I live in Central TX and have a 10x12 insulated shed turned into a home office.

In the summer I run my AC window unit - https://www.geappliances.com/appliance/GE-ENERGY-STAR-115-Volt-Electronic-Room-Air-Conditioner-AHS12AX 11,600 BTU, Cooling EER 12.1. It's 5 years old now and getting very loud


In the winter I run a Vornado Electric Space Heater - https://www.vornado.com/shop/heaters/whole-room/velocity-3-whole-room-heater 3 heat settings (750W,1125W, 1500W). I have a smart timer that turns it on 2 hours before I start work. I use the medium setting because that smart timer, while rated for 20a gets warm on High. I don't like it running all night without me in there. This morning the low was 45 and took about 4 hours to get to 65.

I got a good quote from a local HVAC company to install an LG LS090HXV2 - https://www.ecomfort.com/LG-LS090HXV2/p99988.html SEER rating of 20. In the summer our bill came out to $.13 per KWH user. No option for gas where I live, electric only. Thankfully I do have a dedicated 115V for this project already. The minimum temp setting is 60 but if it's efficient I think it'd still come out ahead running overnight at that temp?

Should I go with the mini-split system? I believe it's going to be more efficient, quieter, safer and also keep me more comfortable in the winter.

Man, that's a really small space to spend $1,500 ish on a minisplit. And you still have a compressor on the outside.

If it has a window, I'd probably go with a high efficiency inverter a/c like a Midea 8k and a high efficiency oil heater. Both with apps so you can control them from the house to warm up or cool off the space while you're getting ready in the morning.

Both combined about $500 and both would be extremely quiet and easy on the electric bill.

I agree with the 115v mini-split that can run all night if thermostat demands it, fewer worries, warmer welcomes.

Would prefer a window thru-wall PTAC/Heat Pump single unit if only you could get 230v arranged, otherwise it's a long shopping trip to find a 115v version ala GE 115 Volt Built-In Heat Pump SKU: AJHQ08AWHBarcode: 084691864417 Noise/db unknown.

If the mini deal falls through, then replace heater with auto/all-night running Dyson https://rebrand.ly/ylr1ed2 on sale and when the time comes, a quiet LG window AC - they have been very good to us.

If the heater is the focus NOW and budget limited, a cheaper-than-Dyson (what isn't) option might be https://rebrand.ly/gxd3ev6 but I have no experience with it.

Yeah it's a tough decision. Just wanted to make sure it was clear that this is my primary office and I WFH full time.

My issue with the window unit idea is that, because the space is small, dealing with the noise they produce can be problematic. Currently I have to turn my AC off sometimes because it interrupts zoom calls on occasion.

I think Midea make one that also does heat too which could be interesting.

The Midia inverters are library quiet and extremely efficient. And you can open the window when weather is nice. Don't have heat though.

I'd almost worry 120sqft is too small for a minisplit to be efficient. Definitely would be loud.

I say go with the mini split
You will really enjoy how quiet it is.
I have been involved on projects with them installed in small 150 sq ft garages all the way up to 500 sq ft cabins. Everyone has always loved them after the install. What is your total install price on the unit ? Bonus if you are self employed then this home office improvement becomes a tax write off.

Mini split would be louder?

Midea says 42DBa, https://www.midea.com/us/air-conditioners/window-air-conditioners/8000-btu-u-shaped-air-conditioner-maw08v1qwt

JP76 said:

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I say go with the mini split
You will really enjoy how quiet it is.
I have been involved on projects with them installed in small 150 sq ft garages all the way up to 500 sq ft cabins. Everyone has always loved them after the install. What is your total install price on the unit ? Bonus if you are self employed then this home office improvement becomes a tax write off.

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Thanks! What's the smallest BTU you put in to the 150 sqft? Heat work well in the winter?

The cheapest bid was $4,500 so now I'm thinking about going with one of the mrcool DIY kits

https://www.costco.com/mrcool-e-star-diy-4th-gen-12k-btu-ductless-mini-split-heat-pump-complete-system-115v60-hz.product.4000043469.html

I believe it was this one


https://www.lowes.com/pd/MRCOOL/5013738093

It was a 110/115 unit


22.5 to 38.5 decibels depending on the fan speed


They heat fine but under 32 a heat pump can struggle


How tall is the ceiling ?

What kind of insulation is in the walls and ceiling and how thick is it ?

Thx. Yeah, I his would be 110 as well.

Understood about sub 32 temps. I'd keep the space heater around just in case.

Ceilings about 10 feet tall. Batt insulation, don't remember the thickness though.

AgsMyDude said:

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Mini split would be louder?

