Why Do My Air Temperatures Fluctuate Between Rooms?

September 22, 2023

Why Do My Air Temperatures Fluctuate Between Rooms?


There are various reasons why air temperatures fluctuate between rooms. They range from the obvious to more obscure. Simply leaving the door open for even a short period of time will either raise or lower the temperature depending on the conditions outside. While this factor should be fairly obvious, here are some others that may not be so clear or easy to identify:

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Drafty Windows or Doors

If you notice a hot or cold spot in a room, the first place a homeowner should look is to the doors and windows, even if they are closed. The settling of a house or some other physical damage can cause a gap to be created around the perimeter of the fixture. This will make your air temperatures fluctuate.

Even a small gap can allow a significant amount of outside air to infiltrate the living space. This exterior air will accumulate near the afflicted window or door and create a fluctuating air temperature. This problem can also occur around vents and other penetrations in the wall or ceiling of a home. Read 10 Family heating and cooling tips for home comfort.

Degradation of Insulation

Less obvious is heat transference that occurs directly though the walls even though they are not actually penetrated. Insulation between the interior and exterior walls is intended to mitigate this problem to a large extent but insulation does degrade over time, especially if allowed to get wet. Unless the homeowner is unusually skilled, it takes a professional insulation company to diagnose and fix this problem.  

Blocked Interior Vents

The improper placement of furniture can significantly block the air flow of wall events and create a temperature fluctuation nearby. It will significantly block the air flow and create the difference in your home's climate. It is essential to keep these areas free and clear so that the conditioned or heated air can flow into the entire space. If the flow is too much, use the baffles on the interior of the vent to lower the flow. This problem is even more pronounced if the homeowner places a rug over a floor vent.

Faulty Dampeners

All modern zoned HVAC systems control air flow through the use of dampeners insider the ductwork. Balancing is the process of adjusting dampers and valves so that the rooms heat and cool evenly.

An unbalanced room will blow too much cold (or hot) air into one room and not enough in another.These devices control the flow of air to the living spaces. They are intended to keep every space at the desired temperature as controlled by a series of thermostats. Sometimes, however, the dampener can become stuck in either the open or closed position or otherwise not work properly. In this case, the system is unable to moderate itself and the temperatures will fluctuate.

Non-Functioning Chimney Flue

Probably one of the most misunderstood problems when it comes to fluctuating temperatures is the chimney and its flue. This device is designed to eliminate exterior airflow into the space when the chimney is not in use. Many homeowners forget to close the flue after extinguishing the fire and the result is cold air entering the room.


As you can see, identifying the real reason for a temperature fluctuation from room to room in a home can be fairly easy or extremely complicated. Obviously, the homeowner should start by investigating the simplest causes and then call in a professional if unable to resolve the issue.

A good HVAC professional will be worth talking to in order to tune your system and get your air temperatures to stop fluctuating between rooms.

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