Kerry,
Congrats on the new building!? Hop it has all the access you want!
I have had a mini split in my last shop for 3 years or so.? 18k BTU for a 440sqft shop.? Poorly insulated and a 16' insulated garage door was a source of heat gain and loss for sure.
I have had pretty good dust collection so the build up was not a thing for me.? I cleaned it one time when I noticed the air flow drop.? It kept up well, but in 100+ degree days, if I opened the door to use the slider, the thing would take hours to catch up.
For the new shop (which is 924 sqft inside and a foot taller at 10'), I went a bit deeper.? I went with 2x6 construction which gave me R-23 in the walls and I had R-36 blown into the ceiling.? So the building is much tighter and better insulated.? I am moving the 18k to the rear of the shop and adding a 24k to the front of the shop.? I should be able to keep up with any weather and a short opening of the garage door.? I am installing them in two weeks, so I should know then.
Mine are wall handlers and there are specific instructions on wall height based on total ceiling height.? So I will be following that in the shop.
PK
PK