Questions tagged [mini-split]
A mini-split is a smaller HVAC unit with the blower and control unit inside a room, while the condenser unit sits outside. Use with any relevant tags (i.e. [electrical]). Use for questions about DIY installation of these unit.
131 questions
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How to balance minisplits and oil furnace for winter heat?
We had a full set of Carrier mini-splits installed (1600 sq. ft, 2 stories, 5 heads), added to a very senior oil furnace.
We're still getting used to them. We opted out of the "smart" ...
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Mini-split system or furnace for an old house [closed]
I bought my first house in August of this year. It was built in the 1930s, approx. 825sq ft, and has needs a lot of updates for it to be livable. I recently found out that the current furnace is not ...
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Auxiliary gas heat for ductless HVAC
Background:
I hate ducts. I hate them passionately. Maybe the dust and gunk they collect irritates my asthma. Maybe the constant rumbling, whooshing, or whistling noise drives me up the wall and ...
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Daikin Mini Split Runs Constantly V2
While googling my issue I came across the following post which describes the exact behavior I am observing as well.
Daikin Mini Split Runs Constantly
I have three indoor units.
Two of them are ...
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Is it a problem that the indoor unit of a mini-split AC/heat pump is not properly leveled?
I noticed that the indoor component of my new mini-split installed by the handymen today is not properly leveled. It's off by about 0.3 inch (0.75 cm). I believe that would amount to a 0.5 degree ...
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Mini-split options and its suitability? [closed]
I recently bought a new home with no central AC, except for one in-the-wall unit in a bedroom. The house spans 2,000 sqft across three floors and is heated with hot water baseboards from an oil ...
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Where should I place mini-split heads in a converted building?
I've got a 600 sq. ft. metal building I'm turning into an ADU. The interior is insulated with 2" of closed cell spray foam all the way around, and finished with 1/2" drywall on 1x4 furring ...
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Tricking a Mitsubishi MR SLIM outdoor unit to run without the outdoor fan?
Our AC just died at the start of a heatwave! When it starts up, the the compressor turns on but the outdoor fan does not start spinning. Then after 60 seconds the compressor turns off and it gives an ...
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Insulation and A/C system selection in a metal shed
I've got a 20x30 metal shed that I'm trying to finish out as an ADU. I don't know enough about insulation and A/C to choose what to install. The construction will be as follows from exterior to ...
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#8 wiring to mini split keeps getting hot with only 20 Amp draw?
Okay I'm stumped here. I just had to repair the wiring to my mini split for the second time. The first time was last year when a fuse able link burned out at the unit.
This year the wire at the ...
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1000-watt mini split needs 6 AWG?
If I'm reading NEC correctly, my mere 1000-watt mini splits will require whopping 6 AWG wire, for the legs from the attic junction boxes through the exterior conduit to the panel.
MCA (Minimum Circuit ...
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Do I have room to add a 240V breaker in my panel?
I’m trying to see if I have room to add a 240V line for a mini split. The mini split I got is a Gree with nominal 9 amp pull and manufacturer recommended breaker size of 20 amps.
Any thoughts on an ...
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Meaning of water droplets symbol on mini split?
Not sure what this symbol means on the right - “water droplets down lines” is the best I can describe it.
You can see it on the middle right of the display on page 19 here, but it does not explain it.
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Suction pipe freezing when blower is on low speed, and runs fine when blower turned to high speed!
I have 12000BTU unit running on R22, and I'm facing a strange issue with my split AC.
When I run it with the indoor blower on low speed, the outdoor starts freezing on the suction pipe. But as soon as ...
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What type of fuse for mini split?
I have a fused disconnect installed for a mini split on a 25A circuit.
Should I use a FRN-R or NON 25A fuse?
I believe it should be FRN-R since that's for protection of a motor, but looking for an ...
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Can I use an overpowered mini split to rapidly cool a space?
I have a garage/gym that I’d like to condition with a minisplit. Since I only use the gym 1 hour a day, I have the idea of cooling it on-demand instead of keeping it at temperature all the time. At ...
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Can a mini split handle six air exchanges per hour?
