Mini Split Installation (DIY & Professional): How to Install & Placement Tips

Whether you’re a professional contractor or a handy homeowner, installing a mini split system can be a daunting task. But if you purchase a mini split, you might be surprised to learn that the installation process isn’t all that difficult if you know what you’re doing.

If you’re a DIYer and thinking of installing a mini split yourself, you’ll be happy to know that doing so can save you money. Whether you are planning on installing a traditional mini split and having a professional come in to charge the system and start it up or going for the even easier option of installing a 100% DIY mini split system, you can reap some pretty serious saving. And to top it all off, you’ll end up saving money in the long run since mini split systems are highly efficient compared to central heat and air.

If you’re a professional contractor, you understand that installing a mini split is a bit different than installing other types of HVAC systems. Since there’s no need to install ductwork, you may find that the mini split installation process is actually quite simple.

In order to successfully install your new unit, there are a few key details to keep in mind to make the installation process a bit easier. By taking these factors into consideration, you’ll ensure that your mini split installation is as smooth and successful as possible.

How to Install a Mini Split in 3 Steps

Installing a mini split system can be divided into 3 parts:

  1. Install the indoor unit
  2. Install the outdoor unit
  3. Connect refrigerant piping from the indoor unit to the outdoor unit

Before you begin the installation process, it’s essential to have a few key tools and parts on hand.

Tools & Parts for DIY/Professional Mini Split Installation

A mini split installation will require the following parts for a professional installation:

  • Mounting plate*
  • Clip anchors*
  • Seal*
  • Drain joint*
  • Wall sleeve*
  • Nitrogen Tank
  • Drill
  • Hole Saw
  • Torque Wrenches
  • Vacuum Pump
  • Flare Tool
  • Tube Cutter
  • Screwdriver
  • Allen Wrenches
  • Spray-on Leak Detector
  • Adjustable Wrench
  • Digital Refrigerant Scale
  • R410a Manifold Gauges
  • Tape Measure
  • Line sets*

*Included in a DIY mini split

For a DIY installation, you will only need the following tools to complete installation:

  • Drill
  • Screwdriver
  • Hole Saw
  • Adjustable Wrenches

Mini Split Indoor Placement Considerations

It’s important to consider the following factors when deciding on a location for a mini split’s indoor unit:

Wall Placement/Height

Select a location that’s solid enough to support the unit’s weight. This will also help prevent vibration, which can make the unit excessively noisy. Placing the unit at a decent height (at least 7 feet off the ground) allows for good airflow and convenient drainage. You’ll also want to take sound into consideration, as installing the indoor unit too low can be disruptive.

Avoid installing the unit in a location that receives direct sunlight, and make sure to install the unit away from any doors. Every mini split has its own clearance requirements. Some can be mounted almost flush with the ceiling while others need to be mounted a foot or more down. Be sure to check your installation manual and look for an image like the one below to make sure your unit is installed for optimal performance.

Image of indoor mini split unit

Proximity to Furniture & Appliances

Choose a location that’s at least one meter from all objects, especially electrical devices such as TVs and computers. Do not install the unit near flammable objects or heat sources.

Maintaining Access to the Filter/Louver

Make sure you install the indoor unit at a height that will allow easy access to the filter and louver.

Aesthetic Considerations

You may not be too keen on having your mini split be the focal point of the room. In that case, choose a location that’s as inconspicuous as possible. Installing the unit at a proper height will make it less noticeable than if you were to install it at a lower height.

Mini Split Outdoor Placement Considerations

To begin, it’s important to choose a location that can support the weight of your mini split outdoor unit. Condenser units can weigh anywhere from 80 to 250 pounds, and soft ground may cause the unit to shift, resulting in issues with the connections.

For the most secure placement possible, pour a concrete pad on the ground and mount the unit with anchor bolts. If you do not have the ability to mount the unit to concrete, a great alternative is to use a pre-engineered condenser pad. These pads are designed to support the weight of a unit when placed on solid ground. Always make sure to level your pad prior to securing the unit to it.

