Read the Furnace Vent Condensation Concerns thread. That may make up your mind for you. I think you want at least a two stage furnace. Make sure sealing the ducts is a part of the bid. $3000 seems to be quite a high spread between the two.

I did the upgrade from 80 to 96% the year before last (in Jan with a broken furnace) and the difference was only ~$1000. I'd get another quote.

Another advantage to the high effiency furnace was - it allowed me to tear down my brick chimney that would have eventually needed repars.

Also in Chicago - and very happy with my lower heating bills from the high eff and never having to worry about a chimney repair.

:-)

For bpchill

Unless there are installation issues and/or bldg obstacles, an 80% eff furnace even the Infinity series is a dinosaur for Chicago location/winter climate..

IMO

thanks for the perspectives. Tigherdunes, the models are:

80% comfort 58STA110-22 (132K BTU) furnace
24ABC660A003 AC, coilCNPVP60 (5 TON 13 seer)
COST $6800

96% Infinity (don't have model #, variable speed, 2 stage gas valve)
15 SEER AC
Infinity thermostat
COST $10160

It sounds like the consensus is that I'm paying too much for the Infinity if $3000 more.

mdin, you mention lower heating bills. Can you guesstimate in % how much lower compared to before?

"Living in Chicago, and faced with the sub zero we recently had, my 80% Infinity did just fine - never kicked into second stage the entire time."

This would imply your furnace is over sized.

Parts are not more expensive on a higher efficiency furnace. There are additional parts which may fail, but it still does not justify buying a furnace that uses 20% more energy. Your 80% AFUE Infinity furnace has the same variable speed motor as the 96% AFUE furnace. This is the most expensive part which could need replacing.

A high efficiency furnace qualifies for a $150 federal tax credit. There are often local utility rebates available. These credits help reduce the cost differential.

jaan

I don't believe you ever answered my question as to your location.

In earlier post, I stated that the $3 K upgrade price was too high if you were within same series level of brand. In fact you were not. You were quoted a bottom end builder grade Comfort series sgl stage 80% eff furnace. The Infinity 96 is top of line two stage var speed 96% efficiency. Big difference.

As a compromise, see what dealer will quote on a Performance 96 model.

BTW, what size is your home, and what size furnace are you replacing?

Post back.

IMO

Here is a link that might be useful: Carrier Furnaces

This post was edited by tigerdunes on Mon, Jan 13, 14 at 9:16

sorry, we live in Yardley PA, near Trenton. The house is 3300 sq ft and we are replacing the original Carrier 135K BTU furnace.

Do I understand that you feel the 3K higher price might be justified? My main driver is overall cost assuming we stay for 10 years. I must admit I am worried about the higher price to replace parts on the higher end machines.

Check warranty.

Parts should be covered under warranty first 10 years. Lifetime on heat exchanger. I don't even think that should be a concern at all.

I would think a 100 KBTU size in the 95+% efficiency would be fine for your home.

Again, I would get a price on the Performance 96 furnace for comparison purposes.

Good Luck!
IMO

Jaansu,

I live near Princeton, NJ. If you are interested I can send you the contact information of the Carrier dealer I used. They are a located in Mercer County and I think you are within their service area. He will do a load calculation and provide you a spread sheet of various furnace and AC configurations in 80% and 95%+ efficiency ratings. You will have a lot of choices and it will be properly sized.

Send me an email. Don't forget to allow viewing of your email address otherwise I can't reply.

Excellent...can't beat that kind of help!

TD

@ jaansu - would estimate heating bills deceased by ~25%. Enough so that I initially thought there was a billing error. I wasn't really expecting it, so it was a nice surprise.

The major reason I went with the upgrade was so I would not have to repair my aging chimney.

However, the difference in price I was given was only ~$1,000., so it was a much easier decision.

This post was edited by mdln on Mon, Jan 13, 14 at 11:11

the first contractor dissed the Performance model as not worth considering, although they admitted they didn't handle it or perhaps didn't want to handle it. I'll see what the other bidders say about it.

I realize now that the price differential between the Comfort and Infinity is probably justified but my decision pt still rests on overall savings. It seems to me I am looking at ~$300/yr saving between the two. Assuming 10 yr tops before the next move, payback seems too long. I will have 3 teenagers in the household soon and I'm wondering if the whining I will experience might suggest I will be paying for more comfort as we go ahead.

