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# suction line size for 5 ton unit

#1
01-26-03, 10:15 AM
jova757
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suction line size for 5 ton unit

I have a 5 ton unit (goodman unit) liquid line 3/8 and suction line 1 1/8 and the run is about 45ft long. I was told that i would have a lot of problem. does any know what kind of problem would i be facing? last summer the unit run all summer long and one problem arise (one of the wire connect to the contactor relay on the out side unit was burn up at the ternimal end).

#2
01-26-03, 10:18 AM
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Join Date: Aug 2001
Location: NW atlanta
Posts: 3,147
i believe

goodman rates the suction line at 45 ft to be 7/8. if it did not give you trouble why change it? 1 1/8 is ok from what i can tell. is the condenser above, below or level with the evap coil? to get technical, lift would have to be considered.

#3
01-26-03, 01:08 PM
bigjohn
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Refrigerant tubing is sized by OD- Outside Diameter. Refrigerant tubing is sized based on equivalent length. The idea is that whatever state the refrigerant is flowing in, it will see the fittings/valves as though each one were X number of feet. So, if you have 45 feet of tubing, you then count the number and type fittings/valves and calculate the equivalent length. Your 45 foot run is probably closer to 50 to 60 feet of equivalent length. 1-1/8"OD is fine on the suction line, especially if the condensing unit is below the cooling coil. The 3/8" OD liquid line might be a problem. My charts call for 1/2"OD. If your condensing unit is below the evaporator, then you're probably ok. I agree with hvac4u, you made it thru at least 1 season, you're probably going to be ok. One thing that is important is that, on horizontal vapor lines, you want to pitch the line in the direction of flow at 1/4" per 10 feet of horizontal run.

#4
01-26-03, 02:09 PM
jova757
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my coil is about 8 feet above the condensor unit.
thank you for the very good info. this is the best site i have been visited. every information is alway good.

#5
01-26-03, 02:21 PM
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jova757:

My charts show your capacity and line length to be right in the middle of 7/8" and 1 1/8".
Your installer made the correct line size choice for the higher evaperator.

If the coil were 8' below the evaperator I would have gone with 7/8"

#6
01-27-03, 08:41 AM
jova757
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unit size

how do i find out what size is my condensor and my evap. coil? what do you look for to get this info? if the tech-man said your unit is a 5 ton would you take his word for it or there is a way to find out?

#7
01-27-03, 12:09 PM
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jova757:

I have also found two other threads on this same subject.

Thanks.

The model number found on the evaperator coil and outdoor unit can be used to determine it's capacity.

Post those numbers here.

#8
01-29-03, 10:40 AM
jova757
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heat pump making noise

house two level in tx
heat pump 5 ton 12 seer 3/8 for small line 3/4 for big line
out door unit to indoor unit is about 45ft with arise of 18ft high
out side temp is about 50deg f
with a scroll compressor control by a digital honeywell thermostat
about one yr old making all kind of noise from a buzz sound to a loud bann

#9
01-29-03, 12:50 PM
bigjohn
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Where's the noise? In the outdoor section or the indoor section? If it's outdoors first lalce to look is the compressor contactor. It may be malfunctioning or full of ants/critters.

#10
01-29-03, 06:47 PM
jova757
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the out door unit all the electrical is clean

#11
01-31-03, 09:04 PM
jova757
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what does filter\drier do for a/c unit?

I 've read a statement on a/c that "the a/c unit is operate correctly if the temp. on the return side and the temp. on the supply side is 20 degree difference" is this truth or not? if it is the truth is it the same thing with heating?

what cause an a/c unit to have the use of start capacitor?

#12
02-01-03, 06:54 AM
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Join Date: Aug 2001
Location: NW atlanta
Posts: 3,147
just the facts

capacitors are used to give added torque to the start winding in a single phase compressor or fan. a drier removes moisture and contaminants from the refrigerant system using dessicants. the 20 degree drop you describe is excellent for temp difference between return and supply air.

#13
02-02-03, 06:14 PM
jova757
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over and under

what would happen if you over charge the a/c unit and if you under charge the unit?

#14
02-02-03, 08:46 PM
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I have merged four threads to try to figure out the root of your problem.

jova757:

I'm really puzzled.

I have asked you to post questions on the same equipment in the same thread so that we can make some sense of your issues.

I have now joined two more threads to make one so that we can get an idea about what's going on with your equipment.

1. We are still waiting to hear about the coil and unit model numbers so we can determine if you have the correct line size.
2. We are still trying to determine why your unit is noisy.
4. We now have a new question on refrigerant charging.

At first you told us you have 1 1/8 suction line and now it is 7/8.

What do you really need to know???

#15
02-03-03, 07:53 AM
jova757
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yes i have 1 1/8 line and i ask you what would happen if the line were let said 3/4 line? I think you come up with that 7/8line. sorry for the miss understanding

#16
02-03-03, 12:02 PM
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jova757:

You are right, you said 3/4 inch and not 7/8.

jova757 wrote:

"I have a 5 ton unit (goodman unit) liquid line 3/8 and suction line 1 1/8....."

"heat pump 5 ton 12 seer 3/8 for small line 3/4 for big line "

It would be helpful if you would ask a question relating to a specific problem you may have.
It is ok to ask technical questions, but you have not responded to our request for specific information to help complete answers to questions you have already asked.

I'll take a wild guess in that you say your system is about a year old.
Now that the warranty may have just, or is about to expire, do you have some concerns that there may be something wrong with your system?

Like I said, ask away, we just not may be getting to the root of your problem.

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