Anchor BoltsMini Split Mount Points

 

Airflow

Airflow is the key to your mini split’s performance. When looking for a place to install your mini split, you should choose an area that offers optimum inlet and outlet airflow and is easily accessible for inspection, maintenance, and service. Do not install your unit where it will be exposed to heat or steam from sources like boiler stacks, chimneys, steam relief ports, other air conditioning units, kitchen vents, plumbing vents, etc. Such extreme temperatures may degrade performance or cause damage to the unit. When using multiple outdoor units, avoid placing them where discharge of one outdoor unit will blow into the inlet side of an adjacent unit.

LG Outdoor Unit Clearance Guide

Appropriate airflow through the outdoor unit coil is critical for proper operation. Clearances ensure that heat radiation and discharge airflow aren’t restricted around the outdoor unit. The exact dimensions will depend on your specific unit, but in general it is best to keep any objects 28 inches from the front air outlet, 12 inches from the rear air inlet, 40 inches from the top, and 12 to 24 inches from either side. The diagram on the right shows the basic configuration.

*Pro Tip: If only the minimum amount of clearance is used, the unit performance can decrease by up to 15%. Never use less than the minimum clearance. Excess heat buildup or poor airflow can cause the unit to fail.

Wind

Windy conditions can interfere with your unit in several ways. From knocking the unit over to disrupting the condenser fan, you want to make sure that wind gusts do not have a negative impact on your mini split.

Wall and rooftop installations are most susceptible to wind issues; therefore, any unit installed on a wall or roof must be secured using the unit’s mounting points.

Ground installations are not without risk of wind issues, either. If you live in a high wind area like a coastal location, a wind barrier may be necessary in order to achieve the best performance.

Diagram of a windbreaker/barrier and mini split unit Mini Split Installation in Coastal Area

The wind barrier needs to be constructed of a strong material like concrete in order to effectively obstruct the wind. The height and width of the barrier should be large enough to fully shield the unit. It should be at least 50% wider and taller than the dimensions of the outdoor unit. The unit must be placed at least 28 inches away from the wall to allow for proper air flow around it.

*Pro Tip: Anti-vibration dampers are critical in high wind areas. These are often included with wall brackets and stands, but they may be added if you’re ground mounting. Dampers will not only prevent the unit from audibly shaking but will also help to keep it secure and level.

LG Roof Mount Installation

Rain

Rain itself will not have a major impact on the performance of the unit. However, the unit should never be placed in an area where there is standing water. If your location is prone to flood, consider a mini split stand, wall mounting, or roof mounting. The outdoor unit is water resistant, not waterproof. If you are in an area with a lot of rainfall, it may be wise to install hoods over the unit’s air inlet and outlet. A roof or covering may also be used, but it must be at least 40 inches above the unit.

Snow

As heat pump performance has improved, so too has the usage of mini split units as primary heat sources. If you plan on using your heat pump as a primary heat source, you must make sure that your unit is clear of snow. Keep the following in mind if you’re concerned about snow’s effects on your mini split:

  • The unit should be mounted higher than the anticipated snowfall for that location.
  • The front fan and rear coil must be free of snow and ice. Ice buildup on the coils can cause the unit to shut down or unexpectedly malfunction.
  • The mounting platform should not have any additional flat surfaces for snow buildup.
  • If more than 4 inches of snow has accumulated on top of the unit, it must be removed prior to operation.

In very snowy areas, a hood or roof may be advisable. This surface must be at least 40 inches above the top of the unit, and it should be wide enough to fully protect your mini split. It is also important to install the outdoor unit air inlet and discharge areas away from prevailing winter winds. Always be sure to seal all piping and electrical access panels to prevent any moisture from getting inside.

Mini Split Insulation

All refrigerant piping — including connections, service valves, and elbows — should be completely and correctly insulated with closed cell pipe insulation.  To prevent heat loss or heat gain through the refrigerant piping, all refrigerant piping including liquid and vapor lines should be insulated separately.

