Room won't cool

[bplocke]

Hello, I have a central a/c that is working fine except that the master bedroom stays very hot. I've had two different companies look at it and so far one said that they could not do anything and the other installed a scoop in the plentum to direct more air down that duct. All of the other rooms have great airflow, but the scoop didn't help much. I really don't know what else to do. Does anyone have any advice? Thanks!

[paul52446m]

Hello, I have a central a/c that is working fine except that the master bedroom stays very hot. I've had two different companies look at it and so far one said that they could not do anything and the other installed a scoop in the plentum to direct more air down that duct. All of the other rooms have great airflow, but the scoop didn't help much. I really don't know what else to do. Does anyone have any advice? Thanks!

This run going to this bedroom either is a much longer run, a lot more ell, or restrictions of some kind
or your blower is not pressurizing the ducts enough to get the proper flow of air. Can't answer this question with out a lot more info. Later Paul

[manhattan42]

Room

Where is the room located?

Is it over an uninsulated garage?

Next to a walk-in attic?

How old is the house, where are you located, and what insulation levels are present in the structure?

[bplocke]

The house is single story in Arizona and is about 6 years old. It should be well insulated - it is an energy star home. The master is at the end of the run. I've tried closing off the other two vents on the same run but it does not direct any more air into the room. When the scoop was installed, I was told that if it didn't work that the only other thing he could do would be install a fan in the run that would force more air that way.

[paul52446m]

The house is single story in Arizona and is about 6 years old. It should be well insulated - it is an energy star home. The master is at the end of the run. I've tried closing off the other two vents on the same run but it does not direct any more air into the room. When the scoop was installed, I was told that if it didn't work that the only other thing he could do would be install a fan in the run that would force more air that way.

Do you have rectangular ducts coming off your plenum? How many ducts do you have coming off the plenum, and what size are they? How large is the duct going to that end of the house where the bedroom is at. Does it run straight?
How large is the pipe running off the main line, and how many ell does it have.
What size is the bedroom, and what size are the windows in this room? Is there
just one opening in this room? Is there a return air in this room? Is this return air
at the floor line or in the ceiling, or hi in sidewall? Is your blower running on hi
speed. later Paul

[bplocke]

Do you have rectangular ducts coming off your plenum? How many ducts do you have coming off the plenum, and what size are they? How large is the duct going to that end of the house where the bedroom is at. Does it run straight?
How large is the pipe running off the main line, and how many ell does it have.
What size is the bedroom, and what size are the windows in this room? Is there
just one opening in this room? Is there a return air in this room? Is this return air
at the floor line or in the ceiling, or hi in sidewall? Is your blower running on hi
speed. later Paul

Thanks for the help Paul - I only have some of the answers to your questions. I hope they help... The ducts are circular and there are three of them coming off of the plenum. Sorry - I don't know the size but I was told that the run to the master is coming off of the top of the plenum. The duct seems to be run like the letter V with the master at the end of it. It can't be straightened out unless a hole was cut into a wall in the attic that seperates the attic of the master with the rest of the house. There is a return high up by the ceiling in small room (the enterance to the master bedroom). The blower is running on high. I don't know if that is enough info for you to help, but I appreciate your efforts!

[paul52446m]

Thanks for the help Paul - I only have some of the answers to your questions. I hope they help... The ducts are circular and there are three of them coming off of the plenum. Sorry - I don't know the size but I was told that the run to the master is coming off of the top of the plenum. The duct seems to be run like the letter V with the master at the end of it. It can't be straightened out unless a hole was cut into a wall in the attic that seperates the attic of the master with the rest of the house. There is a return high up by the ceiling in small room (the enterance to the master bedroom). The blower is running on high. I don't know if that is enough info for you to help, but I appreciate your efforts!

let me give you and idea of how we engineer a house job. first i take a heat loss
or heat gain of each room in the house. This tells me how much heat and cooling is needed. Next i find out how much cubic foot of air there is in this house. The blower in a heating or cooling unit, to treat the air in the house, should move all the air in the house through the heating or cooling unit 5 times per hour, Now i select a unit with the proper blower. From my heat loss and heat gain chart i can figure out how much air i need to put in each room.
Now with all this info i can size the ducts to do the right job. So as you can see, with out a lot of pictures and all of your info, its hard to help you.
If i could see it and check it out, i could tell you whats wrong. Later Paul

[Home]

I recently ran into the same problem. I had to remove the insulation to rework a DIYS mess from the previous owner. I found that some of the pipes were leaking air pretty bad. One line had 2 5' sections that had the seams come loose the whole length.

Not only was the air escaping when it was running but, it also drew in hot air from our 140 degree attic when it was shut down.

Now that I have reworked the air ducts, we are able to cool a 1940 sq ft home in Oklahoma with a 2 ton air conditioner.