it will provide you with good comfort, operating eff, and many yrs of dependable service.

If not a system like this, then forget the pump and get a quote on the top end 3 stg 95% gas furnace mdl paired with either the two stg Infinity 17 AC or the Performance 15. Good alternatives but I believe higher operating costs compared to your hybrid quote.

IMO

I asked the dealer for the COP but he said they don't use it any more..they now use SEER. Even Carrier support did not have this number.

So it seems like the choice at this point would be the hybrid system (HP+gas) or the 'regular' way (A/C+gas). The hybrid would cost an additional $975. With my already relatively low gas+electric bills, the pay-back might not be so quick? (Yesterday, I added 22 bats of R30 insulation on top of my already insulated attic.)

Also, if I wanted to go with the scroll, Infinity 19, it would be an additional $510. But you said it is not as efficient as the Infinity 16, right?

I can't go with a high efficiency unit because it can not be installed with the needed clearance for the PVC pipes.
Good to hear your confidence with the hybrid system.

Thanks... Gary

goddi

since you can't consider the high eff 95% condensing furnaces, then it appears your decision is already made for you.

your existing AC is also five ton? and ductwork has been inspected and is sized correctly for your new system?

after you sign papers, insist that a man j is performed for both cooling and heating and get a copy in writing. this is a measure of insurance for both you and the dealer.

IMO
Good LucK!

tigerdunes...
Yep...can't consider the 95%. Yes, my current system is the standard 5 ton AC+gas. The duct work is sized for the 5 ton.
Ok...will have them do the Manual J as they said they would. I just have to convince myself to go 'hybrid' as opposed to stick with the type of system I have, straight A/C+gas.
Thanks for your help... Gary

tigerdunes...
Yep...can't consider the 95%. Yes, my current system is the standard 5 ton AC+gas. The duct work is sized for the 5 ton.
Ok...will have them do the Manual J as they said they would. I just have to convince myself to go 'hybrid' as opposed to stick with putting in new system similar to what I have, straight A/C+gas.
Thanks for your help... Gary

"I asked the dealer for the COP but he said they don't use it any more..they now use SEER. Even Carrier support did not have this number"

C.O.P. = Coefficient of Performance = btu's produced / electrical btu's in. This number varies with outdoor temperatures. It is not a single number like SEER. You need the Operating Technical Data for the heat pump to check COP as well as other info. COP determines operating cost of the heat pump in heating mode.

"I am in Northern Virginia (24 miles from DC). My bills last year for gas was $926 (.099/kwh) and electric was $1,214 ($1.61/ccf)."

Lok at the cost of one milion btus of heat for both fuels based on your utility rates:

Heat pump w/electricity at 10 cents per kw-hr delivered price, COP = 3.25 at 35F ambient
(1,000,000 / 3413 btu per kw-hr) x .10 / 3.25
= $9.77

Natural gas at $1.61 per therm, 80% efficient furnace
(1,000,000 / 103,000 btu per therm) x 1.61 / .8
= $19.53

The heat pump costs 200% less to run than the 80% gas furnace (19.53 / 9.77).

As ambient temps increase from the 35F example above, COP increases and the heat pump is even cheaper to run.

Here are the COP numbers for my 3-ton 14 SEER Goodman heat pump based on ambient temps:

Ambient temp----COP
65F-------------4.37
55F-------------4.04
45F-------------3.64
35F-------------3.25
25F-------------2.82
15F-------------2.46
5F--------------2.06

Below the balance point of the home (around 32F or so), the heat pump cannot keep up with the heat loss of the house because the btu output of the heat pump drops with temperature. Supplimentary heat is required below the balance point. My balance point is mid/upper 20's.

Your climate is perfect for a heat pump. I'm in Baltimore - same climate. If you go dual fuel (heat pump plus gas furnace back-up), you have a choice if the price of one fuel drastically changes in the future. Choices are a good thing.

A few notes about a heat pump (just so you know):
- Heat pumps do not produce the hot 120F air temp of a furnace. They produce heat in the mid to upper 90's.
- Heat pumps have a shorter operating life than straight a/c because they run in all 4 seasons.

Best to you.

garyg...
Thanks for the detailed response. Very interesting. It seems that the question of going HP+gas (hybrid) vs. A/C+gas is hinged on 1) do I want lower operating costs with the hybrid over the next 10 years (that I will be in this house) but might face having to replace the HP sooner because it will run all 4 seasons (and might have to replace the furnace too to match the new HP??), or 2) stay with the non-hybrid A/C+gas system and pay the higher operating costs but the system will last longer (mine now is 22 years old). It is too bad the Infinity Series HP does not come with a scroll compressor.
Gary
P.S. The actual savings in having hybrid is questionable in my mind. Even with the HP being '200% less to run', these 'operating costs' estimates that I get from the dealers are so overblown, I need a truck-load of salt. One told me I'd save "$1700" per year. I figure I might save 10%-13% per year. If my overall gas+electric bill last year was $2,100 (including the gas water heater), the amount attributable to the heating/cooling is, say, $1,800, I would save about $200 per year. Not huge but worth thinking about, I guess.

goddi,

you have been thrown some numbers that certainly make a compelling case for a high eff heat pump. I will again say that an 80% eff gas furnace by itself is a dinosaur for your area. High Eff HPs properly maintained with a yearly professional service can easily have a life of up to twenty years. After fifteen years you would probably want to consider new HVAC to take advantage of new technology that has much better efficiencies that are not available today. Keep in mind that most people believe that the gap between nat gas prices and electric prices will only widen especially in service areas that have a nuclear electric generation footprint.

The suggestion that Carrier can not provide a COP number for the dual fuel configuration you are considering is absolutely absurd. I estimate you will save around 35%-40% over an 80% nat gas furnace when the HP runs and is able to maintain your home's inside comfort. When the nat gas furnace takes over at or lower than the balance point, that is when you start offsetting your savings but still most likely better than your existing furnace. Also, you save some dollars in AC mode.

You seem to be concerned that a HP is not a good choice and that potential savings don't make its purchase worthwhile. I would respectfully disagree.

IMO

tigerdunes...
I truly appreciate all of your advice. Before I do a project, I ask myself, "What can go wrong?". And I try to educate myself so I know/understand as much about the project as possible...sometimes more than the contractor. Never having had a HP just makes me wonder a bit. Only one other guy in my development replaced his unit a couple years ago with a hybrid...a Trane...and needed frequent repairs, and too hot upstairs/too cold downstairs, etc. But that might not be a HP problem...maybe design of the system. But your logic sounds good. I may opt for the Carrier's 10 year parts/labor warranty for an additional $750.
Thanks... Gary

"Only one other guy in my development replaced his unit a couple years ago with a hybrid...a Trane...and needed frequent repairs, and too hot upstairs/too cold downstairs, etc. But that might not be a HP problem...maybe design of the system."

You can't let that become a major issue with your decision. Many issues with HVAC are ductwork-related, or installation-related.

If you go dual-fuel, you don't "have" to use the heat pump for heating. Use the gas furnace if that makes you feel better. Use the heat pump only when you want to save money on your utility bills.

Take care.