help in sizing Mr slim mini split unit

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I am installing a Four Season sunroom at my house.

Size - 16 L x 11 W x 9 H

Glass is high performance, insulated safety glass with Argon glass filling. Glass has R value of 4.

All walls and roof are glass, with the exception of the back wall which will be the exterior of my brick house.

Room faces west and I live in northeast.

I would expect lowest o/s temps to be around 10, and highest around 90 during summer. I'd like to use this as much as possible but, obviously, will refrain with extreme weather conditions.

I want to install a split Mitzibushi Mr Slim heating/cooling unti.

I figured I needed around 18,000-24,000 BTU's.

Am I correct about the size needed , and can you recommend a particular model?

[jpsmith1cm]

Freezeking2000,

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[comfortdoc]

If it were mine and the brick wall is 16' long, I would use a dual head MXZ inverter heat pump. if the brick wall is 11' you can get away with a single. Do proper manual J sizing for the space. Keep in mind with the V/S compressor, oversizing will not hurt you from a comfort or energy use standpoint. The larger units do cost a bit more up front of course.

[cuchulain]

Have your installing contractor do a Load calculation on the room and they will then be able to give you your best possible choices.

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thanks to all for reply..

I had two different hvac companies visit and provide quote. The issue is one suggested 22,000 BTU's and the other between a 36,000-48,000 unit.

Big discrepancy.. I'm not looking to cut corners, just wanted to buy the correct sized one as I was told that oversizing could result in too much humidity.

I eevn called the manufacturer (Mitzibushi) and they won't recoomend but felt the 3-4 ton quote was too much machine for the space.

I'm leaning towards purchasing the 2 ton unti but was looking for some additional advice before I pull the trigger.

[cuchulain]

which one did a heat load calculation for the room? That's the one I'd go with.

[talktowags]

Get a heat calc done to be sure. But sounds like 22 would be plenty.

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thanks.... much appreciative of your comments