Can I Install A Mini Split Head On An Inside Wall?
Finding just the right place to install the components of a ductless mini split is critical to the comfort and performance of these highly efficient units. Split means they are divided into two main parts. The outdoor units come in cooling only units or heat pumps and the indoor unit is referred to as a head. If you want to know some important things to consider before investing in a mini split, go to this article.
A mini split head can be installed on almost any wall within your home, but with some caveats. The least expensive installation will usually be on an outside wall. When choosing an inside wall for the head location you will invariably pay more in installation costs.
The beauty of installing the head on an outside wall is the ease of installation. The refrigeration lines that connect the indoor and outdoor units are easily routed through the wall along with a power cable and the condensate line that drains off the the condensation from the head to the out of doors.
The reason the labor goes up when choosing an inside or interior wall to mount the head is because all the lines that connect the two unit have to be routed either through an attic or a crawl space. Sometimes the lines can be run along the wall exposed but looks aesthetically lousy in my opinion.
Notice the condensate pump mounted under the head in the image below. They add to the cost plus labor of the installation. This customer wanted to build his own cover over the line set that pokes up into and across the attic to the outdoor unit.
I get to hear a lot of opinions about the appearance of installing a mini split on interior walls as it is. Adding exposed lines only deters from the overall looks of things that may have a bad rap to begin with.
They make line covers that go over the lines of copper, power wire, and drain. I’ve provided a link here for both Home Depot or Amazon so you can see a variety or makes and manufacturers that are paintable and easy to install.
Can Mini Split AC Lines Be Run Inside The Walls?
That’s always an option to run the lines inside the wall. Vertically is usually easier than horizontally. Horizontal runs inside a wall would include notching every stud to allow the lines to recess into the wall to be covered over by whatever you removed, which in most cases would be sheet rock.
I have a friend whose entire business is patching sheet rock. He’s a expert in matching texture. That’s who you’ll need to find. Maybe not him, but someone who can make it look like the wall had never been cut into.
Hopefully you kept the left over bucket of paint that matches also and hopefully it’s still usable.
I have another friend who recently built an addition onto his kitchen. Running line sets in newly framed walls without insulation and sheet rock is a piece of cake.
Having refrigeration copper lines inside of unfinished walls can be hazardous to the health of your new mini split if the sheet rockers are careless and willy nilly run screws where not enough care was taken to prepare the lines.
I’ve seen sheet rock screws penetrate copper lines and become an absolute nightmare to locate and repair. Cover every spot where a possible screw could damage a refrigeration line with a metal plate.
Vertical runs either up or down the wall from the head are slightly easier. Your will enter the crawl space or the attic and then have the line set on the exterior of your home where you can use these covers again to help the aesthetics of all the lines being exposed.
Best Places To Put A Mini Split System
Many a good installation has suffered by poor location. You probably wonder how I can call it a good installation if it’s located improperly. I was referring to the workmanship.
The installers best practices, good flare connections, evacuation, and charging of the unit with refrigerant or Freon as most people know it by brand name can all be defeated by placement of the equipment.
So an installer can do all the right mechanical things and screw up the location to deliver the proper air flow into the room. And think about the outdoor unit being place by a bedroom window where even though these units are amongst the quietest on the market even a slight noise can be irritating as you try to sleep.
The phrase location, location, location is very applicable to not only real estate, but mini splits also.
I’ve noticed that with a lot of the installations I’ve done that you don’t have a lot of choices. It may come down to dividing up the area and installing two or more heads depending on the size and layout of you home.
What’s The Proper Distance From The Ceiling For A Mini Split Head?
Each manufacturer has a little bit different thing to say regarding the clearance from the top of the heat to the ceiling. There are two reasons for this gap.
- Air flow
- Room to lift the lid to access the filters
Many if not all ductless units pull air through the top and discharge the conditioned air out the louver at the bottom. One of the biggest and best rules of air conditioning is air flow. Restrict the air flow and suffer the consequences of poor heating and cooling.
