The system configuration is a valid AHRI match, but I agree it is a mixed bag of systems. This configuration does not qualify for any Carrier rebate, assuming the contractor participates in the rebate program.

If you upgraded to the Infinity controller you would qualify for a $150 rebate. This would offset most of the cost and you would have a communicating thermostat.

If you upgraded to the Infinity AC (24ANB7) and controller you would qualify for a $1100 rebate. I would think this is going to be close to the same price you have been quoted.

Is it possible to install the Carrier Infinity 95% AFUE furnace? It is more money, but the added efficiency is worth the extra cost in my opinion.

Finally did the contractor do a load calculation?

Thank you, Mike for your opinion.

I will ask them to for another proposal with Infinity Controller and AC (hope they participate in the rebate program).

I was not at home when the person came to the house (my own mistake, couldn't get back home in time) so I do not know if they did a load calculation. How would I know if they did it or not (Sorry for a stupid question. I am sort of learning this stuff, and not very well :-). If they did, would they have sort of paper work? Thanks again, Mike. appreciate your help very much

Regards,
Nirun

I have another question.
Is it necessary to have both 2-stage furnace and 2-stage AC?
Or mix of stages for furnace and AC is OK ?

Thank you again
Regards,
Nirun

Joe

I generally agree with Mike.

The system quoted is nice if sized correctly.

I can't believe you need a 90 KBTU furnace though even at 80% efficiency. I would drop down to the 70 KBTU mdl size. I would consider changing the AC condenser to a HP model. If not a HP, then look at the 95% eff 58MVC Infinity furnace. I personally would go with the high eff furnace rather than upgrading to a HP condenser.

And by all means, Infinity furnaces should have the Infinity controller. Any Carrier dealer worth his salt should know this.

And to be clear, you do not have to have a two stg condenser whether AC
or HP paired with a multi stage var speed furnace.

IMO

The contractor has to at a minimum first measure rooms, windows, duct work, and determine insulation values in order to create an accurate load calculation. The indoor and outdoor design tempertures must also be established. These values are then entered is a sofware program to determine the heating and cooling loads. The software will print out the data for your house and the calculated loads. The print out should say the name of the software and state it was based on some edition of ACCA Manual J.

If you don't see any of this, then the contractor is doing a gross estimate based on the equipment you now have and the area of the house. This method tends to oversize equipment. This is probably what is going on with your quote.

Good morning guys,

I have another stupid question. I wasn't at the house when they came to estimate. The proposal doesn't have that load calculation result attached. I guess in order to prove that they did load calculation, should I just ask them to send me a print out? Thanks again for all your valued opinions and comments.

Regards,

Yes, ask for the load calc in writing and on the software letterhead that will provide all details.

You should be interested in the design temps used by dealer both inside and outside and for cooling and heating.

IMO

Be aware a real load calculation takes time and requires the use of an expensive piece of software. Some contractors will only do the calculation after you have signed the contract. Others may perform it before a committment, but may not give you a copy until after the contract is signed. Contractors don't want you taking the calculation and sharing it with the low bidder.

For a home this size, load calc should not take more than 1 1/2-2 hours. And software is relatively cheap. I would want to know the software used as well as version.

IMO

Natural gas or propane?

What TD says about using a HP is good for this area. It can do very well during those shoulder months when the lows are still above freezing. And it can still do well lower than that depending on it's numbers.

Combining a HP with gas is a 'dual' fuel configuration (not 'duel'). You would need an additional outdoor temperature sensor to tell the thermostat what is going on. It will then chose which fuel to use. You can then chose (by experience) at what point you want the changeover to occur (lowest HP temperature and highest gas temperature).

Weedmeister is correct.

If staying with 80% eff Infinity furnace, then I would upgrade the AC condenser to a HP condenser.

However, if your home is suitable for a high eff condensing furnace, I would upgrade the furnace to the 58MVC model and forget about the HP.

