Single Room with AC Heat Issues

[bombermwc]

So i have a normal HVAC guy, but im curious if anyone has had an issue like this and what they may have done.

We have a room that has 3 outside walls. It also has a high arched ceiling. It's the last room on a hall and tends to collect hot air and not cool down. The thermostat happens to be right outside of this room. Mostly its an issue in the summer because when its cooler in the winter, it's much easier to heat it up. It's used as an office so that's why its not much of an issue in the winter. In the summer though, it keeps the house hotter than it should be.

We had a sweating window but we had that repaired and also have UV curtains on the window as well as blinds. When we use the ceiling fan, it just seems to circulate the hot air and not bring in any cool air in.

So i'm wondering if anyone else has had this sort of issue. The room seems too small for a minisplit and so im wondering if there is some sort of even smaller AC option out there. The portables a/c units require the the air exhaust somewhere, but i dont have anywhere to shove the hot air. Possible cut to send it to the attic???? I'd like to be able to set some sort of timer for it to time it with the rest of the house too.

I've attached a couple of pictures (dont laugh at my quick 5 minute MS Paint drawings) to help show the layout.

[mugofbeer]

I'm definitely not an HVAC expert but passing on info from my Denver house. My house was built in about 1982 without AC (you can get away without AC here if you don't mind an occasional hot night). AC was added after the fact so l have 2 bedrooms that don't cool easily. I was told it can't really be fixed without getting in the walls and changing the duct size. So, if you have an older house it could be this. It could also be a matter of adjusting how open or closed other house vents are or the unit you have not being big enough for the unusual room you have the problems with. I have to change mine winter to summer. Good luck!

[bombermwc]

Built in 94 to she vents are in the floor. The main unit was replaced 4 years ago and still puts out plenty cold air. The room just hijacks the rest of the house making us bow to its hot-natured whims...

[kukblue1]

Does it cool down any. Would a smart thermostat with room sensor help any. You can program it so that your office becomes the main temperature and the thermostat will run off what that room is saying?

[mugofbeer]

More insulation for the room?

[FighttheGoodFight]

More insulation for the room?

I was going to say the same thing. More insulation or have a duct test with smoke for leaks?

[Dob Hooligan]

Have you considered a ductless unit? I’m no expert, but basically they use piping to separate the indoor and exterior parts of the unit. So you get the cooling in a smaller space while being quieter.

[bombermwc]

I actually have looked at some small ductless mini-splits. For that size room, they really aren't as bad as i thought they would be. Im always a bit nervous about those though. Every job i've been at that has had one in the server rooms, the pumps fail or something and then they leak all over creation. But since those can also heat in the winter, it really may turn out to be the way to go.

I do need to get over to that part of the attic and check out the insulation. It's the exact opposite corner of the house from my access (and it's stupid hot up there right now) so i haven't been too motivated to check it out. Could be that the blown insulation didn't get in there very well or maybe adding some will help.

With the way the room is shaped, ive always wondered if it's just holding the hot air in that vault and it doesn't have anywhere to go???

And to answer the question, eventually it does cool down (dont ever close the door or it'll be 3 hours before it does). WIth the heat this week, it's taking the house about 5 hours of constant run to get from 77, down to 74.

I'm going to have my AC guy out to give it a check just to make sure nothing else it up too. It didn't take as long when the system was brand new, so maybe it just needs a tune-up. We had new lines run for the coolant when we replaced the unit because the old one kept leaking. With the earthquakes, we did have some cracks we found when we replaced the carpet, so we thought might as well replace the line up into the attic while we're doing this so we aren't re-filling the thing every 6 months like we used to.

[OkiePoke]

If you are interested in a portable a/c unit, I have one I need to get rid of. I bought it for my garage but is undersized. 12,000 btu.

I would assume it is vent sizing and having 3 exterior walls. Assuming those walls are insulated, there is an unknown if that insulation has been damaged or not from water, etc. Blown in insulation may help.

Does the vent seem to be blowing similar to the other vents in the house?

[jn1780]

How about something like this? A electric fan, to help your vent out. https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Maybe your HVAC guy can clean out coils and everything else and it will help airflow out. I'm sure you replace filter regularly.

Blowing hot air into attic I think is a no-no because there is moisture in that air.

[Dob Hooligan]

I have a house with 3 1/2 walls exposed. Sux. I notice nowadays when I am driving in the new and expensive neighborhoods that houses have several electric attic vent fans lined up right at the peak on some of them. Some have 4 side by side. I wonder if venting more heat out of your attic would help? I also understand that too much air movement can be counter-productive.

[rezman]

The vaulted ceiling is likely one factor, in addition to the 3 outside walls. I agree with mugofbeer that balancing your registers would be the easiest and most inexpensive first step. Are the doors to your rooms around the house all kept open? You mentioned a ceiling fan. Have you tried running it in both directions to see if that helps?.