Mini split sizing

[brent5631]

With all the new developments and costco selling the mr cool mini split i think I have made my mind up on getting one of those for my attached garage. I could use some insight on if 12k or 18k is the right size though?

The attached is 23x25 with a vaulted ceiling going from 8ft to 16ft at the other end. Its insulated and has an r13 foamed garage door facing north. No windows anywhere. Usage will be more like a mancave, playroom, theatre. Finishing wiring it for speakers and projector now.

Any help on size? I'm not sure if 12k is enough. And 18k bumps me to 220 power. Any benefits there?

Thanks

 

[Fixin'Stuff]

If you plan to keep it conditioned 24/7 then a 12K should do nicely. If you want to only condition it occasionally, then the extra BTU/Hr of the 18K will be nice to have for quick cooldowns. The 12K can be ordered in either 120 volt or 240 volt models. The 240 volt unit will draw half the current, but still the same amount of watts (Watts=Voltage x Current). Note that they are supposed to be installed as the only device on the circuit. If this means that you have to run a new power circuit anyway, then I'd go for the 240 volt model, if you have space for the double breaker in the circuit panel.

 

[finn]

The smaller unit will do a better job of removing humidity, as it won’t be short cycling.

23’x25’ isn’t much area / volume even with the oddly shaped ceiling.

Fixing has the right idea.

To me , high humidity is uncomfortable, so I would go with the smaller unit.

 

[brent5631]

Thanks guys. This wont be conditioned 24/7. Wife will still park in there and pulling a hot car in makes it so hot. I'm thinking more of movie nights/ family over etc. I'm adding a circuit so thats not a problem. And would prefer 240v. Im leaning toward the 18k just for quicker cool down.
Arent the variable speed splits better about humidity anyway? They have a humidity mode.

 

[Fixin'Stuff]

Arent the variable speed splits better about humidity anyway? They have a humidity mode.

Yes, because once the room temp is satisfied, they slow WAY down, run almost continuously at a greatly reduced BTU/Hr, and keep the temp steady, all while still removing humidity as air blows across the cool evaporator.

The "dry mode" is mainly for use during spring and fall, when the outdoor temp isn't high enough to require cooling, but it would still be more comfortable if the humidity in the space was lowered.

 

[Browneye]

I have two of the MrCool units, a 12K btu in a 12x15 bedroom, a bathroom, and additional office/bedroom adjacent - maybe another 150sq ft, about 400-450sq ft total. Works perfect, cools everything. Can't even hear it.

Our other one is a 24K unit in the main part of the house with high ceilings and poor insulation - at 116deg it could cool down to 84 with the heat-gain from west-facing windows. That area is about 700sq ft. Under 100* it maintains a comfy 75-78.

You being right in the middle, for Dallas, I think I would do the 18K unit. It might run slower more of the time, but that's fine. It will also provide extra for when it's really hot out - high 90's and over 100.

If you're running a circuit for it the 240 will be easy to do, it's a 20a breaker set for that size, but they only pull about 8amps on full tilt.