Why Is This Room Hotter Than That One?

Do you find yourself asking “Why is this room hotter than that one”? You’re not alone. There are many reasons that your air condition system can be inconsistently cooling your house. These are the things you can check for yourself.

• Vents — Closed, or partially closed, vents in rooms will restrict airflow and cause temperature differences in rooms.
• Dirty air filters — Dirty air filters restrict airflow, which doesn’t allow the cold air to fully circulate to all parts of your home. Make sure to change your air filters regularly.
• Windows/Doors — Air conditioning can flow out of open/damaged/or poorly sealed windows and doors. Make sure to close/repair/and properly seal your windows and doors.
• Air ducts — Kinked, crushed, or leaky air ducts, will restrict air flow and or divert your cold air into your non-living spaces, and introduce hot dirty air into your air ducts. Here’s how to tell if your ducts are leaking.

If one of these is not your issue your HVAC system is likely unbalanced. Below are some potential reasons for an unbalanced system, which will likely need to be address by an HVAC professional.

1) You Have a Multi Level Home

It is difficult to properly balance a multi level home, because you have to account for heat rising, and the long duct runs needed to move air into all the rooms. The best solution for this problem would be a multi zoned air conditioning system. Creating multiple zones will break up your home into different areas. Each zone has a thermostat so that you can keep them at the temperatures you want them to be at.

2) Uninsulated, and Long Runs of Ducts

When cold air travels through ducting in unconditioned areas, like your attic, it will gain heat. Therefore, rooms at the end of long runs of ducts and uninsulated ducts means rooms farther away from the AC unit are much warmer. Thus, rooms that are closer to the AC unit will be cooler. A fix for this problem could be as simple as adding additional insulation to your ducts. Or you might need to restructure all your home’s ducting to more evenly distribute the air throughout your home.

3) Inadequate Intake Vents

Many homes only have a single intake vent. Many times that one intake can’t adequately bring in the hot air from the areas that are far away from it, or from rooms with closed doors that don’t have enough space between the door and the floor that prevents adequate air movement. In this case you will have cool air mixing with the warmer air that hasn’t had the chance to be cooled yet. Leaving the doors to your rooms can help with return airflow. If that doesn’t solve your issue, you probably need to add more return ducts to your home.

4) Over or undersized system

If an AC system is too large (oversized) it will shut off too quickly, leaving some of your rooms too warm. An undersized system, too small, may never be able to cool the entire house properly. If you have an oversized system you can try using fans to circulate the cold air to the warmer rooms in your home. If your AC is undersized, you will likely need to add an additional system, or upgrade to a bigger system, if your current system getting to the end of its useful life.

5) Home additions/renovations

A remodel/addition, done by you or a previous homeowner, can be a great way to add or reuse space, but it may have upset the balance of your AC system’s balance. The solution to this could be anywhere from minor adjustments to the dampers in your ducts. They could also mean that you may need to run additional ducts, add insulation, and in the case of a home addition, you may need to add an additional air conditioner.

So if you find your wife asking “Why is this room hotter than that one?”, you know what to look for.