Air Conditioning - Up grade AC unit
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bigwyt1
10-31-08, 12:23 PM
The square footage in my house is 1718. I have a 3.5 ton unit. The copper is 3/4". The ac unit runs all day and the house does not stay cool. I have had the unit checked and recharged. Fiberglass insulation and new dual pane windows low E glass.
I am going to purchase a new AC unit. Actually i am taking 2 unit from my dad house that are very new maybe about 4 years.
1 is a 5 ton unit Rheem and a 4 ton unit made by corsaire. I have been told that the 5 ton unit will be to big for the SQ footage of my house. The house has vaulted ceilings in the master bed room and leaving room. Go figure those are the rooms that do not cool down.
I was figuring if the 5 ton unit is too big i could vent some of the air in the garage. would that add the sq footage that i need to gain.
I understand that i will need to have the copper changes to 7/8 and may need to change the ducting.
I am totally lost on what to do.
The old unit passes a pressure test and is not leaking. This unit is only about 3 years old. I wouldnt mind if the unit ran all day but it just does not cool the whole house.
Any advise on what to do?
I am going to purchase a new AC unit. Actually i am taking 2 unit from my dad house that are very new maybe about 4 years.
1 is a 5 ton unit Rheem and a 4 ton unit made by corsaire. I have been told that the 5 ton unit will be to big for the SQ footage of my house. The house has vaulted ceilings in the master bed room and leaving room. Go figure those are the rooms that do not cool down.
I was figuring if the 5 ton unit is too big i could vent some of the air in the garage. would that add the sq footage that i need to gain.
I understand that i will need to have the copper changes to 7/8 and may need to change the ducting.
I am totally lost on what to do.
The old unit passes a pressure test and is not leaking. This unit is only about 3 years old. I wouldnt mind if the unit ran all day but it just does not cool the whole house.
Any advise on what to do?
airman.1994
10-31-08, 02:38 PM
Think you need to jump back and do a heat load on the home to find out what size unit you need.. Both of the units could be to big for your home.
mike n
10-31-08, 09:36 PM
Yes before you go through the trouble of replacement I would do a load but before I did anything I would like to ask the tech who worked on your system exactly why it does not cool (because it should) many times improper service techniques or a system failure (one heat strip stuck on or return picking up attic air) will cause the situation you describe and I would just like to see a bit more info on why it is not cooling before the replacement happens.
Jay11J
11-01-08, 07:34 AM
I don't know where you are out of, but my guts say you won't need anything more than 2 tons of the info you have given us. But as other said, a Manual-J needs to be done, and duct sizing may be not sized right for your home, and could be cause of poor cooling.
Oversized unit cost more to run, and you won't be comfortable due poor humidity removal.
No, you can NOT dump any conditioned air into the garage space from the home's system. There are codes/law on not allowing this to be done due to fire, and other risks.
Oversized unit cost more to run, and you won't be comfortable due poor humidity removal.
No, you can NOT dump any conditioned air into the garage space from the home's system. There are codes/law on not allowing this to be done due to fire, and other risks.