Can’t access your filters easily and you will neglect the head ache you created by not reading the instructions and allowing enough room above the unit to remove the filters and clean them.
I’ve seen the allowable clearance as little as a couple inches but the last unit I installed the instructions said about 7 inches. I had to install my own unit in our apartment and had no choice other than to install it close to the ceiling. Getting the lid up high enough to clean the filter was a bit harder than I thought it would be.
Conclusion For Mini Split Head Location
I know of an installation of a mini split that looked absolutely hideous. My daughter had it installed in her duplex. I won’t discuss here why she didn’t have me do the job, but it had to do with rebates which I refuse to participate in the programs.
After a winter of the unit running constantly and not heating the apartment she finally added another unit to the back end near the bedrooms. With some improvement gained she proceeded to arrange for the relocation of the first unit.
The hideous part was the refrigeration lines running clear across the front of the apartment. The covers were large and squared off metal channel. Something made in there shop.
I thought it amazing how some company could bodaciously add a system with no insight to how distracting those lines were to the front of a nice building.
Be sure to plan your installation with your contractor and make sure you can live with the end result.
I’m trying to decide on placement of mini-split heads in my 3-storey, 4 bedroom old house. It is mainly for cooling purposes in summer. I plan to put a head on the 3rd floor and a head on the main floor. The 2nd floor has the 4 bedrooms, basically one in each corner of the 2nd floor, with a hallway in the middle. The hallway has no exterior walls. So I could either put a head in each bedroom, which would be quite costly, put a head in the hallway, which would require routing the lines through 2 or 3 closets to get to the outside (which would perhaps be costly?), or only put in one or two of the bedrooms. One of the bedrooms has windows that face south and west, the other 3 bedrooms have windows either east or north.
Do you have any advice? If I put in the hallway or just one or two bedrooms, how well would the cooling get distributed around the 2nd floor in summer? Or would there be any benefit or cost savings to getting two slim duct units that could go in the 3rd floor knee wall attic spaces and duct into the 2nd floor bedroom ceilings?
Joe, I really don’t have much help for you. It’s a bit of a complicated issue. I’d get about three bids and you will have some ideas to work with. Chad
Hi, Chad:
I got a hybrid mini-split for my bedroom and I want to mount it on an interior wall. There is plumbing nearby so I am expecting that I can tie the condensate drain pipe into that. My question is this: is there a significant performance hit if I run the refrigerant lines 6 inches up inside the wall to the attic and then about 18 feet horizontally to drop down from the roof? I know the lines are pressurized and I can slant them downwards a bit on the horizontal run, but I am worried I will be putting a strain on the unit. Your thoughts?
Debra, you should be fine with running your line set that way. I would be aware that connecting the drain line to an existing house drain you should look into having a trap of some kind to prevent sewer gases from entering the unit and the room. -Chad
I purchased a 4 head mini-split heat pump set. The condenser unit came with a bag full of reducer pipes soldiered together – different sizes. i.e 1/2 ” down to 3/8″, some just 3/8″ and some just 1/4″, all about 6″ to 8″ long. What are these adapters used for?
Also, the same manufacturer offers line sets which include aluminum armored 4c 14 gauge wire sets. How do you tie in these wires to the head units? I don’t see the connecting lugs anywhere on the heads. And would you need a special connector socket which screws into the aluminum armored jacket and attaches it to a steel bracket inside?
And one final question: Anything wrong with making flange connections inside the house in a closet or behind the head on a living room wall? None of my connections will be outside, unless my runs to the condenser are too short for the prefabricated line sets.
David, the reducer pipes should aid you in connecting to your line set. If the line set is the same size as the fittings on your units you don’t need them. And yes you can make those flare fitting behind the head in the closet. Chad
Hello, Chad. My question is why do they say you should not mount a mini split indoor unit near/above a door?
