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Mini-split A/C Shopping...

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mpire

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Gauges measure in inches of hg.

Doesn't the manufacture require it to be pull to a 500 micron or less vacuum?
I have no idea to be honest.

I don't plan on opening up the valves, I am only going to pull a vacuum and let it sit for a day or so to make sure there are no leaks in the system.
 
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rickairmedic

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Hook up the vacuum pump and guages . Pull a vacuum to 30" should go pretty quick once there let the vacuum pump continue to run for an hour . Then shut down the guages and then shut down the vacuum pump. Leave it for an hour if you still have 30" of vacuum your golden ( yes I have a digital micron guage ) but thats an expensive piece of equipment to buy for a homeowner . Once you pull it down to 30" and it holds for an hour after shuting down the pump you most likely dont have a leak. These are small short linesets with mechanical seals if it is leaking it will show up pretty quick.


Rick
 

crazy wheel

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Gauges measure in inches of hg.

Doesn't the manufacture require it to be pull to a 500 micron or less vacuum?

I have no idea to be honest.

I don't plan on opening up the valves, I am only going to pull a vacuum and let it sit for a day or so to make sure there are no leaks in the system.

I just looked up their installation manual.

lol, their evacuation procedure is really nonexistent.
 
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mpire

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My concern is that I don't want too much R410 in the system if its pre-charged for 25' and I am only using 17'.

While I am not sure how long the tails are coming off the upstairs unit, so I am still working on that part. Also, I am still working out the whole mounting and positioning of the outside compressor unit.

However, all of this is irrelevant until after I get the 12/2 wire run from the breaker box to the compressor unit location.

Do I need to put the electrical wire inside conduit or can I get away with just putting it inside the line-set cover?
 

crazy wheel

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My concern is that I don't want too much R410 in the system if its pre-charged for 25' and I am only using 17'.

While I am not sure how long the tails are coming off the upstairs unit, so I am still working on that part. Also, I am still working out the whole mounting and positioning of the outside compressor unit.

However, all of this is irrelevant until after I get the 12/2 wire run from the breaker box to the compressor unit location.

Do I need to put the electrical wire inside conduit or can I get away with just putting it inside the line-set cover?

I would be as much concerned about the proper evacuation as I would the refer charge.
 

rickairmedic

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I would run the electrical inside a conduit as that would be up to code and I doubt code would allow it to be run inside the lineset cover . You could run the conduit up next to the cover though which would help to hide it from prying eyes.

Rick
 
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mpire

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Wait, it has to be inside the line set cover. Granted the HOA are not electricians, but thats the ruling. However, I have no problem putting the grey plastic conduit inside the lineset cover if thats the best move. Regardless, the lineset cover is probably 10x too big for the lines, so I am not worried about space. I am planning on doubling up everything for my office next year if this unit works out.

Crazy, I expect since I am paying the a/c guy $100 to come out and check the charge for 15 minutes, he will verify the vacuum and the wiring install. I tend to do everything myself, and double check it. I am really cheap, and I admit it. I also do not plan on paying an electrician to run the wiring, but I will have him inspect it and plug it into the breaker just to be safe and make sure I am up to code.

I don't need to pay his apprentice to run wire. That seems pointless to me.
 

rickairmedic

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Mpire I couldnt agree with you more :D. I am one cheap bastage myself . Running it inside conduit inside the lineset cover will most likely be ok .

Rick
 

theoldwizard1

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Hook up the vacuum pump and guages . Pull a vacuum to 30" should go pretty quick once there let the vacuum pump continue to run for an hour . Then shut down the gauges and then shut down the vacuum pump. Leave it for an hour if you still have 30" of vacuum your golden
Amazing !

What I learned 40 years ago (and never used) is still accurate !
 
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mpire

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Once again, I am using my automotive pump/gauges to test and verify the vacuum and that the system is sealed. I see no reason on paying any more than the minimum service call. I can do the easy stuff. I have more than one useless college degree after all.
 
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mpire

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Ok, new question.

If I run #6 wire to the 15 amp breaker over 10 feet to a junction box, and then run the 12/2 from there, is that even legal?

I don't see much point in putting in a sub panel until I add the second A/C system.

So it would just go to a small electrical junction, and be connected in there to the other wire. I am trying to figure out how to wire all this stuff.

I can splice the wire anywhere I want to right? Just as long as its an accessible electrical box thats to code. I figure I could go ahead and run as much of the second run as I can without buying even more cable, then just complete the task later on when I start on phase two.
 

rickairmedic

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Mpire I will ask an electrician buddy of mine but I am pretty sure without asking that that would be a no no . I would say you need to go ahead and put in your sub panel now even if you only run the one 12/2 to it for the moment .


Rick
 
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mpire

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Well, better safe than sorry I guess.

If you are asking, see about splicing the 12/2 wire together if I am using an electrical box in an accessible part of the attic.

Thanks again.

:)
 

rickairmedic

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That one you can do ( as long as we are talking about splicing one 12/2 to another 12/2 ) :D. You still cant splice 2 12/2's to a single 12/2 :D. They must be spliced inside a box that is easy to spot and make sure you use clamps where the wires enter the box.


Rick
 
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mpire

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Well Duh.

I have 100' of 12/2. I figure I will need around 60' to get to the A/C.

So I can run a second 40' line up to the attic since thats the hard part, and then run the last 20 feet to the second A/C next year when I get around to buying it.

If that makes any sense.
 

Jackfre

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Is this a multi evaporator unit? I do not know how LG handles this but some manuf require that if you buy the multi that you have at least two evaprators on it...or it will not start. Go ahead, ask me how I know! :(
 
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mpire

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Is this a multi evaporator unit? I do not know how LG handles this but some manuf require that if you buy the multi that you have at least two evaprators on it...or it will not start. Go ahead, ask me how I know! :(

Well, I can buy 3 9000btu systems for the price of one dual unit, so I should be OK.

