Thanks Tom. The intake for both the fans and the "wings" will be fresh air.
The concrete slab lags behind the temperature of the air by zero to 5°F. The temperature of the slab in front of the fans, which are at floor level is only one or two degrees colder than the air. I suspect that there...
I realize there are lots of things missing from the following calculation. I just wanted to make sure I'm not way into the perpetual motion world.
6000 cu ft of air/ min.* 0.07 lbs/ cu ft = 420 lbs. / Min. That seems huge.
I measured the air speed coming from a 30 in floor fan at ~1800...
I will look into those fans.
I'm not depending on entrainment.
It just adds to the air moved by the blowers.
From russ_watters's reference he,
He agreed that there is a multiplication but only of the air moving through the slot. First there is a reduction before the slot.
I'm sorry, I think I was not clear.
You all schooled my on the ceiling vents and natural ventilation. I don't expect much from it.
I will open a second door to let more air out.
@jrmilcher thanks for the graphic that makes it very clear.
I have fans installed. Here is a picture of the box...
Ok things were going so well now I'm probably going to throw a monkey wrench in the works.
So I estimate that I'm moving 6000CFM into the building which has roughly 6000 sq. ft. and a 20 ft ceiling. I'm blowing air in at ground level and at lease some of it is leaving out the makeup air vents...
Thanks Russ Watters. I went back and read it more closely. I think I understand things a bit better. The Dyson Bladeless fan is an air flow amplifier but before that it is and air flow attenuator.
From the study
"The flow rates calculated are as follows:
0.2242 m^3/s for DAM
0.2414 m^3/s for...
And in this way it is a "air multiplier." I have a strong expectation that I'm trying to pick myself up by my own boot straps, which is why I'm trying to understand where the error in my thinking is.
If I can use your term "real" fan, can I replace the air moved by the "real" fan with the air...
Thanks for the reference Russ
From my reading of that link, clearly the Dyson is far more costly. But he did not compare energy efficiency.
I expect that if he measured the complete Dyson fan vs just the fan in the base there would be an increase in the flow rate.
(One would have to correct...
Thanks 256bits. I clearly got that one wrong. The hottest air is up high.
So I looked it up and Delta P=Cah((1/T0) - 1/Ti)). So if I wanted more draw I would have to extend the stack above the root further. Correct?
Thanks. I appreciate the advice and your experience. I don't own the building so installing those ventilators would be complicated.
I really want to understand the answers to the questions that I asked. It is a forum full of geeks after all.
Let me clarify one point. I'm not asking about...
Thanks. I don't want to just move air I want to exchange it. Particularly at night with the stack effect or natural draft.
The pressure inside of a pipe during natural draft is already lower.
Would the low pressure from the Coanda effect add to, subtract from etc. the natural effect?
I'm still trying to understand the operation of these fans. How does the geometry downstream influence the flow. Specifically, there is an 8" ventilation tube in the ceiling of my warehouse. I'm thinking that I can extend it until it is 3/4 of the way to the floor. If I crack open an overhead...
Sorry if I missed the answer in my search. I expect I'm not use the correct terms. I want to design a Galilean/opera glasses style steampunk monical mounted to my reading glasses. I already have a simple lens that I can swing in front of my one eye.
When using commercial eyeglass mounted...
I remember doing a physics problem over 30 years ago but I can't remember enough to do it again. The only reason I remember it is that it seemed like it would be so useful when I had teenage kids. Funny how the brain works sometimes. Got teenagers now. We were working on acoustics. If I...