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.

We use radiant heating AND cooling in the the ceiling- no ductwork required! (www.therma-hex.com). Radiant systems don’t heat air the heat objects so the work on the second principle of thermodynamics, where heat moves to cold in a radiant system it moves at the speed of light so if you walk into a room from outside in the cold winter you will immediately feel warmer yet on the opposites side of the room the temperature hasn’t changed at all. And the stored energy in the water and your ceiling drywall radiants that energy with out the need to initially open a valve and start fluid flow into the radiant system the thermal mass of the fluid and the drywall handles the energy transfer and at the speed of light. You will be way more comfortable in a house with this system so you are not blowing dry dusty air around and spreading disease!