Who’s familiar with mini split AC

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Rene T

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I’m thinking about installing a mini split AC on our trailer and attached Florida room. I want to put a evaporator in the trailer section and another one in the Florida room. I’ve been looking at video’s and they all show the piping and wiring going through the walls then down the outside wall in a type of PVC wire way which has a cover to hide everything. On the installation they show the piping being pulled out so they’re 90 degrees to the evaporator.

Does anyone who has installed one of these know if the piping can be bent down so that it will run on the face of the wall? One of my evaporators would have to be that way and either I would use the manufactured PVC wireway or I could box it in with wood. I’m just in the planning stages right now.
 

msw3113

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Rene,
This is not the best photo but it illustrates that said tubing can be bent to go parallel with the exterior wall. In our case there are two bends: one coming out of the evaporator and another bending to horizontal which then reaches the condensor.
mini split raceway.jpg
 

Rene T

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Thanks msw, but my question is can the piping coming out of the evaporator be bent so that it runs down on the wall inside the house and not go through the wall behind the evaporator. The case would have to have a oval hole cut out of the edge for the piping.

Is that your condenser buried inside those schrubs?
 

msw3113

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Ah, I think I understand. Sorry, I don't know. On another evaporator at our home they ran the tubing down immediately behind the evaporator in a stud cavity to the basement, then out. I assume the tubing has a minimum bend radius; then there's the insulation that has to cover them.

That is a condenser attached to the wall. It's time again to whack those arborvitaes back from the consdenser
 

Rene T

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Do any of your evaporators have a slot cut in the front cover close to the wall which would allow the tubing to run down on the inside wall?
 

msw3113

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Huh. I never looked before, but at each corner there appears to be one knock-out on the side and two on the bottom. I'd bet that's what they're for.
 

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Rene T

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I think that answers my question. So it looks like the lines could run down the wall. I wonder why there is only one on the end because any wiring should run with the pipes unless it would come out the side then drop down to join up with the pipes. Is it the same thing on the other end ?
Thanks
 
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TonyL

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Hi Rene, and thanks. At last a question that I am very qualified to answer 👍 The evaporator or indoor unit will have two refrigerant pipes, probably 1/4 and 3/8 depending on what size unit you need. Both pipes are contained in the unit for shipping and can be bent to exit the indoor unit either straight out the back, to the right or downward. The small pipe does not require any tools to bend but needs to be bent slowly and carefully to avoid kinking. The larger pipe will have a bending spring already fitted to allow it to be bent, but again should be handled carefully. The pipes will be wrapped together in a foam insulation and can be bent together. My advice is to slit the insulation back to near the start and bend them separately. Once bent into position, ensure that you wrap the insulation back around the pipes again and secure with zip ties.
To do the installation you will need to borrow equipment to pressure test the pipework and to pull a deep vacuum before you open the valves on the outdoor unit which will contain the refrigerant. Normally there's enough for 15 metres of pipe.
If you want more information on installing, drop me a PM.
Regards
TonyL
 

TonyL

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I have all the tools and equipment you would need in my garage, it's just a shame that it's in the UK 😫
 

Rene T

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I want to give a super big thanks to both of you guys for all the help. I have a much better understanding on the installation. Now I need to get down to FL and continue my planning. I’m hoping it can be done.

The way the trailer is laid out with the attached FL room , I think it’s going to be very difficult but we’ll see. I want to put a evaporator in the trailer and one in the FL room. There is only one place in the trailer where I can mount it. It’s in a slide out between a window and the end of the slide, not sure if there’s enough room. Depends how long the evaporator is. That one the pipes would go through the wall and down the outside right where the condenser oils go.
The other evaporator would go in the FL room attached to the trailer. That one the piping would have to go down on the wall inside then go through the wall and then run under the trailer to the condenser.
Thanks again guys.
 

Rene T

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Tony, One of my neighbors in the park had a system put in 3 months ago. He also has a trailer with a attached FL room. The installer put a evaporator in the trailer with its own condenser and a evaporator in the FL room with its own condenser. He said it was best to do it that way. the condensers sit side by side. Now I I saw one video where the guy put in three evaporators with one condenser. Did my neighbor get ripped off?
 

TonyL

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Rene, try if you can to avoid pre-insulated pipe sets. The quality of the tube is extremely poor. I used to make a decent living from ripping it out and fitting quality grade refrigerant tube when it leaked. You're better off buying separate tube, insulation and a bending spring. The 1/4" tube never needs a spring to bend. Just bend it gently. Don't try to bend the bigger size tube, it could easily link and that causes a restriction.
 

TonyL

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No, he did not get ripped off. One condenser to several indoor units is called a multi- split. Problem is if the condenser fails you lose all air conditioning. The electronics to enable each indoor unit to work independently is also expensive if it fails. I used to quote for both options. Virtually the same installation cost, only difference was the cost of the equipment. The most important thing is to ensure a deep evacuation of any pipework and the indoor unit before refrigerant is let into the system. Refrigerant and moisture creates acid which attacks the compressor windings.
 

Rene T

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Rene, try if you can to avoid pre-insulated pipe sets. The quality of the tube is extremely poor. I used to make a decent living from ripping it out and fitting quality grade refrigerant tube when it leaked. You're better off buying separate tube, insulation and a bending spring. The 1/4" tube never needs a spring to bend. Just bend it gently. Don't try to bend the bigger size tube, it could easily link and that causes a restriction.
Got it Tony. I wouldn’t be doing the install. I’ll get a contractor to do it but I surely will keep an eye on him. I don’t have all the tools and equipment to do a install like a vacuum pump, gauges, hoses etc..
 

TonyL

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Multisplits are best suited to where there is insufficient space for several condensers. I don't know if Mitsubishi split systems are available in the US, that was what I installed most of. Daikin, Toshiba, are also extremely reliable. Lennox tried to break into the split market here, but we're never as good as the Japanese equipment. Sorry, but it was the truth, they may be a lot better now.
 

TonyL

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You could save some money by installing the equipment and pipework yourself. Then let the tech do the skilled bit.
 

TonyL

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I've seen systems literally thrown in in around a couple of hours. Loved charging to go in and put right. Pay cheap, pay twice. A good tech will install it like it was their own.
 

Rene T

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Multisplits are best suited to where there is insufficient space for several condensers. I don't know if Mitsubishi split systems are available in the US, that was what I installed most of. Daikin, Toshiba, are also extremely reliable. Lennox tried to break into the split market here, but we're never as good as the Japanese equipment. Sorry, but it was the truth, they may be a lot better now.
The area where the condenser would go if right adjacent to the carport of my neighbor. They sit out there all the time. I know the condensers today are very quiet so I think one would be quiet enough but two may not. The condensers would be about 20’ away from where they sit. And there is heat being discharged from the condensers. One wouldn’t be too bad but two, I don’t know. They are nice people so I would hate to upset them.
The other thing I just thought of is electrical power. I believe I only have 50 amp available at the CG pedestal. I currently have a small electric stove which runs off 220 volts AC but I started installing piping last winter before we came home and a new gas stove will go in. I don’t know if there’s enough power to run 2 condensers .
 
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TonyL

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What you need to remember is whether it is one condenser or two, the power requirements will be the same. Virtually all but the cheapest units are inverter driven, one unit driving two indoor units will be working just as hard as two separate systems. At 20' from their preferred sitting location, I would not expect any issues, certainly with the quality brands. When you get down to your property, have a wander and listen to other people's units.
 

TonyL

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You could always add a noise screen about 4' away from the fan to diffuse the sound.
 
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