oversizing residentual unit wjat problems? - http://www.hvacmechanic.com/ Forums
Original message
| jimholzman
 |  "oversizing residentual unit wjat problems?"
, posted Fri 23 May 11:49  
I have read that one of the problems with oversizing is that the system will not dehumidify adiquately, but in Denver we are extreemly dry and we sometimes have to add humidity.
What other problem is there in oversizing, and how much is too much.
Usually the answer is waist of money but good used compressers are available, typically 3 ton and up.
my application I am thinking about is to replace a 2 ton with 3 ton and acoil.
Older compressors would eliminate the need to change lineset size.
Does anybody realy know the outcome if no one has ever done it?
Is upsizing 1/2 tone likely to cause much of a problem.
Jim in Denver
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Replies:
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| Freon
| "Re(1):oversizing residentual unit wjat proble" , posted Mon 26 May 09:38
Remember, the outdoor condenser coil is designed to remove heat from a 2 ton compressor, not 3 ton. Possible result is higher than nominal head pressure with possible early compressor failure.
Short cycling due to oversizing is why humidity can be a problem in humid climates. Short cycling is also inefficient... your electric bills may increase.
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| theduke03
| "Re(1):oversizing residentual unit wjat proble" , posted Fri 23 May 18:45:
What's the deal with all these oversizing qustions? The answer is always NO. A reputable contractor simply will not do it anyway. If you decide to do it anyway you can look forward to freeze-ups, compressor failure, higher electric bills, and lower comfort.
I'm not from Denver but I'm sure you don't need to add humidity in the summer.
"My dad was the most feared furnace fighter in Northern Indiana."
[this message was edited by theduke03 on Fri 23 May 18:50] |
| yuri
| "Re(1):oversizing residentual unit wjat proble" , posted Fri 23 May 13:59:
Not recommended. Going from 2-3 ton usually requires a larger suction line. If it is oversized the A coil may freeze up as the fan may not have enough capacity or there may not be enough heat load across/on it. It may slug liquid refrigerant back to the compressor and wreck the valves etc. No such thing as a "good used" compressor in my view. Also will short cycle the compressor and reduce its life. Larger A coil may not fit the air handler/plenum. Been in the biz 29 yrs and have seen lots of oversized units and wrecked compressors.
Yuri
[this message was edited by yuri on Fri 23 May 14:01] |
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