Rick, Don’t know for sure other than headers over doors create quite an obstruction getting lines through the wall. If you have a high ceiling that would allow the unit to mount above the header then I see no reason why you can’t hang it there. If you have access to installation instructions then that’s the resource to use. Also technical support for your equipment will walk you through any installation issues. Good Luck, Chad
I’ll take a jab at your question, re: mini-splits and doors. . .
Here are some of my thoughts. They may be more than the manufacturer has considered, but I think they’re logical.
–Noise–
Doors in general have poor noise attenuation compared to a wall. If the unit is above or close to a door, the noise of the blower motor may be heard more easily outside the room even when the door is closed, whereas if it is just a few feet further away, it may not even be heard outside the room with the door open.
Even a solid core door may transmit more noise than the average wall assembly, and definately more than a well insulated wall with sheetrock (even better if it has acoustical caulk between each stud and the drywall).
If attached to the header above the door, and not just near the door, it’s possible they’ve discovered on average install that low frequency vibration noise of the blower assembly running could pass more easily to the other side due to the nature of the wall core.
Lastly, on the subtopic of noise, most all door latch striker plates affixed into a door jamb are a small fraction larger than the lock plunger that fits into them. You don’t much notice it on exterior doors because the weather stripping acts as a spongy or springy material that at least when new keeps some of the rattling down. In contrast, bedroom doors never have weatherstripping (except maybe for the kinkier homeowner, lol) and you may have noticed on some houses, while trying to sleep, these doors rattling in their frames due to an exterior door being opened and causing a change in air pressure, or even vibration from outside by certain aircraft. I seem to recall putting a pillow against my hollow core bedroom door as a child because walking in the hall rattled it, but I may have just now “dreamed” up that memory from thin air. Anyway, put that mini-split above the typical closed hollow core door, and I suspect BOTH the vibration on the wall AND the movement of air would rattle the door. It would do it when the fan started moving air from a completely off state, and probably during the cycle as well because the air would move along the face of he door and reduce the air pressure on that side. Mildly bothersome while awake, but since many people install these in bedrooms, that noise could be sleep depriving at night.
–Stray air currents–
Since most mini-splits blow downward, if you mount it above a door, which is at some point closed, the air blowing down across the face of the door will reduce air pressure relative to the face of the door. When it meets the floor, the air will change direction based on several variables, two of which include the gap size below the door and the surface texture of the finished floorings on each side (there are other variables, just pointing put two obvious ones). So for example, the air goes down, hits a smooth hardwood floor, and as the air pressure at the gap is reduced, it could pull warmer air in from the other side of the door. But maybe you’re thinking some of the air will exit, so you won’t have that problem… correct, you’ll have the problem of losing some cool air. Neither scenario helps cool the air in the room. Also, that air moving under the bottom of the door adds more to earlier issue of noise, both by the speed of the air as it passes under, and/or more movement of the door in the jamb.
You might say, really now, how much noise could that little bit of escaping air make? Well, if you owned a gray 1985 Chevy Silverado with an igloo rockin’ A/C, you’d know that if you didn’t barely tap the window handle one-thousandth of an inch to change the rate of air escape out the truck, the air whistling would drive you mad. So how much noise? Maybe almost none, maybe insane, but more than on a flat wall away from a door.
— Building Code —
If you tell joe-diy he shouldn’t drill a 3″ hole in a door header because that violates code, don’t ya think many would do it anyway? But if you give him vague instructions not to install above a door, being joe-diy, he might assume the whole unit could self destruct, sending his long saved $500 of Mister McCoolio to utter destruction.
–Life safety–
This usually trumps creature features and comfort. Maybe there’s realistic consideration that in the event of a fire or earthquake that the thing could start “mini-splitting” away from the wall, and just as you’re about to make it out alive, WHAM (!) it whacks you in the head! You’ll never need A/C again… because you’ll have all you need down at the morgue.
Or maybe a fire breaks out on the other side of the door, and as things “heat up”, the a/c kicks on, pulling more of that nice smoky air and fire into the room through gaps around the door.
