New Furnace/Central AC Quote

[jj3down]

Hello. Hoping I can get some subjective advice from professionals regarding my new furnace/AC that I am getting quotes on now. I dug up local installers who got the highest reviews for customer service. I've had 2 quotes and I'm getting a third tomorrow.

I live a 2 story 1350 SF bungalow in Cleveland, OH, south facing, with no shade trees. The exterior walls have blown-in insulation. The lone 170 SF second floor bedroom is supplied by a single 6" duct. There's no return. There's no second door at the top of the stairs - just the door to the bedroom.

UNIT SIZE:
Of the two quotes I had, each had a differing opinion of the size of the AC unit I needed.

Contractor A recommended a 2.0 ton unit, stating that a house of my size wouldn't allow a 2.5 ton to run long enough to take the humidity out of the air thus making it feel cool but slightly damp.

Contractor B said that he would agree with Contractor A if it was a single level house, however he said that his experience with my type of house is that the AC units struggle way too much to cool the upstairs and that a 2.0 ton unit will barely cool it at all although the unit would be running all day long trying too keep it cool. He said the 2.5 unit would struggle much less, but would still be on long enough to adequately remove the humidity from the air. However he did warn me that on those 90 degree days it still may not be very cool upstairs.

BRAND:
Contractor A quoted me Rheem Prestige Series for both the furnace and AC
Contractor B quoted me Carrier Comfort Series for both the furnace and AC

The Carrier quote was a couple hundred more than the Rheem was, however the Carrier was 2.5 ton and the Rheem was 2.0 ton.

Anyone have good or bad experiences with these units?

Any insight, suggestions, or advice would be greatly appreciated.

[wizedup]

I don't have an exact answer (& I'm not a licensed HVAC tech).
One resource is consult local utility company - for advice, resources, point you to published data, research groups / universities, for your area.
"Real" studies done for climates similar to you probably have good info.

Lots of factors affect how large an AC unit is needed. Like how the house is constructed [ceiling / wall materials, sheathing, type vapor barrier used (& where)], R-value of insulation in attic & walls, average summer temps & number of cooling days.

Old, drafty house vs. new, tight construction (or remodeled, tightened) have different AC / heating needs.

[Admin]

The factors mentioned above are important no doubt.  It sounds like a poor duct design.  You can always cut the bottom of the door up a couple of inches to act like a return.  Without a return it will be hard to keep that room balanced.

I'm not familiar with your area or housing construction.  Until now I had never heard of a 2 storey bungalow.

In my area I would be considering a 1.5 ton system, but Cleveland probably has alot more cooling hours than Ottawa.  Contractor A sounds like he has a better understanding.  Bigger is not better when it comes to air conditioning and comfort.  A larger AC won't necessarily improve things on the second floor if there is a problem with the duct design.

I would say Carrier makes a superior AC.