Can an appropriately sized mini split handle 6 Air changes per hour?
Our current gas boiler and air handler are failing and so we are looking into replacing the system.
We have had a few heating/...
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Verify correct disconnect installation for mini split
I am installing a 27K BTU Mr Cool min split (install guide) that requires a disconnect/shutoff.
I want to make sure I am correctly wiring the disconnect, as I cannot find a wiring diagram for it and ...
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Convert a 240V dryer outlet to go through the exterior wall to an AC Disconnect?
I'm a DIY-er. I have a house built in 1972 with an unused 3-prong dryer outlet (I'm on natural gas now) that's on a 30 amp breaker. I want to remove the outlet and instead run wire from the box ...
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Mini Split with Central AC
Is it possible/efficient to have One mini split unit in the living room and remove all the ducts in that room to then have the central AC only cool bedrooms?
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Can a heat pump designed for mini-split system be used for central AC ductwork?
I am looking at replacing my old central AC unit with a heat pump one using existing ductwork. A contractor quoted me Fujitsu Airstage indoor unit AMUG48LMAS with outdoor unit AOUG48LMAS1. I checked ...
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Should I replace the HVAC or install a mini split in my garage?
I have a detached garage that was built with an HVAC system. Don’t think anything has been updated since the house was built 20 years ago. It was disclosed when I bought the house that it was ...
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For a HVAC condenser rated for minimum of 26Amp and max fuse 40 AMP what should be the disconnect sizing 30 or 60 AMPs?
For a HVAC mini split condenser rated for 240v and minimum of 26Amp and max fuse 40 AMP what should be the disconnect sizing 30 or 60 AMPs,
I am looking to hookup the mrcool 27k condenser which is ...
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Should I replace an old furnace with a mini split unit? [closed]
I have a very small house that is close to being 700 ft.². I live in the middle of Illinois some winters it gets really cold , many degrees below zero. Last winter I noticed my furnace having a bad ...
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What should I consider when deciding between a PTAC and a mini-split?
I have built a workshop addition to my garage and both will be insulated. I'm located in Central Indiana, so we get chilly winters (often down to 0°F) and hot, muggy summers (90°F and 80+% humidity).
...
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Should I use a 15 amp or 20 amp breaker for a mini split with max current at 13.0 Amps?
Installing a garage mini split with AC and heat. Running <25 ft of 12 gauge to disconnect and 10 gauge whip to condenser. Unit specs say rated for 8.7 Amp with max Amps in heat mode at 13.0 ...
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Installing a series of FS140 surge protectors to prevent mini split board burnups
I'm having some issues with my current electrical setup. I had an electrician install a 36k Eaton whole house surge protector about a year ago, and the hvac company installed a gree mini split. Since ...
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Do I need to vacuum-test the lines for a new mini-split?
Sanity check for installing a multi-zone mini-split system: I pressure test each zone individually. Then I vacuum each zone and release the refrigerant into that line set (assuming no leaks). Then ...
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Is there a category of ducted HVAC/IAQ parts but sized for what is typical for ductless systems? [closed]
There's old houses with extensive remodels that are in need of some kind of "zoned" help in interior air quality (or "IAQ", I'm not sure how common this acronym is just yet), ...
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Minisplit Install With Thin-Walled Lineset
I'm currently installing a multi-zone minisplit in my home. Unfortunately, I bought the cheapest linesets I could find. The 1/4" line has thinner walls and is very difficult to flare and torque ...
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Can I cover part of my mini-split cooling coil to remove more moisture?
At night during the summer, we run the kids room mini split with the door closed, and I've noticed the humidity gets really high (measured at > 70%). This surprised me, as I assumed the AC would be ...
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Mini split to cool one room and heat another
We live in a three story house, with our bedroom in the third story loft. On sunny days, it gets too warm up there, even with the windows open (not to mention the neighbor’s 4:00am rooster crowing). ...
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Couple of questions on the outside unit of a split heat and A/C installation
I have a Viessmann heat and A/C installation where a single large common outside unit located on the roof connects to split units on three separate floors.
First question:
There is a pair of copper ...
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Possible to install a mini-split condenser inside-ish?
