We are laying out a customer's home for framing stage. We are considering putting the HVAC unit in the crawlspace in Montana. IT is a very dry climate where we are, the crawlspace already has vapor barrier placed in it. What are your thoughts on putting the unit down there? I am aware of accessibility issues, there was no radon when tested. Just curious if we should just find a place to put it in a room upstairs.

Guessing are in a area that requires more heating then cooling...being that heat rises placing the unit lower is better for heating distribution

Also because of getting utility's to the unit is usually easier in a crawl space....like you said though the unit has to be able to be replaced down the road.