what size furnaces are being quoted?

what size is existing furnace?

a 95% eff furnace with HP is overkill for your area/climate. if you elect 80% two stg VS furnace, then I would recommend HP consideration.

zoning the basement would come with a nice cost. you would have to decide if that's worth it. plus there would be ductwork modifications as well.

what's the price difference between the two systems quoted?

post back.

IMO

Hmmm. I can't figure out the size of the furnace from any of the quotes I have. Plus, I don't know the size of the current one.

The only reason I could potentially see to do the ductwork to the basement would be for the case of eventually selling the house. It's not that I plan on moving immediately, but I'd give it a few years. So, we could list the basement as finished square feet by doing that. Unfortunately, we haven't spent a winter here yet, so we don't know how cold it gets.

The price difference for the two systems is about $1600 (Trane more expensive). It's $8,500 for the Trane and $6,900 for the Carrier.

What about 95% furnace only vs. 80% two stage furnace with HP? Which would you say would be better over the long run?

marchube

there has always been a tendency for HVAC dealers to oversize furnaces. Still is IMO.

I would like to know what size furnace you were quoted and what existing size is.

Most homeowners don't realize that the heating/cooling load for basements partially or below grade is usually very small.

Going to the expense of expensive zoning controls/ductwork modifications for just 650 sq ft does not seem very practical. Perhaps dealers can offer a less expensive solution. I will say for a homeowner to include sq footage for basement living area, it must be comfortable yr round. A HP minisplit might be a good alternative. Of course dealers are supposed to be the experts so rely on their recommendations vs the cost factor.

IMO

Is this the information for the Trane?

Model : Height (in.) : Width (in.) : Depth (in.) :
Nominal Capacity Output (BTUH) : Stage1/Stage2 ICS* AFUE
TUH2B080A9V3VA : 40 : 17.5 : 28 : 49,500/76,000 : 95.0

For the Carrier, I have heating load 48,772, Cooling Load 38,827 for the guy's calculations for our house as it is.

marchtube

Trane dealer has oversized you on furnace if the Carrier dealers load calc is correct. a 60 KBTU mdl would be more appropriate.

also, what size is existing AC?

IMO

I know that the existing AC is 3 tons. The Carrier guy gave me the most thorough load calculations of all. I may have misread the details. Anyway, he has it broken down by floor and then a 4th category called "other equipment loads.

1st floor 18921, 2nd floor 13556, basement 8489, other 7805 for a total heating load of 48772.

For cooling:
16565, 12720, 4983 for 1st, 2nd, basement, then
2718 "other equip loads" and 9434 "latent cooling" for a total of 38827.

I know that the existing AC is 3 tons. The Carrier guy gave me the most thorough load calculations of all. I may have misread the details. Anyway, he has it broken down by floor and then a 4th category called "other equipment loads.
1st floor 18921, 2nd floor 13556, basement 8489, other 7805 for a total heating load of 48772.

For cooling:
16565, 12720, 4983 for 1st, 2nd, basement, then
2718 "other equip loads" and 9434 "latent cooling" for a total of 38827.

marchube

so a 60K furnace two or three stage VS plus a 3 ton AC condenser.

It should be noted that Carrier quote appears to be their top of line 95% Infinity furnace paired with their bottom of line base series condenser which I would not recommend.

Did Carrier dealer include the Infinity thermostat? He should have.

I would also want 4-5" box filter media cabinet with either system.

IMO

In a mild climate like NC I would go with a heatpump for sure. You get a lot of weather that isn't super cold that a heatpump does well with. You could go either straight heatpump with electric strip backup. Dual fuel with 80% dual stage furnace or if you want to go all out get 95% furance with a heatpump. Heatpump shouldn't cost too much over straight a/c. I think a heatpump is something to consider whenever replacing an A/C because its only incrementally more expensive and offers a bunch of flexibility.

marchube

as stated in previous post above,a 95% eff furnace with HP is overkill for your area/climate. if you elect 80% two stg VS furnace, then I would recommend HP consideration.

IMO

Actually, the Carrier guy gave me lots of quotes, with different combinations of furnaces and condensers. In fact, the highest price unit he quoted me seems really overkill - 58MVC Infinity Furnace + 25HNA9 Infinity Series 2 Stage Heat Pump. I think the deal with the furnace is that this one qualifies the system for the federal tax credit.

marchube

was the Infinity controller included with the Infinity furnace?

you should give consideration to upgrading from the low end Base series AC condenser.

IMO

Yes, Tigerdunes. I didn't know that this was a low end AC condenser until you mentioned it. The Carrier guy didn't recommend that combination, but it is listed and I wanted a way to compare his price to the Trane system. I was hoping to find a relatively apples to apples comparison to the Trane system I started out talking about this morning. I guess that one was not it. In any case, I'll ask about the Infinity controller. It's helpful to know what to ask. The Trane guy just called me and said he'd come by again next week and talk about hybrid systems. We'll see what he says on that.

marchube

if you are truly looking for an "apples to apples" comparison to the Trane XL16i AC condenser, then ask for the two stg Carrier Performance 17 AC condenser.

And with the Infinity furnace it would be a big mistake not having the matching Infinity controller.

IMO