Does anyone use a whole house propane generator ?

Looking into upgrading my portable generator so I can use my air conditioning unit and or heater when needed with everything else in my house .

I use a 5500 watt generac portable now that runs everything except our electric stove and heat pump ( which is a heater and air conditioning unit in one )

I am just wondering how much propane a 14000 watt system would use - and seems it would cost me $4000 to purchase and more to install .

I can get a 17500 watt gererac portable generator for $2600 and it has a 16 gallon gas tank , and uses about 1 to 1.5 gallons per hour .