How long is an acceptable pay back period for a more efficient furnace?

Mike - I had four (4) different quotes for HVAC work. Kinda strange that you suspect that it is over sized. Each of the four contractors all performed load calcs and everyone of them came up with the same size furnace.

Tiger - no dinosaur here.. I'm burning natural gas not fuel oil
Even at 80% I am still putting money in my pocket versus the ineffcient 23 year old York that I replaced.

For bpchill

You don't want to believe it.

But yes, your furnace choice is a dinosaur.

No consideration to resale if and when you decide to leave home.

Sorry if the truth hurts a bad decision.

IMO

Bpchill,

It was extremely cold in Chicago last week. I have to believe you were much below the design temperature of zero degrees plus you had a terrible wind chill factor. Yet your furnace still did not go into the high stage. The furnace is either not working correctly or it is over sized.

Your old York furnace was probably rated for 78% AFUE. I don't think you see much savings with the new furnace unless the old furnace was constantly short cycling.

Natural gas prices are low right now, so it may look like you are saving money. You need to look at the amount of cubic feet of gas your burned with the old and new furnaces if you want to calculate how much you are saving.

what is the opinion on the Comfort Carrier 80% furnace? While I would save more money obviously getting the 96% Infinity, is the Comfort still a decent furnace or something made cheaply for those who just don't wish to pay up front or don't know better? I've requested a bid on the two stage Professional furnace but so far I can't justify the extra $3000 on the Infinity if the Comfort is still a quality machine.

It's a low end builder grade furnace with 10 year warranty on parts, 20 yr on heat exchanger.

More suitable for rental.

I hope you will follow up on Mike's excellent help and suggestion on nearby Carrier dealer he recommends.

IMO

Here is a link that might be useful: Carrier STA58 Carrier Comfort furnace

The Comfort line is the lowest level of equipment and is typically used by builders. The furnace is single stage and would probably last past the warranty. The AC is also single stage. This combination is not very good when it comes to humidity control in the summer. The condenser does not have some items to protect the compressor as the better models have. The condenser has the lowest SEER rating allowed by federal law. This equipment will heat and cool your house. I am not sure if it is the best value for someone who plans to live in a house for another 10 years.

I agree it is hard to justify an extra $3000. This contractor has quoted you the bottom and top of the line equipment so there is big difference in price. He has not told you which Infinity models would be included for the extra $3000. In my opinion you don't have a valid quote.

I also don't think you need a 5 ton condenser. If you do then the contractor had better make sure your duct work can handle the 2000 CFM of air flow, otherwise you will have many long term problems. The furnace size of 110K BTU also seems large. You should ask the contractor how he come up with these sizes.

Do you know your average annual heating and cooling costs? Once you have this information you can make a better informed decision about investing in more efficient equipment. You also have to decide how much you want to spend on being more comfortable.

The high end bid just lists an Infinity furnace with no model number. On line, I only see one model listed for 96% Infinity: 59TN6. Should he have specified something else besides this model number?

For AC, both bids list the same Comfort AC 24ABC660A003, although the high end bid says 15 SEER instead of 13. If I did get the Infinity furnace, should the AC be Infinity equipment too for better comfort?

He did perform a load calculation and examine the ducts, so I can only assume the 5 ton recommendation is correct. I looked at the existing AC but don't see a ton rating anywhere. Any way to tell? I can ask him how he did the calculation but I doubt I would be able to challenge any numbers.

For the 96% furnace bid, it is a 100K BTU not 110K BTU unit.

A good estimate for heating/cooling bill for 2013 is $1500. It doesn't seem I would recoup the investment but if comfort is a factor, maybe worth paying more.

I did follow up with Mike's contractor but he won't be here until next week.

There are two high efficiency models currently available. The 59TN6 and the 59MN7. For $3000 I would expect you be getting the 59MN7 plus a better AC condenser.

There are other old Infinity furnaces which may no longer be in production. There are still good furnaces. You want to know in writing exactly what you are buying. There is no excuse not to do this.

You should ask for a copy of the load calculation and have the contractor explain it to you.

