JJ

I will say from the start that I don't like the idea of 80% eff furnaces for DC area unless paired with high eff heat pump.

To clarify , what is age of your home and its insulation qualities?

If not a heat pump paired with an 80% eff furnace, then I would look at a good 2 stg furnace 80K size 95% eff like Trane/AmStd XV95. Do you have
basement or crawl space?

Post back. In meantime I will review your quotes closer.

IMO

Didn't see your response until just now.

Built in 1880. Corner town house. West wall ajoins a neighbor. Good attic insulation.

Crawl space is very tight - more like a belly crawal and I have never been down there.

JJ

Where is existing furnace located?

Have you even asked dealers about a 95% eff condensing furnace?

And if so, what was their response?

Post back.

IMO

Furnace is in a closet/pantry in the kitchen with AC and water heater. Tight squeeze.

I'm going over to see the Carrier people momentarily about the 90 or 95 your earlier suggestion.

I understand 95 AFUE, but not sure what the "95 eff condensing furnace" is.

Although the Trane people are my current service people, I think they are taking my business for granted. I am leaning towards Carrier; know the people and trust them.

JJ

Both Trane/AmStd and Carrier/Bryant offer 95% eff var speed 2-3 stg condensing furnaces. All high eff furnaces are condensing furnaces.

High eff furnaces though are usually located in basement or crawl space for venting purposes.

Post back and let me know what dealer says.

IMO

IMO

I visited with the distributor, and they are coming over this afternoon to take another look. (The owner who is on vacation right now did see the set up a couple of weeks ago.) From the conversation at the distributors, I think the tight squeeze and venting issue (city codes to deal with and added expense) means that anything other than an 80 will be impractical.

I'll let you know about the visit of the owner's son to my house which is likely to happen later this afternoon.

This is a family-owned business that has been around 125 years.

It would be good to know your NG rates. I assume the electric is around $0.08/kwh, though I know it just went up.

"95 eff condensing furnace" = 95% efficiency condensing furnace.

You will want the variable speed blower for the AC. Does wonders for humidity extraction.

Going from 13SEER to 15SEER is about a %10 reduction in electrical usage. You can figure what this would mean in payback time.

Adding a HP to this would be interesting. It would require a new Tstat and outdoor temp sensor. I think with an 80% furnace you might find additional savings if NG is somewhat higher than electric. I guess what I'm saying is that with an 80% furnace, you will be burning more gas. You might find that the HP is cheaper to operate than the gas furnace during those shoulder periods when the temperatures are above 35f-40f.

i just got a quote for a similar system. 100k, 3 ton, for 5800. i see your 3 quotes are all within 100. is my quote at 15% higher reasonable?

IMO

Contractor's son came by. Space and construction consideration, I anticipate, will run up the price considerably so I will be using a 80 AFUE.

So I am focused on:
Carrier gas furnace, 110,000 BTU 80% Comfort System 58STA110-16
Condenser and coil 36,000 BTU @ 13 SEER 24ABB036
Price $5195

And will probably go with these optional add ons:
16 SEER - add $400
Infinity system on gas furnace - add $600

I heard some talk about Carrier that when it was taken over by United Technologies, UTX switched away from aluminum coils that created real problems for them in the early 2000's. Carrier claims they have corrected that problem. Any insight on that?

I am not ruling out the American Standard yet, but the system they proposed is comparable in price to the Carrier distributor's quote, and I assume - maybe wrongly - that comparable upgrades from American Standard will be about the same price as the Carrier upgrade prices.

I would just get model numbers for each of those upgrades. 16 SEER doesn't necessarily mean a 2-stage unit, which would be nice to have with the Infinity control.

Here is the system I would recommend. I'm going off your current equipment size but a load calc should be done to ensure correct sizing. How did the old 3 ton air conditioner perform. Looks like the dealer proposes a jump to 110k furnace -- any explanation why?

24APA736 outdoor unit
CNPVP3717 coil
58CVA090-16 furnace
Infinity Control

I would replace the thermostat regardless of which system you go with.

He is getting back to me with a new proposal incorporating all the changes.

Pretty sure the AC is a two stage motor.

Although we do now have a programmable thermostat, my wife wants to replace it with a new one. You know how that goes.

This decision is once every twenty years, so it's good to have a resource like you to guide me. Thanks very much.

JJ

Ryan has configured a very nice Carrier System. Similar system also available from Trane/AmStd.

As said in earlier post, I don't care for 80% eff furnace for DC area unless paired with HP.

You have 4 questions to answer.

What are you looking for and how much do you want to spend?

Do you want a two stg var speed furnace?

