Both of my units run on R-22. By the time they need replacing we're probably be told R-410A is now bad and start using a 'new' refrigerant.
Central A/C question kinda long post
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Originally Posted By: sleddriver
I've noticed an interesting effect in more-than-a-few houses down here in the humid South that the indoor air feels damp (stuffy) upon entering. Even though the temp control might be set at 72°, it feels warmer. About 5 min. after the air handler stops, you can feel the presence of heat...far off heat, but still. I later realized it's long-wave heat coming through the ceiling. Either not enough ceiling insulation, uneven insulation, poor attic ventilation, no radiant barrier, etc. Very interesting effect.
I have to disagree with you Steve that the evap coil would dry out in 'seconds' in an area with a high latent heat load such as Florida or the rest of the very humid South. Doesn't make sense that the dew point could be that low indoors in your area. Your nasal passages would be cracked. Nevada yes. Utah yes. Arizona yes. Florida? Texas? No way. Care to share your indoor relative humidity readings from your hygrometer? Mine is at 40% and the evap coil still sweats. Current outdoor Rh is 91% and outdoor dew point is 77°. It did rain last night...in central Tx....in July...amazing.
I do appreciate the movement of air: most all rooms have ceiling fans. Definitely makes a difference.
Temp & humidity shouldn't 'spike' in any room with the indoor blower off. Something else is going on and your a/c is having to constantly deal with it. Perhaps the same issue mentioned above? Perhaps air flow is insufficient to those areas? Or they have windows where the Sun hits the glass? Face South? Or West? Even East? Doing a cooling load calculation (Man. J) on your house might yield surprising results.
The last bill I paid amounted to $110 for 970kWH's for a small house (~1,500sqr. ft). And that's with a recent price increase....and on a now 23yr old system.
Not wanting to start an argument here, just adding in my two cents.
Sled,
No worries here, just enjoying the convo.
My house is quite a bit larger but with lower ceilings than many newer homes. On a per square foot basis my electrical bill is much lower than yours.
Totally agree on the long wave infra red from the ceiling. We have attic fans and ridge venting as well as a lot of insulation. Since we have an old plaster ceiling (with strange patterns!) it conducts heat very well.
When my 18 SEER Amana system was installed a few years back by my personal friend who runs a small local AC biz we actually sat in the attic and talked while we ran it for a while. I then sat up there for a few days tinkering with the fan speeds. Generally the evap is completely drained in about 45-60 seconds after the condenser shuts down (remember the fan stays on, very low, but still on). Our hygrometer rarely goes much below 50% around here. Outdoor temp was 97 yesterday with rh at well over 90%.
I personally hate ceiling fans. Just can't stand the bulk in a room, remember low ceilings here. Plus, they do not move any new air in or out of a room, just stir it up. I have a very efficient filter in the ac that is better than HEPA and I like to pass the air over it as much as possible.
Temps here will unavoidably vary due to windows and exposure. I have carefully balanced the system but if you allow the fan to shut down there are rooms that will unavoidably get warm faster than others, you would have to overcool those areas to have everything be a similar temp at the next system startup.
I've noticed an interesting effect in more-than-a-few houses down here in the humid South that the indoor air feels damp (stuffy) upon entering. Even though the temp control might be set at 72°, it feels warmer. About 5 min. after the air handler stops, you can feel the presence of heat...far off heat, but still. I later realized it's long-wave heat coming through the ceiling. Either not enough ceiling insulation, uneven insulation, poor attic ventilation, no radiant barrier, etc. Very interesting effect.
I have to disagree with you Steve that the evap coil would dry out in 'seconds' in an area with a high latent heat load such as Florida or the rest of the very humid South. Doesn't make sense that the dew point could be that low indoors in your area. Your nasal passages would be cracked. Nevada yes. Utah yes. Arizona yes. Florida? Texas? No way. Care to share your indoor relative humidity readings from your hygrometer? Mine is at 40% and the evap coil still sweats. Current outdoor Rh is 91% and outdoor dew point is 77°. It did rain last night...in central Tx....in July...amazing.
I do appreciate the movement of air: most all rooms have ceiling fans. Definitely makes a difference.
Temp & humidity shouldn't 'spike' in any room with the indoor blower off. Something else is going on and your a/c is having to constantly deal with it. Perhaps the same issue mentioned above? Perhaps air flow is insufficient to those areas? Or they have windows where the Sun hits the glass? Face South? Or West? Even East? Doing a cooling load calculation (Man. J) on your house might yield surprising results.
The last bill I paid amounted to $110 for 970kWH's for a small house (~1,500sqr. ft). And that's with a recent price increase....and on a now 23yr old system.
Not wanting to start an argument here, just adding in my two cents.
Sled,
No worries here, just enjoying the convo.
My house is quite a bit larger but with lower ceilings than many newer homes. On a per square foot basis my electrical bill is much lower than yours.
Totally agree on the long wave infra red from the ceiling. We have attic fans and ridge venting as well as a lot of insulation. Since we have an old plaster ceiling (with strange patterns!) it conducts heat very well.
When my 18 SEER Amana system was installed a few years back by my personal friend who runs a small local AC biz we actually sat in the attic and talked while we ran it for a while. I then sat up there for a few days tinkering with the fan speeds. Generally the evap is completely drained in about 45-60 seconds after the condenser shuts down (remember the fan stays on, very low, but still on). Our hygrometer rarely goes much below 50% around here. Outdoor temp was 97 yesterday with rh at well over 90%.
I personally hate ceiling fans. Just can't stand the bulk in a room, remember low ceilings here. Plus, they do not move any new air in or out of a room, just stir it up. I have a very efficient filter in the ac that is better than HEPA and I like to pass the air over it as much as possible.
Temps here will unavoidably vary due to windows and exposure. I have carefully balanced the system but if you allow the fan to shut down there are rooms that will unavoidably get warm faster than others, you would have to overcool those areas to have everything be a similar temp at the next system startup.
A 13 SEER system is pretty much guaranteed to have single speed air handler, compressor and condenser coil fan. If you have that, running the air handler fan continuously will increase the electricity bill quite a bit, unless the heat gain is so great during the day that the AC off-time is very short (like 5-10 minutes) and on-time is very long (like 45mins-1 hour).
There might be some odd ball combinations where a 13 SEER AC unit is mated to a variable or multi-stage air handler, but those would be very rare.
Those with 16 SEER or higher systems will have a combination of multi-stage or variable air handlers, compressors and condenser coil fans. That's how the high SEER rating is achieved. Basically you have a system that's say 3 tons, but it only utilizes all 3 tons of cooling during peak loads. Once the set temp is satisfied, the system switches to a lower stage or speeds, making a 3 ton unit behave as if it were 1 or 1.5 ton unit, just to keep the temp steady.
These systems have the added advantage of increased comfort and steady humidity levels because there is constant dehumidification and air circulation.
There might be some odd ball combinations where a 13 SEER AC unit is mated to a variable or multi-stage air handler, but those would be very rare.
Those with 16 SEER or higher systems will have a combination of multi-stage or variable air handlers, compressors and condenser coil fans. That's how the high SEER rating is achieved. Basically you have a system that's say 3 tons, but it only utilizes all 3 tons of cooling during peak loads. Once the set temp is satisfied, the system switches to a lower stage or speeds, making a 3 ton unit behave as if it were 1 or 1.5 ton unit, just to keep the temp steady.
These systems have the added advantage of increased comfort and steady humidity levels because there is constant dehumidification and air circulation.
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