The goal is to get things to balance out. Right now I am trying to figure out how to run the thermostat cable downstairs.

I have flex ducting run down through chases and I am going to run the wire up through the attic and then down through the chase and put it on a wall downstairs that doesn't get direct sunlight.

I hope this makes the system work more efficiently since the downstairs cools off much faster than the upstairs.

I am considering adding a new baffle system and diverting the air that would go to the bedrooms to a new larger duct in the foyer. That way I won't be adding back pressure and will still avoid cooling the rooms that never get used.

So the project is shaping up. :thumbup:
 
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mpire

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OK, I got a new one. I have a chase in the master closet. Inside that chase is your standard flex tubing from the main unit. It runs down to my office where I spend most of my time. I would just need to add a T fitting to the duct, right?

Could I cut open the chase, then install a duct fan to **** cool air out of the master bedroom with the new mini-split and dump it into my office?
 

rickairmedic

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Ok now ya lost me why are you adding a T fitting and why would you take air from the mini split and send it to your office downstairs :D.


Rick
 

rickairmedic

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I would simply move the thermostat downstairs to a main hall area and let the thermostat control the central system for the downstairs and let the mini split handle the fact that the main system doesnt cool the upstairs well.

Rick
 
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mpire

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Well, I only use 2 rooms in the house to be honest. The bedroom is directly above my office. I was just brainstorming on how to limit using the inefficient system as much as possible.

Oh well, can't hurt to think outside of the box.
 
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Well, I only use 2 rooms in the house to be honest. The bedroom is directly above my office. I was just brainstorming on how to limit using the inefficient system as much as possible.

Oh well, can't hurt to think outside of the box.
 
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mpire

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OK, on to the next problem, I mean challenge.

They company shipped everything but they didn't send the line-set covers.

They did send the end pieces for the line-set, and I plan on installing it all this weekend, but I don't have the 10 foot pieces of line set cover.

So, are there any alternatives for line set covers? Or can someone recommend a place besides lowes and HD that sells this kind of thing?

I was thinking of just stuffing it all inside some conduit. Think I can get away with that?

754826044563lg.jpg


088700569737lg.jpg
 

rickairmedic

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Mpire I have used 3" schedule 40 PVC with Long radius 90's i n a pinch to run the lineset through and it worked out great . The location I was installing the units intended to paint the lineset covers anyways so it worked out great and looked good once painted . One other option that will work is to use plastic downspouts like you would use on your gutter system .

Rick
 
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mpire

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Thanks Rick!

I can get some 3 inch conduit and that should do pretty good I think.

I am just concerned about the initial turn when coming out of the wall. I don't want to kink any of the lines and want to make sure the drain line is all down hill.

Its cheaper than the line-set cover anyway, so why not.

The painter is going to be here in 3 weeks so I have to hustle to get everything ready for him so it can be painted to match the house.

I have to add new wiring on the front and back of the house for new light fixtures too. No rest for the weary!
 

rickairmedic

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Notice I said 3" schedule 40 PVC and Long radius 90's and not conduit :D. The long radius 90's is the important part . The lineset will run through them much easier than trying to go through an LB like you have pictured above.


Rick
 

Jackfre

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If the systems are on top of each other or if you are trying to conditioin an adjoining room I'd suggest you look at www.tjernlund.com Look at the Airshare product. they have a floor to floor model and a room to room model. Excellent fans!

On the line set cover, I'd try your local Johnstone Supply or other HVAC supply house for the line set cover. I've found it to be the best looking. I know it can be done less expensively, but I don't think anything trims out as well as the line set cover. There is a HOA to please, right?:bowdown:...and you may want to do more.
 
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mpire

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If the systems are on top of each other or if you are trying to conditioin an adjoining room I'd suggest you look at www.tjernlund.com Look at the Airshare product. they have a floor to floor model and a room to room model. Excellent fans!

Wow, its people like you that are going to cost me a whole bunch of money. I could just put a vent in the floor and have the cool air come straight down, however I am trying to keep as much sound insulation between the two rooms as possible. The wife works nights sometimes so I don't want every phone conversation I have to be broadcast upstairs while she is sleeping. This stuff is just about what I was thinking.

On the line set cover, I'd try your local Johnstone Supply or other HVAC supply house for the line set cover. I've found it to be the best looking. I know it can be done less expensively, but I don't think anything trims out as well as the line set cover. There is a HOA to please, right?:bowdown:...and you may want to do more.

Oh, well there you have it. There is a Johnstone supply in Orlando. Do you have any idea how many useless listings come up when you search for HVAC supply in Orlando. I think the reason I don't like this lineset cover that they sent me is because its too big. They appear to have two different sizes on their johnstone website, so I will go back and check it out. I want the absolute smallest lineset cover I can get that will fit a drain line, lineset, and the power wire.

Thanks for the pointers!
 
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mpire

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On a somewhat related note, I just ordered a couple of these duct dampers.

AFASCD.jpg


The consensus is that I do not want to cut off the flow of air to the bedrooms because that would cause backpressure in the system and that would be a bad thing for the inside air handler unit.

I plan to put in a rigid T adapter and put one normally open and one normally closed duct on each one. Then I can flip a switch and send air to the bedrooms when I have company, and otherwise just have it dump into the foyer when I am not using the rooms. Combining that with moving the thermostat should make a noticeable difference I think.
 
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mpire

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The true irony is that they are by far the cheapest option, and I found them on a pot growers supply website. How funny is that?
 
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mpire

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I don't smoke or drink. My only vice is projects.

My friend challenged me to name something I owned that could be modified that I had not yet modified.

I am still trying to think of something.
 
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