With all the work and thought put into this reply I just had to approve it. Mr Coolio could add it to their manual.
Good afternoon Chad,
I’m having a hard time connecting the lineset to the indoor unit. I have the indoor unit on an interior wall. Trying to connect the linesets vertically but is challenging do to the lack of flexibility of the line set. Any advice?
Michael, It’s tough sometimes. You have to be extremely careful not to kink the lines. If you do you can usually round them back off with a cresent wrench. Tubing benders are helpful if you can put your hands on a good one. If your bending by hand make the bends long and slow bending throughout the length of the bend little bits at a time. Some of the units have wire shields that aid in the bend. Wish I could help more. It always makes me a little nervous bending those lines. Chad
I have a mini split on an inside wall. The copper lines, power line, and drain go through the wall behind the unit, into a closet area almost a couple feet deep and 5 ft wide. It’s an open area with No door.That’s an important point later .
The lines then run vertical downward close to the closet wall, and down through the floor under the mobile home. Then horizontal a few feet to the outside unit.
One problem was the lousy insulation of pipes that caused condensate and a musty smell. I replaced the top portion of the insulation with the soft black pipe insulation making sure there were no open areas from top to bottom. And I taped them closed with duct tape. I also insulated the top half of the drain line. I also put insulation in the hole the lines came through and taped it closed.
Prior to replacing the insulation, if I put anything close to the lines in the closet the unit just would not cool properly. It would either not cool enough, or keep cooling. Like having the thermostat set at 73 and it would cool down to 65.
Now that the insulation is replaced I put a 6ft tall cabinet in the closet space in front of the lines but not touching them, and it’s not cooling well. What am I doing wrong? If you can put a cover over lines why can’t there have a cabinet with shelving in it sitting in front of the lines??
Kathleen. I’ve never heard of such a thing. The sour smell and condensation, yes, but the change in cooling capacity, that’s a weird one.
Installing the garage. Can I come out of the inside wall unit and run a serpentine type line set to take up the extra length and then drill the hole and go straight out into the outside unit and also the disconnect switch.
Ronnie, That would be the cleanest way. Be careful bending the copper! Chad
I assume the refrigerant line can come out of the air handler sideways. I have a two blender and plan on taking it about 6 ft out and put a 90 in it take it a couple feet down put another 90 in it to bring it back under the air handler and then down to the bottom of the wall and out to the unit. I also plan on putting joist hangers where my studs are and put blocks maybe 3 in into those studs and then covered the whole section with sheetrock so it will be a 4 ft wide cover extending from the wall about 4 in we should give me plenty of room to put the line set? I know that sounds weird but in my mind it sounds pretty easy to use up all the line set and cover it. Interested to see what you say because I read all your topics.
Ronnie, Sounds pretty clean to me. I did a similar thing with my electric panel that hung on the outside of my house. And yes the line set can come out of the side of the indoor unit, at least they have that ability on all the units I’ve installed. Chad
Hi,
I live in a split level home and been debating where to install the inside air handler.
1. Outside wall in the living room? (but dad does want air directly on him)
2. Inside wall, will it cool the bedrooms room?
Any suggestions?
Alberto
Alberto, seeings how I don’t know the layout of your house I would get a couple of estimates and pick their brains on the best location. Chad
I have an addition to my house which abuts my garage. Can I install the split unit in the new addition with the evaporator on the wall in the garage? The garage is not heated or cooled and not finished.
Deborah, I’m a little confused by your question. Evaporator=indoor unit. You want that in the garage or in the new addition that is connected to the garage? I wish I had a way to draw or exchange pictures.
