I have psoted ob here several times with the same problem. This start in the early spring of 2004. I have a one story ranch style house that is abotu 1,972 sq. feet. when the temp. hits 90 plus outside my thermostat goes up 5 and 6 degrees above setpoint and it use to not do that. some people on here that have tried to help, I dont know if they live up north or what but I need someone that understands the weather in the south with all the humidity. Nothing has changed with my house, AI have lived here for 4 summers and the first two didnt do this. I use to leave my setpoint on 72 when I would leave for work in the morning and when I would get back it would be held on 72 during the hottest part of the day in the middle of august! I do not have a false memory, I have a digital thermo. and know exactly what it was set on and besides july and august weather in the south is always the same! I have called tech after tech and finally one of them thinks it might be an airflow problem and did some tinkering to the unit but it is still doing it. Everything is charged correctly no dirty coils or filters.
need help please!
what is South Texas, Georgia Arizona, ?
maybe one of these things
low on refrigerant.
black roof & no attick fan.
leak in ductwork, only start to notice the effects on them real hot days, with this one.
need to close the drapes, blindes during hot days.
You need a competant tech to look at your system. This means you'll probably have to pay more unfortunately. If you say this system used to keep your house at 72 and now it won't, somethings changed obviously.if system is correctly charged and is putting out the correct amount of cfm, I would thoroughly investigate your duct system, as it might be leaking now, taking away from the system's ability to cool the house. Have them check the static pressure.Doing the load calculation on the top of this page will tell you right off the bat if your system is correctly sized for your house.They can also do a capacity check to verify the systems output.
If everything was always done "by the book"....the book would never change.
I do have a black roof but I have always had it. I have exhaust fans in the pancake vents but they are not hooked up. would those make a significant differance or would more insulation make a differance? I have the same amount of insulation I have always had and I know thr r-value can break down over time but not in one summer! my insulation is about 5 or 6 inches deep but you can still see the ceiling joints. I dont have any soffit vents but I have 3 pancake vents, 2 turbines and gable vents. would soffit vents make a significant differance?
if you had the attic fans on last year then have em on this year.
yes it would make a differrance.
also did you recently paint the house a darker color over past year or removed a tree that shaded part of the house.
or added a room or added vents to a room.
or did you add a skylite.
something had to change if it cooled house year before but not now.
find any cold spots in your attic around duct work if so thats cold air going into your attic and not the house.
or any return ducts sucking up hot attic air.
if none of the above you need a tech to check your refrigerant charge.
undercharge will make it not cool as good
Have a pro clean the coils.
Hot first tell us where you are be specific.
There are many valid reasons your system is not cooling, as it should. If you have an older system the condenser coils degrade over time reducing efficiency and capacity. You have had many techs out many are lazy and just want to sell equipment or just don't want tot do the hard work. What brand unit is it Rheem/Rudd and their many sub names get very dirty condenser coils and they just will not cool. Cleaning them properly is allot of work. If the unit has a recip compressor the valves can be going bad this can be hard to determine if checking at the onset and when it is cooler out.
Have tech been adjusting the charge I find more units overcharged than I do undercharged and this can affect system performance than a slight undercharge.
We need some specifics to help you out, equipment model numbers and age. What type of coil and what type of metering-device, what is the temperature drop across the evap coil. Have any techs left invoices with spec like Superheat or Sub-cooling these will help we also need indoor and outdoor temps when readings were made.
If you tell us where you are maybe we can suggest a good tech in your area.
reply to all
I live in n. alabama and I have not had any tree removed or painted my house a darker4 color , I have a brick home that was built in 1972 and the duct work is not in the attic , it is underneath the home. My unit did the same last year too, it has been two years during the summer that it has worked right and again up to about 85 degrees it works fine and blows ice cold air but when it gets above 90 that is when the problem starts.
i would have youe condenser coils cleaned. a lot of times tehcs will miss this because they think if it doesnt look dirty it not but you cannot tell if a condenser is dirty by just looking. so have it cleaned then recheck the charge.
if nothing else have someone come out and give you the pressures, superheat and subcooling and we will tell you whats wrong. make sure to get all these reading because if ones missing you will not the corrcet answere.
I will agree with mattm on this. Don't go with the $19.95 special either. A real pro will charge you around $100 - $150 and will get-r-done right.
Originally posted by mattm
Have a pro clean the coils.
to airworx and others
after you gave me the advice about cleaning the coils , a tech just left and cleaned them and also got me some readings. The head pressure is running about right for a 95 degree day at about 280 or 285 which he said is a little high and the suction was about 60 and when he cleaned the coils it went up to 68 then dropped back down to 60. temp. drop is about 17.5 but sometimes it fluxuates. again then temp. in my home is fine up to about 87 degrees and when it gets above 90 that is when is rises. I understand the hotter it gets the more your unit will run but the temp. has always been held right on the setpoint, that is the mystery. one time another tech. used dye to check for a leak and this tech said the freon ay be obstructed by that and he may have to recall it back in and put new refrigerant back in. does this make since?