If your home has a central air conditioning system, you expect it to cool every room evenly. However, homeowners often find that their home’s second floor stays consistently warmer than the first floor. Some of that is due to heat’s natural tendency to rise. However, a variety of other factors can contribute to the problem. Here’s a complete explanation of why your home’s second floor is so much warmer than its first.
How Your AC Circulates Conditioned Air Throughout Your Home
Your central AC relies on a network of ducts to move air around your home. A typical residential ductwork layout includes one or more supply air vents in each room. And it should have a large, central return air intake. When your AC runs, it draws air into its air intake, pulling it in from around your home. That air passes through your cooling system’s indoor unit, where it extracts heat. The now-cooled air then returns to your home via the supply air vents.
Why Upstairs Rooms Are Often Hotter
There are a few main reasons why your upstairs rooms stay hotter than those downstairs. One is that a hot attic can increase the heat load in those rooms. In the summer, attic temperatures can reach 160°F on the hottest days. That heat often bleeds into upstairs rooms. In theory, your attic insulation should prevent any significant heat transfer. However, even a well-insulated attic allows some heat to escape into living spaces.
Another common reason for upstairs rooms to remain hotter is your home’s thermostat placement. In most homes with single-zone AC systems, you’ll find the thermostat somewhere near the middle of the first floor. Conditions there almost certainly don’t reflect conditions upstairs. As a result, your AC will always turn off when the downstairs reaches your desired temperature. Unfortunately, that almost guarantees that your upstairs rooms will remain warmer than you want them.
Finally, airflow problems can leave your home’s upstairs rooms feeling too warm. Your ductwork design should account for the higher airflow needed to cool second-floor spaces. However, as your home’s ductwork ages, it can develop leaks that reduce the amount of air reaching those spaces. Eventually, the losses can grow severe enough to produce a noticeable temperature differential between floors.
When to Be Concerned About Uneven Cooling
In general, you should expect a well-designed central AC system to keep your home’s floors within 3°F of one another. So, if your upstairs rooms are only a few degrees warmer, that’s not necessarily cause for concern. However, if the temperature gap widens beyond that, it’s a good idea to have your ductwork and AC inspected.
You should also be wary of large temperature differences between second-floor rooms. That can indicate damage to a ductwork branch, such as a disconnected joint or a blockage. When your AC works as intended, it should keep all your upstairs spaces within the same temperature range. However, this assumes that your home has well-designed ductwork and a properly sized AC.
Tips for Evenly Cooling Your Home
If your upstairs rooms remain too hot for comfort, there are some things you can do about it. The following are some tips to help you solve the problem.
Best Thermostat Settings for a Hot Second Floor
Making some changes to your thermostat settings can help keep your home’s second floor comfortable. The first thing to do is make a habit of setting your thermostat 2 to 3 degrees lower than you want the upstairs temperature to be. That will help ensure your AC continues running long enough to cool your home’s second floor.
Also, avoid setting your AC’s fan mode to On instead of Auto. The Auto setting ensures that your AC’s blower fan will turn on only when it’s cooling. Otherwise, the fan will run full-time, which may push even more warm air into upstairs rooms.
Consider upgrading to a smart thermostat. Some models allow for the use of remote temperature sensors. You could use one to let your thermostat track the upstairs temperature along with the downstairs temperature. In some cases, you can set sensor priorities to alter your thermostat settings based on the time of day. For example, you could prioritize the sensor in your upstairs bedroom for overnight use. That way, the room you sleep in will remain comfortable while you’re in it.
Adjusting Your Dampers
If thermostat settings alone don’t help, you may need your home’s ductwork dampers adjusted. Dampers are adjustable doors that control airflow to the branches of your home’s ductwork system. Their purpose is to allow HVAC technicians to fine-tune how much air passes into each part of your home. Incorrect damper settings can lead to uneven temperatures, especially between floors.
An HVAC professional can check your home’s ductwork dampers and make adjustments when necessary. To do this, they’ll check your AC’s total airflow and calculate how much airflow each branch should receive. Then, they’ll measure actual air output from the vents around your home. If your upstairs vents aren’t getting enough airflow, they’ll adjust the dampers to compensate. For example, they may reduce airflow to the downstairs rooms to force additional airflow upstairs. That should help close the temperature gap between the two floors.
Can Mini-Splits Help Cool My Second Floor?
If your hot upstairs rooms are a result of undersized ductwork, solving the problem can be costly. After all, tearing open finished walls to replace ducts isn’t a simple proposition. Fortunately, there’s another option: installing a ductless mini-split. This is a type of AC that can efficiently cool one or more rooms in your home, independently of your existing AC. And a single mini-split can cool up to eight separate rooms. That makes it a perfect solution for warm upstairs rooms.
Mini-splits rely on an outdoor unit and individual wall-mounted air handlers in the rooms you need cooled. Importantly, each air handler has its own thermostat and temperature controls. That means you can use air handlers in upstairs rooms to produce the exact amount of additional cooling you need. And installing a mini-split to augment cooling in a few rooms can be cheaper than replacing your ductwork. It also gives you added flexibility, since you can turn off mini-split air handlers in rooms you’re not using.
Contact Farnen & Dermer Today for Cooling Services in Baltimore County
If your home’s upstairs rooms never quite cool down in the summer, Farnen & Dermer can help. We’re a fifth-generation HVAC company that’s served Baltimore County and its surroundings since 1902. We offer a wide range of HVAC services to ensure your comfort. For starters, we provide annual maintenance to keep your AC working optimally. We also install and replace thermostats, which is often necessary to rectify uneven cooling. We also install and service ductless mini-split ACs if you need a secondary cooling solution. We can offer you financing on approved credit to make it affordable.
Contact our team at Farnen & Dermer today to solve your home’s uneven cooling problems.
