Air movement dynamics

No difficulty at all, as long as the pressure is higher in the 3 cubic ft area than where you are moving it to. The question is how much air do you want to move, and why?

I'm thinking he wants to move air at the 13.8 cfm rate. I haven't had a chance to do the calculation, but my instincts tell me this will require a much larger pressure differential than any "fan" will pull...

I would like to move the air from a toilet bowl, with someone seated on it, and pull the air through a filter. The unit where the fan (a reverse radial blower motor) is located is connected via the hose to the seat ring that takes in the air from the toilet bowl. Thanks.

Ah! Then all you need is enough pressure differential to ensure the air moves that direction. Shouldn't take much...

I am not vey competent in air flow dynamics...in your opinion would a motor with a 13.8 CFM rating be sufficient to move 3 cubic feet of air continuously, including being forced to flow through the 2 feet of 1/2 inch hose prior to the flow source (blower motor) and eventual exhaust? As a matter of fact, if you don't mind, would you be interested in expanding futher on this subject as I have had a difficult time finding someone specifically knowledgable in this area and this info is critical to the design and component of my companies products. Your knowledge may prove profitable to yu if you are interested as I have startup company that is nearly ready for initial product launch and I am lacking in someone with your specific air flow knowledge. Thanks. My perssonal email is jsanabria@sanithrone.net

so you want to vent the odor of the poopies out the bowl and make a fortune doin' it. Well I have worked out some design issues for similar. And may I suggest the XXXXXXXXXX XXXXX XXXXXXX XXXX XXXXXXXXXXX XXXXXXXXXX and that will help alot just out of the gates.

Oh and don't forget XXXXX XXXXX XX too!

cr3

All kidding aside I wish you the very best. Please keep us posted as to your progress.

Need to make sure that you can't pull a vacuum on someones butt. I read about a woman stuck on a air craft toilet because she flushed while seated and the suction was such that she could not get unstuck...

I think 1/2 inch hose is too small for use with your fan, but I have not done the calcs. Have you built a prototype? That might be the best way for you to proceed.

I have the plans for this drawn up in my sketchbook. Pressure switches on the seat and everything, including a charcoal filter pad.

Sooooooo, good luck with that.

cr3

These are available commercially. They are called a Pan Fan. The air is taken from the cistern the fan is a 50mm unit installed in a 50mm pipe the 50mm pipe from the cistern to the pan has no water in it except when flushing so is an ideal air path just google Pan Fan and you will get all the info you need

Hello Jsanabria,

There will be "steady movement" of the air, but first you will have to allow air into the "catchment area" to replace the air being removed,or there is going to be a large insurance claim a'comin' your way.

The easiest way to provide what you are asking, is to have a coaxial vent pipe, with the fresh air coming in through the outside pipe,and the "exhaust" through the inner pipe.

The central pipe exits at a higher level than the intake pipe, of course, to minimise "feedback".

Don't forget screens or similar, made from stainless steel,to keep nasties out of the system..........

Are we talking Crap here or what? The biggest bum in the world is not capable of sealing of a toilet seat from the room. You dont only have to seal the centre of the seat. Your Bum would have to overhang the outside edge by a consideable margin and drop down, and move inward against the force of gravity and also have the ability to climb up and over the modesty flap at the back and seal that area as well. are we talking elephant bums here or what

PS Pan fan is an NZ invention

Forget all the fans and piping, etc. Just strike a good old wooden match (sulphur), and all odors rapidly dissipate (KISS)

Hello Johnjohn,

Your method above works very well.

The essential precaution before striking that sulphurous match, is to ensure that there is not a build up of Methane in the air, as the match is struck.

Otherwise all your troubles are over, with a....

I suppose one would have to be quite cautious if the offender were of the nature described by coconutpete in #14!

If so, maybe we could pipe the gas into a 20 lb barbeque propane tank. Just don't cook your steaks while I'm in the neighborhood.

I know what you mean, Johnjohn,

We have local buses here experimenting with using a mix of standard diesel and bio-diesel.

As they go past, the origin of the vegetable oil used is easily determined.

• Fish & Chips
• Fried Chicken
• Hamburger shops
  
• Chinese takeaway
• Indian Curry shop
• And so on.

At a bus depot, when these experimental buses have their engines running, one can be assailed by a real cornucopia of aromas, to titillate or offend the olfactory sensors.

Biogas, to be useful as a fuel in any cooking process, must first be well "scrubbed" to remove the origin indicating molecules.

Kind Regards....

I can easily get hungry when most busses go past except for the Indian Curry (not a big fan).

"Biogas, to be useful as a fuel in any cooking process, must first be well "scrubbed" to remove the origin indicating molecules".

And there in lies the rub...

Maybe we need to go back to jsanabria's original question after all. Looks to me like a better idea would be to "sulpher" the individual components of the "gas" problem(?) and do like many municipalities are already doing- harvesting the landfill methane. Got to be a better return on the $$$, don't you think? I think the scrubbing issue is also contained.

You will need a fan of min capacity of .5cfm to give 10 airchanges per hour in a 3 cu ft box. you MUST alson have an inlet. your duct size must be at least 1 inch in diameter and no morw than 2 ft in length. The fan you have must flow at least .5 cfm at .2 inch water gauge. Hope this helps. Phill L

It shouldn't need much airflow as it can carry on running for a minute or so after use. best was is to experiment (as has been suggested) I'd think and old PC would provide a couple of suitable fans for experimentation).

The 1/2 inch is the worring factor... I'd go as big a diameter as possible...even if the hole in the pan is limited to 1/2", I'd open that out to the largest convenient standard size of pipe as quickly as possible, to maximise the airflow.

Matching the fan size/power is important...no point having a big fan thrashing around just stirring air...you want one that is just big enough to do the job...as presumably low noise is also an issue.

Mind...how much air is produced by a good fart? That must be the worst case air removal requirement...

Del < parp, toot >

The other problem that occurs to me is that you will need some sort of liquid knockout hooked to the sewer. If your system ingests urine it will get nasty if there is no way to deal with it.

The 1/2 pipe sounds a worry, I imagine it whistling, wonder what tune it will play?

Regards JD.

Hello jdretired,
Your answer Sir:

Kind Regards....