Thru the wall vs Mini Split for my Sunroom Florida (roof, windows)

[Alan1949]

I have a 192 SQ. Ft Florida room with large windows. I have an 8,000 BTU thru the wall Ac that does not keep it cool as it should. It is 4 years old and has never really done a good job in the summer months here in Florida. The windows are good and the walls insulated. Gets a lot of sun. I am tying to decide between: should I purchase a 12,000 btu thru the wall ac or go with a mini split?

The thru the wall is cheaper, around $5-600 hundred vs $1,200 to $2,000 for 12,000 btu mini split. I spend a lot of time out here but not sure the extra cost is worth it? Is there a good thru the wall ac out there that will keep my room cool or is the mini split the best choice? Is the mini split cheaper to operate vs the thru the wall?

[mic111]

While I can't answer your questions regarding operating costs I think you may be more pleased with the mini-split. Because the cooling is done up high when it is on you feel the cool air falling around you. And since heat rises it can take care of the hot temperatures alot more efficiently than a unit that is located near the floor. If you spend alot of time out there then the mini-split is the way to go. Consider carefully where you place the indoor unit. You want it high but you also want to be able to get up there to clean the filter.

[MrRational]

Originally Posted by Alan1949

I have a 192 SQ. Ft Florida room with large windows.
The windows are good and the walls insulated. Gets a lot of sun.

192sf x8 =1536 watts (x3.14) = 4823 Btu (for a regular house).
For a glassed in sun room? You'll have at least twice the load.

I have an 8,000 BTU thru the wall Ac that does not keep it cool as it should.
should I purchase a 12,000 btu thru the wall ac or go with a mini split?

Since you don't need heat... you don't need (or want) a heat pump.

I'd suggest using another AC (at the other end of room).
And probably some window shades too.

Start with a cheapo 5000 btu.
See how it is.

[LifeIsGood01]

Keeping the heat out in the first place would be where I start. I would put in some room darkening curtains that keep heat out, You can keep most of them shut during the day and just open them when you want to be in there.

[imagardener]

Originally Posted by LifeIsGood01

Keeping the heat out in the first place would be where I start. I would put in some room darkening curtains that keep heat out, You can keep most of them shut during the day and just open them when you want to be in there.

I agree with this but more can be done. I have lived in Florida a long time and always own south-facing living area but it's really important to shield glass from direct sunlight. You want to LOOK at the sunshine but not have it hit the windows.

First see about installing an awning (wood or fabric) outside deep enough to keep direct sun from hitting the glass. If the sunroom faces west that will be almost impossible, the other 3 compass points can be blocked easily. There's a good reason southern people have lanai's, blocking direct sunlight.

I have a mini-split in a rental property that most windows face south. The only time the sun hits 1" on the windowsill is February, when a little heat is desirable.

When we called company to install A/C they sent someone to do the math of how large a unit we'd need. Because of how old, shallow and uninsulated the roof is we needed a larger unit than we thought. But the electric bill is never over $40/month because whole house is just 625 s.f.

Our mini-split does go through the wall because the house is "pre-duct" era.

I think you can save the most money by first blocking the sun as much as possible, then get a quote from HVAC peeps and compare their solutions.