From the let’s argue about something department
A few weeks ago, I was in a restaurant with the current interior decorating style called retro warehouse… No ceiling above you, just the plumbing, air conditioning ducts and the girders holding the roof up. This place had a ceiling fan hanging down, maybe 12 feet above the floor. The place was air conditioned and the temperature was fine, but it go me thinking about the purpose of ceiling fans, whuch direction they should spin, and why – so I created a poll to ask what people think.
The main thing I know is that without a fan, hot air rises, so colder air will be near the floor and hot air will be at the ceiling. One train of thought is that in summer you want the fan pushing air down – if you’re sitting under the fan, there will be a breeze that increases evaporation of your sweat, even though the fan is pushing the hot ceiling air downward and warming the cool air that was in the room. If the fan is to cut cooling costs, why do they have lights that generate heat if you turn it on in the middle of the afternoon?
In the winter, people don’t want to be cooled by cold air coming from above so they reverse the fan to pull warm air upward and push it outward toward the exterior walls.
Almost every house I’ve seen in real estate listings Has these (especially in NC) and I’m confused.
What to you think the “rules” should be?
The purpose of ceiling fans in otherwise heated and ventilated spaces could simply be to keep body odor and expelled gas away from the customers.
At the 4 or 5 restaurants that I worked at with ceiling fans they were for ambiance and did not move fast enough to move serious air. There was a regrettable but short lived design fad in the restaurant industry for ‘novelty’ fans.
How about inside a house? Same thing?
How about this mobile phone app, just for show too?
http://images1.fanpop.com/images/photos/1600000/Get-Smart-get-smart-original-series-1678366-200-270.jpg
Can’t have menus blowing around, candles going out and particularly at business lunches and dinners can’t have the customer’s papers blowing around. Most restaurants have a minimum of 2 usually 3 – 4 air handlers – they are rated by the ton – they move enough air in indirect ways. If you have a bar or a ‘family’ style restaurant (puke) I don’t really know. The places I worked priced children out of the place (no children’s menu, no booster seats, no crayons, no juicy cups, none of that crap).
The phone dial seems a couple digits short
OK Art…I’ll argue with you.
My ceiling fan pulls air up in the summer. The air conditioner is on the first floor (whole house AC) and it pulls the cooler air up to the two lofts on either side of the house (no walls). In the winter the temperature can be more than 10 degrees warmer than the downstairs so the fan is set to blow air down. When the power goes out, the temps between the first floor and second can be dramatic without the ceiling fan. The ceiling fan is a big deal with cathedral ceilings. Downside: they need frequent cleaning…and I do mean frequent.
I think it depends on how your HVAC system and rooms are laid out. WesternMA’s argument for pulling air up makes sense for his house. My house in Georgia has a family room with a cathedral ceiling. The upstairs portion of the house has a loft that overlooks the family room. We have dual HVAC systems, one for each floor. The family room has a wood stove on the fireplace hearth which is against the main outside wall.
In the summertime we have the family room ceiling fan blowing down at medium speed. That’s nice for comfort when you’re sitting in the family room, but it also pulls stagnant air down from the cathedral ceiling and thus makes that air circulate through the HVAC system. The entire house stays cooler with the fan blowing down.
In the winter we reverse the fan so that it pushes air up. The up-moving air column pulls cold stagnant air from the ceiling and outside wall over the wood stove, so that when you’re sitting in the family room you get a gentle breeze of warm air from the wood stove moving towards the center of the room where the fan is pulling the air up.
Bottom line is that ceiling fans help the main HVAC systems work better by mixing the air throughout the house at minimal energy cost. The optimal direction for moving the air depends on the house/HVAC design, as well as the season and locality.
What about the idea that in winter if you push warm air down, you’re keeping the roof cooler and reduce programs with snow melting and creating ice dams?
That’s a good point, reinforcing my observation that it depends on the locale and season. In Georgia ice dams and snow accumulation/melting are not a concern unless we get one of those once in a century blizzards. And when we get one of those (see 1993) the power goes out and the ceiling fan is the least of our concerns. 🙂
Without a ridge vent on the roof, you’ve got a very good point.
Not to mention if the roof has ineffective vapor barriers and you start getting ice on the inside of the roof from frozen condensation
My neighbor works for one of the sterling companies in our vicinity BigAss Fans,
http://www.bigassfans.com/. He travels all over the country and Canada as a service rep. You can find these fans in huge shopping areas (think WalMart Garden area). They are huge and rotate slowly but move a lot of air. Very cost efficient in a commercial setting. During warm months, we use standard ceiling fans in our house (4 out of 6 rooms). We keep the thermostat setting about 4-5 degrees higher due to the air movement of these fans. We don’t perceive a great advantage during cold weather.