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Why Is My Room So Hot? Here’s How to Fix It

It can be really annoying if a room you spend a lot of time in is constantly hotter than the rest of your house. There can be different reasons why your room is so hot. But it’s often because your AC can’t replace the warm air in the room with enough cold air.

In this article, we’ll outline some of the main reasons why this can occur and provide solutions to those problems. So keep reading to learn more.

If your room is so hot, check if you have one of these most common problems:

Closed or blocked supply vents

Supply vents are what your HVAC system uses to dispense cold air into a room. When these are closed or blocked, the system won’t be as efficient at cooling down that part of your home.

That’s why a good first step is to make sure that you don’t have any closed or blocked supply vents. Make sure no furniture is in the way of these. And look to see if you’ve closed any damper controls on individual supply lines that go to the room in question.

An HVAC damper

If you’re not familiar, damper controls are tiny levers that are usually found inside each pipe. These should be fully open in the room that’s been too hot. If they’re not, try opening them up before doing anything else.

Blocked return vents

It’s also possible that return vents are the reason why your room is so hot. These pull air into your HVAC system so that it has enough air inside of it to cool down and then disperse.

If too many of your return vents are blocked, the system won’t be as efficient as possible. And that can lead to one of your rooms being too hot.

So make sure that return vents in the room and throughout your home are open and unblocked.

Dirty or clogged air filter

Your air conditioner’s filter can have a huge impact on its efficiency. When it becomes clogged or gets very dirty, it can impact airflow and reduce the cooling impact of your system.

So if you haven’t changed your air filter in some time, be sure to check it and potentially swap it out for a new one.

Issues with fan and blower

Sometimes problems with your fan and blower can be the reason why your room is so hot. If either of these isn’t working properly, you usually won’t get enough airflow coming over the evaporator coil. The efficiency of your system will suffer because of it.

Dirty evaporator coil

Your evaporator coil also needs to be clean to give you the best cooling results. When this gets too much dirt on it, you lose airflow and could end up with a hotter room.

Open windows

Opening up your windows while running your AC is rarely a good idea. Not only is it a waste of energy, but it will also keep a room from cooling down as much as you want it to.

When you have warm air outside, the cool air in your home will rush out the window quickly due to the nature of pressure. The bottom line is that your home will likely get consistently warmer the longer you leave the window open.

Faulty thermostat

Your warm room may also be indicative of a problem with your thermostat. When this part isn’t calibrated correctly or malfunctions, it can impact HVAC airflow in many different ways.

  • The first step to solving this problem is to look at your batteries. Make sure those are working fine before continuing.
  • Then, open up the cover and use a soft brush to remove any dust or debris that you see inside the thermostat. You can also look for any bent elements that may be causing the problem.
  • You may also want to check to see if your thermostat is properly calibrated. You can do this by taking a simple glass thermostat and placing it next to the one that controls your HVAC. They should show the same temperature after about 15 minutes. If they’re off by more than one degree, it’s likely a calibration issue that you’re experiencing.

You’ve got a lot of electronics running

Another thing to keep in mind is that modern gadgets generate heat. This includes things like:

  • Televisions
  • Computers—especially ones with high-end graphics cards
  • LED clocks
  • Lights and lamps

If you’ve got a ton of these running the room that’s too hot, that could be your issue as well.

Air duct trouble

It’s also very possible that your air ducts are the cause of this issue. If they’re not aligned properly, not sealed well, poorly insulated, or dirty, it can lead to uneven temperatures throughout your home.

The solution to this problem can be complicated or simple. So it’s best to call out a professional HVAC tech to come to evaluate your situation.

Why is my room so hot compared to the rest of the house?

The problems we’ve already covered are the most likely reason why your room is so hot. But if none of them solve your issue, then you likely have an unbalanced HVAC system.

This can happen for each of the reasons covered below.

Your AC system is too large

Your AC system needs to be the right size for your home. Bigger is not always better. Because when an air conditioner has too much power, it cools your home too fast.

Basically, you get fast cooling cycles that don’t leave enough time for the AC to remove humidity from your home. So your home will often feel a lot hotter than it really is. And some rooms could be impacted more by this issue than others.

If you think you have this problem, bringing a dehumidifier into your home may be enough to solve the situation—especially if it’s limited to just one room.

But it may be a more cost-effective decision, in the long run, to just swap your old AC unit for a newer one that’s properly sized for your home.

You’ve got poor insulation

It’s also a real possibility that insulation is the culprit behind your hot room. Poor insulation lets the heat sink into your home faster. So even if your AC works perfectly, any rooms with bad insulation are going to get hot.

Older windows can have a similar impact on your home’s temperatures. You may want to upgrade to double-pane windows with special types of glass so that less heat gets into your home from them.

It may also be possible to fix the problem by adding a tint to your windows or placing some heavy blinds over them during the day.

Your home’s layout isn’t optimized

Your weirdly warm room could also be the result of a poor home layout. For example, it can be harder to keep a room cool when it’s got a lot of windows in it. There are also often temperature disparities in multi-story homes.

If you think the problem is tied to your windows, then you may be able to plant trees outside of those windows to prevent as much sunlight from coming in.

The room is an addition to your original home

Another question to ask yourself is whether the room that’s too hot is an original part of your house or an addition to it. Because your original HVAC unit may not have been designed to accommodate the addition.

So if your hot room is an addition, then your solution may be to install ductwork that carries cool air to that room more efficiently. You may even need to upgrade your HVAC system to give it more power so that it can cool another room.

It’s also worth mentioning that smaller purchases like a window AC unit or a box fan can do a lot of cooling. So investing in one of these may be a good decision if you’re not ready for a more expensive upgrade just yet.

You’ve got a multi-story home

Finally, it’s also possible that your problem is stemming from the fact that you live in a multi-story home. The top story in these homes is generally hotter during the summer and cooler in the winter.

There are two main reasons for this:

  1. The thermostat is usually on the first floor, which means it may not register just how hot it is on the top story.
  2. Your top floor has more direct contact with the outdoor temperatures.

One way to solve this problem is to keep your AC fan running all day, even when the cooling feature isn’t active. This will ensure that air is flowing throughout your home constantly and may reduce any temperature discrepancies.

That being said, if you want a lasting solution, then upgrading to a zoned AC system will likely be your best choice.

These let you control the temperatures in each different part of your home. So you can be more precise about the temperature you keep your upper level at. A zoned system is a relatively expensive upgrade, but you should get a lot of value out of it.

Have a proper load calculation test performed

The word ‘load’ refers to the amount of heating and cooling required to heat or cool a living area. This is measured with the use of proper load calculation tests.

These tests take several things into account, like the size of your living area, the height of the ceiling, your windows and the different kinds of appliances you have hooked up.

The problem is that several contractors choose heating and cooling units for their clients without doing the proper load calculation tests.

Proper load calculation tests are important in making sure that you install the right sized HVAC system into your home. An HVAC system that’s too small for a home won’t be able to properly heat the entire living space, and it won’t be able to cycle it properly.

In addition to this, different rooms have different load sizes. For instance, rooms with tall ceilings, rooms that are built over a garage and rooms that have windows that face either east or west are all prone to have much higher heat loads than the rest of the house.

Why is this? All of these rooms allow heat to travel up through the floor or have three sides that face the outside. In many situations, it’s a combination of both. As a result, these rooms will heat up a lot faster. So, what’s the solution?

An experienced professional will be able to perform the proper load calculation tests and recommend the right system for your home.

Michael Joseph