Why is One Room in My Home Always Hotter Than the Rest? A Phoenix Tech Explains

Do you have a room in your home that’s always too hot? You’ve probably tried turning down the thermostat, but then the rest of the home got too cold (and your AC bills skyrocketed).

So what’s the deal? And how do you fix it?

Well, this uncomfortable situation could be caused by one of (or a combination of) two things:

• Too much heat is leaking into that room
• AC is not removing the heat properly

You see, your home is like a leaky boat. Only instead of leaking in water, it leaks in heat (when it’s warm out, anyway).

And instead of using a bucket to remove the water, you have an air conditioner that continually removes the heat.

So to fix a room that’s always too hot, you need to focus on either:

• Plugging more of the heat leaks or
• Fixing the problems that prevent your AC from removing the heat as it should (or both)

If there’s a room in your home that’s extra warm, it’s usually because it’s extra leaky. Here are some of the most common places heat leaks into your rooms.

According to energy.gov, energy loss from windows accounts for 10-25% of your heating and cooling bills.

Consider upgrading to double-pane windows with a Low-E coating to reduce how much heat can pass through your windows.

Double-pane windows increase your home’s efficiency by adding a layer of insulation between the 2 panes of glass. Low-E coatings help reduce heat transfer through the air, acting as a sort of radiant barrier.

(Here’s a quick way to tell if you have single or double-pane windows)

The walls and ceiling in the room may not have enough insulation, allowing heat to leak in.

If you can, check in the attic above the room that is always hot. Uneven insulation can cause the room to be hotter than the rest of your house. (The U.S. Department of Energy recommends at least R30 insulation in the attic for Phoenix-area homes.)

Which direction do the walls in the hot room face? West-facing walls soak up a lot of heat that can then be transferred into your room. This is made even worse if you also have windows on the west-facing walls.

If you can, consider planting trees that shade the west side of your home. An awning or patio on that side can also help.

The most common AC problems that cause one room to be much warmer than the rest of your home are:

• Leaky/disconnected ductwork — The ductwork that feeds into the room may be leaky or disconnected, keeping cool air from reaching the room.
• Uninsulated ducts — Similarly, a long, uninsulated duct can lose much of the cool air by the time it gets to your room.
• Poor duct design — It could also be that the ducts are not designed to bring enough cold air into the room.
• Oversized AC — If your air conditioner is too large, it won’t run very long and won’t evenly spread the air throughout your house, leading to hot and cold rooms.