Pond Boss Forums AERATION Systems questions Aerator Cabinet

Here is my cabinet. 20 bucks at the pet storeand a couple pieces of wood over the top. Works for a nice place to put your drink or your worms or tackle box while fishing from the shore!

I have a Gast rotary vane 1/3 hp pump in it and it works fine! It was a little tight fit but I got it and with the vents on the side it gets plenty of air. Just make sure you do your math on dimentions before you go get one and you will be fine.

RC's shelter is creative. If it has provision for air to be drawn in through the bottom makes it better. Adding window screen over the side openings eliminates insects from getting inside.

Hey thanks Bill for the money it is what it is. Of course depending on gauges and hight of those gauges is a factor when buying a pet crate. That's why I say do yor math first. I have had to manipulate mine some to make the 25 psi gauge fit that I got from Bill.

Bill - Any insight on thermal management for these compressors?

Have a narrow control panel going in a really hot factory, and the numbers worked out that the filtered vent's on the upper sides will convection the heat off, just because heat rises, and has room to move out the vents.

""Bill - Any insight on thermal management for these compressors?"" How are we defining thermal management? With or without accessory fans? Natural or artificial air movement? Is a little compressor humming noise acceptable? Is ambient temperature important? Air temps of 90F+ with midday sun shining on the pump house without any shade changes the need or requirements for thermal management. Operation 24/7 vs only nighttime compressor operation also has to be factored into the management plan.

FWIW my 1/3 HP rocking piston compressor came with a pretty small cabinet. The manufacturer installed a 15W cooling fan. IMHO 15W is cheap insurance.

Just wondering if anything was more concrete with the rotary vane compressors.

When you have a heat producing compressor the general rule would be the more air flow and cooler the motor operates the better it is for improving motor life span. I've seen compressor shelters get hot enough to melt the coating on the plug wire plus who knows what else inside the motor; that is obviously why the motor failed. Excess heat build up is generally a problem for all electrical motors and probably electrical circuit boards, including the computer you are using to read this post.

I appreciate all the ideas. I am going to build a cabinet. Just have to make the time for it and get it done. I am a carpenter and a carpenters projects are always last. I have an idea in my head and will post pics when completed (hopefully soon, I will be pulling my small aerator and firing the Gast up soon).

FWIW My parting words of advice...IMO Bill C has it right. You can't have too much ventilation. Only thing I would add is monitor your air inlet filter and keep it nice and clean. A dirty filter will make the entire system work harder which means more heat to dissipate, higher electricity useage and lower compressor motor life.

In hindsight on my cabinet, I wish I would have reversed where the fan and vent is. With the compressor intake right in front of where the air is drawn in through the vent, I'm having to change the filter more often that I should be. I supposed it will draw some dust in regardless but probably not as much if it weren't right in front of the vent.

It seems like all the important thoughts come AFTER my projects are complete .

Yeah Bill - In NEMA rated enclosures it's fairly easy to calculate your thermal dissipation requirements, and be it either by convection thru upper vents or the addition of fans or other cooling devices, you can keep it within operating temps. Home made rigs would be much more difficult, so I see where you are coming from.

The Gast 75R looks promising for an enclosure mounted device, as far as utilizing it's fans to suck in and blow out air. Just picked up the leg kit this morning for a Hoffman box I have here. Gast said these can be mounted in any orientation. I'll fill you in later.

As Bill C said above I do not run my pump during the day only at night so that help my situation out a lot! I don't have any fans but I do have several 3/8ths inch drilled holes in the bottom on the pet crate for the best ventiloation I can get. So far so good.

RC

As long as it works OK, that's all that matters, correct?

I am working on my enclosure. I am thinking of using two fans one to draw air in and one for exhaust. I would like to use dryer vents to direct any noise down. I lined the inside with 1 1/2" foam for sound. Any ideas for a fan? I have been searching the internet for one and haven't come up with one that trips my trigger.

Just a thought...they make cheap dryer vent boost fans. They are like 5 or 10 bucks and fit inside a dryer vent pipe. All the big box stores have them.

BTW IMHO I would only use one fan and put it on the exhaust side. I would position it so the airflow has to go across the compressor motor.

I get my stuff from Saginaw Control & Engineering: http://www.saginawcontrol.com/product-lines/272/273
You can buy your stuff anyplace you want.

You most likely will not need two fans, but do not put your fan on the draw end, but push the air thru.

I'll let someone else here explain that one

OK, waited 2 minutes, times up.

When you draw something thru, you create a lower pressure on the inside, but when you push it thru, you create a higher pressure on the inside. Go to 10,000' elevation and what do you have? Lower pressure, which has considerably less cooling capacity as something at sea level with the higher pressure. Same goes for enclosures that are generating heat. Pull it thru and there is lower pressure, push it thru and there is higher pressure.

Higher pressure = better cooling.

Won't disagree. I will offer why I suggested for an aerator cabinet in a harsh environment, like by a pond, the fan should be on the exhaust. On the inlet side I would place a coarse air filter to prevent bugs, coarse contaminants, etc from entering the cabinet.

so then I would think the inlet side should be larger than the outlet side, right? Is there an easy way to figure out the cfm's needed to pull the proper amount of air through?

No size difference between the inlet and outlet. Two holes have the same area and can only allow so much thru.

Need to know how many BTU's you need to dissipate, and the dimensions of the enclosure.

The home made ones are nearly impossible to work with due to the various sizes, shapes and locations of components.

As has been mentioned before, a fan is better than no fan at all.

And as also been stated many times, it all depends.

IMHO I wouldn't get too hung up on exact sizes. In this case, bigger is of course better than small as everyone knows! Heck a lot of guys just drill holes etc. in the cabinets and let convection heat transfer run its course. As JKB said, any fan is better than none.

Whatever works best for the situation. Aluminum filters work pretty good, but just a standard screen should be sufficient.

Kenz,

FWIW here is a pic of a unit (cover removed) I have from one of the manufactures of turn key systems. The gray rectangle piece in the lower part of the cabinet wall on the far left is the coarse inlet filter. The air enters there and is pulled across the compressor by the exhaust fan located on the far right. It is a 1/3 HP compressor and I THINK the exhaust fan is 140 CFM.

Hope this helps,

Bill D.

I'm no expert! But we all have opinions.
For explosive/flammable/contamination critical installations, definitely pressurize the enclosure so leaks go out and you aren't pulling in bad stuff. This requires you actually design the enclosure. Knowingly consider CFM and size fans and all exhaust port sizes. Otherwise you will not achieve a higher pressure. Think about it, if you just remove one wall, you can pull air in with a fan but the enclosure will be ambient pressure, no positive delta P. Exit velocity has to be high enough to generate a loss.

For aerator cabinets, I doubt we have critical risks so we DIY the design and build and get by with it.

I get the value of filtering BOTH inlet and outlet. A wasp can go in either side when fan is off. You can filter upstream of a fan on the inlet side. We filter inlet air regularly in our line of work... up to 50 lb/sec in one of my favorite playgrounds at work. Not a Lowe's item though.