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-   -   R22 change out (http://www.diychatroom.com/f17/r22-change-out-177863/)

subcool 04-22-2013 07:33 PM

R22 change out
 
Hey I am doing my first complete new install. When I am going from R-22 to 410, do I need to install new lines sets? I have a customer that the line sets are running up studding, walls, brick, 3 story, this guy probable has 100 feet of line set and it would be a nightmare to replace. Someone told me you could use some type of acid to burn the line sets. If I have to change them how would I do one this complicated?

Thanks

Doc Holliday 04-22-2013 08:13 PM

cut the sheetrock open and pay for a repair. include in your cost the price of the wall and possible ceiling repair in your bid with installation of new line set. you hire sheetrock/painting company. may need a helper to push and pull, strongly suggested you have one so also include his pay in your bid. I do. :)

very easy but not needed. use a bunch of nitrogen, triple evac. even easier.

beenthere 04-22-2013 08:31 PM

Just blow them out with nitrogen, at a high pressure.

You NEVER use an acid cleaner in a refrigerant line set.

wirenut1110 04-23-2013 05:39 AM

I use this http://www.nucalgon.com/products/tsp/rx11-flush when I do change outs and the line set is difficult to replace. It runs about $50-$100 depending on the size can.

COLDIRON 04-23-2013 06:09 AM

Not to change the subject , just a couple points.
100 feet is pretty long line set make sure you check the specifications for the length and diameter requirements for the equipment your installing. Just saying.

yuri 04-23-2013 08:02 AM

That's right. You may have to upsize them. Check the install info as some manufacturers have their own methods they want followed for reusing line sets. Lennox is now allowing liquid R22 to be flushed/has a procedure as long as it goes into a recovery machine and recycled properly.

beenthere 04-23-2013 01:59 PM

If the evap is above the condenser, no need to increase the vapor line size. May not need to increase the liquid line either, depending on height.

bobelectric 04-24-2013 03:32 AM

You don't sound knowlegable enough to handle this project.

ben's plumbing 04-26-2013 08:30 AM

maybe for your 1st time full install...pass on this one....it may be to much to handle at this point ...no disrespect intended..imo ben sr

jagans 04-26-2013 08:57 AM

Quote:

Originally Posted by ben's plumbing (Post 1167584)
maybe for your 1st time full install...pass on this one....it may be to much to handle at this point ...no disrespect intended..imo ben sr

OK in a previous post you all said that it is not at all necessary to change out the line set if they are properly sized, you just blow the lines with nitrogen. Some also recommended a cleaner that I think you said smelled like alcohol. 100 bucks a gallon is a lot for alcohol, so I would think you guys would find out whats really in the cleaner.

Now what is the issue with the height of the evaporator coil relative to the condenser? My evaporator coil is about 2-3 feet lower than my condenser coil which is on a pad outside. Does this present a problem when switching from an R-22 system to a R410a system? My lines are 3/8 and 3/4 respectively and are only about 35 feet long.

As far as passing on the install, it sounds to me like the guy is asking some pretty basic questions. Maybe he just needs to elaborate a little? Sounds like he is fully engaged at this point.

yuri 04-26-2013 09:12 AM

AC compressors if they have to lift the suction vapor more than 10 feet may need to be upsized and have a p trap to get proper oil return. definetly at 20 feet lift. not everyone follows proper piping practices but it makes for good compressor sales later. If the coil is much higher than the cond then gravity does the job BUT the reverse is true for the liquid which now has to be pumped uphill so the line may need upsizing. all depends on the specific manufacturer specs and nowadays that is VERY important. all has to do with the work the comp has to do to suck/lift the vapor and/or pump the liquid. larger lines make it easier to do.you will be OK with your setup but may have to upsize the suction if the manufacturer recommends it. liquid should be OK. once again lots of guys don't follow proper practices and I see LOTS of 3/4' fittings on conds squashed down to 5/8 and re-using the old smaller 5/8 line. works but is NOT a good idea in the long run.

COLDIRON 04-26-2013 09:24 AM

Quote:

Originally Posted by jagans (Post 1167601)
OK in a previous post you all said that it is not at all necessary to change out the line set if they are properly sized, you just blow the lines with nitrogen. Some also recommended a cleaner that I think you said smelled like alcohol. 100 bucks a gallon is a lot for alcohol, so I would think you guys would find out whats really in the cleaner.

Now what is the issue with the height of the evaporator coil relative to the condenser? My evaporator coil is about 2-3 feet lower than my condenser coil which is on a pad outside. Does this present a problem when switching from an R-22 system to a R410a system? My lines are 3/8 and 3/4 respectively and are only about 35 feet long.

As far as passing on the install, it sounds to me like the guy is asking some pretty basic questions. Maybe he just needs to elaborate a little? Sounds like he is fully engaged at this point.

" We already know what's in the cleaner"

av-geek 04-26-2013 03:14 PM

This is a good question though...I have a 35 year old air conditioner I am scheduled to replace this summer. The lines go inside of drop-tile ceinling in my basement for about 12 feet. I am wondering if I need to take the tile out, or if the new system will be able to use the old lineset.

beenthere 04-26-2013 03:40 PM

While many still practice up sizing vapor lines on lifts of 20 to 30 foot.Many manufacturers recommend against it. They have found out it can impede oil return due to the velocity being too low. Same as a trap can help or hinder. R410A requires a higher velocity for good oil return then R22 does.

Liquid line size should only be increased if the liquid line pressure drop will exceed 35PSIG for r22, and 50 PSIG for R410A. On some heat pumps increasing liquid line size is detrimental in heating mode.

All manufacturers have extended piping guides that should be used in long line and or extended lift applications. 50 long is not a long line set. 20 foot of height is common.

yuri 04-26-2013 03:43 PM

Quote:

Originally Posted by beenthere (Post 1167786)
While many still practice up sizing vapor lines on lifts of 20 to 30 foot.Many manufacturers recommend against it. They have found out it can impede oil return due to the velocity being too low. Same as a trap can help or hinder. R410A requires a higher velocity for good oil return then R22 does.

Liquid line size should only be increased if the liquid line pressure drop will exceed 35PSIG for r22, and 50 PSIG for R410A. On some heat pumps increasing liquid line size is detrimental in heating mode.

All manufacturers have extended piping guides that should be used in long line and or extended lift applications. 50 long is not a long line set. 20 foot of height is common.

nowadays that is the main thing. some of what I am talking about is related to pure Refrigeration piping theory as I am a Journeyman in that and had it drilled into me at school. very interesting stuff though.


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