Carrier 96 or American Standard 97 or Carrier 92?
In a prior post (Which of these two Carrier gas furnace and A/C systems? Posted on 8/18), this system was the preferred one due to better dehumidification:
AC 24ANB 636 16 SEER/13 EER � 3 ton AC
Furnace 59TN6AO80V17-14 96% 2 stage ECM � 80,000 BTUs
Thermostat Infinity Touch (WiFi)
Net cost to me after various rebates and discounts: $7,928
A second contractor has proposed this system:
Furnace American Standard model AUH2B080A9V3, 2 stage variable speed (American Standard Gold ZM-80,000 Btu�s, 97%)
AC American Standard model 4A7A6030H1, single stage (American Standard Gold XI- 15 SEER 2.5 ton)
Coil American Standard model 4TXCB036BC3
Thermostat American Standard digital programmable
Net cost to me after rebate: $6,285
Which is the preferred system? Why the difference in AC size 2.5 v 3 tons? It is hot and humid here in the summer but I have a 2.5 ton AC currently. I think Manual J might say 3 tons? Will that be more costly to run on my electric bill?
And finally, a third contractor besides quoting a price on a very efficient system (Carrier 98% - cost to me $8,465), also priced this one:
Carrier Brand Comfort 92 Single Stage Gas Furnace model #:59SC2060S17-16 with a 60,000 Btu input capacity and a 56,000 Btu heat output capacity and a PSC blower motor
Carrier Comfort 13 series outdoor air conditioning condensing unit model #: 24ABB336W003 with a 3.0 ton cooling capacity
Comfort 13 all aluminum N series vertical evaporator coil with insulated jacket model #:CNVP4217ALA with a 3.5 ton cooling capacity
Carrier programmable thermostat model #:TCPAC01
Cost to me: $4,300
This price is for a 60,000 BTU furnace � not 80,000 � why the difference in BTU�s? I hated the heat pump I got rid of in 1996. I had big utility bills AND was cold. I do not want to be cold. I think my current furnace is an 80,000 BTU furnace.
In discussing the project with contractor #3, he asked if I was happy with what I have and I told him if the furnace didn�t have a crack in the heat exchanger, we would not be having this discussion. What I currently have is a Carrier gas furnace 58 MXA 080-01-12 92% AFUE, a Carrier AC 2.5 ton 13 SEER, 38 TRA 030-3, Advanced Products coil with time delay HA 10436-175, and a programmable thermostat. And I am happy with it.
While I can afford any of the options, it seems to me since I use about 500 therms (heat and cook top only � gas is .50/therm here) and 20,000 kWh annually (AC and hot water and everything else � 8.8 cents/kWh), the price difference ($3,628) to gain 4% extra efficiency in a furnace (is that really $10 � 500 times .5 times .04???) and to go from 13 to 15 or 16 SEER (I have no idea how to calculate that potential cost savings) when I use the AC only May to September (sometimes April to October �it is very humid here in Maryland), I am not sure spending all that money is wise. My total gas and electric in the last 12 months was $3200.00. Gas is cheap. Electricity is not.
Contractor said that is what he would do if it were his house ($4300 option) plus simpler system � less costly parts/repairs and less to go wrong/break.
I think I agree with him.
Or am I thinking about this all wrong?