I settled for the Performance 2-stage level. While I'd like some features of the Infinity, in the long run I just wanted an efficient system. It's doing fine.

To go from an 80% Comfort to a 96% Infinity is like going from a base model Chevy, to an Infinity (lol). There are models in between to consider.

My dealer really wanted to sell me the Infinity. I think because he probably had a great profit margin in it and because it makes the repairman's life easier. The thermostat alone was a big increase over a decent 2-stage. I figured I was spending enough at the price point of a 96% performance. But, like cars again, I'm happy with my upgraded Nissan and didn't need the Infinity (but didn't want the Chevy Geo either!)

I would not consider the 80%. We were the only ones in the neighborhood to go 90% when our house was built 18 years ago. Our bills were ALWAYS a good bit lower than our neighbors. It's a bonus for resale when the time comes. I am in South Jersey and I grew up in Lower Makefield, so I know we are dealing with the same weather. You will see a savings. If you're not comfortable with the Inifinity $, split the difference, and find a contractor who will do it. (I think they might get spifs, or incentives from Carrier to push the highest end models....just my suspicion though.)

Thanks Cindy, maybe you used to live in my neighborhood - I live in Yardley PA now.
I got a second contractor to visit yesterday and a third will come Monday. Maybe I will get some more answers at that point. It does seem I will pass on the 80% builder model furnace.

My primary contractor says the Performance furnace system will be $8200. This is versus $6800 for the bare bones Comfort furnace and $10200 for the Infinity. All with the Comfort level 13/15 SEER AC.
I'd like to upgrade the AC but otherwise I'm leaning on taking the Performance package. Any thoughts?

Mike, the Hopewell NJ contractor you recommended came by and did a load calculation on the house and left me a stack of bids. Very professional I thought of his methods. His load calc placed on a bit on the high side of 4 ton. The bids are also on the high side of what I have seen but it does leave me with a question of whether it makes sense to go for the two stage AC if I go with the Performance or Infinity furnace with the two stage or variable blower. I like the idea of being able to run the AC on a lower setting for longer to better control humidity. Or go cheaper with the single stage AC?

My impression so far is that it makes more important to have AC of multiple stage operation rather than for the furnace.

I am happy to hear you got a good response from the contractor. Hopefully he explained all the choices he presented so you can make an informed decision.

The 2-stage AC works great in my house. I can set the thermostat at 78-79 degrees and be at 40% humidity. It feels very comfortable.

The variable speed furnace is also very nice. They are very quiet in the low stage. At the very least you would have to get a multi-speed furnace to work with the 2-stage AC.

Can you wait until March 1st? This is when the spring rebates usually start. Don't forget the federal tax credits and any local utility rebates.

It seemed to me that you need at least a two stage blower to take best advantage of a 2 stage AC, even if I didn't go to the Infinity grade furnace.

Except that the blower goes continuously, our furnace is perfectly fine. I could wait until March 1. Could you give me an idea of how generous the spring discounts are? I wonder if I could strike a deal with the contractor to give me that discount now rather than waiting?

Here is the rebate matrix from Spring 2013. The upcoming rebate should be similar.

Here is a link that might be useful: Carrier Spring 2013 rebate

I guess I could wait a month or ask if they would give me that discount now. Does anyone know if heating contractors might work on a monthly quota, sort of like car salesmen? Either for the company or the manufacturer? WIth the end of Jan coming up, I'm wondering if the saleman would become more accommodating.

I'm fairly sure I am going with the Infinity TN6A100V21-22 furnace with a two stage Performance AC 24ACB760A003. This set up requires the Edge t-stat. While I don't think I will ever recover the higher cost over the 80% furnace, it seems the variable speed AC will improve summer comfort.

Right now, in the Chicago area, I would not be surprised if they charged extra. High temperature tomorrow predicted to be -1 and low -16.

Mike
Carrier tells me they are almost certain to have another Cool Cash March rebate program, which may save me $1000! Thank you so much for the idea. The contractor admitted as much that it makes no sense to buy now if I can wait.
It sounds like the rebate schedule may not come out until March 1 so I'll probably need to wait that long to see if they will match last year's numbers.

You would have to get an Infinity furnace with a 2-stage AC in order to get a $1000 rebate.

The details for the Spring rebates should be available by the middle of February.

