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Hvac question on R410A lines

2437 Views 6 Replies 3 Participants Last post by  zootjeff
What are peoples thoughts on the size of the refrigerant lines. Can you go a size larger on the bigger of the two lines?

I notice the datasheets on the condenser say that a 2.5 ton unit should have a 3/4 line, a 3 ton unit should have a 7/8 line, and a 3.5 ton unit should have 1 1/4 line. Is it ok to use a 7/8 line on a 2.5 ton unit? Does it buy you anything? Does it hurt anything? I'm running my line 32 feet. If I go with the 2.5 ton unit, my coil will have 7/8 fittings and the condensor will have 3/4. Either way I'm going to need a reducer. I'd like to spend the extra 10 bucks for the larger line for ease of coolant flow and future proofing if I upgrade to a larger unit. Any flaws with this logic?

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So, did you determine that you could utilize a 2.5 ton because of size and load? I notice you can utilize the CAPF3642B6.

Just make sure that you are choosing your new size based purely on load and not on physical design. You can always make transitions to accommodate for size.
I can't seem to find any info on the: CAPF3642B6

They have C6 and D6 but no B6.

Do you have a datasheet different then the one on the website?

Sorry Jeff.....My Bad

I have never printed the spec sheets so I turn my head and read sideways:wink:

You are correct, no B.

Did you ever say what size drive your existing furnace has? Since you have stepped your unit size down, I noticed that some of the VS 3 & 4 ton drives work with the 3636 coils.

Since you are keeping your existing furnace drive, you will never get a perfect system match, but now that you are in the 2.5 ton arena, it seems there are more options.
I have a Trane XV90 80,000 btu furnace. Dual stage burner, variable speed fan. It has dips witches for 2, 2.5, 3, 3.5 ton outdoor units.

Also dips for 350, 400, 450 CFM/TON.

So in theory if I set it to 3.5 TON and 450CFM/TON, the unit will try to do 1575 CFM...

I'm leaning towards the 2.5 ton 14SEER, and yes it is because of the coil more then anything. I think 2.5 Tons will be fine based on all my experiences thus far. I also plan to put in dampers and zone the house by turning off rooms we won't be in much, so 30,000 BTUs seems like it will be plenty..
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