Are you sure the downstairs unit is 4 tons. This sounds oversized for the first floor. The basement does not add any cooling load to the AC.

What are the model numbers of the condenser and coil? The price suggests to me it is a builder's grade model. What furnace do you currently have and what is the age and condition? If it is 20 years old, it may make sense to also replace it as this time.

I don't have the model numbers for the new unit, but the model numbers for the existing units are: ATR042C100A0 (is this 3.5 tons?); and 2A6H1024A100AB (Heritage 11 - 2 tons?)

Before we owned the house, it went through a large renovation in 2004, when the smaller unit was installed as a secondary. The larger unit probably covered the entire house before that?

What is a builder's grade model?

It looks like you have 3.5 ton and a 2 ton units. It is possible the 3.5 ton unit was originally intended to cool the whole house.

Your quotes should contain model numbers of all equipment, otherwise you don't have a guote in my opinion.

A builder's grade model is the cheapest model offered by a manufacturer. It usually contains the most inexpensive internal components and a flimsy chassis. I recommend spending a little more money and getting an upgraded model. Don't be impressed by the 13 SEER rating. It is lowest rating allowed by the US government on new equipment.

Thanks -- I know about the 13 SEER rating, but I don't know how to price a 3.5 ton unit installed. What model number should I be looking for in American Standard?

Do you get coil and condenser ? or just coil ???

Micah

You need a load calculation for both heating and cooling on the lower zone. I can't understand the recommendation of the 4 ton size. What is the size living area for main floor? Keep in mind, basements at or partially below grade have typical low heating and cooling loads.

Tell me about the existing furnace you plan to keep and use. Brand, age,
model, size, efficiency.

Not certain I agree with dealer's advice on HPs. It would be helpful to
know your electric and nat gas rates.

If AmStd HVAC, you want to be looking at the Allegiance series for AC condensers, Heritage Series for HPs, probably the 13 SEER models. Of course matching evap coils as well. AmStd is very good HVAC. Hope you have a good dealer.

Post back.

IMO

Thanks for the questions. Our lower living area is approx. 1850 sq. ft. (with higher ceilings in parts than the second floor).

The existing furnace is AmStd, 2004, 100,000 BTUs, 5 burner. I don't have the model number, but if you need it, I'll dig for more information.

The city reports the electric rate at $.0844 (1000 Kwh per month). I'm not sure how to calculate the natural gas rate, but city says average single family usage per month is 5,620 cf, costing approx. $70.

Our tech is recommending 13 seer, 3.5t unit; says 14 seer unit coil isn't compatible with existing equipment and would produce on 13.4 seer output.

Price is for condenser and coil.

Thanks again for your thoughts and advice.

Further question: is there a major difference between the AmStd Silver SI 13 Seer and the Gold SI 13 Seer?

There is difference between the two.

You want the Allegiance 13 which is the gold model. Mdl # 4A7A3042.

I would like to know your furnace mdl number and if interested I can do a fuel comparison if I know your electric and nat gas rates to see if HP is a worthy upgrade.

IMO

Thanks -- can you tell me something about the differences? I'll try to get the furnace numbers.

Is the difference between the 4ttb3042 and the 4A7A3042 in efficiency, noise, build quality?