Mini-split HVAC

We have an elevated sunroom which is exposed to the outside on 5 of the 6 sides of the “box”. In the blazing summer sun it is incredibly hot, in the winter too cold. (We use a space heater in winter and 2 small window air conditioners in summer, but even then…)

I am wondering about getting a mini-split, but am concerned about the noise level; it’s the place we both retreat for quiet and solitude in the day, and where we start our mornings as well. It’s a lovely room except for being, you know, really uncomfortable :wink:

If any of you have a mini-split, would you comment on the fan noise, please? The outside unit is not that much of a concern.

(The room is nearly all glass, including skylights in the ceiling, so “insulating it better” is not an option. The windows are new, thermo-pane, and has skylights in the vaulted ceiling to boot. We already have two sets of layered shades which help, but rolling them down sort of defeats the purpose of having the view.)


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@Domeyrock said he has Mini-Split’s Goofy, maybe he can give you some tips on them.


We’ve had mini-split heating/cooling systems for nearly 10 years in 2 different homes. I think you’ll be pleasantly surprised at how quiet the fans in them are. I wouldn’t say they’re silent, but – to my ears, anyway – it’s amounts to non-intrusive, low-level background noise. I can’t imagine it would be any sort of a distraction to reading or working, or even just relaxing.

Now, the bigger unit that sits outdoors … is a different story. That fan can get fairly loud when the unit is working hard.


Hi @Goofyhoofy,

I have 2 Mitsubishi mini’s in my shop. They have plenty of oomph to quickly raise the inside temperature from 47 degrees to 65 on a 7 degree day recently.

After I turn them on, I see the 2 green LED’s on. Fairly soon, one LED goes off, meaning the temperature has been reached and it (they) shutdown. If I stand in the “right spot” I can feel the air blowing, lightly.

The shop is quite quiet since I built it using 8 inch ICF, about 15 inches through-wall depth. I do not hear the 2 outside units at all.

I have not run them for AC yet.

Does that help you?

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We have a Mitsubishi mini split in our sunroom. I hate noise, but this is remarkably quiet. Am looking to replace a window unit in another house with one of these. Doesn’t block the view and isn’t noisy.


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Beautiful shop Gene. Well done.


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They are nearly silent when they are maintaining temperature. Of course, when they’re heavily cooling or heating, they’re noisier, but it’s not buzzing loud compressor noise like an A/C. They’re perfect for the space you describe, the separate compressor will be outside on the ground. You just need 3x1.5" space on the non-glass wall.

new splits June '22


Now we have to wait for pictures with it full of toys. So much room, so many possibilities. :sunglasses:

Hi @buynholdisdead & @RHinCT,


Well, it is kind of full now. I moved a lot of stuff from the conex that is still on the floor and about 1/2 of the stuff I had stored in the grain bin near the driveway entrance. I have a lot of excess building material that I started making a bench from before other priorities came up.

But this weekend, one of the hoses on my loader started to leak oil. Not a big leak but oil spray at 2,600 psi can do a lot of damage. So I dropped the loader in there to replace the hose set. It looks like I may have to have them made.

And to make it all perfect, it looks like the o-ring on the fuel drain on the tank is leaking. I just hope I don’t have to drop the tank because that is a true hassle!

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Hey Goofy -

We had Mitsubishi mini-splits installed back in 2017 and we wish we had installed them way sooner! We LOVE them! We have 3 wall mounted units on the first floor and the second floor is heated / cooled by an air handler in the attic with air vents into each of the rooms.

The wall units are virtually silent. Incredibly silent. I don’t think you’ll hear them unless you crank up the fan to full blast. We keep ours on the “variable” setting and the fan speed is managed by the sensors in the unit.

Go for it - you won’t be disappointed. But remember, these are Mitsubishi units, other manufacturers may not be as quiet.


This is certainly true. I had a great Carrier dealer in the early 2000s - before we moved. If someone asked him for a Carrier split, he said he would order one, but personally used and recommended Mitsubishi units because there were more reliable and much quieter.

Things do change - but the people on my current neighborhood who have these units are universally happy.

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Anyone have experience with Daikin mini splits? Our experience has been with Mitsubishi, which is whisper quiet, but one of the contractors coming out to give us a quote on a system sells Daikin.



Nope. Sorry. I have 3 quotes for Mitsubishi, very similar if numerically different model lines (virtually identical specs, so…) $3900, $5500, $6800. Odd, All the same SEER and BTU (12,000)

I have also seen a guy on Facebook marketplace offering a 12Kbtu for $1900 installed. It’s Senville, which actually gets good reviews.But I want a dealer so if service problems erupt I have someone to squawk to. There are several you can get with DIY installation for $800 and up. Anyway, went with the popular vote here: Mitsubishi.