Shopping new CAC install questions

[djmdammit]

I've been using window units for years but I had enough and finally got some estimates for central air conditioning. I had a couple of estimates done both recommended a 2.5 ton setup for my 1200 sq ft home. This is what they had for equipment. The air handler will be in the attic.

These two plans call for 1 return. Rebates make the first option a lot cheaper than the 2nd.

1) 16 SEER Lennox Merit 14ACX condenser with Elite CBX27UH air handler.

2) 16.5 SEER Lennox signature XC17 conditioner with signature CBX40UHV air handler


I also got an estimate with Rheem 16 SEER equipment using 2 returns. No product numbers were given (still waiting for that). Price is about the same as the 16.5 setup above.

How are these two systems? are they comparable assuming both 16+ seer setups are within a couple hundred dollars of eachother?


Is there an advantage to a variable speed fan? Can it really clean the air if kept on?

I dont know what else to ask since i have no experience with central air. Should I push for certain kinds of ducts, dampers, anything like that? My attic is truss and kinda tight. The air handler will go above the garage on one side of the house where its completley open. The ductwork will run about 45ft to the other end of the house (ranch) through the trusses. maybe thats why 2 returns versus 1? Not really sure. Thanks in advance !!

[djmdammit]

I was really hoping for a response. AM I asking the wrong kind of questions? As far as i can tell i am following posting rules.


I guess the bottom line for me is whether or not the equipment is comparable, and more inportantly is it really worth paying an additional 30% of the total install price to get a variable rate fan?

Also, I found out the RHEEM 16 SEER system used model # RAPM-030JAZ for the condensor and the air handler is RHLLHM3617JA.

[BaldLoonie]

In a steamy climate, VS is nice as they have the dehumidify on demand or possibly a slow ramp up to increase moisture removal.

The RHLL is high efficiency but not variable speed. It does appear you can do dehumidify on demand with the appropriate control.

Unless you have a long summer and/or very high juice rates, often super SEER units have a very long return on investment. What else could you do with that premium that pays back faster? Insulation?

[skibme]

Look for returns from all the bedrooms and the hall.What kind of material is the duct constructed of?Dampers on main trunk where branch lines connect.Emergency drain pan under unit with wet switch to kill the unit should water accumulate.Duct sealing of all joints.Programmable stat? Load calculation done?

[djmdammit]

Thanks for the responses.

Im in NJ.

I dont want to be cheap if what I'm paying for is useful. On the other hand, the money difference for the variable speed fan is significant enough that I can install replacement windows throughout the whole house (DIY).

I also need to consider the noise levels of the units mentioned above. It will be located next to my deck up against the house because there are walkways around the perimeter of the rest of the house. In your experience do you know if there is much difference between the Lennox 14ACX, XC17, and RHEEM RAPM-030JAZ ? I'd rather pay for a quieter fan than to have a noisy fan going all summer long. I read that the XC17 is one of the quietest but have no real world experience.

[vstech]

changing windows will not necessarily improve your building envelope. get an energy audit and find out where your house has issues, and see about that.
since you've never had CAC, all the ductwork should be sealed tight, and be sized for proper air flow for the equipment, and your home.

[energy_rater_La]

I agree.
windows don't provide much savings. (14% savings for a big investment)
air sealing the house, on the other hand, is
very cost effective.
caulk is cheap, when applied in the right places
it make the difference between trying to heat and cool
a leaky box, and heating and cooling a non leaky box.

stop the air leaks, then insulate the attic. then
you'll see savings & comfort.

I've read on here about really cheap blower door
testing thru the utility companies in your area.
take advantage of it and make them show you
the areas that leak. .

best of luck.