Trying to install a multi-zone mini-split heat pump system in a small condo that does not have any accessible outdoor space* for condenser unit, however in the region jalousie windows are common and ...
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Configuring FHW heating system as a backup to minisplit
I installed a minisplit HVAC (well, HAC) system a few years ago. Very happy with it as housewide AC, mostly happy with it as heating (more efficient than the high-efficiency gas forced-hot-water ...
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Insulating outside minisplit lines
I need to insulate two outdoor minisplit lines. They are 3/8 and 1/4 inch copper lines - approximately 15 feet.
Edit: They came with insulation but after several years it is damaged and needs ...
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How do I wire a mini split that requires 208-230V with a 15A breaker, but came only with single pole wiring?
I am installing a Rovsun 12,000 BTU mini-split with heat pump. The voltage range is 208V-230V. The wiring for the unit consists of L1 Black hot wire, L2 White neutral wire, and the green ground wire. ...
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Can I use just split units for winter heating if I have both mini splits and hydronic base board heaters?
We're trying to go all-electric/solar and reduce reliance on fossil fuels. We currently have an 11 year old propane tankless combi-boiler that supplies hot water and also circulates water through a ...
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Multi-split Daikin air-conditioner errors and temperature issues
I have two indoor Daikin Perfera FTXM-R units hooked to a 2MXM-N9 outdoor unit. What I noticed is that the indoor unit closer to the outdoor unit (A) will start to report a very low temperature if I ...
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What data is available to support decisions about thermostat set point with mini split heat exchangers?
I have seen tons of references that say that the best way to run a mini split heat pump is to set it to target temperature and to let it maintain that temperature all day long, not differentiating ...
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Mini split beeping every 34 seconds
My Mitsubishi MSZ-FH09NA mini split head just started beeping. It beeps every 34 seconds whether on, off, or disconnected. This beep sounds slightly different than the on/off/function beep (quieter, a ...
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Heating is not working on DIY Dr Cool Mini Split
I recently installed a 3rd Gen 24k BTU DIY Dr Cool Mini Split Heat Pump, but I'm not able to get the heat working. The indoor unit does cool, but it doesn't doesn't do anything when I switch to heat ...
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Can my mini split disconnect be around corner of wall
I am looking at locations to install my mini split outdoor unit. One location would be: you are facing the outdoor unit, on the right of the unit, the wall ends about 12 inches away and turns back ...
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MRCool 24k BTU breaker size, wire gauge and disconnect box
I am looking to install a: MrCool E Star DIY 4th Gen 24k BTU Ductless Mini-Split Heat Pump Complete System 208-230V/60Hz
I reached out to MRCool support and they confirmed what I found through google ...
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Wiring mini split external and internal
I am looking to install one of the MRCool DIY mini split in my garage.
I currently have a 30amp 240v break and have run 10 gauge wire to a 20amp receptacle for my air compressor.
Can I just use some ...
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How to connect the refrigerant lines of the DIY Mr Cool Mini Split in Tight Space?
I want to mount the indoor unit of the DIY Mr Cool mini split on a wall inside the house that is a few inches across from a shed. Unfortunately, the proximity of the shed prevents me from accessing ...
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Should I cut out this repaired kink in a copper line set? (3/8")
I'm installing a mini-split, and in a moment of carelessness I slightly kinked the 3/8" copper line (the larger one). I repaired it using the 'wrench method' with some nylog to lubricate, and now ...
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Mini split for 14x15 room addition
We have a 14x15.5 family room addition on a slab. For summers we've used a window a/c. The room connects to the kitchen via a small 4.5 x 4.5 foyer. It has a doorway with the door removed.
The rest of ...
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Understanding heatflow, minisplit vs. open stairwell
Still getting used to the minisplit heat-pump HVAC (well, HAC) system I put in a few years ago, along with improving the house's insulation.
One of the differences I'm noticing from when I was heating ...
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Wiring for mini split sysytem
My mini split system call for a 12/3 wire on a 30amp circuit. I thought i had to use 10/3 wire on a 30amp circuit. Is it safe to use the 12/3 wire?