I've been monitoring the Carrier website but nothing about a Cool Cash 2014 rebate. My contractor says he knows nothing about any unannounced rebates coming up either besides a $150 rebate. I'm curious if anyone knows anything about a more substantial rebate since I was hoping to save $1000 on the full system.

Another thing to consider with the condensing furnace is the drain - we have an ongoing problem with the condensate drain freezing every time the weather gets below freezing for more than a day. I can put a heat tape around the drain exit from the house but if the pipe freezes inside the walls, we just have to wait until it thaws out. Luckily, this is our upstairs system and we can just crank up the downstairs system to get some heat to the bedrooms when this occurs (hot air rises, and luckily, the downstairs systen never freezes up). But clearly a major problem if we only had one system. Just an FYI. Oh, and our gas bills didn't go down appreciably when we replaced our old 80% furnaces with the 96% systems.

I figure the savings are more hype than reality but since I need to replace the system anyway, just trying to see what I can save upfront. Thanks for the warning on the freezing.

Jaansu,
Are you planning on staying in this house longer than 10 more years?

"I figure the savings are more hype than reality"

The furnace has to be sized and installed properly in order to realize the savings. It also has to be connected to a properly sized duct work that does not have major leaks. If you don't follow those simple rules, then the savings will be minimal.

You will not have a freezing problem if your furnace is installed in a conditioned space. A high efficiency furnace installed in an unconditioned attic will be subject to freezing if the contractor did not install it properly. This is why most contractors want to avoid this and use a non-condensing furnace.

You might want to consider the comfort improvement that might be possible with a more sophisticated heating and cooling system.

Sometimes hvac install techs will wire your 2 stage furnace for highstage only and the same for your 2 stage A/C either because they dont care or don't know how to set it up for 2nd stage, imo the 2 stage a/c or super high end 96% furnace with the variable speed over priced motor will not pay for itself your unit is only as good as the installer

Direct vent combustion air is always better than passive. You only get that with the high efficiency. The direct vent keeps the combustion chamber, air intake, and exhaust separate from the conditioned air. This is wise as a safety feature to prefent backdrafting and it also keeps the furnace from creating negative pressure in the conditioned space by using conditioned air for combustion.

This also applies to water heaters.

In a cold location, furnace is typically found in the basement, not in the attic due to the freezing mentioned above by others. Basements are common in cold areas considering they have to get their footers below the frost line and they might as well make a basement out of it (or an extra large crawlspace).

I realize I'm late for this party but feel I needed to add info for similar questions in the future. I've been an HVAC licensed contractor since 1979 and now support 3 equipment manufactures with onsite consulting and training. This is a very common question easily answered. What are your needs? How long will you be in your home? I'll start with the difference in 80% and 95% (condensing) furnaces. With an 80%, every dollar you pay the gas company 20 cents goes up the flue. With 95% only 5 cents goes up the flue. So basically you save 15 cents on every dollar previously spent. Now for single vs. 2 stage. Your home has an average heat loss figured for anywhere in the US. A competent contractor will do a Manual J calculation to determine the load of your home (more on this later). This load will provide enough heat for your average lowest temperatures in your area. But how often do you hit these lowest temperatures. Generally only a few hours a day or a few days every month. Which means you actually burn more gas than you need to and your furnace cuts on and off often (short cycles). Basically it's oversized for most of the winter. With a 2 stage furnace the furnace fires at a lower rate when demand is lower then bumps up too second stage if the demand becomes greater. This creates far more comfort in the home by reducing the hot and cold spots in rooms which are more prevalent when a furnace short cycles. So efficiency (80 or 90+%) reduces your money up the flue and staging reduces your money spent on comfort. Here's a problem I run into often. A contractor sells you a 95% efficient furnace and removes your 80%. After a month or 2 you see your gas bills go up! What happened? Furnaces have an Input and Output (or bonnet) rating. A 100,000 btuh 80% puts out 80,000 btuh. A 100,000 95% puts out 95,000. Some contractors just look at your old furnaces input rating and goes "like for like" rather than a proper Manual J calculation because it's easier. So if you remove your 80% 100,000 btuh furnace for a 95% 100,000 btuh furnace as you can see from the example above you would burn 95,000 - 80,000 = 15,000 btuh's more of gas than you did with your old furnace. Choose a dealer wisely and ask to see the Manual J of your home (also shows cooling needs). Hope this helps....

