Sealed grow with window ac, do they leak?

Considering changing from mini split to window AC on my sealed room grow in the basement. the mini split installed did not last as long as expected and it was very costly to purchase compared to a window unit. however im concerned the window AC will leak too much air and odor and CO2 supplementation will be lost. any advice?

buy another split and install it correctly
we can help for installation if needed

window ac are ac ersatz

Smell will leak without air exchange pushing thru filter and out another outlet to outside. Of course if the exhaust cuts off smell will start to leak out AC. If you use one get a good one and it will last few years usually.