Hello
This is my first post in the forums. I did a search to see if I could find an answer but didn’t find anything that really worked for my situation.
My question relates to fan placement.
I live in an apartment building with a 14 foot ceiling and quite a few 10 foot height windows. Heating is expensive in the winter and cooling is a little challenging in the summer.
I’m looking at installing a ceiling fan. The area I want to cool is about 400-500 square feet.
There is a large concrete bulkhead ( 3.5 feet tall and 2 feet wide) on the ceiling so it is conceivable that heat gets trapped in one of two areas (see areas #1 and #2 on the attached diagram)
We have a gas fireplace (the black box on the diagram) but the fireplace company says the BTUs aren’t enough to warrant installing a blower or fan kit. So the air around the fireplace gets hot, presumeably goes straight up, and I would expect gets stuck in area #1 mostly. So should I install the fan in area #1 to circulate the hot air around (pull the air up so it travels down the walls — or is it force the air down?) or should I install the fan in the centre of area #2 at a higher speed to try and circulate air through the whole space?
Any advice is greatly appreciated!
Regards
Aaron
Replies
My vote's for #2, as central to the room as is reasonable.
every room in my house has ceiling fans, they stay on 24/7 all year round
I agree with CH.
But you might also stick a thermometer up in space #1 when the fireplace is going. If it is much hotter then the rest of the room I would a small 6" or so room fan that could be mounted up in the corner of that section to help mix the air up.
You should put the fan in area number 2.
The convection caused by the heat coming off that gas radiator will circulate warmed air up into pocket #1 but continual convection will also push it back out again. Lateral circulation to pull that warm air toward the center of the room is what is needed and this could be provided by a down-draft centrally located in the larger ceiling bay. The downdraft will also tend to push air back toward the gas heater along the floor so it can be rewarmed and rise again.
As to cooling: Those 10' windows you mentioned; I would hope the tops of them are openable and that they are not too far below the ceiling. If that's the case, in summer when the outside temp drops below the inside temp, and you need to cool things off in that room, you open the tops of the windows fairly wide and the bottoms only about a foot. Then run the fan in its updraft mode to push the air out the top of the windows and suck in cooler outside air through the bottom opening.
Dinosaur
'Y-a-tu de la justice dans ce maudit monde?
500 sq ft is at the upper end of what a 52" 5 blade fan will do, then figure 14' wow. it was mentioned that the trapped heat in 1 will spill over but it will also escape?. if you have upstairs neighbors theyll be happy.
if there is power existing id install one there and re-evaluate. otherwise while your doing it put in the second box with a coverplate then you would only make one mess.
to answer your question 1 for heat and 2 for cooling. hope that helps????
i guess i made an assumption to window location. saying 2 for cooling.
Edited 4/2/2005 7:12 pm ET by Brian
Welcome Aaron -
If possible, I would mount it on the bulkhead. It is the ideal location from a number of perspectives. This would still give you sufficient clearance from the floor, and a downward-blowing fan would extract the warmer air from both areas of the ceiling. Also, the farther the fan is located from the ceiling, generally, the more efficient it will be (less "throttle effect"). "Ceiling hugger" fans are not efficient for this reason. The location of the fan also depends on where people will be situated in the room.
In the majority of situations in my climate (Southern Ontario) under both heating and cooling conditions the fan should blow downward, unless you are located directly underneath it (such as in a chair or couch) during the heating season. You are probably already aware that the effect of stratification is much more pronounced with higher ceilings such as you have. Put up a high stepladder and climb up it if you doubt this.
Unless you are using radiant heating where vertical stratification is minimal, you will find (use a thermometer) that there will be a plume of warmer air directly under a ceiling fan. Blowing downward is a much more effective way of stirring the air, which is what you are trying to accomplish. Hold your hand in front of a small table fan, then behind it. The blowing effect can be felt quite a distance in front of the fan, but the suction side diminishes quickly with distance. When a fan is set to blow upward the ceiling acts as a barrier and greatly decreases the ability of the fan to cause vertical mixing of the air. It will mix the top 6 or 8 feet of the air and leave the remaining air near the floor, where you are, largely unmixed. The upward setting is more for comfort when you are sitting directly underneath it and the "wind chill" effect on the skin offsets the warming effect. Of course, this wind chill through evaporative cooling on the skin is exactly what you might want in the cooling season.
During the cooling season when windows are open you might also want to run the fan downward to efficiently get the hot air trapped up there down to the levels of the windows so air currents will move the warm air outside. Also be aware that hot air trapped up there in hot weather, even though it is above your body and you are not located directly in it will warm your body and other things in the room by radiation.
I know that at first it might look like you are getting conflicting information from different people in these threads, but there are so many variables that you will have to experiment with your own specific situation to find the best set-up.
Hope this helps, let us know what you do and how it works. Regards - Brian.
ps. you might want to look for a fan that uses the airplane- wing cross section type blade. They use the Bernouli / Coanda effect to more efficiently move the air and can be run at a lower speed and use less power and produce less heat than the conventional blade fans. I think they're called "Gossamer" or something like that. Big box stores did carry them at one time. I have two.