Keep the following insulation tips in mind when installing your mini split system:

  • Insulation should be a minimum of half an inch thick.
  • Thickness may need to be increased based on ambient conditions and local codes.
  • All insulation joints should be glued tight with no air gaps.
  • The insulation material must fit snugly against the refrigeration pipes with no air space between it and the pipes.
  • It is best to purchase pre-insulated lines to ensure proper coverage. All DIY mini splits include a pre-insulated line set with the system.

*Pro Tip: All pipe insulation exposed to outdoor elements should be properly protected with PVC, aluminum vapor barrier, conduit or wide vinyl tape, or alternatively placed in a weather-resistant enclosure such as a pipe rack with a top cover. This will protect the insulation from drying out and cracking over time.

Mini Split Line Set Guide

Buying a Mini Split

There are multiple types of mini splits on the market, but only a handful are designed for do-it-yourself installation. MRCOOL DIY mini splits are specifically designed for convenient, easy installation, and the best part? They ship with everything you need to complete the installation! No running to the hardware store to buy last-minute parts and accessories — all you need is a drill and drill bits to install a mini split yourself.

If you are a contractor (or plan on hiring a professional contractor), you have a wider selection of choices. We offer mini splits from renowned brands like LG, Daikin and Panasonic. To determine which model is right for your needs, check out our Air Conditioner BTU Calculator.

Image of MRCOOL DIY Mini Split

The MRCOOL DIY mini split system is easy to install and requires no special tools.

In Over Your Head? Call Us for Guidance

If you’re hesitant about installing a mini split yourself, be sure to hire a reputable, qualified HVAC professional who can tackle the process for you. Need some guidance? Call us and we’ll be happy to answer any mini split related questions you may have.

Mickey Luongo

Mickey is the resident heating and air conditioning expert.

68 Comments

Bryan Spanos

about 2 years ago

I live in Massachusetts and would prefer not to attach the unit directly to my house. How much vibration or noise is expected if I did? I will have a TV on the inside of the wall.

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Mickey Luongo

about 2 years ago

It depends on the bracket you use. We carry the Quick Sling QSWB2000 which includes rubber washers that help to prevent vibration.

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Bryan Spanos

about 2 years ago

Thanks! Would you recommend putting it on the ground or on the house? It will have a heat pump

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Mickey Luongo

about 2 years ago

Since you are in Massachusetts, you have to worry about snow. Putting it on the ground would eliminate any vibration issue, but you would need to make sure that it is 1-2 feet off the ground.

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Nick

about 1 year ago

I would like to mt the outside unit on my house foundation about 12" from the ground. How close can the back of the unit be to the fondation?

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Mickey Luongo

about 1 year ago

It should be at least 12 inches from the foundation.

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Vince

about 1 year ago

Hi - Is it possible to install one of the smaller Minisplit condensors in a PTAC space?

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Mickey Luongo

about 1 year ago

No, you can't really reuse the space that the PTAC was in. The mini split condenser must be fully outside. It can either be placed on the ground or mounted to an outside wall.

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Andrew

about 1 year ago

Is there a maximum distance that the compressor can be from the air handling unit? I would like to install my compressor unit on the ground, and my room being cooled is on the second floor. Can I simply pipe everything up and across the roof to the air handling unit? I am looking at a Gree Rio 18k btu unit. Trying to avoid noise/vibration caused by mounting the compressor on the roof as I the application is for a sound studio.

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Mickey Luongo

about 1 year ago

Every unit has a maximum distance that the line set can be run. There will also be a maximum height separation. Check the specs of the unit you are looking at to be sure that it will work for your application.

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Scott S

about 1 year ago

1. how long of a run can the piping be from the condenser to the head units? 2. does the length of run effect the efficiency of the head units? 3. where is the ideal location for the condenser ion regards to the sun , shade, north east or west side of house etc., also can it be installed under a porch ?

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Mickey Luongo

about 1 year ago

1. It depends on the specific unit you choose. Some are limited to 25 feet. Others can go over 100 feet. 2. No, length does not impact efficiency. 3. It can be installed under a porch as long as there is still enough air flow around the unit.

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Danny H

about 1 year ago

can the condenser unit be mounted higher then the wall units?

