Any help/advice would be greatly appreciated

SunStarsMoonJune 1, 2011

Hi everyone. I came across this forum via Google search and I am hoping someone may be able to offer us some advice on an ongoing problem we have had with our AC. I apologize in advance for the length of this post, however, I feel it is important to provide all of the information.

My husband and I moved in to a brand new home November of 2005. It is a split level house, however, there is not heat or air on the bottom level (much of that is an unfinished basement and bedroom) We noticed that first summer (2006) that our AC was not properly cooling one side of our house off. With the thermostat set on 75 it gets up to 83-85 degrees in the heat of the summer in our family room and even hotter (up to 90 degrees!) in our master bedroom while the other side of our house is freezing cold.

The side of our house that cools off has standard size ceilings. There is a hallway that leads to our family room and once you exit that hallway we have very high ceilings on the other side of the house- this is the side that does not cool. You can literally feel the heat walking from the hallway to the next room where the ceilings are high.

The first summer we were in our home we called our builder to complain. Unfortunately he had filed for bankruptcy and was not much help. He instructed us to call the heating and air company that installed the unit- we did and we were told they no longer serviced our area. We explained the problem to them and their response was, "It's extremely hot outside and you cannot expect your house to cool down to 75 degrees when it is 100 degrees outside."

After that response we knew we weren't going to get anywhere with them so we called a local company to come take a look and see if they could tell us what the problem was. The company that came out said that our unit itself was working fine but there seemed to be a problem with the duct work. We were told this was a builders flaw and that there was very little - no airflow on the hot side of our house. We were told by this company to contact our builder. So once again we did but got nowhere due to the fact that he was no longer building and had filed for bankruptcy.

Since that time we have had several different companies come out to our house and give us their opinion as to what the problem is. Just about every company has said there is a problem with the duct work, we have had several companies tell us our unit is too small for the size of our house, we've been told the air distribution needs to be fixed, we have been told we do not have enough vents on the side of our house that is hot and has the high ceilings, we have been told we need an extra return vent on that side of the house, etc. (We have one return vent in our house and that is located on the side of the house that cools off with the low ceilings).

We have a 3 ton unit (as do all of the other houses on our street) Even the small ranches have 3 ton units. There are several houses on our street with floor plans such as ours, however, we are the only house with high ceilings. Everyone else has standard ceilings. We have spoke to each of our neighbors and no one has the problem we do with their AC. I'm not sure if this matters much but we have 14 vents and we were told that a maximum capacity a 3 ton unit should only be putting out to 12 vents.

On top of all of that we have had to paid more than $1000 for repairs on the unit due to the fact that it runs constantly in the summer- we've had to have a coil replaced, we've have the compacitor replaced, and we were told last summer when the compacitor was replaced that they feared our compressor was on it's way out. This is all on a unit that was brand new when we moved in to our house in November of 2005.

To cut a long story short, we have suffered through the last few summers having to put a window unit in our master bedroom and paid $400+ electric bills in the hottest months of the summer just to cool the house down to 80. Our unit runs constantly and it'll be 70 something degrees outside at night or early in the morning and still 80+ on the hot side of our house. We have gone back and forth with the original company who installed our AC for the last 5 years now and after threatening to contact the Better Business Bureau they finally agreed to come out to our house two months ago to take a look at things.

They did a few things which they claimed would help but it didn't They said some of the ductwork had come unhooked and they added something called a "scoop" that was supposed to push more air to the opposite side of the house. When they came out it was 75 degrees outside and we never have a problem with the AC until it gets in the lower 80's and above. So now that it's summertime we're having the same problem we've always had. After going back and forth with the company for several weeks now they have agreed again to come back out.

My question is do you all think this is only a problem with the duct work? Does it sound like the air distribution needs to be balanced? Do you think we need a larger unit? Or does it sound like it may be all of the above? I think this company is going to try to get by doing the very minimum. It doesn't matter to me what the problem is, I just want it fixed.

Thank you in advance!

