The upstairs is always hot. Closing vents won't fix it; zoning will.
Half the territory's two-story homes run the same argument every evening. Zoning ends it without a second system.
The complaint
A two-story in a St. Johns County subdivision. The thermostat is downstairs in the hallway. Downstairs is 74 and pleasant. Upstairs, where the bedrooms are, it’s 80 at bedtime in July, and the kids sleep with fans. Set the thermostat to 70 and downstairs becomes a refrigerator while upstairs reaches 76.
The myths
“Close the downstairs vents.” This raises pressure in the duct, strains the blower, can ice the coil, and leaks air at every joint. It moves a little air upstairs at the cost of the system’s health.
“Put a fan at the top of the stairs.” It mixes the air a bit. It doesn’t change how much cooling reaches the second floor.
“Add a second system for upstairs.” It works, at the price of a complete second system, a second outdoor unit and the space for a second air handler. For many houses that’s more than the problem deserves.
“Just set the thermostat lower at night.” The power bill answers this one.
The reality
The second floor is hot because heat rises, the roof bakes the upstairs ceiling, and a single thermostat downstairs has no idea. Zoning fixes the last part. Motorized dampers in the supply ducts divide the house into areas; a thermostat or sensor in each; a controller that opens and closes the dampers so each zone gets air when it calls for it. Downstairs holds 74. Upstairs holds 74. The system runs for whichever zone needs it, and on a variable-speed Lennox system it modulates its output to match how many zones are open.
Lennox’s iHarmony zoning ties into its communicating systems and the iComfort thermostat, managed from one screen with room sensors instead of a thermostat on every wall.
The right fit for this market
Two-story homes, which fill the newer subdivisions of St. Johns, Clay and Flagler counties and the older ones around Jacksonville and Ormond Beach. Long single-story ranches with a bedroom wing on the sunny side, common around Ocala and Gainesville. Homes with a bonus room or a guest wing. Any house where one thermostat is being asked to speak for rooms it can’t feel.
Where it doesn’t fit: homes with ductwork that can’t be sensibly split, or where the real problem is undersized duct to the second floor. Cook’s inspects the attic before quoting zoning and will say if duct repair is the honest first step.
What Cook’s installs
Lennox iHarmony zoning on Lennox communicating systems, and conventional zone panels and dampers on other equipment where it’s compatible, with sensors placed where they read the living space. Installed in a day in most attics. Maintained at the regular visit, with dampers exercised and sensors checked. Manufacturer warranties are registered by Cook’s; ask for the labor warranty term before the dampers go in. [[CONFIRM WITH JERRY]]
Zoning questions
How many zones can a house have?
Two is the most common, upstairs and down. Three or four work for larger homes with a master wing or a bonus room. Beyond that, a second system or mini-splits usually make more sense, and Cook’s will say which.
Can zoning be added to the system I have?
Often, if the ductwork has a layout that can be split and the equipment can tolerate reduced airflow when zones close. It works best on variable-speed systems. A single-stage system may need a bypass or an upgrade; the estimate visit tells you.
Does zoning save energy or just fix comfort?
Both, modestly. Conditioning the unoccupied floor less saves something; the bigger win is comfort and the end of the thermostat war. Cook’s won’t promise a percentage.
What about the single-story house with one hot wing?
Same solution. A ranch with bedrooms on the sunny end and living space on the other is a two-zone house laid flat. Zoning is about duct layout, not stories.
Tired of the thermostat war?
Ask for a zoning assessment. Free, in every market Cook's serves.