Help! Why Is My House Hot Upstairs and Cold Downstairs?

Is your second floor hotter than the rest of your house? Here’s how to keep it cooler, especially in the summer.

A lot of people ask this question, particularly in the summer months. It’s actually a common problem that usually results in people cranking up their air conditioning and still not getting the cool temperature they’re looking for. No sweat! Keep reading to find out why this happens and what you can do about it.

Key Reasons It Gets Hotter Upstairs

Warm air rises. Physics is the challenge here, because hot air rises and cold air sinks. So your upstairs has a natural tendency to be warmer than lower levels.

Hot roof. Your roof absorbs a ton of heat from the sun, unless you have a lot of shady tree cover. All that hot air moves through your roof, into the attic and ultimately into your top floor. If you don’t have an attic space to buffer the heat or your roof isn’t well insulated, this will increase the heat factor upstairs.

Faulty ductwork. Ducts take the cool air from your HVAC system and distribute it throughout your home. If any of your ducts were installed poorly, leak or are simply old, then your air conditioner will struggle to get the cool air into your home efficiently. Sometimes you may not even have the right amount of ductwork to properly cool your second floor.

7 Ways to Cool Down Your Second Floor

    1. Block the sun
      Close blinds and shades to block light and UV rays. You can even try heat blocking shades or  UV blocking film. Be sure to seal all cracks, holes and gaps around windows to prevent air leaks. You might want to consider upgrading to more energy-efficient double pane windows.
    2. Insulate and ventilate
      Add extra insulation to your roof and attic. You can even air seal your attic to prevent heat from seeping in. Also, adding an attic fan will help cool things down by circulating the air up there and decreasing the amount of hot air reaching your second floor.
    3. Reduce use of lights and appliances
      Avoid generating additional heat upstairs. Keep the lights off or dimmed. Limit use of appliances that generate heat — like hair dryers, curling iron, dishwasher, oven and stove. Even if appliances are located on lower floors, the heat will rise.
    4. Change air filters
      It’s a little thing that can make a big difference, because a dirty filter can block the flow of cool air. But as a bonus, air filters can also reduce allergens!
    5. Adjust the fan setting on your thermostat
      Switch it from “auto” to “on”, so the blower fan will run constantly and create a more even mix of air throughout your home. Don’t worry, running the fan doesn’t use a lot of energy. It actually may lower energy usage, because your HVAC system won’t need to cycle as often.
    6. Create climate zones
      The DIY way to do this is to close a few (not all) vents on the first floor. This forces your A/C system to direct more air upstairs. Take this concept to the next level by having an HVAC professional install a climate zone system, like the Trane ComfortLink™ II Zoning System. Trane uses exclusive motorized modulating dampers inside your ductwork to open and close in partial increments. That means heated or cooled air is directed where it’s needed. That’s how these fine-tune zoned areas provide maximum comfort.
    7. Fire up the fans
      Sometimes the old-fashioned way works best. Ceiling and floor fans do a great job of circulating the cold air that may be lingering near the floor. Just remember that fans cool people, not rooms. So if you aren’t going to be in the room for awhile, turn the fan off to limit energy use.
    8. Consider adding an extra HVAC system
      If you’ve tried everything and can’t get your upstairs to cool down, your home may be too large for your current system. Talk to a Trane Comfort Specialist about upgrading to a larger HVAC system or adding a second system upstairs.

One Last Tip

You aren’t alone. Air temp differences between upper and lower floors is a very common problem in the summer. Here’s one final thought to keep in mind — be realistic about the temperature. If it’s 98 degrees outside, your A/C unit may never be able to get you home down to 68 degrees. But you can survive the season by being smart about your summertime thermostat settings and using these tips to keep your upstairs cool.

Worried your air conditioner isn’t working properly? Call your local Trane dealer for a seasonal inspectionThey can also help you decide if climate zones or an additional system could make your home more comfortable.