Height of mini split head

[pfettig77]

Welp, after a lot of help from folks on here I bought a mini split for my garage with bonus room above. I mostly bought it for heating. In the bonus room I just planned on putting the indoor unit on the 4’ knee wall (centered in the room) because of where the condenser will be located outside. I know they’re supposed to be 6’+ above the floor, but I figured that would be close enough. I installed one in my kids’ room at 55” (had to) to the bottom of the unit and it does fine.

Now I’m afraid I messed up. I could install the upstairs unit on the gable wall, but I already bought the unit and two 16’ line sets (I would probably need about 35’ to put it on the gable end). I’m thinking it’s going to be pretty expensive to send the 16’ line set back and upgrade to 50’ plus I’m really trying to get it done before thanksgiving. Any thoughts about putting the head on the knee wall? This pro did it, but admitted it’s not ideal. I realize it’s not perfect, but at this point in the project it just needs to be usable.

 

[justinjoyal]

Will it be pretty ? No. Will it work just fine, most likely.

Why not use a "floor-standing" console ? They work great in applications such as yours.

https://www.daikin.com.au/sites/default/files/FVXS-F_002.png

 

[pcmeiners]

As justinjoyl advises a floor mounting unit looks good and they are designed to provide air flow for their install height . I used two single zone units for my irregular shaped living room, indented in the wall so that only about half of the units depth shows; with floor mounts you lose a bit of efficiency in place of esthetics. A regular mounted head or is a floor mounted is not going to provide proper circulation in a knee wall, unless you have multiple heads. Even then there my be uncomfortable air currents at that height in a knee wall. Go the extra lineset length to the gable wall

 

[pfettig77]

You guys are both right - shoulda bought a floor unit. Dang it. I don't think that's practical right now since I've already made the purchase. I'll try to install the head on the gable wall at normal height.

Here's my follow up question:
Instead of ordering and waiting for a new line set, would it be possible to splice new copper lines and and communication wire onto the 16' I already have.

 

[SVibs]

Instead of ordering and waiting for a new line set, would it be possible to splice new copper lines and and communication wire onto the 16' I already have.

I think you'd be better off buying a couple of 50' coils of copper refrigeration tubing and a couple of sections of armaflex insulation and making your own lineset.

 

[pfettig77]

I think you'd be better off buying a couple of 50' coils of copper refrigeration tubing and a couple of sections of armaflex insulation and making your own lineset.

I measured 1/2" and 1/4" OD on those lines. Does that sound right?
What about the communication wires?

 

[TnClimber]

Have you looked at ceiling mounted units?

 

[pfettig77]

Have you looked at ceiling mounted units?

Yeah, probably another good option but I already bought the stuff and had it shipped here. I did weeks of research on this but didn't really go down the right research paths I guess.

 

[SVibs]

I measured 1/2" and 1/4" OD on those lines. Does that sound right?
What about the communication wires?

You didn't mention the size or manufacturer of the mini split you bought so I'd hate to hazard a guess.

For the cable, you can purchase a 40' length of "Tray Cable" from ebay for $26 + $8 shipping. You may want to have a look at this thread--there's info regarding the cable that ships with lineset kits that may be interesting to you. The TLDR; version is these kits typically SO cable which isn't rated for in wall, in conduit, or permanent connection use. The correct cable for this type of usage is TC or "Tray Cable".

 

[pcmeiners]

Trouble with using (upper) wall units on a knee wall is the air flow is pretty much straight out from most manufacturers, so one end of the room will be at the set temp, the other end is in question depending on the room length. If installed on the gable wall toward the ceiling the air flow will go over 30 ft.

" I think you'd be better off buying a couple of 50' coils of copper refrigeration tubing and a couple of sections of armaflex insulation and making your own lineset.

 

[pfettig77]

You didn't mention the size or manufacturer of the mini split you bought so I'd hate to hazard a guess.

For the cable, you can purchase a 40' length of "Tray Cable" from ebay for $26 + $8 shipping. You may want to have a look at this thread--there's info regarding the cable that ships with lineset kits that may be interesting to you. The TLDR; version is these kits typically SO cable which isn't rated for in wall, in conduit, or permanent connection use. The correct cable for this type of usage is TC or "Tray Cable".

Great info. Thanks. I'll check that out.

It's a 28k dual zone Senville Aura (hyper heat) with an 18k head and 12k head (for upstairs).

 

[pfettig77]

Trouble with using (upper) wall units on a knee wall is the air flow is pretty much straight out from most manufacturers, so one end of the room will be at the set temp, the other end is in question depending on the room length. If installed on the gable wall toward the ceiling the air flow will go over 30 ft.

" I think you'd be better off buying a couple of 50' coils of copper refrigeration tubing and a couple of sections of armaflex insulation and making your own lineset.

I know on this unit you can adjust the louvers to adjust the horizontal direction. I thought about putting in a ceiling fan too.

