HVAC consideration upright location - no room in attic
Hello fellow knowledgeable BPers-
I have just had to replace entire HVAC unit due to mold. I bought my upstairs, downstairs duplex last year. The HVAC system was laying on its side underneath the house and moisture, flooding, humid Texas environment really did it in. There are no considerations inside the downstairs unit. It is not feasible to place it upstairs in this 1914 house. I was discussing space requirements just now with the installation crew. I will be building out my back of house and adding a laundry room addition on the back of the house. We discussed moving the HVAC out to the corner of the new room. I was told last night that I would need at least 14 feet to clear the unit in an upright corner and a 3' by 3' space. I am not sure if this is best placement or if it could lay on it's side at the ceiling of laundry room. Nothing currently exists and I haven't spoken to contractors. I may have a 5 foot by 13 foot area to build out in a rectangle. I could also add a corner just for the HVAC area off of the laundry room dimensions. It needs to be contained in doors in a humid environment. I know I will need additional ventilation in the room as well. Is this the best placement or could it be on its side and have the ducts run underneath the house? I am brainstorming right now until I find someone qualified to do the work. I will make them call the installation crew with the company as I have already purchased the entire system replacement. I am just waiting to get the room built for placement and they will come back and move the location of it from under the house. This is gas and a furnace as well. I know I will need water, gas, and new electric ran to supply it. Any ideas or additional considerations would be greatly appreciated.