HVAC Specialists (Central Heating & Cooling)
nope you didnt get screwed
Member
Joined: Jun 2005
Posts: 66
Likes: 0
CIA-Agent, bare with me, hopefully this can be of some help.
As previously stated, the generally accepted average of 600-800 sq.ft. per ton of cooling is correct, but a proper Heat Gain Survey should be done because oversizing your unit by even a 1/2 ton can affect optimal efficiency. Basically, this takes size, type of construction, #/type of exterior doors and windows, type/amount of wall/attic insulation, etc. into account for determining unit size. Most people that I know that have replaced their 15-20 year old units(9 to 10 SEER) with 12 - 14 SEER units, have experienced a minimum of a $40.00/mth decrease in their utility bills here in SW Louisiana.
There are several other factors to also consider when the old A/C just ain't cutting it anymore. Attic insulation; what type is installed, has the insulation settled enough to be causing heat transfer into the interior living space? Are window and door weather stripping still sealing like they should? How is your attic ventilated; without proper ventilation, the heat is just building in the attic which makes it easier to transfer into the house.
A few years ago, when I was still making my 20 year old unit limp along, we had our roof re-shingled which also caused me to replace the large aluminum ridge vent that we originally had, with a newer much lower profile vinyl vent.
That summer I noticed that my poor old unit was running pretty much all through the day to maintain the 71 temp we like. Couldn't find anything wrong with the A/C other than age! By the next spring, I finally got my head out of my you-know-what, thinking about "other" things that had possibly changed and remembered about the ridge vent. I then installed a new powered roof vent and wha-la, could surely tell the difference in attic temp and run time on the A/C unit.
The compressor burnt up later that summer, so I installed a complete new 12 SEER system and saw a $40 - 50.00 drop in the bill for the next two hot months we had.
Double filters- Guys/Gals, don't do this unless your system is designed for and set up for this. And IMO, throw away those darn "cheap" blue fiberglass filters that you buy at Wal-Mart and other places. These things allow too much trash to pass through them. If you are having to have your evaporator coils (inside) cleaned every couple of years, it's because you are using these cheap filters or your have an air infiltration leak after the filter and it is allowing dust to get to the evap coil. All duct joints and unit panels should be tight and sealed with gaskets or tape.
Know this was long winded, but hope it helps someone. Good luck to all.
As previously stated, the generally accepted average of 600-800 sq.ft. per ton of cooling is correct, but a proper Heat Gain Survey should be done because oversizing your unit by even a 1/2 ton can affect optimal efficiency. Basically, this takes size, type of construction, #/type of exterior doors and windows, type/amount of wall/attic insulation, etc. into account for determining unit size. Most people that I know that have replaced their 15-20 year old units(9 to 10 SEER) with 12 - 14 SEER units, have experienced a minimum of a $40.00/mth decrease in their utility bills here in SW Louisiana.
There are several other factors to also consider when the old A/C just ain't cutting it anymore. Attic insulation; what type is installed, has the insulation settled enough to be causing heat transfer into the interior living space? Are window and door weather stripping still sealing like they should? How is your attic ventilated; without proper ventilation, the heat is just building in the attic which makes it easier to transfer into the house.
A few years ago, when I was still making my 20 year old unit limp along, we had our roof re-shingled which also caused me to replace the large aluminum ridge vent that we originally had, with a newer much lower profile vinyl vent.
That summer I noticed that my poor old unit was running pretty much all through the day to maintain the 71 temp we like. Couldn't find anything wrong with the A/C other than age! By the next spring, I finally got my head out of my you-know-what, thinking about "other" things that had possibly changed and remembered about the ridge vent. I then installed a new powered roof vent and wha-la, could surely tell the difference in attic temp and run time on the A/C unit.
The compressor burnt up later that summer, so I installed a complete new 12 SEER system and saw a $40 - 50.00 drop in the bill for the next two hot months we had.
Double filters- Guys/Gals, don't do this unless your system is designed for and set up for this. And IMO, throw away those darn "cheap" blue fiberglass filters that you buy at Wal-Mart and other places. These things allow too much trash to pass through them. If you are having to have your evaporator coils (inside) cleaned every couple of years, it's because you are using these cheap filters or your have an air infiltration leak after the filter and it is allowing dust to get to the evap coil. All duct joints and unit panels should be tight and sealed with gaskets or tape.
Know this was long winded, but hope it helps someone. Good luck to all.
Member
Joined: Mar 2005
Posts: 18
Likes: 0
Here's a forum you can check out. There is a residential sub forum. Be sure to check out the "wall of shame' sub forum with all the hack jobs by amateurs.
http://hvac-talk.com/vbb/index.php
http://hvac-talk.com/vbb/index.php
Thread Starter
|
Bighersh Alter-Ego
Joined: Nov 2003
Posts: 178
Likes: 0
From: 33.02N / 96.66W
AC went **** up again...
This time, it's the compressor. It was gonna cast me $1,625 to add a new unit (Which ain't bad- but the timing couldn't be worse)
What you guys do if in a similiar situation. I could credit card it; but wifey was up in arms about having to drop darn near 2K.
What exactly is a compressor (I know, I'm HVAC Ignorant) and what is it that they are replacing? Will a replacement compressor be adequate as opposed to gettign a new unit?
Talk to me Goose.....
This time, it's the compressor. It was gonna cast me $1,625 to add a new unit (Which ain't bad- but the timing couldn't be worse)
What you guys do if in a similiar situation. I could credit card it; but wifey was up in arms about having to drop darn near 2K.
What exactly is a compressor (I know, I'm HVAC Ignorant) and what is it that they are replacing? Will a replacement compressor be adequate as opposed to gettign a new unit?
Talk to me Goose.....