Air Conditioning - Need a new air conditioner...many questions

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JWBLue
06-28-09, 06:08 PM
I will be replacing an exiting central unit.

Do I need to hire a HVAC contractor to tell me what size I need?

What is considered the best brand/model?

Is there such thing as an energy efficient unit?

We have a 3 bedroom, 1,500 square foot home.


gilmorrie
06-28-09, 07:00 PM
Why are you replacing the unit?
Doug

daddyjohn
06-28-09, 07:25 PM
HVAC Software, HVAC-Calc for Heat Loss, Heat Load Calculations (http://www.hvaccomputer.com/)

Start here- you know your home intimately; this will be $49 well spent.

There is a lot of parity among the brands. Do some Internet searching for other folks experiences.

Efficiency involves the entire system, not just the equipment. If you couple high efficiency wquipment with inadequate ducting, you lose efficiency. All these numbers you see for equipment SEER were achieved in laboratory conditions; don't expect to replicate that in the real world.

Where to spend the money depends on where you live. Long Winters, shorter Summers- buy a high efficiency furnace but not so high on the cooling side. A place like Houston for example, do the opposite.


PoorJohn
06-28-09, 07:30 PM
JWBLue said:

I will be replacing an exiting central unit.

Do I need to hire a HVAC contractor to tell me what size I need?
>>No, but if you get the right contractor you might end up with a system that better fits your needs. Or you can read the nameplate on the one you have, which the contractor might also do.

What is considered the best brand/model?
>>A recent Consumer Reports article listed brands by reliability, but pointed out that the difference between best and worst were almost totally within the margin of error. Another measure of "best" has to do with features, and from my brief survey I think most brands will offer you a range of models from gold plated to basic.

Is there such thing as an energy efficient unit?
>>Yes, if there's an FAQ here somewhere (or ask Wikipedia) there's a rating system that involves SEER and EER (efficiency) numbers. SEER < 13 and your building department probably won't allow you to install it. SEER 16 and above and Barack will start thinking about paying you a little money (up to $1500).

We have a 3 bedroom, 1,500 square foot home.
>>Nice, but just a tiny part of the "how big" equation.

HVAC RETIRED
07-04-09, 08:51 AM
I will be replacing an exiting central unit.

Do I need to hire a HVAC contractor to tell me what size I need?
The first thing everyone should do is evaluate what can be done to reduce, as much as is cost-effective, the heat-gain heat loss of any home or small business.

What is considered the best brand/model? (N/A)

Is there such thing as an energy efficient unit? (N/A)

We have a 3 bedroom, 1,500 square foot home.
You should to be able to reduce the heat-gain so that a ton of cooling per 750-sq.ft., (2-ton) to 1000-sq.ft., (1.5-ton) would cool your home.

Then, Optimize the ductwork system & the airflow & you will have a comfortable low cost system winter & summer.