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First of all, I am so sorry you have had these ongoing problems.

I believe you may have several factors all interacting to cause the situation. Here is some background info for your general knowledge.

Your home's system was likely designed for the a sample home in your subdivision. With a particular floor plan, number of windows, room sizes, and facing a certain direction (north, east, etc.) Then as options are added like a vaulted ceilings (which increase the cubic feet of air that must be conditioned, possibly changes positions of ductwork, and may also mean that the attic insulation changed from the sample home) it may be that the heating and cooling system was not re-calculated for these changes. Even if you have more windows facing east or west vs. north and south can make a difference in the cooling load of a home. Skylights, insulation, what type of glass all make a difference.

This is a pretty common problem.

So what I am saying, is that unless you have another home in your subdivision by the same builder, with the same floor plan and options AND facing the same direction, then you may not have any examples to compare to your home. IF you can find such a house, I suggest finding out if they have had problems like yours, and what they have done to solve them.

So, how to fix your house.

I recommend calling 1 or 2 heating and cooling distributors in your area, and asking them to recommend a dealer to use to do a load calculation and ductwork analysis on your home. Or call 3-5 residential heating and cooling dealers in your town and ask the same thing. Say that you are not in a big hurry, and that you want to work with the person there that has the best experience and expertise.

I suspect that you may find that your ductwork is too small in size. I also suspect you may find that the size of your system is too small as well.
If this is the case, there are different options on how to best fix this problem.

But I cannot stress this enough--in our ductwork training we learn that "you cannot power your way out of too-small ductwork" Think of air like a liquid. If you need to move more air, you need to address the ductwork capacity. If it is too restrictive, it can't fit any more air in it to move through it.

Also, is your too-warm space next to the garage or basement that is not being conditioned? This may also be a factor when comparing your home to others in your neighborhood.

I wish I had better news, but I think you have a pretty complex situation, and need to find someone who will help you.

    Bookmark   June 1, 2011 at 7:52PM
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Very hard to answer. Of course you have a duct work problem and only after that is addressed can you tell if you have a size problem.

You may have a size problem if you have more East or West windows than your neighbors or if you have more windows in the areas with higher ceilings. You can most likely muscle through the size issue with better air sealing and window treatments if other similar houses are fine.

Just for info - what is your sq footage, location and foundation type? Where is your air handler and ductwork (ie attic?). Do you have access to dampers? Is your air handler on the cool side of the house?

There is no fixed number of vents per ton but 14 is a lot for 3 tons. But the size of vents matters as does the size of the ductwork. There definitely is not enough air for the size of your house and I bet it is because of leakage. Do the other houses of same floorplan have the same number of vents? If they have airflow better than yours, then you have your answer.

    Bookmark   June 1, 2011 at 8:01PM
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Thanks so much for the replies. I appreciate it more than you know.

There are several houses on our street which have the same floor plan (split level with the same amount of beds, baths, etc.), however, we are the only house that has the high ceilings. And when I say they are high, I mean they come up on either side and then meet at a point in the middle (hope that makes sense).

It's funny you mention the load calculation because the original company that installed everything told us they performed one of those (that it was required) before our house sold, however, we never received paper work on it and they seem to have "lost" their copy. We had a company that we were going to have perform the calculation but they said it would be at least $250 and at that time we could not afford to have it done.

The side of our house that is not cooling sits over an unfinished basement. The basement stays very cool though. It's cooler than our family room and master bedroom :-/ Our family room (which is also hot) sits over our garage.

Our house is close to 1600 square feet but this includes an unfinished basement as well as small bedroom downstairs that do not have heat or air. The hallway downstairs does have a vent for heat/air though. We are on a slab foundation and live in Georgia. Everything is up in the attic and the unit is on the side of the house that cools off fine. The only return vent we have is also located on this side. I am assuming the other houses have the same amount of vents. The only difference is that they have standard ceilings and we have very high ceilings. Our house also gets full sun pretty much all day long.

    Bookmark   June 1, 2011 at 8:52PM
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