Air Conditioner not cold enough

Aug 13, 2007 12 Replies

Hello,



For some reason this year my air conditioner is not producing enough cold air to cool the upstairs of my house. When I go to the ground floor there is enough cold air coming out, and it's nice and cold, but upstairs, it's too hot. I try to lower the thermostat to 70 degrees, and "cool" air comes out of the vents on the upstairs, but for some reason, the house is not cooling down enough to make the thermostat shut off. What's the most likely culprit?



Thanks Sam



Sam;

What change has occured? If last year it worked well, and this year it's not, perhaps there has been some change. Like a tree being trimmed? Like the air filter is clogged and needs changing? Perhaps a refrigerant leak?

Call you friendly neighborhood HVAC repair person and have them check it out. You'll save in the long run.

Zyp

Clogged filters comes to mind, but there may be other causes. If a filter change does not correct it, call a service tech. There are many other possibilities and they are beyond what the average homeowner can do with simple tools.

Any chance someone changed or closed a vent or blocked a return? Even a clogged filter can cause a problem. In addition have your local temperatures been higher in your area?

I closed the vents downstairs in hopes that the cold air would come up to the upper floors, but this has not helped. There does seem to be some cold air coming from the upstairs, so I'm confused as to why the upper floors are not getting cold enough. Is it possible that the air conditioning unit is not generating enough cold air? It seems cold enough downstairs. How would changing the filters or opening a vent change things. If it's generating enough cold air this should continue until the thermostat shuts it off, right?

Thanks Sam

Do not close any vents.

A clogged air filter reduces the amount of air coming out of your vents.

You might even have some duct work that has come apart.

Call out your HVAC company to have them check your system.

A malfunction with the HVAC system.

I can't tell you for sure what the issue/s are right this minute, as I sent my crystal ball in for calibration last week.

Heat rises. Close off the upstairs by hanging blankets over the stairwell. Sleep on a couch in the family room.

when my upstairs starts getting to hot,it usually means my power attic vent motor is bad. happened twice so far. thought id throw that in.lucas

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Did you check the filters as many recommended? If yes, did it make a difference? If no, do it now and if it does not fix things, call a pro. Could also be a coil freezing up too.

Judging from your comments you don't have enough understanding of how an AC works to do anything more than that so call the service guy. I don't mean that in a nasty way. You may be the best computer programmer or undertaker and nicest guy in the world, but not everyone can fix some things.

You have some things to learn about Air Conditioning Systems.

Air Conditioners don't "generate" cold air. They remove heat from the space being conditioned and transfer it to the outdoors.

In order for the evaporator to absorb the indoor heat, it requires hot air to travel across the fins. So with a dirty filter/coil, closed off registers, inadequate ducting, etc... it's cutting down on the capacity of the overall system.

In order to cool the upstairs, you need adequate ducting to pull the hot air to the evaporator, while discharging conditioned air back into that space.

Airflow is a key to an efficient/balanced running system.

The only way for this system to shut itself down is for the indoor temp to reach the stat's set point. This can only be achieved if the unit is capable of removing more heat from the space then it's gaining.

Try leaving the A/C indoor fan in the on position. If it's on all the time, it lowers the differential between the floors. That's what you need to do when it's really hot like this.

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