9k vs 12k BTU for an open-ish first floor with awkward placement?

Installer #2 is spot on here. In a space where the air is alredy hitting a wall 10 feet away, a 12k unit is going to **short cycle** like crazy. The unit's internal sensor measures the air returning to the head. When you have a wall that close, the cold air bounces back, the intake thinks it's already hit the target temperture, and it ramps down or shuts off before the dining room even feels a breeze. Bigger isn't better for comfort. You want that unit running at a low, steady speed for hours to pull the moisture out of the air. A 12k will turn the kitchen into a meat locker and then shut off, leaving the rest of the floor humid. Even with an inverter, every unit has a minimum output, and a 12k unit's minimum is often higher than what your kitchen actualy needs once it’s staged down. You're effectively paying for capacity you can't actually use. Since this is in a kitchen, you have to be obsessive about cleaning those filters. Mini splits have basic filters that don't catch much, and cooking grease will gunk up the **blower wheel** in no time. Once that wheel gets weighed down with grime, your airflow drops significantly and the unit will struggle to reach past the kitchen regardless of the BTU rating. It’s a nightmare to deep clean those heads once the internal fans get sticky.

Stick with the 9k. It’s better to have a unit that runs longer and stays more efficient. Fans can help move some air, but they aren't going to fix the physics of a unit that's sized wrong for its immediate surroundings. If the game room stays too warm, you’re better off adding a dedicated small unit there later or sticking with a window unit in that specific room rather than trying to force one oversized head to do the job of two.

The point about the blower wheel getting greasy is something I never even thougt about. My kitchen gets super smoky when I sear steak, so now I'm worried about gunking up a brand new unit. If I go with the 9k like you suggest, does the fan speed help push the air further without it short cycling? Or does a lower BTU unit always have a weaker fan? I'm curious if a high fan setting on a 9k whould just hit that wall and bounce back anyway, or if it acutally helps it reach the game room.

acutally, many brands use the exact same chassis and blower for thier 9k and 12k units, so you won't necessarily lose 'throw' distance by going smaller. The 9k will just run its compressor at a lower frequency. One thing that helps with the 'wall bounce' issue is getting a unit with a remote sensing feature, often called iFeel or Follow Me. If you keep the remote in the dining area, the system ignores the air temp at the wall and stays on til the remote actually hits the target. It solves the short cycling problem way better than just bumping up the BTUs.

Check the submittal sheets for the specific units. You want to see how low the minimum BTU goes on that 12k. Some high-end 12k units throttle down realy well, but the cheaper ones have a high floor and will definitely short cycle in that 10ft space. Also, consider the noise. A 12k moves more air and the compressor works harder, so it's usually louder. If you're hanging out in the kitchen or dining area, that constant 'whoosh' of a bigger unit ramping up and down is a pain. The 9k will stay in a quieter, low-power hum most of the time.