IMO

Good morning guys,

Thank you again for great suggestions. I have learned a lot in the process.

When I asked the contractor about upgrading to 95% efficiency, they will have to run new venting at the back side of the house it will add an additional $1500 minimum for the extra cost of the equipment and labor.

What are you guys' recommendation on this? Thanks a million again

Regards,

Joe

Where is current furnace located?

Where would a new high eff furnace be located? How close would this be to an outside exterior wall?

Just to be clear, the $1500 cost includes the upgrade to the new high eff furnace?

What is your nat gas rate? What is your electric rate?

Ask for a price on the HP version of the AC condenser quoted?

Then I would weigh the cost difference for the HP upgrade versus the high eff furnace upgrade.

And make no mistake. That furnace size in original quote is highly questionable!

IMO

I got another quote for fully Infinity System. (I didn't get a chance to ask about HP condenser)

Total cost of approx. $9,300 INSTALLED
-Carrier gas furnace- 58CVA090-1-16, Infinity 80 FURNACE WITH TWO STAGE HEATING AND A
VARIABLE SPEED BLOWER
-Carrier Air Conditioner-24ANB736A003, 17 SEER A/C, WITH A TWO STAGE SCROLL COMPRESSOR
-Carrier Evaporator Coil-CNPVP3617ATA
-Carrier Infinity control thermostat- SYSTXCCUID
-System qualifies for a $1,100 rebate

We also got another quote from a different company:

-Lennox Gas Furnace : Lennox Signature Series SL280V
-Lennox Elite Series XC14 Air Conditionaer
-Lennox ComfortSense 5000 Thermostat

Original price was: approx 8,300 but was able to come down to less than 7,000 (very strange indeed).
I checked lennox website, and they seem to have a rebate as well, though I am not sure if this proposal qualifies for the rebate.

Now, I am confused even more, LOL

What do you guys think about those 2 new proposals.

Thanks again

I would not go 80% eff furnace unless paired with a heat pump.

And your dealers continue to oversize you. On the Infinity 80, you should not need more than the 70 KBTU model. Pay attention.

I still would prefer the 58MVC 95% eff Infinity furnace-60 KBTU size.

And just going by the brand, I prefer Carrier over Lennox.

IMO

that is a high price on the carrier quote for a 80% furnace in my opinion.

So just to be clear, what is your net price for this new Carrier system after all rebates?

You would want to check to see if the Commonwealth of Virginia offers any help with HVAC tax credit incentives. A good dealer would know.

Post back.

IMO

Thanks again, agree on BTU and I am asking them to redo the load calculation.

The net price after rebate will be ~ 8,200.00

I will give you guys update regarding lower BTU and/or HP condenser. Thanks again

Regards,

Check with Dominion Power (if that is your electricity supplier) for any rebates or incentives for HP.

Ask if this unit has demand defrost or timed. Demand is better (doesn't activate until needed versus timed).

Joe
Where is current furnace located?

Where would a new high eff furnace be located? How close would this be to an outside exterior wall?

Just to be clear, the $1500 cost includes the upgrade to the new high eff furnace?

What is your nat gas rate? What is your electric rate?

Ask for a price on the HP version of the AC condenser quoted?

Then I would weigh the cost difference for the HP upgrade versus the high eff furnace upgrade.

And make no mistake. That furnace size in original quote is highly questionable!

-----

Posted by tigerdunes (My Page) on Fri, Jun 1, 12 at 12:05
I would not go 80% eff furnace unless paired with a heat pump.
And your dealers continue to oversize you. On the Infinity 80, you should not need more than the 70 KBTU model. Pay attention.

I still would prefer the 58MVC 95% eff Infinity furnace-60 KBTU size.

And just going by the brand, I prefer Carrier over Lennox.

IMO

Thanks again you guys.

I will ask then to send me proposals with heat pump option as well as the ones with lower BTU size. Thanks a million for your opinions.

Regards,