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Mickey Luongo

about 1 year ago

Yes, they can be, as long as the height difference does not exceed the maximum stated in the specifications.

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Jason

about 1 year ago

How do you handle going around gutters for a 2nd floor mini split? Not really finding any examples online.

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Mickey Luongo

about 1 year ago

Do you have a picture of the gutter you need to go over?

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Adam A

about 1 year ago

How far should the condenser be placed from a neighbor's window, or from an attached party wall? Is it better to attach the condenser to the foundation or on a stand on concrete floor in order to prevent any potential vibrations or noise issues with the neighbor? I was told the line set should be 18" away from the party wall separates the 2 houses.

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Mickey Luongo

about 1 year ago

Installing the unit on the ground or a stand would prevent the most vibrations.

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Eugene

about 1 year ago

Is it advantageous to install the air handler above a window within 7 feet of a ceiling fan to help circulate the air around a larger room?

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Mickey Luongo

about 1 year ago

Any additional air circulation will always help an air conditioner.

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Ted

about 1 year ago

I was wondering if I can mount the exterior unit higher off the ground, say 4 feet or so. It will be mounted with brackets to the wall. I'm nervous about having to cut down the included piping. Also, I've bought a 240 system. I can just wire that to a 220 exterior plug, right? I was using a 220 interior plug for a wall unit that I'm replacing with this. Thanks so much for replying to all of us!

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Mickey Luongo

about 1 year ago

You can mount the unit as high as you want using a bracket. In most cases, 240 volts is the same as 220 volts. It cannot be wired to an exterior plug that is already in use, it needs a dedicated line. Also, most mini splits are hard wired and require this use of a quick disconnect switch.

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Ted

about 1 year ago

Thank you!!!

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Ted

about 12 months ago

I am installing the outSide part of my ductless heat pump in a screenroom attached to the house . My installation Manuel say that 24" clearance is required above the outdoor unit . How important is this ? I would like install it with 18" clearance above because of limited space .

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Mickey Luongo

about 12 months ago

The clearance is very important. If you do not have enough clearance, it can cause the unit to overheat and could void your warranty.

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Ron

about 10 months ago

I bought a senville quad mini split. I'm having trouble on mounting the heads in the rooms. I bought 2 with 25' line sets the other 2 have 15’. Would it be ok to run the lines through the ceiling? I'm mount the outside unit on the gable an running the lines through the attic. So the lines would run up about 18" then 90 towards the outside unit. Then 90 in to the unit these are fixed lines I will have excess line any special way to leave the excess lines? The gable side I'm mounting does face the wind i wouldn't think it would be any different than mounting it on the roof.

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Brenda

about 9 months ago

Is it ok to install the outside unit on a stand in front of a window but the unit will be higher than the window. So looking out the window the stand would be on either side of the window and the unit would be on the stop of the stand . Or should the unit be installed a certain distance from the window Tks

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Mickey Luongo

about 9 months ago

I don't see any issue installing the unit like this.

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Brenda

about 9 months ago

Hi : I am wondering if the unit is mounted on the inside of a basement room, then the hole in the foundation going from this inside unit to the outside to connect it to the outside unit, can this be laying on the ground. In other words how far above grade should the inside connection going through the basement wall be. Question #2 Can the outside unit be mounted under a 4 ft. high by approx. 20 ft. long patio with the front side of the step open but has lattice wood covering for looks only. In saying this the piping for the 2 basement units would then be run through a closet up by the rafters inside the basement. The basement has ceiling tiles but inside the closet it is wide open to the rafters. Is it a safety concern to run the piping inside a closet that is all exposed in the ceiling. thank you

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Mickey Luongo

about 9 months ago

There are no special requirements for how far the above grade the connection needs to be. Keep in mind that with this type of setup you would need a condensate pump for the indoor unit. Installing the outdoor unit under a deck would most likely not provide enough clearance for the unit. Please check the manual for the unit you are considering to see the exact clearances. The piping can be installed in a closet that is exposed, no issue there.

