Do people upgrade their AC to make it colder? Or make it colder faster? Just a random question. My ac is working fine.
I am far from an expert, but a not insignificant number of builders will undersize the AC units as a way to cut costs on a house. My understanding is that the loose rule of thumb is to size the unit at 1 ton per 500 sq ft. So lots of builders will do stuff like put a 4 ton unit in a 2450 sq ft house. Or undersize the intake so that the system doesn't put as much air across the coils. It isn't uncommon for HVAC companies to recommend up-sizing the intakes or duct work to increase the air flow or to upsize the outside unit to address the corners cut by the builder. Sometimes it is a real issue and will make a real difference, other times it is just BS to make more money off of a sucker customer.lancevance said:
Do people upgrade their AC to make it colder? Or make it colder faster? Just a random question. My ac is working fine.
we have a 22 year old 5 ton and a 9 year old 3 ton. 5 ton has given us no problems 3 ton is a lemon. well it still works just needs about $700 every year or two.riverrataggie said:
I just redid my 5 ton and 3 ton units, HVAC, ducts, etc.
They were both about 20 yo and one went out.
I will say this. It is way more efficient and cools down much quicker. That said, they were ~20 yo units.
That's not a bad thing. You want to size the A/C so that it sufficiently cools the house by running continuously on the hottest day of the year. They're more efficient than constantly cycling.Texasyankee said:
I would like to know this too. Our a/c works, but it seems to run an exorbitant amount of time when the mercury goes above 90.
Tomdoss92 said:we have a 22 year old 5 ton and a 9 year old 3 ton. 5 ton has given us no problems 3 ton is a lemon. well it still works just needs about $700 every year or two.riverrataggie said:
I just redid my 5 ton and 3 ton units, HVAC, ducts, etc.
They were both about 20 yo and one went out.
I will say this. It is way more efficient and cools down much quicker. That said, they were ~20 yo units.
if you don't mind me asking, did you redo the whole system into a more modern single unit or keep the dual units?
any idea on energy cost difference or too early to tell?
This is a real issue. People think bigger is better. No. Right size is better.hypeiv said:
It might be how it was set up but my parents got a bigger AC unit and it made things worse. It is feast or famine... so it gets uncomfortably hot because it runs so infrequently the humidity is high and then when it clicks on it gets way too cold.
Furlock Bones said:This is a real issue. People think bigger is better. No. Right size is better.hypeiv said:
It might be how it was set up but my parents got a bigger AC unit and it made things worse. It is feast or famine... so it gets uncomfortably hot because it runs so infrequently the humidity is high and then when it clicks on it gets way too cold.
Salute The Marines said:
We ripped out our central air system and just put large evaporative coolers in a window in every room. Best move we ever did.
bmks270 said:
I replaced my AC a few years ago. It was my first go around on my first property.
Here is what I learned. AC is sized to the sq-ft of the home based on tons. This can be influenced by your insulation in the home, but basically the AC needs to be matched to the sq-ft and heat flux of the home.
If the AC is too big it will cool too fast and in humid climates it will not run long enough to dehumidify the air. It will also cycle on and off more frequently, causing the temperature to swing up and down more quickly.
If the AC is sized correctly, it will run for longer periods of time, which has the benefit of dehumidifying the air, and it also won't cool so fast that it constantly cycles off and on.
More expensive AC systems have variable cooling capacities they can operate at which can control humidity better, but for the more affordable systems, they basically operate at a single Constance cooling capacity, and it's bet for indoor comfort and electricity usage if they are matched to sq-footage and heat flux of the home.
My old system couldn't cool the house in the summer running 24/7 turns out the system was old and the condenser coils were corroded. The heat exchanger efficiency was terrible. I got the cheapest new system they offered and it cut my electric bill literally in half and cools spectacularly. That is due to being way higher efficiency than my old corroded system even though it was the lowest SEER and cheapest system offered.
And I once worked in an office that had a terrible AC system, and it was constantly too cold or too hot, it couldn't hold the temperature between 68-74. It was either below or above that all the time. It sucked.
Cromagnum said:Furlock Bones said:This is a real issue. People think bigger is better. No. Right size is better.hypeiv said:
It might be how it was set up but my parents got a bigger AC unit and it made things worse. It is feast or famine... so it gets uncomfortably hot because it runs so infrequently the humidity is high and then when it clicks on it gets way too cold.
Yep. Guarantee they have humidity issues in their home too since the unit isn't running long enough to dry the air out.
rwtxag83 said:
BTW, sorry if that came off wrong. Your post has a lot of good information; my contention was with you saying it's about Square footage.