Do you want sgl stg or two stg condenser?

Do you want straight AC or HP condenser?

That 110 KBTU furnace even at 80% eff is oversized.

IMO

IMO:

Here is a modified proposal from the Carrier dealer:
AC - 24ACC036 condenser and coil � 3 ton @16 SEER
Furnace � Infinity 80; 58CVA090-16 90,000 BTUH @ 80%
(They agree with you about the 110,000 being too much.)
Both are two-stage.

$6,095.00

Really not sure how to answer your questions. The blower is two stage; I don't know about the condenser.

I have pretty much eliminated the Trane systems originally speced in my initial inquiry due to price.

The American Standard system which is fairly comparable to the Carrier is:
AC - Allegiance 13 - 4A7A3036A1000A, 3 t0n, 13 SEER condensing unit and 4XCB36BC3HCA coil
Furnace - Freedom 80 - AUD2B100A9362A - two-stage 80% efficient

$5,045.00
To up grade to a SEER 13 (Allegiance 14 or 15) add $320.00
To total
$5,365.00

Noise reduction is an important factor.

JJ

The carrier is the nicer of the two systems listed.

Does quote include Infinity controller? It should.

Recheck mdl number of AC condenser and provide evap coil mdl number.

I would want a whole house box filter cabinet.

While the AS furnace is two stg, it is not var speed which I would want. AS is quality HVAC and I would asK Dealer to upgrade to the two stg VS model and provide you a price. You do want a two stg thermostat. What mdl was quoted?

Post back.

IMO

The system proposed by the Carrier distributor does not include an Infinity controller. He is providing a Honeywell thermostat.

Condenser is 24ACC636. Coil is either CNPVP3717.
To repeat, the furnace is Infinity 80, model 58CVA090, 80% 90K BTU.

He will price a whole house box filter for me, but as he explained it so me, its value to me looks pretty marginal.

The American Standard distributor does not recommend a variable speed motor although he can provide one at a little higher price. His reason is that his experience has shown that the variable speed motors are more likely to burn out sooner and if not under warranty, they cost about $1250 to replace.

I asked the Carrier distributor about experiences with the variable speed motor being more likely to burn out. He reports no troubles with variable speed motors and has been using them for 10 years of more. The ECM motors used are covered by ten-year warranty along with the rest of the equipment.

If you get anything with variable speed DC motors be sure to have at least ten year warranty on parts. The minute you need any parts for that electronic motor you have lost every bit of fuel savings over an 80%

JJ

It would be a big mistake to purchase the Carrier Infinity 80 furnace without the Infinity controller. I have always found that the most reputable Carrier dealer's would try to sell you the Infinity controller with an Infinity 80 furnace because of it's very reliable functionality. A third party thermostat hurts the full functionality of that furnace.

If not a box filter, what does dealer propose?

And the AS dealer is blowing smoke about the reliability of var speed furnaces.

IMO

IMO

I now have a standard 1 inch filter. He is not proposing anything other than what is there now. He says there is room for a box filter and will give me a price.

What in your view is the advantage (value vs. cost) of a box filter?

I'll press him more about the Infinity controller and talk directly with Carrier.

Again, thank you. This is a once in 20-year decision for me, but for professionals it's pretty routine.

The benefits are once a year changeout and superior protection of blower motor and evap coil plus improved indoor air quality all an improvement over 1" filters.

IMO

Thanks.

Waiting to hear about final proposal including box filter option. He said once-a-year box filter change was about $25.00.

Go with the filter they recommend , otherwise you will have issues and get error codes on the stat due to static pressure readings on the Infinity System.

Trane/AmStd recently switched to Aluminum Coils in their newly redesigned and possibly recalled AHU...they should have a New Relaunch of the their New AHU soon.

Carrier was good to you for 19 years...sounds like you've made a pretty good decision.

Going with Carrier:

Furnace 58CVA090 - 90K BTU and 80% AFUE. Higher AFUE won't work due to flue configuration and city zoning obstacles.
AC 24ACC636 3-ton 16 SEER and CNPVP3717 coil.

Honeywell box filter may not fit, but they are bringing it along to see if it will. Cost of unit ($250.00) and corresponding filter compared to the one-inch filters we use now makes an investment marginal.

Reviewed with Carrier by phone the Infinity controller. I do not feel it is worth the extra money, and I am going with the contractor-supplied Honeywell 6000 programmable thermostat.

Thanks to all for your patience and advice.

J.J. Smith

JJ

I realize this is your decision but you are being ill advised to purchase a nice Infinity furnace without the matching Infinity controller.

Sorry but it's true.

IMO