 

[PoorUB]

Now I’m afraid I messed up. I could install the upstairs unit on the gable wall, but I already bought the unit and two 16’ line sets (I would probably need about 35’ to put it on the gable end). I’m thinking it’s going to be pretty expensive to send the 16’ line set back and upgrade to 50’ plus I’m really trying to get it done before thanksgiving. Any thoughts about putting the head on the knee wall? This pro did it, but admitted it’s not ideal. I realize it’s not perfect, but at this point in the project it just needs to be usable.

Higher is better than lower as the air circulation will be better. Lower is ok, but not preferred. It will work and you might not notice any issue.

 

[kbeefy]

I'll just put this here as some of my experience that may or may not apply to your situation.

I recently installed a MrCool ductless multi head system.
Due to space issues the air handlers were installed a bit closer to the ceiling than recommended. (like 9" instead of 11").
In cooling mode everything works great.

The ceilings in this area have beams running across them, part of the structure of the house.
I'm not sure if it's a mr cool issue, my installation, or the structure of my ceiling...
When on heat, a pocket of hot air accumulates between the beams and creates an area (where the handler is) that is much warmer than the rest of the room.

Something to think about, I didn't and my installation is sub-par. An auxiliary fan may be in my future.

 

[justinjoyal]

I'll just put this here as some of my experience that may or may not apply to your situation.

I recently installed a MrCool ductless multi head system.
Due to space issues the air handlers were installed a bit closer to the ceiling than recommended. (like 9" instead of 11").
In cooling mode everything works great.

The ceilings in this area have beams running across them, part of the structure of the house.
I'm not sure if it's a mr cool issue, my installation, or the structure of my ceiling...
When on heat, a pocket of hot air accumulates between the beams and creates an area (where the handler is) that is much warmer than the rest of the room.

Something to think about, I didn't and my installation is sub-par. An auxiliary fan may be in my future.

They recommend 11" off the ceiling ? That's ridiculous (in most applications) !

5-6" is plenty for regular setups.

 

[jjrbus]

Make a straight box/drop down on the rafter and mount the head unit?

 

[housewolf]

I put a floor (actually hangs on the wall) unit in a similar room, 26x 34. I run two ceiling fans in reverse during the middle of the summer (105) and it keeps the room plenty cool. It’s completely foam insulated so heat isn’t a problem in our mild(ish) winters either

 

[ALinCarolina]

I would put it wherever your linesets allow and not spend money on new linesets. I bet it will work fine wherever you put it.

 

[kbeefy]

They recommend 11" off the ceiling ? That's ridiculous (in most applications) !

5-6" is plenty for regular setups.

Sorry, hole for linesets centerline at 11". Actual unit is about 6".

 

[SVibs]

I'm not sure if it's a mr cool issue, my installation, or the structure of my ceiling...
When on heat, a pocket of hot air accumulates between the beams and creates an area (where the handler is) that is much warmer than the rest of the room.

Is it possible this is related to louver position? If so, try aiming the louvers slightly downwards or using the "swing" option.

 

[kbeefy]

Is it possible this is related to louver position? If so, try aiming the louvers slightly downwards or using the "swing" option.

I don't think so. I've tried different louver settings, and while they do affect the exit air direction I don't think they affect the air near the ceiling. Hot air rises, and I have the added complication of a beam creating a 10" barrier.

 

[pfettig77]

Make a straight box/drop down on the rafter and mount the head unit?

Thought about this and looked into it. There would be a lot of head bonking for sure.

 

[pfettig77]

I would put it wherever your linesets allow and not spend money on new linesets. I bet it will work fine wherever you put it.

Whether this is correct or not, it's my favorite answer. I just gotta get this thing done.

 

[pfettig77]

I put a floor (actually hangs on the wall) unit in a similar room, 26x 34. I run two ceiling fans in reverse during the middle of the summer (105) and it keeps the room plenty cool. It’s completely foam insulated so heat isn’t a problem in our mild(ish) winters either

That's very similar to my set up. I should have gotten a floor unit. Oh well. Hopefully with a ceiling fan going it heats/cools ok.

 

[pfettig77]

I'll just put this here as some of my experience that may or may not apply to your situation.

I recently installed a MrCool ductless multi head system.
Due to space issues the air handlers were installed a bit closer to the ceiling than recommended. (like 9" instead of 11").
In cooling mode everything works great.

The ceilings in this area have beams running across them, part of the structure of the house.
I'm not sure if it's a mr cool issue, my installation, or the structure of my ceiling...
When on heat, a pocket of hot air accumulates between the beams and creates an area (where the handler is) that is much warmer than the rest of the room.

Something to think about, I didn't and my installation is sub-par. An auxiliary fan may be in my future.

I've been worried about this issue in the garage. I have I-joists overhead that are 16" tall on 16" centers. I'm worried that all my heat will hang out in those cavities. I may install a ceiling fan to see if that helps. I may also insulate and make sure the insulation batts are level with the bottom of the joists to create a level surface - or maybe just drywall.

 

[pfettig77]

I found this article. I didn't go looking for confirmation of what I was already going to do (though I have been known to do that), I just stumbled upon it. This guy actually purposely puts his indoor units close to the floor. I know a lot of you would disagree with the guy, but at least I know it can be done.