there is a surprising amount of this on Etsy 
Discussion
need this for my 3000gt omg
https://www.etsy.com/market/dollhouse_air_conditioner
there are a couple of actual hvacs but they less miniature more 3d print
there is a surprising amount of this on Etsy
need this for my 3000gt omg
https://www.etsy.com/market/dollhouse_air_conditioner
there are a couple of actual hvacs but they less miniature more 3d print