3 HVAC systems in a house?

[cp102]

Our house is a 1.5 story home we have 2 HVAC and 2 heating systems. It works very well and its very efficient, its over 3000 sq ft.

[Uconn97]

I would love 3 zone for cooling! We have 3300 square feet and just 1 zone for the entire house. Very inefficient. At least our heat is 3 zones though.

[markjames68]

2 houses ago we had a 2000 sq ft range with a single AC unit/zone. One room was always hot in the summer (80+ degrees no matter what you did) and the AC couldn't keep up. Obviously undersized and an old SEER 10 single stage unit.

Last house was a 3000 sq ft single story with 2 AC units, each handling roughly half the house. SEER 18, variable speed compressor/air handler and kept the house consistently cool as well as dead on 50% humidity.

Current house is closer to 8000 sq ft, 2 story + finished basement and has 4 AC units, one as a heat pump for the basement, 2 main floor (large + smaller master suite unit) and 1 for upstairs. Single stage SEER 10, so the bills are higher but each one cools adequately (on the hottest of hot days the upstairs unit struggles a bit in the late afternoon to keep up.). 3 of the units are getting close to 20 years old now so as soon as one develops a problem it'll be replaced, but will run them until they are about to die.

The flexibility of being able to set temperatures by area is great - can let the master suite creep up during the day and stay cooler at night, etc.

[Coolair]

The house has been zoned for heating and cooling system. Its add value to your house. Zoned system is always very energy saving option and you can customize the thermostat according to your requirement.