Your location?

Let's see now, you have a 3 1/2 ton system. First a 3 ton replacement, then down to a 2 1/2 ton system. You first need to determine the size you require. Looks to me your quoting dealers are guessing.

I won't say Trane is the best but it is much better than what you are being quoted.

I do like Rheem but not the low end model you were quoted.

Here is my general spec sheet for new system.
both outside and inside units should be replaced to have a properly matched system.

15 SEER, 12.5+ EER, 9 HSPF
best matching VS air handler
full BTUs in both cooling and heating for your rated size
R-410a refrigerant(same as Puron)
scroll compressor preferred
electronic demand defrost preferred
thermostat with "dehumidify on demand" feature
staged backup heat strips
new and correctly sized refrigerant lineset
10 yr warranty on parts and compressor

you want a thorough inspection of your ductwork system. size, overall condition, supply and return lines, insulation qualities, leak test, etc.

any hot/cold spot issues in your home should be addressed.

My personal recommendation is Trane/AmStd, Rudd/Rheem, and Carrier/Bryant.

IMO

"He likes to have 4-5 floor registers per ton."

Wow!
it is the size of the duct not the number of ducts
to move the 400 cfm per ton of air.
many ways to move the air, different
duct size combinations.

I know about rule of thumb sizing of system,
but rule of thumb duct sizing is a new one to me.

I size ducts by how big the room is and what
its heating/cooling requirements.

best of luck

That was so silly and dumb...

IMO

An accurate load-calc needs to be performed; plus doing all Retro-work that will reduce the heat & cooling loads.

There is a FREE Whole House Load-Calc available, learn how easy it is for you & the techs to use it. Do the all the measurements FIRST!

Also, know what the insulation levels are; I'd use 0.45 ACH Air Changes per Hour using the available calculator to figure the infiltration CFM that is put in the appropriate line so it figures the sensible & latent loads.

Here is a link that might be useful: FREE Whole House Load-Calc

"He is old school, been doing this work for over 30 years."

In the the HVAC business this is not always a trait of a good HVAC contractor. The old school method was to over size and use rules of thumb based on the size of the house. The old methods don't work well with modern construction methods and equipment.

Everyone thankyou for all the input.
Tigerdunes:
Location is Belfair, WA
So, the Rheem quoted is a low end brand. I'll ask what the next step up is. But I understand Rheem is a good brand. I also read about the handler (?) should have a variable speed to run efficiently (Rheem).
It sounds like to me that the initial install of my heat pump (3.5 ton) was too big for the duct work and my home.
The 2 contractors are recommending a 2.5 ton.
The 3rd quote I tossed out. They had several things that were not included with their quote plus the person doing the figuring for the quote did not go out to the house to look for themselves.
I looked at the website: Here is a link that might be useful: FREE Whole House Load-Calc. Not that easy for me. :(
Hate to say this but I am starting to feel quite overwhelmed.

You misunderstand. The Rheem model quoted is low end. Rheem is a good brand. Move up to the next level. See below.

Classic Series: Single Stage
Models: RPNL/RPQL-JEZ
Copeland Scroll Compressor
Painted Louvered Steel Cabinet
Hi & Low Pressure Control
Up to 15.5 SEER & 9.1 HSPF

Would you take a moment and describe your typical weather/climate both summer and winter?

Post back. I would like to help you.

IMO

I'm in Western Washington. The weather can get warm in the summer. This weekend was 67 degrees but humid and sticky and light sprinkles. Muggy, definitely needed air conditioning.

In the winter it rains and snows, we get a few inches of snow to about 20". The snow does not last for long though about two weeks.

I really appreciate your help.

I called the guy back about the next size up for the Rheem and the warranty on it. He is to call me back on Tuesday 6/25/13. Thank you.

You need a load calculation performed in writing. I would drop no lower than a 3 ton system for a home your size. Only a load calc will confirm your correct size.

Here is a suggested system.also qualifies for Fed Tax Credit. Excellent numbers.

3393299 Active Systems RHEEM RPQL SERIES RHEEM MANUFACTURING COMPANY RPQL-036JEZ RHKL-HM3617+RCSL-H*3617 36800 12.50 15.00 36000 9.00 23600 1 HRCU-A-CB 297 754 Yes

IMO

This post was edited by tigerdunes on Tue, Jun 25, 13 at 7:41