Why is my upstairs so hot?! A Kansas City tech answers!

Nobody likes it when the upstairs feels like a sauna in the middle of summer.

If your upstairs always feels hotter than downstairs, it’s likely because of 1 of these 3 reasons:

  1. Your attic is poorly insulated
  2. You have leaky air ducts
  3. Your home only has one thermostat—and it’s downstairs

We’ll explain each of these problems in more detail, and how you can solve them.


Want a professional to fix your hot upstairs?

Reason #1: Your attic is poorly insulated

Most rooms in a 2-story home border the attic. During hot days, when the sun beats down on the roof, the temperature of your attic rises significantly (often reaching well over 100°) since it’s an unconditioned space.

So if your attic isn’t well-insulated, then that warm air will transfer into the conditioned rooms of your home, which raises the temperature indoors and makes your AC work harder to cool your upstairs.

Insulation in the attic


Contact an insulation company in the Kansas City area to check the insulation in your attic. If you don’t have sufficient insulation, they’ll need to add insulation to your attic.

Reason #2: You have leaky air ducts

Even if your attic is perfectly insulated, your upstairs will still be hot if you have leaky air ducts.

You see, over time your duct work can develop holes or become accidentally disconnected, which means cold, conditioned air will leak into your attic/walls instead of your rooms upstairs.

A leak in your duct work means you’re wasting cold air (i.e. cold air is entering your attic instead of your upstairs rooms)


Contact a professional to inspect your duct work for leaks. If they find any, they’ll “seal” the leaks using mastic sealant or metal tape.

And don’t be surprised if they find duct leaks: according to Energy Star, most homes lose 20%–30% of conditioned air due to leaks, holes and poorly connected ducts.


Reason #3: Your home only has one thermostat—and it’s downstairs

The brain of your AC system is the thermostat: it detects the current temperature in the room and then determines when your AC needs to turn on or off to reach your desired temperature.

But since hot air naturally rises, your upstairs is always going to be hotter than your downstairs, meaning your thermostat downstairs can never detect the temperature upstairs.


You’ll need an HVAC professional to zone your home. Zoning involves adding a second thermostat upstairs to regulate the temperature there. In addition to adding another thermostat, the HVAC professional will also add a zone controller and several duct dampers.

zone controller is a control panel that controls electronic duct dampers, which are devices installed into your duct work that redirect air to certain parts of your home. These duct dampers allow 2 different parts of your home to remain at 2 different temperatures (represented in the image below).

A visual representation of how zoning works: 1 AC system, 2 different temperature “zones”

Note: Zoning requires a variable-speed furnace/AC blower, so you may need to upgrade your AC system before a professional can zone your home.

Need help cooling the upstairs of your Kansas City home?

One of our certified techs will give you a FREE estimate on the cost to…

  • Fix air duct leaks
  • Zone your home