Trying to sell!!

[behmer]

I am 'hot in the south' part 2 - Atlanta. Have a two story brick ranch (the basement is finished) that has a rear exterior that faces west. The upstairs is completely vaulted and the entire house is approx 4800 sq. ft. Not many trees and 4 turbine vents on the roof. The house is 7 years old - I have lived in it the last two. When the outside temp gets over 90 degrees the house will rise to 82 degrees. Not a big problem unless you are trying to sell!

Reading from the RO, the tech cleaned the condenser coil and washed down the compressor. The RO says, 'had 60 degree supply BMP close to furnace and 78 degree return temp on ceiling, unit may be a little small for 92 degree days. I trimmed back the bushes from the A/C unit. Today outside temp- 92 degrees and inside temp- 82 degrees.

Assumptions;

1) the original owners would not have tolerated this problem and would have forced the builder to correct. So at some time this should have been working properly. If so, what needs to be corrected?

2) Everyone before me was OK with the rising temps? So now what would I need to do from a hardware perspective to upgrade my system? More importantly what should it cost?

[aircooled53]

Need to have Manuel J load pulled by contractor to see what size of system is needed.Sounds like something is wrong with the existing system.

Charge
Returns
Ductwork
The best place to start is to have system checked by PRO.

[behmer]

What the heck is a Manuel J load??

Also I forgot to mention that given the western exposure, we do close all of the blinds.

When you say PRO, what exactly do you mean? How do I know the tech was NOT a PRO?

[dash]

I think he's saying,have the charge checked,duct leaks checked,Correct return and supply duct sizes for required airflow,etc.,by a Pro,yours may not have checked all that could be checked for your insuffient cooling.


Manual J,from ACCA,is a means of calculating the correct size system for your home as it may be too small.



A quality contractor(Pro) can handle all the above,call and discuss your situation with them,before engaging their services,be sure they can do all that is needed to save your time and theres.

[a\c don]

You failed to mention the size of your system.

You did however report an 18 deree temp. drop across the evaporator which should do the job if system is properly sized for the home.

If you dont know system size give us make/model #.

There are many other things to consider, the duct system not being the least of them.

Best to have a reputable pro check the entire system.

BTW, a manual J is a heat load calculation to determine the exact cooling needs of your home.

[dan sw fl]

Originally posted by behmer

Atlanta.
two story brick ranch (the basement is finished) that has a rear exterior that faces west.
upstairs is completely vaulted and the entire house is approx 4800 sq. ft.

Not many trees and 4 turbine vents on the roof. The house is 7 years old - I have lived in it the last two. When the outside temp gets over 90 degrees the house will rise to 82 degrees. Not a big problem unless you are trying to sell!

'had 60 degree supply BMP close to furnace and 78 degree return temp on ceiling

HOW MANY System(s)/ sizes(s) per area?

West .. one problem
Vaulted .. another

Sounds like HOTLANTA!

[beenthere]

Originally posted by a\c don


You did however report an 18 deree temp. drop across the evaporator which should do the job if system is properly sized for the home.

The return temp was taken at the ceiling.

Could be drawing in attic air.

[behmer]

I noticed that all of my windows have serious condensation on the outside every morning. They are thermopane windows. Is that a clue?

[dan sw fl]

Originally posted by behmer
serious condensation on the outside every morning. Is that a clue?

Clue ..Right ___
You must be cooling your house to ~72'F in the evening.

[furnace doctor]

Condensation forms on the outside of the windows if the windows are below the "dew temp" of the ouside ambient air.

[behmer]

You guys are right! The only way to keep the house from soaring above 80 degrees in the afternoon is to cool it down to 72 at 7 am when we wake up.

[behmer]

Is changing the blower speed an option? I am getting poor airflow intothe rooms farthest from the attic unit. How can I tell if the unit has already been turned up?

[amigadude]

Behmer -

It's not a popular option around here, but I had a similar situation (Atlanta area) and was able to get my temps down with attic fans. Pulled all 4 of those useless turbines out while I was at it.

Check out this (looong) post for the discussion on fans: http://hvac-talk.com/vbb/showthread.php?threadid=77345

I've measured the register temps with or without fans and can see up to a 6 degree rise in the registers furthest from the unit. Those attic temps are tough on ducts, no matter what kind of insulation they have.

Also, you must have plantation shutters or something to block that afternoon sun.

Good Luck.

[bob the head scratcher]

What were you setting the thermostat to before or were you turning the system off until you were uncomfortable?

[behmer]

We used to set it at 75 and it would rise to the low 80's. Now when we wake up we try to get the house down to 72 and it will rise and stop around 79.

What about raising the fan speed and baffling some of the vents on the cool (east) side of the house?

[cem-bsee]

install trellis with vines in front of windows -- get sun shade screening -- install awnings -- apply reflective film on windows -- do not show house in hot evenings --

here in Huntsville AL, my house drifts to 80F when temp reaches 92F -- but I am using 5000 btu/h a/c -- bill for 30days ending 7/20 was $63 -- equates to 1.6- 1.74 btu/DegreeDay/sq ft = 2133sf trilevel house.

[dan sw fl]

Originally posted by cem-bsee
here in Huntsville AL,
my house drifts to 80F when temp reaches 92F --
but I am using 5000 btu/h a/c --
bill for 30days ending 7/20 was $63 --
equates to 1.6- 1.74 btu/DegreeDay/sq ft
= 2133sf trilevel house.

I ddn't realize a 1/2-Ton unit could
cool > 2,000 square foot house.

Manual J should be updated to reflect this New Science!