Heating, Air Conditioning, Fridge, HVAC/4 ton condensing unit


I am considering replacing current 4 ton a/c with arcoaire NXA48GKA OR
arcoaire HXA648GKA  How do they differ?? same SEER??


You omitted the "6" from the AC M/N (SHB "NXA6..."). The HXA6 is a heat pump. They're both 16 SEER.

I presume you're replacing outdoor unit, indoor coil and air mover (furnace???), because that's all required for 16. You should also replace the refrigerant tubing, assuming you're on R22 now (cleaning the existing tubing can leave residue that'll destroy the new compressor).

The really big question is why you're replacing an old 4 ton unit with a new 4 ton: You should be thinking 3 tons for the replacement.

1. Your old unit is oversized.
2. Your duct system is restricted and/or undersized.
3. With the present PSC blower motor, that means air delivery is on the order of 300 cfm/Ton, or 3 tons worth of air (1,200 CFM).
4. The ECM will overcome duct restrictions, so a new 4 ton system will deliver rated flow to the home for the first time ever; the system will cycle more than before (it'll probably never run at high speed), so you'll be sacrificing humidity control.

Your replacement would cost about a third less, and you'll have improved dehumidification.


Heating, Air Conditioning, Fridge, HVAC

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Fred Weldin


I can't help you if your whatsis won't work, people (Especially if it's a refrigerator); I have no experience with appliances, and I haven't been involved with H&AC service and repair since March 08, 1996 (Thank the Lord); I always send a "standard" reply to appliance questions and H&AC "Service and Repair" questions (about 20 a month), so if you want to know why your whatsis isn't working like it used to, ask someone else. A lot of my answers arenít read by the questioners; in that event, I always send reminders to read the answers for a month or more (the word "idiots" comes to mind - actually there's another more appropriate word, but discretion prevents its use here). If you have questions about how big a unit you need, if one room's warmer than the others, if you want an opinion oas to scope of work on bids received, etc. just ask. Do visit www.askweldin.com, there's a lot of good information on sizing, ductwork, efficiency, as well as some techniques accomplished DIY-ers can use to troubleshoot and improve their H&AC. Finally, I want to thank all of the kind, serious people whom I meet here: I enjoy working with you. My wife says I'm "snarky" from time to time; as for you others, please use your imagination as to the responses swirling on the snarky side of my brain when I read your questions.


53 years in the business. See www.askweldin.com


B of ME U of D 1965, numerous classes, seminars and a lot of "Hands On" learning since.

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