The real problem is the grown kids living at home. The human body
generates a tremendous amount of heat, even at rest. Once they are
gone the air conditioner and fans could probably be used less. The
fans are cheap compared to extra adults.
I have central AC and also continuously operate ceiling fans in the
two bedrooms and the living room. It keeps the hot air from
collecting at the top of the room. Otherwise, I'd have to crank
down the thermostat even farther and end up with cold feet.
The HVAC vents are at floor level as is customary in the North.
I wouldn't have the fans running in the rooms that are not occupied.
I have fans in my den and in the bedroom. I only put them on if I'm
going to be in there. But in the grand scheme of things, this isn't
a big deal. Those fans don't use much electricity nor do they
generate much heat. That's why they are cost effective to begin
with. So, you could ask them why they run them in unoccupied rooms,
but I certainly would not make some issue of it.
Ceiling fans help even with the HVAC vents in the ceiling. Mixing air
is a good thing. I'd run them in the Winter, too, but drafts make it
feel colder so it defeats the purpose. The really don't use a lot of
We have the opposite problem, keeping warm. No AC except the odd newer
house that has a heat pump that can be reversed to do AC.
BTW here is one quote ......................
"The total amount of heat produced over a period of time is equal to
the total calories consumed minus any useful mechanical work
performed. If a person consumes an average of 2400 kilocalories per
day, the average heat produced is 100 kilocalories per hour or 116
Since a kilowatt = about 3300 BTUs that 116 Watts = approx 380 BTUs.
Since it got a little warmer here recently (mid/late June) have
noticed can often keep house comfortable with the formal heat off and
incidental heat from the fridge, a few lights, in the evening,
occasional cooking, couple of computers, maybe the TV, letting the
shower water to cool down to room temperature etc.
Also the sun is sometimes in evidence but when that happens of course
all the leaves on our approx. 70 trees are out and not much reaches
Each fan probably does not use any more than say 10 to 15 watts? Or
about one tenth the amount of heat of one human body. And fans keep
air moving thus helping human perspiration to evaporate and one to
feel and be cooler. probaly more efficient than cooling all the air in
the house to a greater degree.
Of course if I had the chance I'd build into the side of a hill for
easier and more efficient temperature control, summer and winter. Our
unheated (except for heat filtering down from the living floor above),
almost fully in ground and unfinished concrete walled basement stays
around 50 deg F during our winters.
I don't run them all at once, only the room I'm in. Two if I'm going
back and forth. And regardless of whether I did or not, I wouldn't
be trying to tell them I'm better than they are. Whether their fans
are making the rooms they are not in hotter, and costing them money
just to be hotter, are matters of fact. And the facts don't depend on
the good or bad habits of whoever is teling them about it.
Ok, how much more does it take to suck away the heat generated
by a ceiling fan? A dollar a day? Ten dollars a day?
I'm in full agreement that the heat from the fan has to be dealt
with by the air conditioner, but how much does that really take?
Should I worry more about the insolation from opening the curtain
on the south-facing window so my houseplants can get light?
I don't think it's 10. Probably not even a dollar. I've known for a
while that I treat different kinds of waste differently. If a movie
production wastes loads of film, or gasoline, or has to build a mockup
house to blow it up, that doesn't bother me, but if they take this
year's model car that runs well and blow that up, I really hate that.
Here what bothers me the most is not the wasting, but that they make
heat just to pump it outside where it is already hot. I wouldn't
turn off a fan if I were only leaving a room for 5 minutes, or even
longer, but I think they just haven't realized that they are making
heat with the fans. Like a couple posters said.
Well it's not infinitesimal. The fan uses roughly what the wattage
rating is on the fan itself. I've never looked.
The total heat is like you say, twice that much.
I think they do keep their shades closed. They had a big bay window
facing east on their previous house and put in special glass and
planted a tree to keep the heat out.
Not the best test. The heat from the fan is dispersed all over the
room with the blown air. In fact it's in six rooms, so the most one
can feel is 1/6 of the heat, and that's if he could be everywhere in
one room at the same time.
While fans in rooms not occupied is likely just laziness, I feel that
if you can tolerate the wind and the noise, running fans can save
money on AC. I do it, so I can set the thermostat a couple of degrees
higher, and it works. I have ceiling fans in all rooms, 2 in large
rooms, and run them when I'm there. The exception being the upstairs
bedroom which has one running constantly during AC season so you can
stand to go in there during the setback when it is up to 90 degrees in
there. I also have a box fan and a small oscillator which are used
infrequently but make living at a higher setting closer to pleasant.
Those fractional HP motors all put together don't = the air handler,
let alone the compressor & any heat is produced is negligible. Trust
me, I'd love to run the AC at 72 degrees, and as soon as I win the
lottery I will.
No, fans help move air so AC works better; more evenly.
We do the same, except the ceiling fans in the great room don't get shut off
between April and October. The room is big enough that the air needs help
circulating, even if the AC is off. Yes, we can keep the temperature several
degrees warmer with fans running. I prefer it because I really don't like AC,
but living in AL there isn't much choice.
I don't generally run the upstairs heat pump because the downstairs works fine
as long as air is moved. It gets way too hot otherwise.
I wouldn't. I don't mind it 67F in the Winter, but 72F feels too cold in the
Summer. I guess the difference is the way we dress.
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