flow performance test
flow performance test
(OP)
At work we have a metal shed that sits in full sun. We cut windows (no glass just open holes about 1 x 1 meter) in it to improve ventilation. However the holes had to have louvers in order to keep the rain out. Vermin was also a problem. wire mesh had to cover the 1x1 meter hole. The louvers also reinforced this mesh from wobbling as it is too frail to span 1 meter.
I think the design of these louvers is an overkill. While they do a wonderful gob keeping the rain out, they reduce the ventilation. I would like to remove every 2nd louver. This would increase ventilation but still be adequate to keep the rain out. I can model it in Inventor or 3d Autocad. How do I test the flow? I'd like a before my proposed modifications and after.
I think the design of these louvers is an overkill. While they do a wonderful gob keeping the rain out, they reduce the ventilation. I would like to remove every 2nd louver. This would increase ventilation but still be adequate to keep the rain out. I can model it in Inventor or 3d Autocad. How do I test the flow? I'd like a before my proposed modifications and after.





RE: flow performance test
RE: flow performance test
Or a roof turbine ventilator?
http://www.empirevent.com/vents_turbine-ventilator...
I misunderstood your post on first reading. I think I now understand that you propose removing every second blade from each louver; not removing every second louver assembly, which would let the rain in half the locations.
Under what conditions would you test this modification? What outside air temperature and wind speed? Do you know how much airflow you had before the louvers were installed; how much there is now; how much you need?
What is the cost of items destroyed by excessive heat until a solution is implemented? What is the cost of engineering and management time to agonize over a solution to this problem? How much would it cost to remove every second blade from each louver?
What size fan would accomplish the needed airflow? How much would it cost to install the fan?
RE: flow performance test
Does such software exist?
RE: flow performance test
Why do you think it is a problem that the louvers "reduce the ventilation?"
If your modified louvers let in any rain, then you will probably hear about it:
If no one is looking for a solution, they may not welcome one.
RE: flow performance test
I'll take that risk. The product that risks rain damage is stale bread. We make thousands of loaves of fresh bread each day. We also get back hundreds of loaves that the stores didn't sell that's getting close to it's used by date. We take this stale bread and sell it to a company that adds it to animal food.
RE: flow performance test
What's the next problem - as any air flow restriction would be the result of the wire mesh - not the louvers.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: flow performance test
RE: flow performance test
Since your stored product is bread, I am a little surprised you're not doing more to control the environment in the shed. I imagine the purpose of the ventilation is to increase the longevity of the bread; would not better temperature and humidity control increase the shelf life of the bread further?
RE: flow performance test
RE: flow performance test
A fan, velometer, smoke test, or additional spinner vents on the roof are not an option
As you can see by the picture, the vent is a ridiculous design. The 'keep the rain out' aspect of it is quite an overkill
http://content.screencast.com/users/dchristensen77...
Anyone can see that removing louvers would increase air flow. However I will like to give them numbers, data, or some type of simulated performance test on the computer.
RE: flow performance test
As for the louvres restricting flow - very unlikely however if the mesh is fine then it will certainly restrict any flow.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: flow performance test
RE: flow performance test
Come on now, this is a very serious engineering problem and discussion, with the stored contents far more critical than a lawn mower and a can of fuel, it's stale bread (see earlier post from OP).
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)
RE: flow performance test
Is the bread getting moldy because moisture can't get away?
Is it losing water weight because higher temperature in the shed is driving moisture out and selling the bread by the pound results in less revenue?
What problem needs to be solved?
RE: flow performance test
I would suggest if management are too tight (read stupid) to put a bit of money into "their" problem then bad luck, the problem remains and they need to live with it.
That's the problem, they don't live with it. They live in an air condition mansion worth 2.3 squillion dollars
RE: flow performance test
Similar to this:
https://en.wikipedia.org/wiki/Dutch_door
RE: flow performance test
RE: flow performance test
Are these louvers designed in house or are they engineered by a company who specializes in it? Maybe they can provide feedback on increased flow with removing every other blade.
I also think there is a lot of good feedback from the members already given.
RE: flow performance test
You get 100% free area, no rain intake.
RE: flow performance test
Aside from the free area velocity, the shape of the blades are designed to change the direction of the air and "extract" rain via centrifugal forces.
By removing blades, you reduce the reduce the free velocity needed to keep rain out from 500 FPM to 250 FPM or less. (I'm guessing what the new rain penetration will be, but you get the idea anyway I hope.)
Also the straighter path means easier for rain to get through.
So unless you reduce the amount of air going through the louver (not your stated intent) to keep the free area velocity below the penetration velocity, removing louvers is a bad idea. To add louver area without going below the rain penetration velocity you will need more louvers.
RE: flow performance test
RE: flow performance test
RE: flow performance test
RE: flow performance test
RE: flow performance test
RE: flow performance test
It was not made by a manufacturer that I can ask questions from. The 'water keep out' properties is such an overkill that little or no thought was put into the design. I can't even see through the window. I can only see reflected light. I can't see outside at all. However this is no problem. Ventilation is the ONLY reason why the window was put in in the first place. I think they over did it a bit on the rain protection. I would like to propose an alteration that cost little or no money at all.
http://content.screencast.com/users/dchristensen77...