sanford
Tuesday, 27 April 2010 10:55
I live in Florida. Even the evening, the central air system would be running non-stop and would keep the temperature around 78-80. It does not seem able to lower the temperature to 75 degree. Can anyone tell me how to fix this problem? Thanks very much.
One first needs to know the size of your home, how many levels (1 story, 2 story), the age of the home, how well it is insulated, types of doors and windows, what size of a unit you have (measured in tonnage), how old your unit is, and what side of the house the condensor sits on. These items will help someone help you…,
Mine works like that when the filter is not clean. Put in a new one and hopefully that is the reason. If it isn’t, then a call to an air conditioner repair person is in order.
The best method to optimize your a/c is to clean the coils on both inside and outside units.
Foamy Cleaner made by DiversiTech is what I use but there are others out there. It’s a very caustic chemical made specifically for cleaning a/c coils and is only available at a/c supply stores. Invest in a good quality garden sprayer (the kind with a pump built into the lid) and a pair of chemical resistant rubber gloves (available at any hardware store).
Inside Unit: You start by turning off the breaker or main a/c disconnect switch and remove the screws holding on the coil cover. You will need to have plenty of water ready to spray down the coils since the acid in the foam will ‘eat’ your coils if you leave it on too long. You should also have something to catch the excess water since the drain pan probably won’t be able to handle the flow. Spray the coil cleaner according to the directions and leave it on only as long as recommended. This will make a huge difference in the amount of cold air flow if there is alot of crud in the coils.
Change your filter with a ‘cheap’ filter every month. The expensive filters don’t allow enough air to get the most from your a/c.
Outside unit: Turn of the power to the unit. Remove the top cover and fan. Do the same to these coils as the inside unit. This will also optimize your systems cooling capabilities.
If your inside unit is setup where you can’t get to the coils, call an a/c company to do it. They can remove it and clean it.
Either way, it might be worth having a technician come out and check the freon. If your fan, coils and freon are all ok and the system is designed correctly, it should keep the house at whatever temp you like.
Make sure all windows are covered with curtains or blinds. Use weatherstripping for any gaps around doors and evaluate your attics insulation and upgrade if needed. Ceiling fans help also.
Good luck, I hope this helps.
If the system was designed properly and originally did cool the house down, then your problem is the system is low on freon. You can check this by looking at the expansion coils in the attic to see if they have ice formed on them.
If on the other hand the sytem is undersized, they you don’t have much choice but to install a larger unit or a second unit. Before you do that though, you should consider adding insulating to the attic space of the house. I live on the Gulf Coast, and added 12 inch bats of fiberglass insulation to my attic space. It lowered my cieling temperature in the daytime by 5 degrees, and paid for itself in one summer.
We will assume your a/c is of sufficient size for the home. Take a thermometer and stick it in a register. make sure it’s a register with air coming out. The temp. of the air coming out should be 15 to 20 degrees cooler than the room temp. This will tell you if it’s cooling the air properly. Another test is while its been running a while check the temp. of the larger refrigerant line ( usually has insulation covering it ) and that line should be cool but not iced. If this line is not beer can cold it ’s low on refrigerant. The other smaller line should be body temp. or slightly warmer. If hot it indicates a dirty or plugged outdoor coil and needs to be cleaned. Call a professional if you cant correct it with a simple cleaning
Did the system ever work properly?
Do any of your neighbors have a similar size house
and what is the make and model Number of their outside
AC unit and Your outside AC unit?
You need to know the square footage of your house
Add up the width x length of each room
Roughly, Ballpark Some may say less but
For every 400 sqaure feet you will need 12,000 b.t.u. of cooling
If you have a 1,200 Square foot home then you will need close
to a 36,000 B.T.U. AC unit
You can get this unit sizing information from
Home Depot _ Loews or SEARS for free
Yes the basics, are the filters clean
CAN you feel the air blowing out of the ductwork?
Is it cold?
Place a thermometer near the indoor section of your AC
See what the “return ” temperature of the air is going into the AC
This is the air that is going into the filter
Next
Place the thermometer by any of the discharge air grilles
See what the temperature is blowing out of the grille
If the air temperature blowing out of the grille is at least
15 to 20 Degrees colder than the temperature going into the AC unit then the AC appears to be working good
If not then you may be low on refrigerant
On the outside unit
there are two copper pipes that connect to the unit
the larger pipe may have black insulation on it
if the compressor is running and there is enough refrigerant
in it
This larger pipe will be cool and very wet
If not then let us know
make sure the filter is clean first. Second, make sure you have plenty of insulation and ventilation in your attic. A lot of heat is trapped right above your house, if it cannot vent well it will seep into your living space. Lastly, remember it’s Aug is Florida. An a/c system can only work so hard. If it is cooling down to 75 degrees, it may not get much cooler than that. It’s only designed to lower the temp 12-15 degrees.