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Brenda

about 9 months ago

Thank you but I need to give a little more clarification please on the part about the line coming out of the basement wall. Can it be below grade on the outside of the basement wall. Thanks

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Mickey Luongo

about 9 months ago

It can be below grade. I would recommend running the line set through PVC pipe if it is going to be below grade.

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Brenda

about 9 months ago

Thank you ...just one last question. Is there somewhere I can read the requirements myself to know the clearance needed for a Daikin model unit to see if it can be mounted under such a patio. Or even somewhere on line to tell me. Once again THANK YOU

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Mickey Luongo

about 9 months ago

You can find all of that data in the manual. Simply search for the Daikin model you want at https://www.totalhomesupply.com and then click on the manual and guides section to download it.

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Brenda

about 9 months ago

Thank you....all is clear now......I think.

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Mark Lowery

about 9 months ago

Is there any reason that an inside unit cannot be set near the ceiling next to an exposed wooden beam?

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Mickey Luongo

about 9 months ago

You would need to look at the clearance information for the specific indoor unit you want to install.

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Dave T

about 9 months ago

Is there any code requirements that would prevent me from mounting my outdoor unit 10' up in a gable wall. It would have 40" from the top of the gable for clearance. Also installing the disconnect that high next to the unit? Or am I required to run the disconnect down to a reachable height? Thank you

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Jerry

about 8 months ago

Great subject !! can you further explain why such a large clearance is required? It seems to me that as long as you have more cubic feet of clear space around the unit than that of the inlets of the unit, it should be enough. Mine is wall bracket mounted and has approx. 12 inches at rear and below has about 18 inches. I feel that a housing that is at least 6 inches from both sides and angles upward from the top of the unit at about 45 degrees to the siding, the unit would be incapable of drawing more air that can be provided by this clearance. what am I missing ?? Really appreciate your comments! thanks....Jerry

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Jenn

about 8 months ago

We are considering mounting the inside unit under an existing windowsill that already has holes to the exterior. Is there any overwhelming issue with this from a heating and cooling perspective? The space is otherwise clear on the inside. And if we are to do this, does the outside unit need to be either above or below the inside unit? Preferably we would mount the outside unit much higher than the inside one. Thanks in advance for your insight - we have been grappling with this for months.

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Mickey Luongo

about 8 months ago

Most indoor units are designed to be mounted at least 5 feet from the floor. If it is mounted lower, the airflow will suffer. You should check the clearance requirements for the specific product you are considering.

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Julia Alaniz

about 2 months ago

You answered this grandma's question. I'm short and need to reach to be able to clean filters. Thanks.

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Scott Sturtevant

about 8 months ago

What is the best location for the outside unit ? I have heard that the unit should not be exposed to direct sunlight. I have also heard that the unit should not be placed under a wood porch or deck.

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Margarita Friedman

about 7 months ago

Can the condensors be installed inside of a 70 x 40"feet basement of a building built in 1900? Its walls are made with stone. I can open a ceiling windows under the back porch to create more air flow. Because KCMO has too many subzero days I feel that installing the converters l "inside" , it might prevent them from shutting down because of the cold. Thank you

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Mickey Luongo

about 7 months ago

They can be installed inside, but keep in mind that they may drip water and they will add heat to the space in the summer and cold air in the winter.

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Steve

about 5 months ago

Can the lines from the condenser to the head unit be run through the wall instead being on the surface of the exterior siding?

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Mickey Luongo

about 5 months ago

Yes, you can run the lines through the wall.

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paula

about 5 months ago

what is the Florida code for installing ductless condensers? Due to hurricanes, do they have to strapped down like duct condensers (e.g., masonry blocks sandwiched between two hurricane rated pads about 16 inches off the ground)?

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Noah

about 3 months ago

Can I run the piping lines through the attic 24’ far from the condenser to the indoor unit ? Thank you in advance .

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Brian Roth

about 3 months ago

Can you explain the oil trap concept for line sets? I saw a quick blurb about this on an LG install video. Also, a blurb about a loop right before the line set attaches to the outdoor unit. Thanks

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Mickey Luongo

about 3 months ago

LG units should not be installed with oil traps. That is something that may have been used on older units but now can harm the newer systems. LG does recommend setting up a trap on the drain line to prevent water from going back to the indoor unit.

