Relocating HVAC Unit
 

We are in process of getting garage quotes when my dear wife springs a new idea on me late this evening. This change to our proposed garage would require relocating our existing HVAC unit from the side of our house to the back of our home. Has anyone else done this and how much of a problem was it to do? Our existing HVAC unit is a dual-fuel system (electric and gas). All I know by looking is that we have a massive vent from outside going underneath our hose. I am especially troubled (actually frustrated) by this latest revelation since I am supposed to sign he contract with our contractors this week. Please, just allow any replies to focus on relocating the HVAC and not on the (glaringly apparent) other issues.
Thanks,

I replaced a heat pump for a 1200 sf cottage in Tampa. During the install we moved the unit but kept the ductwork underneath the house. They charged me maybe a hundred extra for materials. In your case the move will require a service call to evacuate the unit and might mean a new or extended refrigeration line set,. I would guess you should be able to do under $500 but larger distances or units and local contractor pricing will obviously be a factor.

I'm going to guess and say the massive vent going under the house is the ductwork. If your HVAC unit is outside it's similar to a rooftop unit that has both heating and cooling. It's a package unit so all you have to do is move the unit to the new spot, run new gas, and electrical (including low voltage thermostat wires) and have the ductwork relocated.
The ductwork will be the hardest part.

Without pictures I'm guessing what you have is the main duct from the HVAC unit runs under the crawl space and then is distributed to the rooms in your house.

Normally the AC condenser is the outside unit and the air handing unit with the evaporator and furnace is inside. Some of the commercial units are "packaged" where the air handling system is packaged with both condenser and evaporator. The unit simply has a large air outlet and large return and the entire unit is outside.

Is this the setup, or is the air handling unit inside?