"So if you remove your 80% 100,000 btuh furnace for a 95% 100,000 btuh furnace as you can see from the example above you would burn 95,000 - 80,000 = 15,000 btuh's more of gas than you did with your old furnace."

Actually, I don't think that's quite correct For a given heat loss (load), the two furnaces would deliver the same number of output BTUs. The 95% efficient ("bigger") furnace would just deliver this in a shorter period of time than the 80% furnace. In theory you should see a 15% reduction in gas usage, but I've never seen this in practice. Efficiency is probably lost because the 95% furnace is now oversized and short cycling to an extent.

For me, it is a lot easier if you use the correct vocabulary. Input capacity is the amount of fuel burned. Output capacity is the usable heat produced. The difference is what goes out the flue or down the drain. If a boiler or furnace is 100% efficient, input=output but that does not happen, obviously.

I you compare two furnaces with the same input capacity, the higher efficiency furnace will look "bigger" to your house, producing more usable heat. In the example above, yes, you get 15% more heat out of the new furnace compared to the old one. If the boilers have the same input capacity, and the old one heated the house well, you are definitely oversized. Efficiency, as already pointed out, will suffer and so might equipment life and comfort.

"Some contractors just look at your old furnaces input rating and goes "like for like" rather than a proper Manual J calculation because it's easier. " should be criminalized. Not only does it oversize in the case of installation of a new boiler on input capacity, but many, even most, homes have seen improvements in terms of insulation and air sealing since the last heating appliance was installed. I suspect that part of the oversize problem is because the contractor is playing it safe. They will certainly get a call back if the heating appliance is too small and the house is consequently cold. Not so much if there is short cycling. What a disservice to the pitiful homeowners thinking that they are getting higher efficiency ;-(

From what I've been able to learn, fuel usage records coupled with local climactic information (heating degree days) is really the best way to estimate heat loss and the required amount of heat needed. It seems easer so much easier than a manual J and there are far fewer assumptions.

Please help me decide which furnace to get...currently have 80% and my gas bill is only $86/month! Purchase price is basically the same for both furnaces when rebates are considered. I don’t have a brick chimney. Furnace is in my insulated garage and I enjoy a warm car on a cold day. Will switching to a 96% make my garage colder? It seems the 96% has more complicated parts therefore more to go wrong? I had a question about the condensation freezing like someone mentioned? I’m thinking that a new 80% will be more efficient than my old 80%. As you can see I’m leaning toward the 80%. I’ve never had to make a furnace decision before so help appreciated.

You should ask your installer about the condensation and the coldness of the garage. I think it won't be any different because the 96% is just getting MORE heat into your ductwork, the 80% is sending 20% up the chimney. Maybe ask if you can have a duct in the garage? With the high efficiency furnace in the garage I'm assuming the condensation only has a short distance to go, so can't see a problem. Even if it did, it's easy for you to get to! The 96% vent only has to go right outside the garage, through the wall, not up the chimney. Can't hurt to save a few $ on the gas bill, just make sure you get a good warrnty.

Also, is that $86 a year round budget bill? If so, then you don't know what heat really costs. My gas bill in non-heat months is about $30...

Can also consider insulating your garage if it's not insulated. What state? If it's a winter state then high eff is also a resale plus.

Where are you located and what is the typical winter low temperatures? If the cost of the furnaces are about the same, then it makes sense to install the high efficiency model if they are similar quality. For example you may be better off with a high end 80% efficiency furnace than a low end 96% efficiency furnace.

How cold does it get in the garage? If there is a chance it will go below freezing then the installer has to make sure the condensate line will not freeze. Some of the wasted heat of the 80% efficiency furnace does remain in the garage, but I don't it will be very noticeable if you have a big garage. You could have a vent installed in the garage as part of the installation. That would probably be enough to solve the freezing condensation issue.

Irishsea: An 80% furnace will be a straight swap. A 96% furnace will need a new venting system and a condensate drainage system. In your situation, I'd go for the 80%.

Get a air conditioner. they have 10 years warranty too.

https://www.air-conditioning-ductless.com/