The effect I've noticed is exactly what you describe. I have mine set to blow down. I only use them in the summer. I feel breeze, which has a cooling effect. I don't notice that the air is hotter.
With it set to go up, I don't notice much of anything. I'm also not buying the theory that in winter it should go the other way and it;s going to be a good thing. If you leave air alone, I would think you'd get some boundarly layer effect, where the air meets the surfaces. By disrupting that, I would think you could have more energy loss, just like air blowing past a radiator transfers more heat.
It does matter because blowing down you typically get a breeze blowing down on you, which has a cooling effect, especially in summer, when you're going to sweat more.
It can certainly change the temperature at the lower part of the room. Hot air rises and a fan blowing down will push hot air down.
It just feels cooler because the air moves across your
That's the main effect that I've seen. The air being pushed down may be a little warmer, but the effect of the breeze is more significant and you feel cooler.
That's why you should only run the fan when you're in the house.
+1
It makes a big difference, because with the air blowing up, there is little direct breeze on you. With it down, there is a direct breeze.
Do you realize the dehumidifier is just an AC unit where the heat is exhausted back into the room? You could do the same thing by running a small space heater which would make the AC run more often which does a much better job of taking the humidity out of the air. Actually, I've never seen a house with AC that still had high humidity, but then I'm not in the Pacific northwest.
I initially thought he was wrong, but consider the two situations. In the day the house is absorbing sunlight radiated from the Sun at many thousands of degrees. At night the house is radiating heat into the void at around -273°C. I'd say the more significant factor is the daylight situation, but the devil is in the details and I would love to see some real data on the situation.
Fans "cool" by moving air across your skin; the moving air evaporates moisture from your skin...the more that moves and the faster it moves, the cooler you will feel. Therefore, blow the air down to feel cooler.
Hot air rises. In winter, blow air up so that the warmer air at the ceiling will be blown down.
Perhaps it depends upon the climate. I've lived in tropical climates most of my life. I've used ceiling fans for decades, long before they were popular or even commonly available. At the same time, central air conditioning in homes was very uncommon; even room air conditoners. My fans ran down, May through October (the other months were cool enough so that they weren't needed).
We now have central air but it is rarely used . It is rarely used because we like open windows and don't often need it. Why don't we need it? BECAUSE THE FANS RUN DOWN.
Just lowering the temp from 78 to 76 would probably make more difference and use less energy. I keep my house at 76/77 here in NJ and never have a problem with humidity. If it's been off because I'm away, within about 20 mins, you can already feel a big difference in humidity dropping.
There is a study that was done in Florida on identical houses where they measured temps and energy usage with a variety of roofs. Between white shingled roofs and black it resulted in something like a 10% savings in AC energy at the peak in summer, with the houses unoccupied. When houses were occupied, that savings got cut in half. The reason I would suspect is that with the houses occupied, a lot more AC is used, so while the savings amount is about the same, the percentage is going to be less, because the overall usage number is higher.
From which I concluded, it doesn't make much difference, at least for me. I'm in NJ and the study was in FL, where the temps are much higher over a much longer period. To make a roof choice color based on saving $15 a year didn't make any sense to me.
I do not know where the code is located but it is my understanding that in AZ it is AGAINST the law in every municipality around these desert communities to paint WHITE, too blinding, just not allowed. Instead, there are a series of slightly darker/offwhite, desert colors, many named for the city of origin trying to obtain some semblance of uniformity, each contiaininng their own city name.
Yes direct sunlight onto a surface is reflected or absorbed, but walls are not direct sunlight, if done properly. They're under eaves in mid day. I even found that our garage interior at mid day was noticeably cooler with the darker color than it was before. I assume radiation of heat OUTWARDS became more dominant a heat transfer. What made me think of it was thinking about how frost used to form on lawns at 38F degrees, night sky radiation sucked the heat right out, In regions of Sahara many desert populations wear a preference of dark clothing too. so thought I'd give it a try. Now, during the transitional seasons, when neither run AIR nor HEAT; the temperature range has narrowed to around 3 degrees, which is very reasonable, before it varied 5-6 degrees. Wake up house cool, during day heats to some temp, with the narrower range we don't even turn on the Heat Pump System, irritating our utilities suppliers to no end, but saving the US overall energy costs.
It is my understanding that according to scripture the purpose of the sky, and its complexity, is a way for God to talk to His people, to those who can read His messages. Not meant for everyone, but makes sense. Certainly explains why earth is located where it is. ;)
If the AC is oversized it is not efficient at removing humidity because it doesn't run long enough. ANd if it isn't warm enough to require running the AC, you still have the humidity.
Running the heater and the A/C at the same time MIGHT help, by forcing the AC to run more, but it most certainly is NOT efficient. At the price of electricity in Ontario, particularly during peak periods, it doesn't make any sense at all. We run the AC off-peak to drop the temperature and keep the house closed up on-peak to keep the heat out. As soon as it cools down outside the wife wants to open the windows - even when the humidity is 81%+ outside and only 40% inside.
Well, our house is pretty well shaded by the tree canopy in the summer - so the absorption heat gain is not terribly high - and it generally isn't hot enough that the colour of out roof would be an appreciable factor in radiating heat over-night, but if /when it gets really Mugglyhot the darker roof is likely an advantage. Often the Mugglyhot days co-incide with significant cloudcover around here too. (Mugglyhot = Muggy/Ugly/Hot weather from hell -used to only get a couple weeks of it, split up into short periods of a couple days - lately we've been gettin 2 week stretches several times per summer.)
OR simply run the fan blowing down to "suck" the hot air down from the ceiling. That's what we did in the shop at the dealership - ran the fans 24 hours a day during the winter - and it kept the floors dry, the shop comfortable, the gas bill down, and the doors ice-free. Heat was by natural gas "unit heaters" in the top corners of the one shop, and the middle/side of the other.
Those fans paid for themselves the first week we installed them!!!!
Unlikely, unless you are 130 years old. In restaurants or even some upscale southern homes they had such fans back then. Often multiple units driven by a common motor and belts. They had less than the usual five blades of modern versions but they sure were ceiling fans.
Even today's style showed up in the stores over 100 years ago:
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Ours doesn't look much different except that it has five blades.
Our AC is a heat pump which does not remove the moisture from the air -- it just cools it. Don't ask me how -- for all I know they have the thing arranged to do it on purpose.
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