HI! We have a mini split in a small apartment. It worked great when first installed, but now constantly drips out the front of the unit. We have had multiple hvac companies look at the unit. The drain line is clean, the filters are clean. The freon level is fine. It still leaks out the front and down on the floor. It is installed in an interior wall that abuts an unconditioned hallway. Three hvac companies have not been able to figure out the problem. We are about to replace the unit, but now are afraid it is the location that is the problem rather than the particular unit. Any suggestions as to what might be causing the water? Or what we should try prior to replacing the unit? Thank you in advance!
Beverly, only a couple of things come to mind but I’m sure the tech’s that have come must have checked these. So if condensate is dripping out the end of the line it’s likely not plugged. Is the unit level or slightly sloped in the direction of the drain. If it’s installed on an inside wall, how does the drain exit? It must have a pump. Condensate pumps for mini splits hang off the bottom of the unit. You can google mini spilt condensate pump and look at the images to see what I mean. I suppose your condensate line could follow the inside wall to the exterior wall? Slope is critical. Maybe a pinched or kinked line. So many things to consider. Can’t understand why a tech can’t solve this for you.
Chad
I have a three bed bungalow and want to fit three units. One in the sitting room with door leading to kitchen. Door to be closed most of the time. The second in my sons bedroom. (spends most of his time there on his computer. The third I want in the hall opposite our bedroom door (door open when no visitors). But my wife wants in the bedroom. Third bedroom seldom used. Where would you recommend bedroom or hall placement?
I don’t want to get between you two. But, I’d do the bedroom. Just sayin ………..
I have a situation close to the first picture on this page. Is the condesate pump inside that bin attached on the bottom of the head? Or is it just the tank and the pump is up in the ceiling?
The lines for mine will have to go up about 3 ft to get into the attic space to be brought over to the exterior wall. Does that impact the functionality of the pump if it is in the bin at the head?
Brandy, that is the pump and the tank. It all has to be under the head for the water to fall into the pump assembly. -Chad
I enclosed my Porch with vinyl windows and want to know if I can add a mini split with the pipes going sideways out to the back of the house?
Jacque, Should be fine to run them most any direction that’s accessible. – Chad
I was thinking of putting a mini splithead air condition on and interior wall near the corner of an exterior wall. Can you run the lines sideways and still drill a exterior hole and run lines. The problem is where I want to put it I have a big bay window that takes up the whole wall and dont have any where else big enough to install. So that is why I would want to install on interior wall near corner of exterior wall and drill my hole out and run refrigerant lines and drain and electrical sideways thru the wall. I attached a picture of area where I would like to install.
Richard, I’m having some issues with the app that allows picture to be uploaded to comment. I’m limited to 512MB. But I understand your question. That would work great. It’s easier to install most heads when the wall you are penetrating us is on the left of the head. The piping in the head is pointed that way. It will require you to carefully bend the refrigeration lines to the right if mounting near a wall on the right. Kinking can happen. – Chad
Can I install a head unit on an interior wall of a finished garage and run the lines along the surface of the wall towards an exterior wall?
Any cons besides asthetics?
Frank, aesthetics is the only draw back. You can buy or make covers that aid to the looks some. – Chad
Hello
May I install a mini split in a condo unit that has a balcony? I’m looking for the smallest mini split available.
I will probably have to keep the power, refrigeration lines exposed in the interior wall and provide a custom cover.
What are your thoughts?
Barbara, I’ve seen that before. It would all depend on your local building department and you condo CC&R’s…. You can dress up those exposed lines in the house so they are hard to even notice. Pinterest is a good source for ideas.
Should say above our bed not aisle
I really dislike where my mini split inside unit. It’s above our aisle I was told it needed to be on an outside wall. I would like it moved about 6 ft over to the interior wall which is not the focal point of the room, and regret that I didn’t realize how much I would dislike this until we moved into the room. Even though the fan is positioned to blow outwards into the room, I still feel,the heat on my face and dislike this over my head while sleeping. I’m hoping my HVAC guy will move it for me. For a fee of course.
Katie, I think we are all more sensitive to what’s going on with air flow and temperature in our bedrooms especially something that is going on and off. Good luck with the move.