24k or 30k BTU mini split for a 2 car garage in las Vegas?

I have a 2 car garage in Las Vegas, NV. I have a Senville 9k BTU mini split that someone installed over 2 years ago and it can't keep up with the heat in the summer or cold in the winter.

I want to upgrade my unit to either a 24k BTU or a 30k BTU Senville mini split. The 24k BTU is $1k and the 30k BTU is $1.4.

Which one should I get? The unit is typically off, I only turn it on when I'm working in the garage. The garage has some insulation and I put up styrofoam insulation on the garage door. I park my car in the garage.

Which unit should I get? Should I go with another brand? I've had no issues with my current Senvill other than it can't keep up with the heat or cold.


Here is my current unit:

https://www.amazon.com/Senville-SENL...dp/B00UV3LGPY/

Here are the two units I'm leaning towards:

The 24k BTU unit:

https://www.amazon.com/Senville-SENL...0UV3LH4Y/?th=1

The 30k BTU unit:

https://www.amazon.com/Senville-SENL...843HK35B/?th=1

source https://hvac-talk.com/vbb/showthread.php?2224212-24k-or-30k-BTU-mini-split-for-a-2-car-garage-in-las-Vegas&goto=newpost