I have a room in my house that I spend a lot of time in. It is consistently uncomfortably hot in the summertime. A thermometer on my desk will read 80 degrees or more in the summertime. I was told that the HVAC likely isn't pushing enough air into the room. I was told that I could pay thousands of dollars for a "mini-split" that would push more cold air into the room. As an alternative, I purchased an evap cooler which works well enough, but at the price of frequently refilling it and keeping the door and window open, which compromises my privacy and comfort.

Now that the mercury is dropping, the evap cooler is in the closet, and it is still uncomfortably warm in this room. The other day, I was on the phone and I noticed my forehead was sweating and the reading on the thermometer was 82. This seems to mean that the same HVAC that was pushing "not enough cool air" into this room is now pushing "too much warm air" into this room. I'm paying money for my HVAC and alternating between sweating my brains out and leaving the window hanging open so that I have to listen to every barking dog in the neighborhood.

All adjoining rooms in the house are a comfortable temperature all year round.

I suspect that if I had purchased that "mini-split" to get more cool air in here, I'd still be unhappy that this room is so hot in the winter time.

What kind of problem am I likely having that a room in my house is uncomfortably warm in both hot and cold weather while the adjoining rooms are all comfortable?

Here is some more information requested:

In answer to some questions that have been brought up, the room only has a single south-east facing window. It is an ordinary room surrounded by ordinary drywall, like all the rooms with south-east facing windows that are comfortable all year long. The room is directly above a kitchen that I have never had an HVAC problem with. The ducts run between the two floors, so it is impossible to take a look at it without tearing holes in the ceiling below.

There is a single compressor that cooler the whole house in summer. There is a single furnace that cools the wholse house in winter.

There is a single vent blowing air into the room. We had an HVAC duct cleaning company in the house a while back. The guy who recommended the mini-split said that duct cleaning companies can be good at finding if there may be a break in the system that causes air to escape.

I want to emphasize that I am not an HVAC expert. I am handy enough to tackle something from time to time when I have the time and motivation for it, such as when I replaced the blower motor several years ago to avoid paying an inflated price to have a contractor do it. I don't know all the lingo, but I will do my best to answer questions to help solve my problem.

  • 1
    Where in your house is this room? Does it have lots of south-facing windows? Commented Dec 1, 2020 at 1:03
  • 1
    Is the room an addition or a type of sun room or enclosed porch?
    – JACK
    Commented Dec 1, 2020 at 1:05
  • 1
    How does air get out of the room? Is there a return vent in the room? If not, do you normally keep the door open or closed?
    – Mark
    Commented Dec 1, 2020 at 1:51
  • There is a return vent, @Mark. Leaving the door open helps with air flow, but no other room requires the door to be continuously open to be comfortable. This room is my work room and I need my privacy and quiet space. We have a child in the house. Commented Dec 1, 2020 at 2:06
  • 4
    Is this room filled with heat producing electronics?
    – Kris
    Commented Dec 1, 2020 at 2:39

2 Answers 2


There are 3 things to confirm about your room: 1) excess heat gain from external or internal sources. 2) inadequate air flows (cfm) into and out of the room. 3) actual air and surface temperatures. An IR temperature sensing gun will locate any hot spots on wall, ceiling or floor. Do temperature checks before the room heats up fully, then do it hourly to find hot spots. For airflow checks, tape a garbage bag to a coat hanger hoop like a butterfly net. Count the seconds to inflate or deflate, then do the math to calculate cfm. You can use the hoop to compare airflows in nearby room also.

  • Thanks for this answer with all-around helpful information! As best I can tell, it turns out that my gaming PC is actually the culprit. I've had computers in my home continuously since I was 10 years old, but newer computers with fancy CPUs and GPUs apparently consume a lot of power, plus I've been running Folding@Home overnight, and that makes the cooling fan on my 2070 GPU spin at full blast. It just hit me the other day when I plugged in a thumb drive that it may as well be a space heater sitting on my desk. I shut it off for a few hours and the problem went away. Commented Dec 2, 2020 at 18:17
  • One more tip for any room where you prefer to keep the door closed and where there is no return vent. Cut 1 inch off the bottom of the door. It will give you a 30 square inch opening.
    – John Canon
    Commented Dec 3, 2020 at 5:40

With the info you have provided we really can’t help you, there are mini splits out there you can install for ~1500$ I would want see how your system is set up because your hvac guy sounds like he knows less than my neighbor and I helped him put in a mini split. Unless you can provide some specifics I vote to close.

  • What kind of information would you like me to provide that would help you answer my question? I told you that the room is uncomfortably warm in both hot and cold weather, the the HVAC guy said it sounded like "not enough air" back in the summertime, that the adjoining rooms are all a comfortable temperature. Commented Dec 1, 2020 at 0:49
  • What kind of hvac? Is there a separate furnace? How do the trunk lines attach? Any pictures as they leave the unit, is this room duct an afterthought or a separate duct cut into the air handler I could keep on going but a room that is hot all the time could be sitting over a boiler we don’t know. Anything about your system.
    – Ed Beal
    Commented Dec 1, 2020 at 1:06
  • I have added information to answer questions to hopefully help you and others help solve my problem. Commented Dec 1, 2020 at 1:36
  • Have you tried partially closing off other vent/registers in the house to direct more air to your work space? Commented Dec 1, 2020 at 8:45

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