Midea says 42DBa, https://www.midea.com/us/air-conditioners/window-air-conditioners/8000-btu-u-shaped-air-conditioner-maw08v1qwt

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Yes. The one you linked shows 47 DBA. For every increase of 3 dBA, the sound intensity doubles. At multiples more expensive and requiring install, the Midia would be the obvious choice for me. For some reason a lot of people can't understand that the Ushaped inverter ACs are much more efficient and much quieter than normal square window units.


https://www.midea.com/us/air-conditioners/window-air-conditioners

40 dB - Refrigerator hum, a quiet office

50 dB - Moderate rainfall


https://www.mdhearingaid.com/blog/decibel-chart/#:~:text=20%20dB%20%2D%20Leaves%20rustling%2C%20a,50%20dB%20%2D%20Moderate%20rainfa

Midea says


"allowing ultra-quiet operation as low as 42dB"

Range is "42-47"


Lg specs say



"indoor unit boasts sound levels as low as 19 dB"

"Maximum Sound Level 47 Db"

Range is 19-47

So at max sound level they are the same decibels and at minimum range the mini split is still quieter by 23 decibels


That I why I linked the Mr cool with specs of 22.5-38.5 decibels as that LG is on the loud end for a minisplit


But your solution is a good choice to drop the noise from the current set up without breaking the bank.

Sounds like your mind is made up.

There's definitely some piece of mind to a more formal solution. I just hope you don't have humidity issues or lesser performance from an oversized system in such a small space. It seems like it would have to cycle non stop to maintain temp, which would drive me nuts. Not to mention paying multiples for a more difficult solution.

That person is not OP, I am

Can you provide a link to your heater recommendation?

If you're suggesting something like below, I tried one of these when I first renovated the structure 6 years ago and it really couldn't keep up compared to the electric space heater I have now.

https://www.homedepot.com/p/Costway-700-Watt-Electric-Oil-Filled-Radiant-Space-Heater-GHM0093/315461817?source=shoppingads&locale=en-US&srsltid=AfmBOoqgjXGAAlesTeAtiU-nTR93f3HehNlDASW0VfpgkQQweMSXS7gVAKc

Walmart has one in that price range with the 25-foot line set. 115 volt. 22 SEER.

https://www.walmart.com/ip/DIY-4th-Generation-E-Star-12K-BTU-Heat-Pump-Condenser-115-volt-22-SEER-with-25-foot-line-set/1795710010

If you install the heat pump, don't forget that you get a 30% tax credit up to $2000 per year.

For sure!

Anyone know if my 20A breaker is sufficient?

this Amazon one says 25a
https://rebrand.ly/kvhc95q
same one?
better check

AgsMyDude said:

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For sure!

Anyone know if my 20A breaker is sufficient?

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I think you should be fine with something 12000BTU or lower. You can check the specs though. The brochures usually show the requirements for the different sizes.

Sorry. Been a hectic week.

I mentioned the oil heater because you stressed efficiencies. Like anything else, it has to be sized to the space. The one you linked is about half the normal watts of the average one I've seen.

My personal preference would be to go with a electric space heater with a programable thermostat like this one.

https://www.amazon.com/Lasko-Electronic-Oscillating-Digital-Controls/dp/B08WB6PFSV/ref=sr_1_1?crid=R2HJS5NAIO6Y&dib=eyJ2IjoiMSJ9.v77nwH3lynw4-DtqIJVe4CBkv2kMHkyKsX8TZWqPXzmPM9OLNgInXTMTsdbP8hswwYsuHSv1s1xydC6XjVzJwA.PazMl9c4oWv86YsAHk0F4qQ2kRwAqFHfXKhBFUuVcE8&dib_tag=se&keywords=space%2Bheater%2Bwith%2Bthermostat&qid=1705003517&refinements=p_72%3A1248915011%2Cp_n_feature_three_browse-bin%3A23992598011&rnid=23992579011&s=home-garden&sprefix=space%2Bheater%2Bwith%2B%2Caps%2C120&sr=1-1&th=1

If you want to go with a cheaper space heater without a built in thermostat, you can always by a $20 thermostat plug from amazon that will power on a heater when temp drops below your setting. I have one like this for my greenhouse.

https://www.amazon.com/Century-Thermostat-Controller-Germination-40-108%C3%82%C2%B0F/dp/B01I15S6OM/ref=sr_1_1_sspa?crid=183UQJZ5U1JQZ&dib=eyJ2IjoiMSJ9.c3gUaJq9ui_jFCJ1s9Q0pcxmrQj0G73JfTQ--wuFcQ8PxLHqIMGVWYR2J27sQ-moFbVtRPv5Vye9JwtZg-AfxQ.xSnQwOgtNR6as0AC_07LH_TUDeu3AQXUGPfdVAGPsZg&dib_tag=se&keywords=thermostat+plug&qid=1705003673&s=home-garden&sprefix=thermostat+plug%2Cgarden%2C114&sr=1-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&psc=1

I have a mini split in a similar use. Most of them have a dehumidify mode which is the fan on low with the coil very cold or warm in heating times. This easily makes the space comfortable and is very quiet. I realize the top sound for the mini split is almost as high, but you will not need it on high.

I keep a portable oil-filled electric radiator in my wife's office for use when she gets cold, which is at least 6 months out of the year. It takes a bit to warm up, but once it does, it puts out some heat. Granted there is a max space in which a portable radiator will heat as intended, but it works well in our application.
I do prefer radiated heat over heat from a fan driven resistance-coil or ceramic heater. Used to keep a small electric radiator in an old Airstream at the deer lease, and once it got warmed up and if we didn't remember to use the heat control, it would chase us out of the trailer so we could cool off.

It is the brand and model in the following link: https://www.delonghi.com/en-us/radia-s-eco-digital-programmable-portable-radiator-heater-with-timer-trrs0715e/p/TRRS0715E