Brand new home cannot cool correctly

[muk33]

Some one please help!! ok here it goes....
I closed on my brand new two story home 2 weeks ago. its 2200 sq ft. with a 1 AC unit with a 10 seer rating and a 2 damper system. i have 1 thermostat upstairs and 1 downstairs. I questioned the builder before the install and asked if i was going to have 2 AC units. He said no, this 2 damper system is great and will cool your home fine. I stupidly agreed and now i am hot. I had the HVAC people come out twice that installed it and they said its working fine.
Before my wife and i moved in we came in on a saturday to paint a room in the downstairs area. it was 76 degrees in the home. i set the AC on 72. When we left 7 hours later, with the AC running the whole time we were there it was 77 when we left. That doesnt seem right to me??? This is my first two story home so i dont know how this damper thing works. Does that sound right to you? It has been mid 90's to 100 here in SC lately. Maybe thats got something to do with it?
Last night at 9:30pm my upstairs thermostat read 80 degrees?!? it was set at 72. i cannot sleep in that kind of heat. when i woke up today i looked at it and it did get to 72 but it probably ran all night long. My first power bill will probably be really high. The new electric company will love me i bet.
One more thing...
Before i closed the building contractor had some ladies in the home cleaning it up before i did my walk thru. he said he came in the home one a.m. and it was freezing in the house. he said the thermostats were set to 58 degrees. He said the cleaning ladies must have set it low to cool off while they were cleaning and didnt set it back up. He said it must have been running for two days straight to get that cool. Would this have messed up my unit-system in anyway? I myself had never seen the thermostat get below 72. i dont believe it can get down to 58.
What should i do? I plan on writing a letter to the companies manager/president that built my home and tell them the whole story. Would a bigger AC unit with better seer help me? I feel i was mis-lead by my builder. Need some direction on what action to do next.

Thanks for your help.

~MIKE

[pecmsg]

Mike

First click on the bull’s eye on top and do your own heat load calc. Then we need the make and model # of your equipment.

As far as Zoning is concerned, it has been around for many years and works fine if installed properly, That also goes for the entire system.

I would have a factory rep come out to double check the instillation. You will have to pay for this service but it is well worth it.

If any monies were held in escrow at the closing then have your attorney contact the builder and express your concern. Don’t release these funds until you are satisfied.

Congrats on your new house and good luck

Paul

[Panama]

Probably another improperly charged builder-grade system without a TXV or with low air flow.

Mike,

What happens to the relative humidity in the house when the system runs for several hours? RH can be a pretty good indicator of air flow problems.

[htrguy]

In my experience the upstairs carries the full heat load of the house during summer. To compensate, the zoning system ductwork is critical and needs to be able to handle the shifting loads between summer and winter I.E. the ductwork should be sized to handle 80-100% of full system capacity in each zone. I've seen more than a few duct layouts that were sized too small and the ducts restricted the CFM in the higher demand zone (mainly upstairs in summer). The layout seemed to be balanced in the CFM per room under design conditions but upstairs carries a much greater load from all the downstairs plus the attic in summer.
This is stating the obvious but two story houses in high heat/humidity areas are tricky when you try to install price competitive systems.

[muk33]

what is TXV?

[fat bob]

I had an inspection after I closed on my new house (my mistake) and he said the units were undersized and weren't working properly. The builder's response was that right before we moved in the cleaning crew was there and it was freezing. In hindsight that was total baloney. However, he did say that getting window treatments up would help and he was right. Do you have all your curtains/blinds up? Also, it would help if you go look at the model # on the outside unit and tell us what it is. That would give the pros here some clue of what you have.

[Panama]

Originally posted by muk33
what is TXV?

A thermostatic expansion valve. A TXV adjusts the flow of refrigerant according to the cooling load. They also compensate pretty well for charging errors. Without a TXV small charging errors can reduce cooling capacity significantly. They add a couple hundred bucks to the cost of a system, and so builders don't like to pay for them.

[muk33]

Here is the info for my ac unit:

BRAND: Goodman
Model#: CKL42-1L
SER #: 0411487628
AC VOLTS: 208/230
VOLTAGE RANGE: MIN 197 MAX 253

i hope that help answer some of my questions

thanks again
MIKE

[fat bob]

It could be a lot of things. Looks like you have a 3.5 ton, which might be sized correctly. Maybe a problem with ducts, dampers, AC installation and settings, attic ventilation, etc. But 80 upstairs at 9:30 p.m. is unacceptable and the builder knows that.

[dash]

Check the attic to be sure it's fully insulated,I've seen areas without insulation,in new homes.

[Mr Bill]

Originally posted by muk33
Some one please help!! ok here it goes....
I closed on my brand new two story home 2 weeks ago.
~MIKE

SER #: 0411487628 Two weeks ago with that Ser. #?

[Panama]

Now there's a builder who really knows how to save money!

[muk33]

mr. bill pro...whats that mean about my ser # and only 2 weeks???? Is that an older unit or something?

thanks
MIKE

[pecmsg]

Mike
I am not a Goodman dealer but if I read that Sr# correctly 0411 was manufactured November 2004. If I am wrong the others will correct me.

Not to throw a monkey wrench into the gears but did the builder offer you a higher SEER unit. In your area and with 10 Seer on its way out I would have thought so???

Paul

[muk33]

Thanks Paul
My builder never offered me a SEER upgrade. if so i probably would have takin advantage of it. I heard for my area starting in 2006 in new construction homes a 10 SEER will no longer be used. 13 SEER will be lowest.

[pecmsg]

It’s not just your area and not just new construction. As of January 2006 manufactures cannot produce 10-SEER equipment. With that being said get the extended warranty for your unit.
I still recommend getting a second opinion on this system. Builders and HVAC contractors will cut corners wherever they can just to save a buck.

[Panama]

Mike,

Go buy yourself a digital humidity meter at WalMart. Your problem could be as simple as low air flow. If the air flow is low the air conditioner will expend more of its energy removing water from the air, leaving it with less energy to cool the air.

When the system runs for an extended period the humidity should hold at around 50%. If it goes much lower than that your system is wasting energy removing water from the air.

But if you change the air flow on a system without a TXV you will have to have the charge adjusted to ensure decent performance.