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Chris G

about 3 months ago

Can I install a 50 foot long split system refrigerant line UNDER vinyl siding. I don't think this complies with best practices for proper installation. Also are pvc line covers available in colors to be less obvious on wall. Thank you.

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Mickey Luongo

about 3 months ago

I would not recommend installing a line set under vinyl siding. Most line set covers are paintable so they can be made to match your siding.

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Alan Douillette

about 2 months ago

RE: Mitsubish MUYGL12NAU1/MSYGL12NAU1...The insulated refrigerant lines/copper tubing connecting the first floor indoor unit and the outdoor compressor only needed about 10 feet of 15/17 ft of tubing to connect. The remaining was 6 ft+ of line were coiled horizontally behind the compressor. Was told in order to maintain mfg warranty the line had to be installed that way. I have a pic but don't know how to send to you. Would appreciate your opinion regarding this type of installation?

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Joe Curthoys

about 2 months ago

Hi Mickey, We recently bought a spec house and all the lines are installed for a ductless system. Is there a way we can determine what units where planned for the home so we can purchase them ourselves.? Or Can we order what units we deem are appropriate .... would they work on the existing lines ? Any info would be greatly appreciated. Thank you. Joe

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Mickey Luongo

about 2 months ago

You would need to measure the lines and match the units up accordingly. For example, if the lines are 1/4" and 3/8" you would be able to use a 9,000 or 12,000 BTU unit from most brands.

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Jim Laner

about 1 month ago

Are factory made brass flare elbows allowed in either the suction or liquid side of the lineset? I have a situation where I really need to turn a sharp corner. 4" radius bent copper tubing will be very challenging. Pioneer 18k wall air handler, 3/8" x 1/2" piping to 3 zone compressor. About 35 ft of lineset to this air handler. Thanks!

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Peter Taylor

about 1 month ago

Is it possible to install a ductless wall unit at an angle? I have a dormer and the slope is the only accessable mounting position.

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Mickey Luongo

about 1 month ago

No, they must be mounted on a flat wall otherwise the condensate drain pan will leak.

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Robin Church

about 1 month ago

Hi Mickey, I have a Ductless Mini-Split Air Conditioner, my room I have it in is all brown wood and I don't want the white unit to stand out, can I Paint or put a wood cover over the unit? Thanks

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Mickey Luongo

about 1 month ago

Painting over covering the unit with wood can restrict air flow and cause issues with performance. It is not recommended.

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Mike

about 4 weeks ago

Thanks for the informative article. Is there a minimum distance between the condenser unit and the head unit? I'm planning on putting one in and it will have about a 9' run to the condenser. Will it be noisier than one with a 15-20' distance? Thank you.

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Mickey Luongo

about 4 weeks ago

It depends on the brand. You would want to check the specs to be sure, but it is usually best to have a minimum of a 12 foot line set for optimum performance.

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AJ Fritz

about 2 weeks ago

Would it be possible to mount the condenser unit on a Widow's Walk? I'm looking at installing a mini-spit system in the 3rd floor of a Victorian house.

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Paul

about 1 week ago

Is there any harm when only using one zone on a multi zone heat pump? Looking ahead for future expansion.

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Mickey Luongo

about 1 week ago

You would have to check for your specific system. LG for example requires that at least two indoor units are used with any multi zone system.

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Wendy McClendon

about 7 days ago

Thank you for your article! We have bought a Gree unit to install in our basement. My concern is location of seating in regards to the unit. Ideally we would position the unit on the wall parallel to the longest stretch of the room, but my concern is that there is TV seating within 4 feet of that wall. Will the air blow right in someone's ear or will the noise be too much? The alternative is to place the wall unit behind the seating, which is perpendicular to the length of the room, right behind the seating area. Having no experience with these unit we have no idea what to expect and we haven't been able to find any tips on-line so far. Any help would be appreciated.

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