This is easy. I live in a building where we have central air run by a
Honeywell Thermostat, model unknown (but it is old and one of the
dial turn ones with the temp on top and bottom). It also has "HEAT
OFF COOL" on one side at the top and "FAN ONLY AUTO" on the other
side at the top. My landlord has set it to fan only and says the air
still running. The air doesn't feel as cool, he says in reply to my
complaint, because the air is not on at that exact moment but that
the fan is always on. He says because of this sometimes we will feel
"cold" air and other times it will be "cool" to room temperature air.
I'm convinced otherwise. I moved in during the horrible heat wave that
came through the midwest a month ago and this is the warmest my
apartment has been.
The simple question is: If he has one switch set to "COOL" and one
switch set to "FAN ONLY", is the A/C still on or not? I always
thought the "AUTO" setting along with "HEAT" or "COOL" is the only
way to have the air on.
Your landlord is right.
If the COOL switch is on (HEAT/OFF/COOL set to COOL), then the air
conditioning is engaged. The fan switch set to AUTO means the fan only
comes on when the A/C is actually running. The fan switch set to ON
means the fan runs all the time, whether or not the A/C is on. This can
help move a little air around and help keep it more comfortable with a
little less A/C.
Ok. Thanks for the input. I guess it probably says "FAN ON" and not
"FAN ONLY". That would make more sense. I guess, thinking it said
"FAN ONLY" meant that it was, somewhat obviously, ONLY the FAN that
was running. But like I said, I guess I must have read it wrong.
Thanks for the help.[/quote]
Yes, this works well and some say it saves a bit. My fan runs all the
time when I am home, but during the day it is off. It keeps the
temperature more uniform as well. It does tend to raise the humidity
level higher than it would be with A/C alone. But all in all I like it.
Probably keeps the air a bit cleaner.
For most residential applications running a 1/3 HP (approximately 250
watts) an extra five or ten hours a day won't save any money. In
addition to the direct power consumption you are introducing the heat of
motor operation into the airstream.
Maybe, but the air that comes out of the ducts on my first floor is
cooler than that already in the room. This probably only works if you
have a basement. Plus we have a high water table and the basement is
always relatively cool. As such the house stays cooler which means the
compressor runs less. Still I am not saying the overall cost is less.
Some have said that. I am not totally convinced yet. My bill was a bit
higher , but this month was a bit hotter.
Sounds like your application is one of the exceptions to the rule. Next
time you replace your air handler / furnace get a variable speed one.
The ECM drives used in VS systems are much more efficient than
conventional motors, and will cost less to run.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.